Vmc demo on takeoff?
Tien Dao
the critical left engine just after I had flicked the gear switch up. We
were at 85 knots (Vyse) but even with full right rudder and considerable
bank to the right, I was unable to maintain straight flight. At one point,
I thought I had the wrong rudder and made the mistake of giving some left
rudder which of course made things worse. I finally lowered the nose and
feathered regaining control. We dropped to about 65 knots IAS before I
regained control and the plane had a Vmc of 61 knots. I had no flaps. I am
wondering if others have had such an experience and whether the Vmc demo at
altitude is aerodynamically different than at takeoff somehow making the
actual Vmc at takeoff much higher than listed in the POH`s. We have been
too chicken to try that exercise again, but I feel we should practice this
worst case scenario.
TD
JerryK
instructors have long ago given up doing a Vmc demo below 3000 feet. Also,
a lot of them will use thier foot to limit rudder travel resulting in a loss
of stability sooner than would normally occur. The result is the same, you
learn that when you loose lost or directional control you must reduce power
on the good engine.
"Tien Dao" <tien...@sympatico.ca> wrote in message
news:6LUh8.108260$JZ.14...@news20.bellglobal.com...
Bob Gardner
thing. Most training accidents occur because an instructor wants to show
that he is a real hotshot, and that the laws of physics do not apply when he
is in the airplane. I get the impression that you finished your
training...but if not, stay away from this guy and tell all of your friends
to stay away as well.
Bob Gardner
THE COMPLETE MULTIENGINE PILOT (asa)
"Tien Dao" <tien...@sympatico.ca> wrote in message
news:6LUh8.108260$JZ.14...@news20.bellglobal.com...
Larry Fransson
"Tien Dao" <tien...@sympatico.ca> wrote:
> At one point,
> I thought I had the wrong rudder and made the mistake of giving some left
> rudder which of course made things worse.
Three words: Think, think, think! If you have full right rudder
applied and the nose is moving to the left, is left rudder really going
to stop that? Don't just react without considering the consequences of
your actions!
> I am
> wondering if others have had such an experience and whether the Vmc demo at
> altitude is aerodynamically different than at takeoff somehow making the
> actual Vmc at takeoff much higher than listed in the POH`s.
Other than that Vmc is defined with the landing gear retracted and flaps
in the takeoff position, there is no difference. Something else had to
be going on there. I can't think of a reason why an airplane with a 61
knot Vmc should not be able to maintain a heading at 85 knots.
--
Larry Fransson
Seattle, WA
Ryan Ferguson
> Other than that Vmc is defined with the landing gear retracted and flaps
> in the takeoff position, there is no difference. Something else had to
> be going on there. I can't think of a reason why an airplane with a 61
> knot Vmc should not be able to maintain a heading at 85 knots.
Well, that's not true. Altitude makes a big difference. Once upon a time the
FAA wanted Vmc demos done at low altitude for maximum engine performance. The
lower the density altitude, the higher the powerplant performance, and therefore
Vmc is increased. Above a certain altitude (usually a few thousand feet DA for
light training twins) the aircraft will stall before it loses directional
control. Of course, low altitude Vmc demos, despite being a true 'worst case
scenario' were not the safest training practice ever devised, and it's generally
accepted that a Vmc demo at several thousand feet is a safer way to go about
things, despite the fact that the lower engine performance results in a lower
speed at which directional control is lost.
-Ryan
Ryan Ferguson
Physically feathering the engine (not simulating the feather) at low altitude is
pretty foolish. Actually, the whole story sounds suspect, but if any of the
elements are true, you should avoid this instructor in the future.
Stupid pilot tricks close to the ground often have predictable results.
-Ryan
Dudley Henriques
"Tien Dao" <tien...@sympatico.ca> wrote in message
news:6LUh8.108260$JZ.14...@news20.bellglobal.com...
I suggest strongly that you find an instructor who doesn't teach Vmc in this
manner.
--
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/CFI
Retired
TD
>
> Three words: Think, think, think!
Easier said than done 50 ft AGL but thanks. The title of this post is
misleading. Yes, it was an engine-out exercise at takeoff but I felt
it turned into a Vmc demo because I could not hold heading even at 85
KIAS when the Vmc in the POH is 61 KIAS. I understand from posts
below that at low altitude, the Vmc increases?? This is what I FELT
that day. If this is indeed the case, are Vmc figures calculated at
sea level or at some arbitrary altitude? By the way, I was stupid and
let my instructor down pressing on the left rudder. He is very good
and one of the best in my school, class 2 in Canada. I did complete
my multi and multi-ifr with him. I apologize to him if this post has
left others with a different impression...
TD
Ron Natalie
Tien Dao wrote:
>
> I flew a light twin with my instructor during my twin rating who took out
> the critical left engine just after I had flicked the gear switch up.
Todd Huvard (former editor of Southern Aviatior) geared a plane up on
a similar "demonstration." He did perhaps the proper thing of closing
both throttles at this point and putting it back down (except the gear
was up).
Dudley Henriques
"TD" <ttd...@hotmail.com> wrote in message
news:e2d0c80.02030...@posting.google.com...
If this "demonstration" occurred exactly as you stated it occurred in your
initial post, in my opinion the instructor is dangerous to the point of
being reckless. I appreciate the fact that you believe he's competent. In my
opinion he isn't. No multi instructor should pull an engine, especially a
left engine on rotation or just after rotation to demonstrate or view a
student's reaction to an engine out procedure. The fact that this aircraft
was by your description as follows; .
" We dropped to about 65 knots IAS before I
regained control and the plane had a Vmc of 61 knots"
is in my opinion a VERY dangerous situation at 50 feet AGL as you indicated
the altitude was at this time.
There is ample opportunity to demonstrate engine out procedures at altitude
without doing it in this manner. If this instructor had been working for me,
I would have fired him on the spot. Better yet, if this instructor had been
working for me, he wouldn't have done this in the first place; he would have
known better!!
Larry Fransson
"Dudley Henriques" <dhenr...@earthlink.net> wrote:
> I suggest strongly that you find an instructor who doesn't teach Vmc in this
> manner.
It didn't sound like a Vmc demo to me. It sounded like a simulated
engine failure shortly after takeoff. The student didn't respond
properly, and the instructor didn't react quickly when the proper
actions weren't taken, resulting in a situation where they were nearing
Vmc.
I don't have a problem with instructors simulating engine failures
shortly after takeoff. It is THE most critical phase of flight in a
multiengine airplane, and the student needs to recognize it and act
quickly. The instructor must also be prepared to take over immediately
if the student fails to do what is needed.
In many emergency situations including engine failures in light twins,
there is time to wind the clock and grab a cup of coffee before taking
action. Not so when an engine on a light twin fails on takeoff. In the
military, we trained the way we would fight. This should be no
different. This requires immediate action, and the student needs to see
it and practice it. The student is set up to fail otherwise.
TD
No multi instructor should pull an engine, especially a
> left engine on rotation or just after rotation to demonstrate or view a
> student's reaction to an engine out procedure.
Oohhh. Not knowing any better, I thought this was part of normal
training. Another instructor at my school also practices critical
engine failures on takeoff with his students, but maybe they are just
better than me and have not had this hair-raising experience. I
appreciated the danger but did not see this as reckless since it is an
attempt to teach what a real engine failure at takeoff is like. The
exercises at altitude were benign and I was able to control direction
pretty well. At takeoff, now that was a different story.
TD
TD
>
> Well, that's not true. Altitude makes a big difference. Once upon a time the
> FAA wanted Vmc demos done at low altitude for maximum engine performance. The
> lower the density altitude, the higher the powerplant performance, and therefore
> Vmc is increased. Above a certain altitude (usually a few thousand feet DA for
> light training twins) the aircraft will stall before it loses directional
> control. Of course, low altitude Vmc demos, despite being a true 'worst case
> scenario' were not the safest training practice ever devised, and it's generally
> accepted that a Vmc demo at several thousand feet is a safer way to go about
> things, despite the fact that the lower engine performance results in a lower
> speed at which directional control is lost.
Thanks for the aerodynamics reminder. My problem, then, is that it
becomes impossible to know what the real Vmc would be for an
engine-out on takeoff. For my light twin, it seemed like the Vmc was
10 knots above rotation speed and close to Vyse (85 KIAS) at sea
level. I guess that is why instructors at our school have a rule of
landing immediately if you are below 90 KIAS when you have a failed
engine on takeoff. This is significantly higher than the 61 KIAS Vmc
of the POH. I wonder if other pilots have been lulled into
complacently at takeoff with this lower published Vmc.
TD
John Stricker
You always know where it is. It's when you run out of rudder and still
can't control the yaw. The only option then is to reduce the power on the
still running engine. If this happens in real life, you won't be looking at
the ASI anyway. There's always a solution, it's just not always the one you
want when you're slow, heavy, and can't climb. Better to arrive at the
crash site slow and in control than fast and upside down.
--
John Stricker
I didn't spend all these years getting to the top of the foodchain
just to become a vegetarian.
"TD" <ttd...@hotmail.com> wrote in message
news:e2d0c80.02030...@posting.google.com...
Michael
> the critical left engine just after I had flicked the gear switch up. We
> were at 85 knots (Vyse)
This is OK so far. With a plane that has good single engine
performance, light on a cool day, blue line attained, any obstacles
cleared, and the gear cycling up, I think it's OK to fail the critical
engine and have the student demonstrate the continuation of the
takeoff on one engine. I know my MEI did it to me. I also know he
only did it fairly late in training - once he knew how I would react.
In the first 10 hours of training, we did not fail engines below 200
ft.
> but even with full right rudder and considerable
> bank to the right, I was unable to maintain straight flight.
That makes no sense. Something else had to be wrong. At Vyse you
might have issues with climb performance, but directional control
should be assured.
> At one point,
> I thought I had the wrong rudder and made the mistake of giving some left
> rudder which of course made things worse.
No kidding. I know a pilot who was trying to land a biplane in a 20
kt crosswind on pavement. He was at full control deflection slipping
into the wind, and that wasn't working so he decided to try slipping
in the other direction. This was a very experienced pilot thousands
of hours, hundreds of them in biplanes. Unsurprisingly, he damaged
the wing by scraping it on the pavement.
What I'm telling you here is that even very experienced people are not
immune to dumb reactions - but that was a dumb reaction. You're lucky
you didn't damage anything.
> I finally lowered the nose and
> feathered regaining control. We dropped to about 65 knots IAS before I
> regained control and the plane had a Vmc of 61 knots. I had no flaps. I am
> wondering if others have had such an experience and whether the Vmc demo at
> altitude is aerodynamically different than at takeoff somehow making the
> actual Vmc at takeoff much higher than listed in the POH`s.
First off, Vmc is at sea level and gear up. Having the gear down adds
stability. It is also at full aft cg. If it was just the two of you,
odds are you were well forward of that. So even at sea level you
should have been able to maintain control below 61 kts. I do not
believe you were losing control at Vyse.
My suspicion is that you were not as fast you think you were. You
would not believe how quickly speed bleeds when you are just barely at
blue line, gear still hanging out, in the climb attitude, and you fail
one. I suspect that what really happened is you failed to get the
nose down to a level flight attitude immediately upon recognition of
the engine failure. You would not be the first. As your speed bled
off, you needed more and more rudder to maintain directional control.
Feathering helped some, I'm sure, but the real benefit was in getting
the nose down. You're lucky you retained enough energy to fly away
from that.
> We have been
> too chicken to try that exercise again, but I feel we should practice this
> worst case scenario.
Light piston twins are not transport category aircraft. Every light
piston twin I know has what I call a period of exposure. This is the
period from rotation (presumably at Vmc) and the attainment of a state
where it will climb on one engine. This state is based on power,
speed, drag, altitude, and delay.
Power is not up to you. Balls to the wall, and the remaining engine
will produce what it will produce, based on condition and density
altitude. Excess available power will determine if and how quickly
you bleed energy as you deal with the problem.
Your major source of drag is the gear. In most cases the difference
between having the gear up or down is the difference between having
just enough and not quite enough power to fly away. You have done a
drag demo, right? In the US this is not a checkride maneuver at the
private or commercial level, but an MEI must demonstrate it on the
checkride so he can show that he can teach it.
Speed is critical. If you are only a few knots slower than blue line,
you probably won't be able to climb. Not being able to climb means
you don't have excess energy. That means you also don't have excess
energy to accelerate in level flight. That means you will need to
lower the nose to trade altitude for airspeed - altitude you may not
have. That's what slow flight is all about - to teach you all about
the back side of the power curve. For some reason I can't fathom,
single engine slow flight is not part of multiengine training. I
think it should be.
Altitude is a consideration. The obstruction that is hardly worth
noticing when both engines are running can turn into a real factor if
one fails. It will do no good to establish a minimal positive rate of
climb (which is all you get with a piston twin on one engine) if the
resulting climb gradient will not clear the obstruction.
Delay is a matter of human factors. How long will it take you to
realize there is a problem, reduce the angle of attack, identify,
verify, and feather (real or simulated by zero thrust) the inoperative
engine? Until you take these steps, you are probably bleeding energy
- either in altitude or airspeed. Usually it will be airspeed. You
need to build in an allowance for human response time, and if you
still have the gear cycling, for mechanical response time as well.
If your condition is favorable - meaning you are in a configuration
that will allow you sufficient time to put the airplane into the
minimum drag configuration with sufficient airspeed to begin the climb
and sufficient altitude to clear obstruction, you're OK. Otherwise
you're exposed, and an engine failure means you will be contacting
terrain shortly. That is the period of exposure - the time required
to reach a sufficiently high energy state to allow you to fly away
from an engine failure. Usually it's less than 30 seconds, so the
actual probability of losing one while exposed is pretty low.
The prudent multiengine pilot gives careful consideration to these
factors, and determines a minimum condition of airspeed, configuration
(primarily gear but also flaps), and possibly altitude (if an
obstruction is a factor) that he will accept in order to continue the
takeoff in the event of an engine failure. Since this is only an
estimate, the options available in the event the takeoff must be
discontinued may also be considered. I personally set my minima a
little higher if discontinuing the takeoff means landing back on the
remainder of a long runway than if it means putting it in the trees.
If these minima are not met and an engine failure occurs, there is no
choice but to land ahead, maneuvering only as much as required to
avoid obstacles, just as in a single engine airplane. In this case,
damage to the airplane is quite likely - but that's way better than a
Vmc roll.
I don't think there was anything wrong with failing the engine on
takeoff at or above Vyse and with the gear coming up if other
circumstances are favorable. Given what you describe, I think there
was plenty of energy available for you to complete the takeoff safely
had you followed proper procedure. As I stated before, I think you
failed to get the nose down promptly, and allowed your airspeed to
bleed off. Don't forget that some lag in the ASI is common.
I also believe you flight instructor allowed the situation to
deteriorate more than was necessary or useful. A student mishandling
an engine failure is far from rare, and an instructor must be ready to
catch it before the situation becomes critical. I think this
instructor failed to react quickly and really scared himself. Unlike
others here who are prepared to crucify him, I think it's a mistake
that anyone could have made - the real question is did he learn from
it. As another poster mentioned, engine failure on takeoff in a light
twin is one of those times when you really can't waste a second or two
- you must react RIGHT NOW. The only emergency procedures I have ever
experienced in any aspect of aviation that are that time critical
involved BASE jumping. Even a high speed malfunction on a skydive
gives you more time to react. The demands on an instructor in that
situation are extreme, which is why the idea that someone with 500TT
and 50ME can be an MEI is horrifying to me.
I believe you also need to realize that what you had was NOT the worst
case scenario. The worst case scenario is when you lose the engine
already airborne but with insufficient energy to continue the takeoff
on one engine. This is a condition that NEVER happens in a transport
category twin, but most of us just can't afford that level of safety.
If you're really sharp and have a long runway, you might possibly land
back on the runway without damaging the airplane but I wouldn't bet on
it.
Michael
John Stricker
I agree. My instructor pulled the engine on me after takeoff several times,
although not at 50', probably more like 100'. The fault lies in the
instructor not immediately correcting the student's incorrect actions. Low
altitude is no place for a Vmc demo, intentional or inadvertant. I also
flew at least 3 approaches to a landing with an engine feathered, although
that is not recommended anymore. Now it's supposed to be "simulated, zero
thrust". My MEI feels that's not good enough, that it's different when the
prop is really stopped. Personally, I think he's right.
Training in general has gotten really watered down. Slow flight
demonstration for the commercial is 1.2 Vso. In a Cherokee, that's 72 mph.
I fly approaches at 75 on calm days to short fields. That's not slow
flight. In contrast, when I got my private in '83, slow flight was with the
stall warning light on but positive control. That's slow flight. I know of
several other examples like this as well. And I don't think they're for the
better.
--
John Stricker
I didn't spend all these years getting to the top of the foodchain
just to become a vegetarian.
"Larry Fransson" <newsg...@larryandjenny.net> wrote in message
news:newsgroups-E2BCC...@news.uswest.net...
Dudley Henriques
"Larry Fransson" <newsg...@larryandjenny.net> wrote in message
news:newsgroups-E2BCC...@news.uswest.net...
I also have no problem with an instructor zero thrusting an engine after
take off. In fact, we recommend it after demonstration at altitude.
I do however, have a VERY BIG problem with an instructor who as this poster
said, "took out" the left engine on rotation( under 50 feet AGL) , and
allowed the student to get to within 4 kts of VMC during what the student
said was a feather to regain control........or did I miss something here
fellas!!! :-)))
Dudley
TD
> > but even with full right rudder and considerable
> > bank to the right, I was unable to maintain straight flight.
>
> That makes no sense. Something else had to be wrong. At Vyse you
> might have issues with climb performance, but directional control
> should be assured.
I agree. AT Vyse, I should not have had any problems but I don`t know
what the problem was. Maybe my speed did bleed off faster than I
thought, but I was not near Vmc when my instructor cut the left
engine. I knew immediately, though, after he had cut that engine that
I had directional control problems and felt the Vmc to be much higher
than 61 KIAS. Could it be due to my high angle of attack? Maybe on
that takeoff, my angle of attack was sufficiently high that asymmetric
thrust from the downgoing blade of the right engine increased and
worsened my directional control? That would increase Vmc. Perhaps
Vmc certification is done at lower angles of attack??
> What I'm telling you here is that even very experienced people are not
> immune to dumb reactions
Thanks. I needed that.
>- but that was a dumb reaction. You're lucky
> you didn't damage anything.
You`re right. But I want to practice engine outs on takeoff again.
Maybe at 200 feet this time...
> I also believe you flight instructor allowed the situation to
> deteriorate more than was necessary or useful. A student mishandling
> an engine failure is far from rare, and an instructor must be ready to
> catch it before the situation becomes critical.
Well, he did shout "right rudder, right rudder!" when I switched to
left rudder.
>I think this instructor failed to react quickly and really scared
himself.
I don`t know if I scared him or he scared himself, but a few members
of our club on the ground were a bit anxious watching this plane veer
left.
Thanks for the exposé Michael. Gotta remember that...lower the nose!
TD
Ryan Ferguson
> Thanks for the aerodynamics reminder. My problem, then, is that it
> becomes impossible to know what the real Vmc would be for an
> engine-out on takeoff. For my light twin, it seemed like the Vmc was
> 10 knots above rotation speed and close to Vyse (85 KIAS) at sea
> level. I guess that is why instructors at our school have a rule of
> landing immediately if you are below 90 KIAS when you have a failed
> engine on takeoff. This is significantly higher than the 61 KIAS Vmc
> of the POH. I wonder if other pilots have been lulled into
> complacently at takeoff with this lower published Vmc.
FWIW, this is stuff that should be covered in any multi-engine training course. You must keep in
mind that Vmc was determined for your aircraft under a set of strict criteria. The most
important of these criteria relate to drag (the aircraft's configuration) and weight. Unless you
exactly mimic the criteria under which Vmc was determined, your 'actual' Vmc on any given day
will be different. Everything - density altitude, aircraft weight and CG, configuration, and so
on, affect Vmc. You should view the placarded Vmc as the number to go by in a worst case
scenario. Here's an example for you - in my Twin Comanche, Vmc is published at 90mph. At 3,500
feet, with two in the front seat and nearly full fuel, my Vmc was demonstrated to be 74mph. I
also know from single engine pattern work that I need to be at Vyse to get 400 fpm climb from a
single engine near sea level. If I drop even 5mph below that the performance suffers
dramatically.
Therefore, I know that my Vmc - at least at 3,500 feet - is well below the published number, even
when we're about 350 lbs. shy of max gross weight. If we were at max gross weight, the number
would have been even lower. (Of course, the TwinCo was originally placarded with a Vmc of 80mph,
which was later artificially raised to 90mph by Piper in response to low altitude training
accidents. This gave the airplane a much undeserved reputation.)
The other factor, which is frequently at odds with Vmc, is performance. You mentioned that your
instructors recommended an immediate landing when losing an engine below 90kias on takeoff. Do
not confuse Vmc, which is by definition 'minimum control speed', with any kind of performance.
If you're at max gross weight, even above Vmc, it's quite possible that your aircraft can't climb
(see my previous note about climb performance in my twin) or even maintain altitude. Most light
twins will climb at Vyse if below their single-engine service ceiling, but remember: our little
trainers do *not* have to prove a single engine climb capability for certification! This is
evidenced by the lack of accelerate-go charts in your POH.
This nebulous area between the red line and blue line on the ASI is cause for much confusion and
more than a few accidents. It's generally better to accept aircraft damage and landing long
(even if you crash through the runway end lights at 40mph) than trying to force the aircraft into
the air below a speed at which it can climb. My plan for engine failures below blue line at max
gross weight is to cut the throttles and land straight ahead. The old saying 'it's better to be
on the ground rightside up than upside down' is a good one for multiengine pilots.
-Ryan
Michael
Yes, I'm sure that's true.
> I knew immediately, though, after he had cut that engine that
> I had directional control problems and felt the Vmc to be much higher
> than 61 KIAS. Could it be due to my high angle of attack?
Let's not confuse angle of attack with pitch attitude - they are not
the same. However, if you are in a very nose high pitch attitude AND
the gear is still cycling AND you have one engine windmilling and not
making power, airspeed can bleed off in a heartbeat.
> Maybe on
> that takeoff, my angle of attack was sufficiently high that asymmetric
> thrust from the downgoing blade of the right engine increased and
> worsened my directional control? That would increase Vmc. Perhaps
> Vmc certification is done at lower angles of attack??
Vmc certification is done at whatever pitch attitude will correspond
to Vmc at the Vmc conditions. I really do not believe you were seeing
a Vmc departure at anywhere near blue line. Everything you tell me
points towards letting the airspeed bleed off.
What worries me about this is that clearly something slipped throught
the cracks. I was taught that in the event of an engine failure on
takeoff, the first step is that everything comes forward. That means
power levers AND yoke. You must establish a level pitch attitude
FIRST - then when you have identified the failed engine and reduced
drag, you establish the climb at Vyse. If you leave the nose up,
speed bleeds very quickly.
> But I want to practice engine outs on takeoff again.
> Maybe at 200 feet this time...
Well, 200 is a good place to start but I think you should be able to
work down to 50. Why don't you consider delaying the gear retraction
and timing your takeoff so you can be in the same configuration as
before (gear just starting to cycle, at blue line) at 200 ft, and try
this again?
> Well, he did shout "right rudder, right rudder!" when I switched to
> left rudder.
But the situation had already deteriorated by then. He should not
have allowed you to slow sufficiently that Vmc was a concern, and I
believe he did.
> >I think this instructor failed to react quickly and really scared
> himself.
> I don`t know if I scared him or he scared himself
No, this is something I'm quite firm on. Students are trying to kill
you - that's a given, and part of the job. If as an instructor you
get scared, it's because you let the student go farther than you
should have - you scared yourself.
Michael
Dudley Henriques
"Michael" <crwd...@hotmail.com> wrote in message
news:449a3d6e.02031...@posting.google.com...
> ttd...@hotmail.com (TD) wrote
> No, this is something I'm quite firm on. Students are trying to kill
> you - that's a given, and part of the job. If as an instructor you
> get scared, it's because you let the student go farther than you
> should have - you scared yourself.
>
> Michael
Hi Michael,
Your explanations I believe are very good, and should be useful to this
poster. I have a question however, that might need a bit of discussion.
Perhaps I'm missing something here.
I've been following this thread after inserting some general comment based
on the initial poster's EXACT description of this incident.
The poster said quite plainly that he had to "feather" to recover after his
instructor "took out" the engine at rotation.
This indicates to me a scenario other than zero thrusting the engine at
rotation. I might be missing something here, but I believe this should be
discussed in detail before opinions on Vmc and Vyse spread are rendered, as
well as Vmc parameters in general. I'm sure we all agree that there is a
HUGE difference between shutting down to the point of feather at rotation
and zero thrusting an engine on take off. Am I the only one picking up on
this? Why is the use of the word "feather" by the poster being disregarded
in the replies? Is everyone on the same page with this, or did I miss
something in what the poster was trying to say? If the poster's instructor
zero thrusted the engine at rotation, which we all would agree is a normal
procedure, why does the poster say he had to " lower the nose and feather to
regain control?"
Tien Dao
> The poster said quite plainly that he had to "feather" to recover after
his
> instructor "took out" the engine at rotation.
What he did was cut the left throttle to idle. Is that "zero thrusting"?
>I'm sure we all agree that there is a
HUGE difference between shutting down to the point of feather at rotation
and zero thrusting an engine on take off.
Sorry for the ignorance, but what is the difference?
I still don't get it because I did not have directional control at 85 KIAS
immediately after he cut the throttle. And even if I let it drop to 65
knots, that is still above Vmc and our aerodrome is at 90 ft. ASL. This was
in May when the temperature is about standard.
TD
Ron Natalie
Tien Dao wrote:
>
> What he did was cut the left throttle to idle. Is that "zero thrusting"?
No. Zero thrust will be faster than idle. It should give roughly the
same effect as a feathered engine. The advantage is that the engine is
still turning so recovery is a lot easier.
Michael
> on the initial poster's EXACT description of this incident.
> The poster said quite plainly that he had to "feather" to recover after his
> instructor "took out" the engine at rotation.
I think this is a question of emphasis. He said that he lowered the
nose AND feathered. I think that lowering the nose is what allowed
him to regain control, and that feathering helped some but was mostly
incidental. However, I'm speaking from the viewpoint of aerodynamics,
not procedure. More on this later.
I think it's important to realize that what we are doing here is
attempting to reconstruct events that took only a very few seconds,
and are not clearly remembered by the participants. That's always a
tricky thing to do, but in this case I think it's worth trying.
It's kind of a shame that teaching precise recall is not normally a
part of flight training - while precise recall of a given incident is
of no particular value in surviving that incident, the majority of
incidents are nonfatal and being able to extract maximum educational
value from each one has high survival value in the long term. In
skydiving instruction in-air communication is extremely limited and
thus the brief and debrief are far more critical than in most other
types of flying. As a result, recall is implicitly taught and tested,
and improves with time.
My experience as a skydiving instructor has allowed me to evaluate the
recall capability of many students, some of them rated pilots. I
found that a pilot was way ahead of the game in parachute training in
most aspects. This of course is reasonable, since a parachute is just
another airfoil, and flying is flying. Where the pilots were not
ahead of the game was recall - their recall of events in the skydive
was no better than average. Until you have heard a 3000+ hour
CP-ASMEL-IA type rated pilot who is also a student skydiver give his
version of events that took only a few seconds (and which take minutes
to debrief) that are completely at odds with what you as an instructor
have observed, it's difficult to realize how poor most people's recall
is of quickly developing high stress situations in flight.
I say all this because I believe that the poster is recounting events
to the best of his ability. However, we know that the airplane could
not have lost directional control at 85 KIAS when Vmc is 61. Vmc is
determined with the propeller windmilling and the engine producing no
power - the worst case. It will be lower with a feathered or
zero-thrusted prop. Thus we know the poster's recall is imperfect,
and whether the engine was shut down or zero thrusted doesn't enter
into it. This is neither unexpected nor uncommon, in my experience.
With that in mind...
> This indicates to me a scenario other than zero thrusting the engine at
> rotation.
Me too.
> I might be missing something here, but I believe this should be
> discussed in detail before opinions on Vmc and Vyse spread are rendered, as
> well as Vmc parameters in general.
That depends on whether you want to talk aerodynamics or procedure.
From an aerodynamic standpoint, it hardly matters. Either way,
there's no way directional control was being lost at Vyse.
> I'm sure we all agree that there is a
> HUGE difference between shutting down to the point of feather at rotation
> and zero thrusting an engine on take off.
Absolutely.
> Am I the only one picking up on
> this? Why is the use of the word "feather" by the poster being disregarded
> in the replies?
Because we all concentrated on the aerodynamic aspects of the incident
and missed an important procedural item.
> Is everyone on the same page with this, or did I miss
> something in what the poster was trying to say? If the poster's instructor
> zero thrusted the engine at rotation, which we all would agree is a normal
> procedure, why does the poster say he had to " lower the nose and feather to
> regain control?"
I was not aware that zero thrusting the engine at rotation was a
normal procedure. If it is, I certainly want to hear about it since
I'm now working on adding a multiengine rating to my flight instructor
certificate.
My experience with failing engines on takeoff is that the engine is
idled, not zero thrusted, by the instructor and the student then
proceeds to take emergency action - lower the nose, identify and
verify the inoperative engine, then bring the prop control back to
feather. The instructor should then catch the prop control before it
comes all the way back, let the student know that the engine can be
considered feathered, and set up zero thrust.
I have always considered this the best way because it allows you to
train the way you will fly - no hesitation to feather in a critical
situation. It does demand a bit more from the instructor, but I think
the demands are within reason. I know some schools have the student
touch the prop control and say "simulated feather" but I think that's
a bad idea for obvious reasons.
If the instructor sets up zero-thrust immediately, rather than waiting
until the student takes action to feather, the exercise is
unrealistic. In real life, energy will be lost while the student
identifies, verifies, and feathers the inoperative engine and this
energy loss is not seen in training.
On the other hand, I think allowing an actual feather at 50 feet on
takeoff is unnecessarily dangerous and thus poor procedure, but that's
only the tip of the iceberg. It is one thing to feather at low
altitude when performing the emergency procedure correctly - as long
as the other engine keeps running and the airplane is flown correctly
it should work out. If this is part of normal training where the
poster was trained, I believe this is poor procedure but I also think
that landing with the engine feathered (as opposed to zero thrusted)
also adds unnecessary risk but is done. Even if it is normal
procedure, there is a world of difference between feathering as part
of a competently handled procedure and a botched one. Personally, I
think feathering a working engine at 50 ft and with the airspeed so
low that directional control is a problem is absolutely unsafe
regardless of what normal procedure is, and I think the instructor
should not have allowed it.
Thus I believe your point is well made - it looks like the instructor
did worse than just allow a student to get critically slow on a
simulated engine failure on takeoff. It seems he also permitted the
prop to be feathered in an unsafe condition.
Michael
Dudley Henriques
>
> "Dudley Henriques" <dhenr...@earthlink.net> wrote in message
> news:Y_5j8.12366$Vx1.9...@newsread1.prod.itd.earthlink.net...
> > The poster said quite plainly that he had to "feather" to recover after
> his
> > instructor "took out" the engine at rotation.
>
> What he did was cut the left throttle to idle. Is that "zero thrusting"?
You don't know?
Yes, this is acceptable multi-engine instruction. I'm still concerned that
you were given any failure "demonstration" on take off before you had a
complete handle on what to expect, and ample practice with this at altitude.
You used the term "feather" in your discription of what you had to do to
recover this airplane during this little "demonstration". What's troubling
me here is that you seem to be having difficulty explaining exactly what
feathering means and understanding exactly what you would have had to do to
feather the prop. To feather, you would have to identify the dead engine,
and bring the propeller into the feathering detent, or use whatever
feathering control this airplane had, and stop the prop with the blades
flattened; a real no no during multi instruction on engine failure at
rotation...at least the way I want it done anyway.
>
> >I'm sure we all agree that there is a
> HUGE difference between shutting down to the point of feather at rotation
> and zero thrusting an engine on take off.
>
> Sorry for the ignorance, but what is the difference?
PLEASE! I mean no disrespect here, but if you have to ask me the difference
between zero thrusting an engine and feathering a propeller during a
complete shutdown, especially if done at rotation, I would plead with you
to get some more dual; preferably from another instructor.
>
> I still don't get it because I did not have directional control at 85 KIAS
> immediately after he cut the throttle. And even if I let it drop to 65
> knots, that is still above Vmc and our aerodrome is at 90 ft. ASL. This
was
> in May when the temperature is about standard.
Did I read you correctly? In speaking about your instructor in another reply
above to Larry Fransen, you said, and I quote, "I did complete
my multi and multi-ifr with him". Is this true? Are you now rated
multi-engine land?
I feel that of all the answers you received in this thread, Ryan Ferguson
answered your questions about this with more than enough correct
information. Quite frankly, I'm a bit puzzled that you have a multi-engine
rating and are asking these questions. I still think we might be losing
something in translation here however, or I'm missing something or
misinterpreting something you have said either to me or to the others. Can
you explain a bit better what you meant by the word "feather"?
It sounds to me from what you are saying that your instructor zero thrusted
your left fan after you rotated between the red and blue line(ok so far) and
allowed a student dead side rudder excursion and airspeed degradation to
within 4 kts. of published Vmc without an immediate decrease in angle of
attack and bank input into the good engine.(very bad.....very bad!!!!)
So far, this reads as a textbook example of an instructor starting off to
demonstrate a normal TOEO procedure; then allowing the student to get way
ahead of of him AND the airplane!!!.
Bad deal my friend.......
This type of thing can be VERY dangerous. I'm with this thing so far, but
bring me up to speed on this "feather" business.
Dudley Henriques
>
> "Tien Dao" <tien...@sympatico.ca> wrote in message
> news:w9bj8.39419$4E4.5...@news20.bellglobal.com...
> >
> > "Dudley Henriques" <dhenr...@earthlink.net> wrote in message
> > news:Y_5j8.12366$Vx1.9...@newsread1.prod.itd.earthlink.net...
> > > The poster said quite plainly that he had to "feather" to recover
after
> > his
> > > instructor "took out" the engine at rotation.
> >
> > What he did was cut the left throttle to idle. Is that "zero
thrusting"?
>
> You don't know?
>
> Yes, this is acceptable multi-engine instruction.
T.D.
Addendum to my above post!
I should have been more clear with this. (You see, you're not the only one
:-))))
I meant that zero thrusting is accepted procedure in multi-engine training.
As for throttle position at zero thrust, figure about 10 inches for your
average light twin. This will simulate a feathered prop for you.
DH
Dudley Henriques
You have made valid points. I'm pasting in below an excerpt from an FAA
directive on this subject.
>The FAA adheres to the National Transportation Safety Board's (NTSB)
recommendation to shut down engines on multiengine airplanes on
certification flight tests. However, the FAA and NTSB agree that
simulated engine out emergencies at LOW altitudes be accomplished by
simulating zero-thrust. For this reason, execution of propeller
feathering tasks should be performed at no lower than 3,000 feet above
ground level and in the vicinity of a suitable airport."
I also discourage actual feathering below 3K. No problem at all with idle
simulations however.
TD
Mr. Henriques,
I want to thank you for bearing with my ignorance. It must be
frustrating for an instructor such as yourself to hear such basic
questions from someone who has his multi-ifr. I feel that I am
announcing my incompetence to the world, but what the heck, better to
learn and improve than make a critical mistake in the air. Atleast
that is my hope. :)
We do not use the term "zero-thrusting" where I train. I have never
heard of it. Maybe I should have run across it in my readings but we
call it simulated feather around here. I needed that clarification.
We do not fully feather at low altitude and in our entire training for
multiengines, we do it only once because it is a strain on the
prop-gov assembly, so I am told.
My instructor pulled the left throttle to idle. After my confusion, I
simulated a feather by bringing the left manifold back up to about 12
inches and prop back to 2000 rpm. I was slow in simulating this
feather because I had alot of problem and confusion in controlling the
aircraft`s direction. I was taught to control the aircraft first
before verifying, feather...etc. I should have been more clear with
my initial description, but did not think a simulated feather versus
true feather relevant to the aerodynamics of the problem.
Respectfully,
TD
Michael
> What he did was cut the left throttle to idle. Is that "zero thrusting"?
It is not, and I find it disturbing that you have to ask. Is Canadian
terminology perhaps different?
What he did is very normal, and is called a throttle cut at rotation -
a common and acceptable training procedure for an advanced multi
student.
Zero thrusting is how you simulate feathering at low altitude so that
engine power may be returned immediately, and generally involves
leaving the prop at full forward and bringing up the manifold pressure
to 9-11 inches, depending on airspeed. Zero thrusting an engine is an
instructor task, and the multi pilot is not expected to do it at the
private or commercial level.
> I still don't get it because I did not have directional control at 85 KIAS
> immediately after he cut the throttle. And even if I let it drop to 65
> knots, that is still above Vmc and our aerodrome is at 90 ft. ASL. This was
> in May when the temperature is about standard.
And if you let it drop to 60? Also, Vmc is determined at 5 degrees
bank into the good engine - being wings level can increase minimum
control speed by several knots.
Michael
Dudley Henriques
> "Dudley Henriques" <dhenr...@earthlink.net> wrote in message
news:<x5cj8.13134$Vx1.1...@newsread1.prod.itd.earthlink.net>...
> > "Tien Dao" <tien...@sympatico.ca> wrote in message
> > news:w9bj8.39419$4E4.5...@news20.bellglobal.com...
> > >
> > > "Dudley Henriques" <dhenr...@earthlink.net> wrote in message
> > > news:Y_5j8.12366$Vx1.9...@newsread1.prod.itd.earthlink.net...
> Mr. Henriques,
>
> I want to thank you for bearing with my ignorance. It must be
> frustrating for an instructor such as yourself to hear such basic
> questions from someone who has his multi-ifr. I feel that I am
> announcing my incompetence to the world, but what the heck, better to
> learn and improve than make a critical mistake in the air.
No TD, you're fine. It's just a miscommunication problem, and your approach
in trying to isolate an answer shows intelligence, not ignorance. The
problem here has been on this end. You see, it's virtually impossible in our
multi-engine community to not know how the actions of "zero thrusting" "Idle
power" and "feather" relate to a simulated engine out procedure.
> We do not use the term "zero-thrusting" where I train. I have never
> heard of it. Maybe I should have run across it in my readings but we
> call it simulated feather around here.
That's fine. It's the same thing really.
I needed that clarification.
Well, we FINALLY got it right, anyway!!! :-)))
> We do not fully feather at low altitude and in our entire training for
> multiengines, we do it only once because it is a strain on the
> prop-gov assembly, so I am told.
Right again. Under 3K feet is considered dangerous for feathering an engine
around here. Aside from the obvious flight risk, our engines can take a hell
of a jolt on the mounts when they restart. (Unless you're Bob Hoover with
BIG accumulators to help out :-)))
>
> My instructor pulled the left throttle to idle. After my confusion, I
> simulated a feather by bringing the left manifold back up to about 12
> inches and prop back to 2000 rpm. I was slow in simulating this
> feather because I had alot of problem and confusion in controlling the
> aircraft`s direction. I was taught to control the aircraft first
> before verifying, feather...etc.
You were taught correctly. FLY THE AIRPLANE......ALWAYS!!!
Never get tasked out with the details until the airplane is under control.
The yaw correction has to be automatic. Don't even think about
it.....working leg...working engine.....dead foot...dead engine. If you have
to think about this action, you're in trouble already on an actual engine
failure on take off.
You said you were past Vmc and rotated at the blue line. This should have
been no problem IF you caught the yaw immediately, AND reduced the angle of
attack at the same time.
There is a marked difference between control and performance.
Control is your first priority in this situation. Based on what you have
said, and the 90 foot density altitude you had on this take off, my guess is
that you became confused during the initial moments of the yaw correction.
It sounds like you might have started feeding in the right side rudder
without reducing the AOA, then seeing that the airspeed was bleeding, you
incorrectly changed the rudder input to the dead side thinking you had
picked the wrong engine. This is just a wild guess, but it fits.
If this is close, you should be able to put the rest together.
I still believe your instructor allowed you into the dead side rudder error
too far with a 4kt. spread between published Vmc for the airplane his
reaction and , but that's another story.
Best of luck to you,
highflyer
Very cogent, Ryan. I have long contended that Vmc makes a nice
demonstration when you get your rating, and you should CERTAINLY
remember that there IS one. However, it is not of ANY importance when
you are flying a twin with one engine out. I can
think of no valid reason to attempt to be in the air with a twin with
one not running at any airspeed other than Vse, unless you have altitude
to lose anyway. Then you can fly FASTER than Vse. There is NO reason
to fly slower than Vse with the possible exception of the brief time
prior to touchdown when you have the runway made and neither engine
should be producing full power! :-)
If you lose one on takeoff before you have attained Vse, LAND. You are
not likely to do anything else anyway! Best you do it before you run
out of place to do it!
:-)
As Ryan said, I would much rather run off the far end of the runway at
40mph than sail into the trees just beyond at 80 mph. Most light twins
will NOT manage a positive rate of climb near Vmc.
--
Highflyer
Highflight Aviation Services
highflyer
>
> No, this is something I'm quite firm on. Students are trying to kill
> you - that's a given, and part of the job. If as an instructor you
> get scared, it's because you let the student go farther than you
> should have - you scared yourself.
>
And that is the instructors dilemma! The student is most likely to
learn something from the excercise if allowed to continue far enough
with the mistake to recognize that a mistake had been made. The
instructors problem is to let the student make the mistake without it
getting unduly expensive! :-) Generally, the instructor will recognize
the mistake LONG before the student can. How long should you wait for
the student to realize that something isn't right and it is probably
because of something they did wrong? At certain critical phases of
flight you cannot afford to wait very long.
Instructors trying to let students recognize Vmc in a Twin Comanche, and
waiting too long when the student slowed down too quickly through Vmc
precipitating a flat spin was the base cause of the Twin Comanche
training accidents that caused them to raise the posted Vmc artificially
to 90 mph. While that avoided the ham handed student dropping
precipitately below the true Vmc, it also gave a false indication to the
student about the feel and controllability at true Vmc. Oops! :-)
Personally, I have no problem with conducting a Vmc demonstration at
high altitude. Once they know that there IS a Vmc and that they cannot
fly slower than that with the blower blowing and maintain control, that
is all they need to know. From then on they should be taught to
maintain an airspeed at or above Vse. Until ready to roundout and
flare.
Just my opinion for what it is worth ...
highflyer
>
> "Dudley Henriques" <dhenr...@earthlink.net> wrote in message
> news:Y_5j8.12366$Vx1.9...@newsread1.prod.itd.earthlink.net...
> > The poster said quite plainly that he had to "feather" to recover after
> his
> > instructor "took out" the engine at rotation.
>
> What he did was cut the left throttle to idle. Is that "zero thrusting"?
>
Probably. Actual "zero thrust" is somewhat above idle. At idle the
airstream is still turning the engine and drag is high. When you
advance the throttle to "zero thrust" the engine is providing enough
power to just keep the prop turning at the windmill speed without doing
more than exactly overcoming the drag of the prop. "Zero thrust"
simulates the drag of the stopped engine with the prop feathered.
Usually the instructor will pull the engine to idle to simulate an
engine failure.
When the student correctly identifies the dead engine and touchs the
feather control for the proper engine, the instructor will advance the
throttle for the "dead" engine to "zero thrust" rpm to simulate the prop
going to the feathered position.
> >I'm sure we all agree that there is a
> HUGE difference between shutting down to the point of feather at rotation
> and zero thrusting an engine on take off.
>
> Sorry for the ignorance, but what is the difference?
>
You cannot feather the engine until it is STOPPED. Once you feather it
you don't get it back. It is GONE. No simulation here.
> I still don't get it because I did not have directional control at 85 KIAS
> immediately after he cut the throttle. And even if I let it drop to 65
> knots, that is still above Vmc and our aerodrome is at 90 ft. ASL. This was
> in May when the temperature is about standard.
>
Perhaps you were not doing the proper things to achieve and maintain
directional control. What kind of twin were you flying where 65 knots
is above Vmc? Perhaps you cranked aileron the wrong way or didn't
provide sufficient, or even correct, rudder pressure. Pitch forward or
back? I have known multiengine students to flip a twin on its back well
above Vmc by improper application of controls and be totally unaware of
why the windshield was suddenly full of the wrong color sky! :-)
jakdedert
training. If he learns the "simulation" procedure and automatically
executes *that* instead of actually feathering the prop during a real
emergency....
I think there are some very serious problems going on at this school.
jak
"Dudley Henriques" <dhenr...@earthlink.net> wrote in message
news:GQoj8.9738$P4.8...@newsread2.prod.itd.earthlink.net...
<snip>
Dudley Henriques
"jakdedert" <jde...@bellsouth.net> wrote in message
news:Vdvj8.49381$Yd.28...@e3500-atl1.usenetserver.com...
> I'm wondering why he's being taught "simulated feather" during engine out
> training. If he learns the "simulation" procedure and automatically
> executes *that* instead of actually feathering the prop during a real
> emergency....
>
> I think there are some very serious problems going on at this school.
>
> jak
I think the only problem here with the student was in translation. I have
definite feelings about the way the instructor conducted this exercise. It
appears as though the instructor idled the engine at the blue line at
rotation, which is fine, and the student attempted a simulated feather in
the confusion that followed by bringing the mp back to 12 inches and setting
the prop at 2K on the dead engine while still having a control problem which
is something I can't figure out why the instructor let happen.
My take on this is that the instructor both set this up wrong and then let
it go way too deep into the error before correcting. The student, as far as
I can tell, reacted as any student would, unpredictably, and this instructor
was behind him for some reason. I wasn't there, and hate to second guess
another instructor, but the bottom line on this thread as I see it is for
all multi-engine instructors and students alike to step back and realize
that things happen very fast in a simulated engine out at rotation; it's
fine to set this up as a demo for a student, but it should always be done in
such a way that at no time during the exercise, is the instructor as far
behind the student AND the airplane as this instructor appears to have been.
A lesson for all of us in this.
Tien Dao
"jakdedert" <jde...@bellsouth.net> wrote in message
news:Vdvj8.49381$Yd.28...@e3500-atl1.usenetserver.com...
> training. If he learns the "simulation" procedure and automatically
> executes *that* instead of actually feathering the prop during a real
> emergency....
Maybe because simulated feather or zero-thrusting is an accepted training
procedure which is much less stressful to the aircraft than a full feather
or do you always fully feather during engine out training yourself? I don`t
think there is any risk of simulating a feather during a real emergency
because the procedure is more complex than fully feathering.
> I think there are some very serious problems going on at this school.
You have no idea, but it has nothing to do with my instructor.
With all due respect to others who have had the kindness to take the time to
respond to my initial and subsequent posts, who have sincerely tried to
enlighten me with their extensive experience, I would stand (and sit!) by my
instructor any day. Perhaps my recollection is also in error amongst my
other mistakes that day. Maybe I was level instead of banking to the good
engine. Maybe there was a strong wind from my right making me think I was
yawing. I think we will have to try that again sometime. But to criticize
my instructor. No. I have an unlimited admiration and respect for him and
for others who put their lives at risk each hour they step into a plane to
teach me and other students the pleasures of flying. This is a bond
between student and teacher which cannot be explained but only experienced
as a mutually respectful symbiosis. His teaching style is to permit the
student to make errors and give them time to correct those erros with
minimum intervention. Only the great love of flying would motivate CFI`s to
take these risks for us neophytes. Whatever his faults as perceived through
the wisdom of master instructors posting herein, I would plow into the
ground by his side if that day ever arrived, knowing that I had gone with a
friend who had dared to live and had dared to teach me this love of life.
TD
Dudley Henriques
>I would plow into the
> ground by his side if that day ever arrived, knowing that I had gone with
a
> friend who had dared to live and had dared to teach me this love of life.
>
> TD
God TD, and all I ever got from my students was a damn bottle of scotch!!!
:-)))))
Best to you,
Dudley
TD
Mr. Henriques, or Dudley if you prefer,
I would fly with you any day! But since that is not possible, please
send me your physical address and I WILL SEND YOU A BOTTLE OR TWO OF
CHAMPAGNE in appreciation for all the help and patience you have
exhibited with me and others here. (And you know I am serious!)
Tien
highflyer
>
> "jakdedert" <jde...@bellsouth.net> wrote in message
> news:Vdvj8.49381$Yd.28...@e3500-atl1.usenetserver.com...
> > I'm wondering why he's being taught "simulated feather" during engine out
> > training. If he learns the "simulation" procedure and automatically
> > executes *that* instead of actually feathering the prop during a real
> > emergency....
>
> Maybe because simulated feather or zero-thrusting is an accepted training
> procedure which is much less stressful to the aircraft than a full feather
> or do you always fully feather during engine out training yourself? I don`t
> think there is any risk of simulating a feather during a real emergency
> because the procedure is more complex than fully feathering.
>
I don't care whether it is more or less complex. It is the WRONG
procedure. The student should NOT be taught how to adjust for "zero
thrust." The student SHOULD be taught to "feather." I learned, many
years ago, that the adjustment to "zero thrust" was made by the
INSTRUCTOR only AFTER the student had a hand on the prop control and
indicated the proper direction to feather.
Michael lets them actually move the prop control in the feather
direction and then halts it prior to passing the feather stop just to
ensure the student learns the proper direction. Some of the twins I
have flown that is not feasible. For example, in the old Beech C-45 you
had two feather buttons. When you hit the button that prop was going
into feather. Unless you had some good "unfeathering" accumulators to
store enough oil to get them back out, once you "feathered" that prop it
was going to STAY feathered! :-) Once you hit the button it went all
the way. In that case I want the student to touch the proper button
with a finger but NOT push it! :-)
Dudley Henriques
TD,
Thank you very much for the kind offer. I appreciate your words much much
more then my proverbial "bottle of scotch", :-) and I accept them in the
name of all the many fine pilots and instructors who post on this newsgroup.
Stan Prevost
"Dudley Henriques" <dhenr...@earthlink.net> wrote in message
news:NVLj8.17119$Vx1.1...@newsread1.prod.itd.earthlink.net...
TD
> I don't care whether it is more or less complex.
I do!
>It is the WRONG procedure.
Why?
>The student should NOT be taught how to adjust for "zero thrust."
Why not? Is there a real risk that during a real emergency the pilot
would simulate a feather instead of really feathering? If not, then
the added complexity of training should be an advantage when the real
emergency arose, no? In a real emergency after one verifies with the
throttle, the prop feathering is simpler. In throttle-idle engine out
simulations, the throttle of the affected engine is already at idle
and the student knows this. This is not the ideal simulation either,
yet it is done. Sure, my instructor switched tanks at altitude and I
got a real engine out but we can`t do that all the time. My point is
that alot of the multi-engine training is artificial already. Having
the student simulate feather is just another artificially constucted
task.
>The student SHOULD be taught to "feather." I learned, many
> years ago, that the adjustment to "zero thrust" was made by the
> INSTRUCTOR only AFTER the student had a hand on the prop control and
> indicated the proper direction to feather.
You know, even the Transport Canada Flight Examiners give the
candidate the option of simulating the feather themselves or asking
the examiner to do it for them once they point out the proper
controls. So the approach you quote does not seem a universal one.
> Michael lets them actually move the prop control...
I don`t think Michael lets them do anything. He is not yet a
multi-engine instructor. But I know what you mean. Thanks for your
input. I know you have about 25 times more experience in this field
than I.
TD
jakdedert
student with absolutely *no* ME experience. It just seems to me that when
teaching emergency procedures that one should teach *the* emergency
procedure until it becomes automatic...not a substitute which may then
become automatic in a real emergency.
jak
"highflyer" <high...@alt.net> wrote in message
news:3C8F6639...@alt.net...
Michael
> would simulate a feather instead of really feathering?
Yes, there is. Further, there is a real risk that he will do
something worse. Under stress, people often revert to initial
emergency procedures training, or, when that's not possible, do
something inappropriate.
I used to instruct at a parachute school that used the SOS system -
single handle on the left side of the harness that released the
malfunctioning main parachute and deployed the reserve. This was very
common then. I trained that way myself. Problem is, the gear for
licensed jumpers is rarely set up that way. We also used to have
people who, long after they were licensed, when their main parachutes
malfunctioned, pulled only the cutaway handle (on the right side of
the harness) and never pulled the reserve handle (on the left) at all.
They were used to only doing one thing...
Who is to say how someone who is used to moving two levers will
respond when the real thing happens? Will he simulate feather and not
get the prop far enough back? Will he perhaps move the prop lever
correctly and then do something nasty with one of the power levers on
the good engine? No clue.
I believe that training should be as realistic as possible. Sure, on
injected engines low altitude mixture cuts are risky, so we do
throttle cuts. But we do mixture cuts on the carbureted engines, not
just because they are safer (though they are) but also because they
are more realistic. Total realism is not possible, but we should
strive for maximum realism.
> > Michael lets them actually move the prop control...
> I don`t think Michael lets them do anything. He is not yet a
> multi-engine instructor.
Yeah, but I'm far enough along that now I'm the one pulling engines
(rather than having them pulled on me) and being subjected to the
worst my instructor has seen in his hundreds of hours of multiengine
dual given. And yes, I do let him get it about an inch back before I
stop the lever. I appreciate than on some airplanes this is not
possible. That means that on those airplanes we don't do it.
Not all procedures are universal. Some people still do low altitude
throttle cuts on carbureted engines, even though this really sets you
up for carb icing. Some people still do low altitude mixture cuts on
injected engines, even though this sets you up to vaporlock the
injector lines and make the engine hard to start. Some people still
do low altitude fuel valve cuts too, but that doesn't mean it's a good
idea. Some people actually feather an engine and then land with it
feathered. It's fine until someone pulls onto the runway while you're
on short final, or the student gets low and slow on final. Lots of
things are done that are suboptimal, and the fact that they are
endorsed by a government agency does not mean they are optimal - or
even reasonably safe. The FAA used to recommend Vmc demos at low
altitude. They don't do that anymore.
There is a difference between being able to follow procedures and
being able to develop procedures. Airlines understand this. They buy
many airplanes of the same make and model, equip the cockpits
identically, set up simulators also equipped the same way, and hire
people to develop optimal procedures for the operation of that
airplane. The procedures are recorded, the pilots are trained in the
procedures, and everyone does things the same way. All pilots are (or
should be) competent to follow procedures, but not all pilots can or
need to be competent to develop procedures.
In the GA world, most of the airplanes we fly are old. When you have
airplanes decades old with all sorts of optional equipment installed,
no two are alike. When a pilot checks out in a new airplane that is
reasonably complex, he must learn new procedures. He need not
necessarily develop those procedures himself - that's something the
instructor checking him out can help him with. Of course that assumes
the instructor is up to the task. He should be, but he may not be.
He may still be teaching procedures he learned in a different airplane
someplace else.
When we're talking about C-172's flying VFR, it's usually not a big
deal. There are so few critical items that it's hard to screw up.
Get into multiengine IFR flying, and procedures become important.
That's one of the reasons it's so important for every flight school to
have a chief instructor - part of his job is to standardize
procedures. To do this competently he needs to have knowledge, part
of which can come from books but some of which must come from depth
and breadth of experience. He also needs to be able to think
logically and work things out.
Not every flight school has such an instructor in charge of
operations. The ones that don't often wind up with suboptimal
procedures, if they have standardized procedures at all. A very few
wind up with downright unsafe procedures.
When you said you feathered the engine, I found that very scary. That
indicated an unsafe procedure. Now it turns out you set zero thrust
on the engine - that's much better, but still suboptimal because you
had to set it. However, IMO that makes the instructor's actions much
more understandable. Allowing you to perform an actual feather as
part of a botched low altitude emergency procedure would have been
grossly unsafe - allowing you to perform a simulated feather was not
unsafe at all.
That still doesn't mean he should have let you mishandle the emergency
badly enough to scare him - but I maintain that this kind of mistake
can happen to anyone.
Michael
Roy Smith, CFI
> These were exactly my thoughts, but I'm just a low-time single engine
> student with absolutely *no* ME experience. It just seems to me that when
> teaching emergency procedures that one should teach *the* emergency
> procedure until it becomes automatic...not a substitute which may then
> become automatic in a real emergency.
This is a good seque into a question that's been bothering me about my own
teaching. I did an engine-out drill with a student the other day in a
retract. We were in the pattern with the gear already down when we
simulated the failure. Making the runway was in doubt.
In real life, I'd pick the gear back up to improve glide performance and
accept a gear-up on the runway vs. not making the runway at all.
The problem is, that increases the risk of forgetting to put it back down
at the last minute in the training scenario and landing gear-up as a
training exercise. How do other instructors handle this one? Is the added
educational value of actually retracting the gear worth the risk?
--
Roy Smith, CFI-ASE-IA
Michael
> teaching. I did an engine-out drill with a student the other day in a
> retract. We were in the pattern with the gear already down when we
> simulated the failure. Making the runway was in doubt.
>
> In real life, I'd pick the gear back up to improve glide performance and
> accept a gear-up on the runway vs. not making the runway at all.
>
> The problem is, that increases the risk of forgetting to put it back down
> at the last minute in the training scenario and landing gear-up as a
> training exercise. How do other instructors handle this one? Is the added
> educational value of actually retracting the gear worth the risk?
An analogous problem exists in multiengine instrument training. Any
non-precision approach requires a level-off at MDA, and maybe other
level-offs. Normally this is accomplished by adding power, since the
gear comes down at or before the FAF and stays down. The problem is
that most light twins will not maintain altitude on one engine with
the gear down in most cases, so what do you do?
Believe it or not some instructors actually do not teach single engine
non-precision approaches, and most examiners will not test them. You
can imagine what I think of that, so I will delete the expletives.
Others manage the descent from the FAF to the MDA so as to arrive at
MDA at the VDP, and simply don't do single engine circling approaches.
This is doable but somewhat marginal without effective vertical
guidance, and anyway that's not the right way to fly a non-precision
approach. Sloppy, sorry VNAV (to borrow a Deakin term) is bad enough
in itself, and worse if you're trying to do it in an emergency when
you normally don't.
The solution, IMO, is to teach the way you fly - with heightened
awareness of the situation. When operating single engine, I believe
that the gear should be dropped at the VDP or, if it is a circling
approach, on the short base leg. This is, of course, too late to be
running the GUMP check. Thus when I do my GUMP check I begin the
mantra - "My gear is not down."
I believe that if there is an instructor in the cockpit, the chances
that both student and instructor will forget to lower the gear are
minimal. In a real emergency situation (and make no mistake, a single
engine non-precision approach is an emergency) if the worst that
happens is that you belly it in, well, that's not so terrible. As in
your situation, any attempt to keep the gear down throughout detracts
from realism and makes the successful completion of the exercise a
marginal thing.
My advice, such as it is, is to suck the gear up and then watch your
student like a hawk.
Michael
TD
> "Roy Smith, CFI" <r...@panix.com> wrote
> > This is a good seque into a question that's been bothering me about my own
> > teaching. I did an engine-out drill with a student the other day in a
> > retract. We were in the pattern with the gear already down when we
> > simulated the failure. Making the runway was in doubt.
> >
> > In real life, I'd pick the gear back up to improve glide performance and
> > accept a gear-up on the runway vs. not making the runway at all.
> >
> > The problem is, that increases the risk of forgetting to put it back down
> > at the last minute in the training scenario and landing gear-up as a
> > training exercise. How do other instructors handle this one? Is the added
> > educational value of actually retracting the gear worth the risk?
>
> An analogous problem exists in multiengine instrument training. Any
> non-precision approach requires a level-off at MDA, and maybe other
> level-offs. Normally this is accomplished by adding power, since the
> gear comes down at or before the FAF and stays down. The problem is
> that most light twins will not maintain altitude on one engine with
> the gear down in most cases, so what do you do?
My instructor did this to me as I was starting the circling, long past
the FAF. I tried to continue with the gears down but could barely
manage to remain level. I had to pull them up then drop them on final
when I was assured of making it. I guess it is better to make the
runway with the gears up if you forget, as you say, rather than no
making it with the gears down. Now I know. I my Cougar, better get
them up immediately.
TD