Hughes 500 Accident
JStricker
I lurk here a lot, but post infrequently because I believe in the saying
better to remain silent and thought a fool than to open your mouth and
remove all doubt. I know so little about the workings of the helicopter,
that I come here to learn not lecture.
Back in December, I was in an accident in a Hughes 269. The aircraft was
part of a corporate flight department including a Hughes 500 (369HS), King
Air 350, and Citation IIsp. My brother was piloting the 269 when it went
down and was chief pilot for the flight department.
Thanks to some patient explanation by Nick and talking to another pilot in
the flight department (high time rotary wing former military), I think both
he and I understand better what happened. So the following hit us pretty
hard yesterday.
The accident isn't on the NTSB site yet, so I'll just copy from the
newspaper article (leaving in the misquotes and errors):
---------------------------------------------------------
Salina Journal, 4/25/00
Helicopter Crashes On Ranch South Of Salina
No one was hurt, but a helicopter was damaged Monday afternoon in a crash 12
miles west of Salina.
Helicopter owner Charlie walker said pilot Duane Gulker was flying about 50
feet above the ground looking for a buffalo bull from Walker's Rolling Hills
Ranch that had wandered onto Jack Vaier's CK Ranch near Brookville.
"They lost tail rudder effectiveness, then lost control of the aircraft."
Walker said. "It's caused by wind coming up through the canyons."
Gulker <I snipped Duane's address> and passenger Mark Johnson, Walker's
ranch foreman, were unhurt. The Federal Aviation Administration was
notified of the 5:30 PM crash.
"I guess I'll buy another one," Walker said of the destroyed helicopter.
This is the second crash of a Walker helicopter in the past few months. On
Dec. 13, Kirk Stricker and his brother, John Stricker, crashed in a field
just south of the intersection of Centennial and Parsons roads in southern
Saline County.
------------------------------------------------------
First off, Duane called Kirk right after it happened. He told him that both
he and Mark walked out to a phone and neither had more than scratches. The
aircraft is a total loss.
When he asked what happened, Duane said that he lost all tail rotor
effectiveness very quickly, but didn't believe it was a mechanical failure
and suspected the winds. They routinely used the helicopter(s) to herd the
buffalo as they aren't very safe to handle with ground based vehicles or
personnel. The buffalo are used to them and normally they just hover near
them, on the opposite side of where they want them to go and they eventually
get tired of getting beat around by the rotorwash and walk the other way.
The area in question has some fairly deep canyons (for KS) and with our
winds here they CAN really funnel some serious air through them. But
because of my lack of knowledge on the subject, I'm asking here.
What kind of winds could cause the TR to lose effectiveness that quickly?
There weren't real strong winds, for KS, maybe 12-15 knots. Duane was
experienced in flying several different types of military helicopters and
had done this particular operation many times in the past. Is the Hughes
500 prone to loss of TR effectiveness in certain conditions? I'm curious
how this could have happened.
FWIW, the flight department has been running there for 15+ years and has
never had an accident or incident. Now there are two in six months. The
owner has never scrimped on equipment, people, training, or anything else.
Needless to say, I'm at a bit of a loss here and am interested in hearing
you folk's opinions, if any.
--
John Stricker
"I didn't spend all these years getting to the top of the food chain just to
be a vegetarian"
Matthew
(snip)
>What kind of winds could cause the TR to lose effectiveness that quickly?
>There weren't real strong winds, for KS, maybe 12-15 knots. Duane was
>experienced in flying several different types of military helicopters and
>had done this particular operation many times in the past. Is the Hughes
>500 prone to loss of TR effectiveness in certain conditions? I'm curious
>how this could have happened.
I'm not experienced in 500s but just thought it important to point out that
you have to be conserved with relative wind. It could be totally calm, but
the motion of the helicopter makes a relative wind that can cause this.
>FWIW, the flight department has been running there for 15+ years and has
>never had an accident or incident. Now there are two in six months. The
>owner has never scrimped on equipment, people, training, or anything else.
>Needless to say, I'm at a bit of a loss here and am interested in hearing
>you folk's opinions, if any.
Two accidents in a short time always makes people jump and think that it
establishes a trend. It's worth a scrutiny to make sure there is no trend,
but all too often it's just bad luck.
>"I didn't spend all these years getting to the top of the food chain just
to
>be a vegetarian"
"If God wanted us to be vegetarians, then why did He make animals out of
meat?"
Matthew.
Dave Anderson
initially written by Don Bloom and published in some Bell letters as well as
in FAA documents. Unfortunately, I don't know which periodicals that it was
published in. Don Bloom is a retired bell Experimental Test Pilot who
co-won the "Ivan Kincheloe" ( Society of Experimental Test Pilots) award for
his work in LTE in 1984. I won't try to summarize all that he says except
to say that if you have winds and you are hovering, any helicopter with a
tail rotor can experience LTE. Makes for interesting reading.
I will fax this to any one who will send me a fax number.
Dave Anderson
"Matthew" <c_a...@bc.symREMOVEpatico.ca> wrote in message
news:zOIN4.81029$2D6.2...@news20.bellglobal.com...
Dave Blakeston
Name is Dave aka Nessy. I'm ex-RAF of 23 years, with experience of 330A &
CH-47C/D.
After a somewhat turbulent resettlement to civvy life, I've secured a job
working on the Bell 412. I'm currently undergoing a 412 training course
under an ex-RN instructor (Falklands veteran) with oodles of Wessex & Sea
King (SK) experience; during the course, he's spent more time telling us
interesting helicopter war stories than instructing us on the 412.
Some, if not all, British SKs have an angle-iron type length of metal
running the length of their tail booms on the left side, which is plainly
evident on RAF models. During one of his Falklands yarns, my instructor told
us that in very windy conditions, RN SK pilots regularly reported that they
had to adjust their rudder pedals from the 'normal' position to maintain the
correct attitude in the hover; the tail rotor was inefficient.
Given that the SK main rotor (MR) rotates a/clockwise and the TR is on the
left side of the AC, the TR must be a 'blower', obviously requiring negative
relative pitch to counter the MR torque; as far as the pilot is concerned,
this would be a 'neutral' rudder pedal condition. Due to the wind
conditions, the shape of the tail boom and the MR downwash, the instructor
explained, the tail boom's aerodydamic shape in relation to the downwash,
was augmenting the effect of the tail rotor and pilots had to apply pitch in
varying degrees, dependant on wind conditions, towards positive to
counteract MR torque.
As a result of investigations at 'spanner monkey' level, and due to war
conditions, angle iron was aquired and 'nailed' to the left side of the tail
boom, to disrupt the effect of MR downwash over the tail boom. It worked and
the evidence is still there.
Hope this may explain something. My first time in this newsgroup and I look
forward to reading/writing again.
S'long.
Nessy.
John Eacott
Interesting application, ask him (what's his name, by the way............?)
if he's heard of Coanda effect. The disruption is more to create lift from
the tail boom; disrupting the flow on the left side would create a high
pressure area, whilst the normal flow on the st'bd side would be a
(relatively) lower pressure. Nett result would be lift from the tail boom
towards the right, augmenting the tail rotor thrust and reducing tail rotor
input, not the opposite that appears to be mooted in your explanation.
IIRC, Falklands ops were generally at war weight, overloaded about 10-15%
over normal MAUW, which would have put a fair old strain on the t/r anyway.
Introduction of the 6 bladed t/r on the Sea King was an enormous improvement
on the original HAS1's with only 5 blades, but Westland encountered quite a
few stress problems with the extra t/r thrust on the tail. First 6 blade I
flew was the Pakistani version, I expect the Coanda strake would be a
similar improvement. Commercial kits are currently available to put Coanda
strakes on Bell 205/212/412 airframes.
--
John Eacott
The Helicopter Service Australia
www.helicopterservice.com.au
"Dave Blakeston" <ness...@skynow.net> wrote in message
news:391e1...@news2.cluster1.telinco.net...
John Bicker
eac...@helicopterservice.com.au wrote on 14/5/00 14:42:
Go take a look at an A109E, AS350B2,B3 and all the Notars. Same stuff
--
neil fraser
I'll have to check on the B3 .
Neil
John Bicker wrote in message ...
Alan Simpson
The Presidents flying sex parlor VH-3s have strakes.
I saw it last week.
Tracy Marchant
I have - its cool!!!!!
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Paul P.
absolute dream to fly...I think it's a bit easier than the JetRanger (I feel
like I have more TR authority on the R44)
Regards,
Paul Papasavas
Nassau Helicopters
Princeton, NJ
Tracy Marchant <tracym...@artwork73.freeserve.co.uk> wrote in message
news:B54F4B25.8EC%tracym...@artwork73.freeserve.co.uk...
Dave Blakeston
OK mate. Only trying to offer a constructive explanation. I know of the
Coanda effect but I'm not trying to start an 'argimint', merely passing on a
war story from a supposed SK 'expert'. And I don't remember the instructor
telling me that the cabs, in his experience, were overloaded, which they
probably were.
However, if the section of the tail-boom when viewed from rear (VFR) is
symetrical, then surely RIGHT ANGLED (not conventional fixed wing, flap type
augmentation) disruption on the left would stall airflow from the MR,
thereby nullifying pressure on the left, leaving the right side to produce
effective lift; if symetrical tail-booms are the norm, there would have been
no need for the modification.
I'm back at work on Tuesday (30th), where I work alongside 3 RAF SAR SKs.
I'm not sure (I'll check) but I think the section of the tail boom, when
VFR, is assymetrical, i.e. less curved on the left and therefore naturally
biased to give positive pressure on the left. Hence, disruption of airflow
in aforementioned circumstances would reduce
lift on the left, leaving the TR to do its job.
If I'm wrong, I'll bang out another e-mail, bowing to your superior
'front-ender' experience.
Thanks for the reply. 1st time in this newsgroup. Not being a flyer, maybe I
should find an engineering orientated NG. Be in touch soon.
Nessy.
By the way, wos yer name again.... Jon?
"John Eacott" <eac...@helicopterservice.com.au> wrote in message
news:1aqT4.48$QY3....@nsw.nnrp.telstra.net...
John Eacott
snip
>
> Thanks for the reply. 1st time in this newsgroup. Not being a flyer, maybe
I
> should find an engineering orientated NG. Be in touch soon.
>
> Nessy.
Don't do it! Pilot talk's often boring, we need ginger beers to keep us on
the straight and narrow :-)
Dave,
I'm not wishing to make any "points", just curious as to who the ex RN
driver is. I left ages ago, but he may be old ships.
The SK tail boom is symmetrical, and as such creates no discernable lift
from the downwash. The Sea King tail boom was designed in the late 50's
(SH-3) when the idea of asymmetric tail booms wasn't considered, and
Westland haven't changed it at all in shape, just beefed it up here and
there.
Most helicopters have symmetrical booms, and the purpose of any coanda
strake is to induce lift away from the side that the strake is attached to.
Breaking the airflow creates a (relatively) higher pressure than on the
unbroken side, thus creating lift in the direction away from the coanda
strake. This holds for most solid tail booms, hence the aftermarket kits
now available.
Cheers,
Steve
> Most helicopters have symmetrical booms, and the purpose of any coanda
> strake is to induce lift away from the side that the strake is attached to.
> Breaking the airflow creates a (relatively) higher pressure than on the
> unbroken side, thus creating lift in the direction away from the coanda
> strake. This holds for most solid tail booms, hence the aftermarket kits
> now available.
I was looking at two of LA Police`s AS-350Bs the other day. Most are B-1 models
although one was just converted to a B-2 model and this included a strake on
the
right side of the tailboom. I also noticed the Exhaust can was angled to the
left
as opposed to straight on the B-1 model.Does this have to do with directing the
exhaust flow away from the side of the tailboom with the strake ?
steve
206,44 and 22, but our 44 is not hydraulic im a bit reluctant to upgrade to
the hydraulic due to our exchange rate at the moment it would push up the
44's price to $550,000 australian and for that we could get another 206, but
im used to the eletric trim on the 44 so it doesnt phase me maybe when the
exchange rate gets better we might think about it, but it is very nice to
fly i will agree.
steve forgacs
Rotorway Helicopters
Newcastle Australia
Tracy Marchant wrote in message ...
dmgu...@gmail.com
> There weren't real strong winds, for KS, maybe 12-15 knots. Duane was
> experienced in flying several different types of military helicopters and
> had done this particular operation many times in the past. Is the Hughes
> 500 prone to loss of TR effectiveness in certain conditions? I'm curious
> how this could have happened.
>
> never had an accident or incident. Now there are two in six months. The
> owner has never scrimped on equipment, people, training, or anything else.
> Needless to say, I'm at a bit of a loss here and am interested in hearing
> you folk's opinions, if any.
> John Stricker
>
> jstr...@russellks.net
> "I didn't spend all these years getting to the top of the food chain just to
> be a vegetarian"