Glide ratios
Rohit Sood
Katana and Piper Warrior. To put in another way, if you were to lose
your engine, what aircraft would you wish to be flying?
-Rohit
John Roncallo
Rohit Sood wrote:
> Does anyone have any comparison for the glide ratios of Cessna 152, 172,
> Katana and Piper Warrior.
I'm going to guess since I don't have the data. But I would say
Katana
C152
C172
Warrior
Now assuming you found a 1000' landing spot within glide range of all of the
above aircraft. Which would be the easiest plane to stick into the landing
area with an absolutely dead stick. Well for me
Warrior
C172
C152
Katana
> To put in another way, if you were to lose
> your engine, what aircraft would you wish to be flying?
Out of the 4 above I would take the Piper with its mechanical flaps and no
BS about slipping with flaps down. Or as long as I had reasonable altitude
or airspeed, I would prefer a helicopter.
> -Rohit
--
/---------------------------------------/
/ John Roncallo /
/ ron...@ibm.net /
/---------------------------------------/
Richard L. Watson
My brother in law is a flight instructor and gave me a bit
of mtn. flying instruction in my plane in CO a few years
ago. He suggested that generally the best emergency landing
place is right below the plane. Sounds nuts right. Well,
within reason it makes a lot of sense for the following
reason. By the time you circle down to a place nearly under
the plane you will have it really well scoped out. You will
know where the rocks, trees, ditches and fences are located.
If you glide off to a distant location near your glide
limit, you may get there to find it is really bad, or you
missed the ditch that will kill you. A worse location
closer that you can really scope out is better.
I have been looking and thinking about this for three years
now and it makes a lot of sense to me.
Richard
Gene Whitt
following summary.
Your quickest Vg speed is half-way between Vx and Vy.
Make your Vg speed errors on the high side.
Best to make as near normal pattern as possible
You will not be able to 'land' as far as you glide.
Don't try to stretch a glide
No flaps until field made.
Have a pre-crash checklist.
More ideas welcome
Gene Whitt
Derek
Andrew Puddifer
sink like a stone too!
Regards, Andrew.
luc...@metrowerks.com
"Richard L. Watson" <rwa...@centurytel.net> wrote:
I agree with this too and find it to be sound reasoning. In fact, this
is a kind of critical thing in my plane. Because of the low speed
(50mph cruise, 40 to 45mph Vbg), my gliding options are very limited,
even at the high-for-ultralights altitudes that I fly at (1000' AGL at
the very least on a trip).
I pay quite close attention to possible put-down areas when flying CA
IV, due to other factors like a lack of a protective enclosure around
me, little less reliability of my 2-stroke motor (no, don't want to
start that thread again, forget it), etc.
In fact, I always plan routes and altitudes so that I fly directly over
(or slightly to the side of) fields, even if it means a dogleg route to
the destination. I never launch off over a large stand of trees (unless
I climb to a suitable altitude from which I can glide to a safe area).
After about 160 hours in the Quick, I've found myself being more
attentive in this regard even in GA flying as a result. Another icing-
on-the-cake benifit of ultralight training.....
Lucien S.
PP-ASEL.
Captain America IV.
Sent via Deja.com http://www.deja.com/
Before you buy.
J. C. Kamienski
: By the time you circle down to a place nearly under
: the plane you will have it really well scoped out. You will
: know where the rocks, trees, ditches and fences are located.
Have you tried this?
Unfortunately, I don't think you'll find that true in general.
Many of the rocks, ditches, fences, etc you won't see until it's
too late to do anything about it.
That's why it's a good idea to do low passes over remote strips or
fields before you land on them (when you DO have an engine, that is).
Because most of it you won't see until you're a couple feet above it.
I think you're better off looking for somewhere that has a general
appearance of being safe, and heading for it.
Once you get close you'll have the same worries, no matter where
you chose to begin with.
Jill
PP-ASEL, TW
EColeson
<gwh...@ix.netcom.com> writes:
>Your quickest Vg speed is half-way between Vx and Vy.
>
No no no! Vy IS Vg speed. Actually Vy and Vg are achieved at exactly the same
wing angle of attack (alpha) and that alpha (at which the difference between
lift and drag are greatest) will be achieved at the same speed, power on or
power off. Also, flying with only as much power as necessary to maintain that
speed (and alpha) in level flight will result in best range.
You're observation that erring on the high side of Vg will take you farther
than a similar error on the low side is correct. In practice, adding half the
headwind component to Vg when flying upwind will take you even farther. If
you want to get the most out of a glide, check your local library for "Joy of
Soaring" by Carle Conway, or "The Soaring Flight Manual" (both are available
from the Soaring Society of America at www.ssa.org or Sporty's Pilot Shop) or
get together with a glider instructor
Cheers,
Eric.
John Lowry
There is a lot of misinformation -- some trivial, some important -- out
there are to various extents you have bought some of it. Vg is the speed
where drag D is least. Vy is the speed where (T-D)*V (T thrust, V true
airspeed) is greatest. Even in a simple-minded theory in which thrust were
constant (along with propeller efficiency), they wouldn't be the same.
The "add one-half the headwind speed" prescription is also flawed. There's
no one fraction to add, but for small headwinds it starts are 1/4, not 1/2.
All of this stuff, and much more, is in Performance of Light Aircraft. With
nice down-to-earth calculations, not just authorities cited and hands
randomly waved. It's tough trying to make sense of the world, but it can (in
part) be done.
John.
--
John T. Lowry, PhD
Flight Physics; 724 Alderson Ave.; Billings MT 59101
Voice: 406-248-2606
Web site: http://www.mcn.net/~jlowry
E-mail: jlo...@mcn.net
EColeson <ecol...@aol.comnospam> wrote in message
news:20000727140200...@nso-da.aol.com...
John Stephens
>In article <8lo5sn$c7f$1...@slb2.atl.mindspring.net>, Gene Whitt
><gwh...@ix.netcom.com> writes:
>
>>Your quickest Vg speed is half-way between Vx and Vy.
>>
>
>No no no! Vy IS Vg speed. Actually Vy and Vg are achieved at exactly the same
>wing angle of attack (alpha) and that alpha (at which the difference between
>lift and drag are greatest) will be achieved at the same speed, power on or
>power off. Also, flying with only as much power as necessary to maintain that
>speed (and alpha) in level flight will result in best range.
Back to school, my friend -- you are dead wrong! Vbg = .5*(Vx+Vy) is a
pretty good approximation for many/most GA aircraft. E.G. C172.
Vx=59, Vy=75; formula gives 67. POH value for Vbg is 65. Close enough!
And significantly better tyhan your Vy!
>
>You're observation that erring on the high side of Vg will take you farther
>than a similar error on the low side is correct. In practice, adding half the
>headwind component to Vg when flying upwind will take you even farther. If
>you want to get the most out of a glide, check your local library for "Joy of
>Soaring" by Carle Conway, or "The Soaring Flight Manual" (both are available
>from the Soaring Society of America at www.ssa.org or Sporty's Pilot Shop) or
>get together with a glider instructor
>
>Cheers,
>Eric.
--
John Stephens (remove spaces for legal email address)
s t e p h e n s @ p o b o x . c o m
Michael Gillespie
> I don't know about the others, but the Katana has an 11:1 glide ratio.
No. The Diamond DA20 Katana has a 14:1 glide ratio. (For comparison, the
Diamond HK36 has a 28:1 glide ratio.) My Cheetah has about a 10:1. My
friend's Cherokee seems about 5-7:1
Michael.
---------------------------------------+---------------------------------
Michael Gillespie | Voice 204.925.9000
Flying Colors Pilot Training | http://www.flying-colors.org
Flying Colors Precision Flight Team | mich...@flying-colors.org
--- No good deed will go unpunished. --+-- Standard Disclaimers Apply ---
Derek
the Diamond Katana DA-20 C1 says a glide ratio of 11:1 at gross weight with
flaps at cruise and airspeed 73.
Michael Gillespie wrote in message ...
highflyer
>
> My brother in law is a flight instructor and gave me a bit
> of mtn. flying instruction in my plane in CO a few years
> ago. He suggested that generally the best emergency landing
> place is right below the plane. Sounds nuts right. Well,
> within reason it makes a lot of sense for the following
> the plane you will have it really well scoped out. You will
> know where the rocks, trees, ditches and fences are located.
> limit, you may get there to find it is really bad, or you
> missed the ditch that will kill you. A worse location
> closer that you can really scope out is better.
>
> I have been looking and thinking about this for three years
> now and it makes a lot of sense to me.
>
> Richard
I do have a fair amount of experience landing without power.
The most important thing is to positively avoid the necessity for
a "go around!" :-)
Given the need for an "off airport" landing, the most important factor
that will make for a successful "off airport power off" landing is a
slow landing speed. Never mind the glide range, ask instead, "How
slowly can I fly?" Then fly it to the most suitable place you can
reach EASILY, to avoid nasty surprises at the last minute, and do a
nice SOFT field landing. This soft field landing at the slowest
possible landing speed works as well as can be managed for landings
on water, tree tops, ploughed fields, pastures, cornfields, and
long paved runways.
I recommend practicing the technique from time to time at some
convienient field. If you have the luxury of practicing at a long
paved runway, pick a specific intersection about a third of the way
down the runway and imagine that land STARTS there. If you touch
down before then you get wet! Then practice so that you can land
from any direction and any reasonable altitude within a plane length
or two PAST your selected spot. Minus points for landing in front of
it, even by a couple of feet! :-)
Then having an engine quit is an annoying incident, but it probably
will not make it into the local newspaper. :-) Been there, done that.
--
HighFlyer
Highflight Aviation Services