Lancair crash at SnF

On 2008-04-24, Brian wrote:
Depends on what you mean by "the impossible turn". If you mean turning back
at 200 AGL, yeah, that one's pretty much impossible. If you mean 600 AGL,
it's pretty much possible in the average aircraft. (Hell, that's pattern
altitude at EFD!) The line lies somewhere in between.

It is statements like this that get pilots killed.

It's statements like 'never turn, always land straight ahead' that also
gets pilots killed. There are plenty of airfields where going straight
ahead is quite possibly the worst option, and the best survivability
options are at least a 120 degree turn away from whatever point you're
at when at 600' AGL.

The only thing you can do is use the best judgement at the time. You get
one chance - it may be wrong. Sometimes, trying to turn back might be
wrong. Sometimes doing anything *other* than trying to turn back might
be wrong.

In gliders, every glider pilot is taught "the impossible turnback" from
200 feet (which, in the typical low performance training glider, is
about equal to turning back at 600 feet in a C172). We actually train
for it for real - there's no other way to do it - the instructor will
eventually pull the bung on you at around 200ft. It's an essential skill
because power failures (rope or cable breaks) are a lot more frequent
than engines quitting on a single. Doing it off a simulated winch launch
failure is quite exciting - we tend to do that at about 400 ft though
because it's an extremely critical manoevre, since you're pitched up at
50 degrees or so and any delay equals a low altitude stall. The ground
looks really, really close when you pitch down steeply to quickly regain
your airspeed and can see nothing but green in front of you. The really
important bit about this training though is you're not taught it as an
absolute. The mantra is to first do what it takes to maintain airspeed,
then quickly decide on a course of action. The course of action could be
any of several possibilities - can you get down on the remaining runway?
Can you turn back? Is what's in front of you landable? Land to the side?
Which way is the wind going? (If there's a crosswind aloft, this affects
the decision on which way you're going to turn: you should have already
decided turn direction in the 'eventualities' part of the checklist
before the slack is even taken up on the cable or tow rope).

The answer is as always training, and having a plan. Think of the
eventualities just as you line up - if you lose power at point X, what
should you do. At point Y, what should you do? What about point Z?

--
From the sunny Isle of Man.
Yes, the Reply-To email address is valid.

On Thu, 24 Apr 2008 12:46:29 GMT, Jay Maynard
wrote in
:

On 2008-04-24, WingFlaps wrote:
When will pilots learn to stop trying to do the impossible turn... and
go for a straight ahead landing on soemthing horizontal?

Depends on what you mean by "the impossible turn". If you mean turning back
at 200 AGL, yeah, that one's pretty much impossible. If you mean 600 AGL,
it's pretty much possible in the average aircraft. (Hell, that's pattern
altitude at EFD!) The line lies somewhere in between.

This subject has been discussed in detail with the assistance of
erudite professor Lowry's input:
http://groups.google.com/group/rec.a...1d80a2e846a88b


John T. Lowry

Best turnaround bank angle phi (least altitude loss per angle turned
through) for a gliding airplane is given by: cos(phi) =
(sqrt(2)/2)*sqrt(1-k^2) where k = CD0/CLmax + CLmax/(pi*e*A) where CD0
is the parasite drag coefficient, CLmax is the maximum lift
coefficient for the airplane's flaps configuration, e is the airplane
efficiency factor, and A is the wing aspect ratio. I know most ng
readers hate those darned formulas, but that's the way the world
works. For GA propeller-driven airplanes, k is a small number (0.116
for a Cessna 172, flaps up) and so the best turnaround bank angle is
very closely the 45 degrees cited by Rogers and, much earlier, by
Langewiesche (Stick and Rudder, p. 358). For the above Cessna, for
instance, it's 45.4 degrees. For a flamed-out jet fighter, however,
things are considerably different. The formulas above, along with
formulas for the banked stall speed, for banked gliding flight path
angle, and for the minimum altitude loss in a 180-degree turn, can all
be found in my recent book Performance of Light Aircraft, pp. 294-296.
The following seven pages then treat the return-to-airport maneuver,
from start of the takeoff roll to contact with the runway or terrain,
in excruciating detail. Including wind effects, the typical
four-second hesitation when the engine stops, etc.

John. -- John T. Lowry, PhD Flight Physics; Box 20919; Billings MT
59104 Voice: 406-248-2606

Nov 1 1999, 1:00 am
Newsgroups: rec.aviation.piloting, rec.aviation.student
From: "John T. Lowry"
Date: 1999/11/01
Subject: Turn Back Maneuver


Best turnaround bank angle phi (least altitude loss per angle turned
through) for a gliding airplane is given by:

cos(phi) = (sqrt(2)/2)*sqrt(1-k^2)

where k = CD0/CLmax + CLmax/(pi*e*A)

where CD0 is the parasite drag coefficient, CLmax is the maximum lift
coefficient for the airplane's flaps configuration, e is the airplane
efficiency factor, and A is the wing aspect ratio. I know most ng
readers hate those darned formulas, but that's the way the world
works.

For GA propeller-driven airplanes, k is a small number (0.116 for a
Cessna 172, flaps up) and so the best turnaround bank angle is very
closely the 45 degrees cited by Rogers and, much earlier, by
Langewiesche (Stick and Rudder, p. 358). For the above Cessna, for
instance, it's 45.4 degrees. For a flamed-out jet fighter, however,
things are considerably different.

The formulas above, along with formulas for the banked stall speed,
for banked gliding flight path angle, and for the minimum altitude
loss in a 180-degree turn, can all be found in my recent book
Performance of Light Aircraft, pp. 294-296. The following seven pages
then treat the return-to-airport maneuver, from start of the takeoff
roll to contact with the runway or terrain, in excruciating detail.
Including wind effects, the typical four-second hesitation when the
engine stops, etc.

John.
--
John T. Lowry, PhD
Flight Physics; Box 20919; Billings MT 59104
Voice: 406-248-2606





Mo
http://groups.google.com/group/rec.a...4829291b24775f
http://groups.google.com/group/rec.a...c37fab40401aba
http://groups.google.com/group/rec.a...73917967e58181
http://groups.google.com/group/rec.a...b42a74fe660741
http://groups.google.com/group/rec.a...73917967e58181
http://groups.google.com/groups/sear...X-Y_&filter=0&
http://groups.google.com/group/rec.a...095b7459a04b3a

theyr are ignoring u boooring
Larry Dighera pretended :
John T. Lowry

On 2008-04-24, WingFlaps wrote:
A Lancair crashed just moments after takeoff here in Mesa, Arizona,
today, too. Plane was headed for California. There was smoke trailing
from the plane on takeoff and controllers cleared them to turn back
around and land. They tried -- they made the left turn but crashed into
the orange orchard. Three fatalities, all in their late 20s. Sympathies
and prayers to the families.

When will pilots learn to stop trying to do the impossible turn... and
go for a straight ahead landing on soemthing horizontal?

We don't know it was an 'impossible turn'. We don't even know what
altitude they were at, whether the engine was still developing power or
not, or whether the plane caught fire, or ... there simply isn't enough
information to condemn the PIC of this aircraft. There was obviously
enough time for ATC communications, so it's possible they had already
gained reasonable altitude from which turning around was eminently
feasable and not even difficult.

Define impossible turn. A friend of mine turned back from 600 feet in a
C150 after the engine ate a valve. (He kept the battered piston as a
soevenir).

--
From the sunny Isle of Man.
Yes, the Reply-To email address is valid.

Shirl wrote:
A Lancair crashed just moments after takeoff here in Mesa, Arizona,
today, too. Plane was headed for California. There was smoke trailing
from the plane on takeoff and controllers cleared them to turn back
around and land. They tried -- they made the left turn but crashed into
the orange orchard. Three fatalities, all in their late 20s. Sympathies
and prayers to the families.

WingFlaps wrote:
When will pilots learn to stop trying to do the impossible turn... and
go for a straight ahead landing on soemthing horizontal?

In this case, straight ahead would have been into a shopping center,
buildings, houses, etc. Having been through an engine failure, I try
not to second guess, but he *may* have thought he had a better chance to
at least turn away from all that.

Dylan Smith wrote:
We don't know it was an 'impossible turn'. We don't even know what
altitude they were at,

Reports said they were only 400 to 500 feet from the field, but don't
know how high.

whether the engine was still developing power or
not, or whether the plane caught fire, or ... there simply isn't enough
information to condemn the PIC of this aircraft. There was obviously
enough time for ATC communications, so it's possible they had already
gained reasonable altitude from which turning around was eminently
feasable and not even difficult.

Define impossible turn. A friend of mine turned back from 600 feet in a
C150 after the engine ate a valve. (He kept the battered piston as a
soevenir).

Weird, the souveniers we keep. I have the two "dead" sticks from my
totaled plane (oil cooler failure resulting in seized engine 6 min into
the flight...just long enough out away from the runways!).

In my checkride, the examiner said many pilots die landing straight
ahead on unsuitable off-field areas because of the "impossible turn"
myth when there is at least one and sometimes two perfectly good runways
right behind them. He advocated pushing the nose over and making the
turn. Of course, this guy was a retired ag pilot, too.
;-)

On Apr 25, 2:06*am, Shirl wrote:
Shirl wrote:
A Lancair crashed just moments after takeoff here in Mesa, Arizona,
today, too. Plane was headed for California. There was smoke trailing
from the plane on takeoff and controllers cleared them to turn back
around and land. They tried -- they made the left turn but crashed into
the orange orchard. Three fatalities, all in their late 20s. Sympathies
and prayers to the families.
WingFlaps wrote:
When will pilots learn to stop trying to do the impossible turn... and
go for a straight ahead landing on soemthing horizontal?

In this case, straight ahead would have been into a shopping center,
buildings, houses, etc. *Having been through an engine failure, I try
not to second guess, but he *may* have thought he had a better chance to
at least turn away from all that.



I had a look on Google earth and there seem to be many fields around
the airport what shopping center are you talking about?

Cheers

Dylan Smith wrote:


We don't know it was an 'impossible turn'. We don't even know what
altitude they were at, whether the engine was still developing power or
not, or whether the plane caught fire, or ... there simply isn't enough
information to

Except we know they didn't make it. Assuming the pilot was reasonably
proficient, that suggests the turn couldn't be made.

Late '20s, flying a Lancair. Well, at least he seems to have lived well.

-c

gatt wrote in
news:ru6dnZlbZ5BGu4zVnZ2dnUVZ_qjinZ2d@integraonlin e:

Dylan Smith wrote:


We don't know it was an 'impossible turn'. We don't even know what
altitude they were at, whether the engine was still developing power
or
not, or whether the plane caught fire, or ... there simply isn't
enough
information to

Except we know they didn't make it. Assuming the pilot was reasonably
proficient, that suggests the turn couldn't be made.


No, it suggests that he probably wasn't prficient, but we don't know and
are unlikely to ever know. There's always a min height that it can be
performed from and only a lot of practice will tell you what that is for
each departure. As i've said before, only proficiency in handling an
airplane in this situation and a carefully thought out self briefing
before the departure can give even a chance of success in the turnback
manuever. Add in a bit of luck and you have it, but it's almost always
safer to go straight ahead if at all possible.


Bertie

WingFlaps wrote:

A Lancair crashed just moments after takeoff here in Mesa, Arizona,
today, too. Plane was headed for California. There was smoke trailing
from the plane on takeoff and controllers cleared them to turn back
around and land. They tried -- they made the left turn but crashed into
the orange orchard. Three fatalities, all in their late 20s. Sympathies
and prayers to the families.

When will pilots learn to stop trying to do the impossible turn... and
go for a straight ahead landing on soemthing horizontal?

What a bummer.

The Jeppeson Instrument/Commercial text has a great illustration of how
turning to land after losing power on takeoff doesn't work.

-c

WingFlaps wrote:

A Lancair crashed just moments after takeoff here in Mesa, Arizona,
today, too. Plane was headed for California. There was smoke trailing
from the plane on takeoff and controllers cleared them to turn back
around and land. They tried -- they made the left turn but crashed into
the orange orchard. Three fatalities, all in their late 20s. Sympathies
and prayers to the families.

When will pilots learn to stop trying to do the impossible turn... and
go for a straight ahead landing on soemthing horizontal?

I saw the local news report and the suggestion was that he hit where
he did to avoid populated areas. A picture shown did suggest that
straight ahead was problematic.

Ron Lee