BD-5 crash in Australia

"Stealth Pilot" wrote

maybe the hotdog method of achieving liftoff then maintaing low level
horizontal flight and accelerating like hell before climb out is a
better way of flying them.
interesting.

You may have finally made a positive point for hot-dogging. Anyone think of
a down side?
--
Jim in NC

Morgans wrote:
"Stealth Pilot" wrote

maybe the hotdog method of achieving liftoff then maintaing low level
horizontal flight and accelerating like hell before climb out is a
better way of flying them.
interesting.


You may have finally made a positive point for hot-dogging. Anyone think of
a down side?

Not a one.

Richard

On Thu, 24 May 2007 03:28:10 GMT, cavelamb himself
wrote:

Morgans wrote:
"Stealth Pilot" wrote

maybe the hotdog method of achieving liftoff then maintaing low level
horizontal flight and accelerating like hell before climb out is a
better way of flying them.
interesting.


You may have finally made a positive point for hot-dogging. Anyone think of
a down side?

Not a one.

Richard
-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Yes, and I'm surprised there is no rebuttal.
If it was better, it wouldn't be called 'hot-dogging.' ;-)

For openers...
The FAA is not known to support 'hot-dogging'.
Neither do legit aircraft manufacturers, AFAIK.

Why?
Like has been said...
It's just hot-dogging.

hot-dogging;

1. to perform in a recklessly or flamboyantly skillful manner,
show off.

2. intended or done to draw attention; showy or sensational.


Although speed can be traded for altitude,
you won't get as much with this technique
or as much opportunity to pick a crash site.


Blast away.
Nomex union suit - ON.


- Barnyard BOb -

On Thu, 24 May 2007 03:58:41 -0500, Barnyard BOb
wrote:


For openers...
The FAA is not known to support 'hot-dogging'.
Neither do legit aircraft manufacturers, AFAIK.

Why?
Like has been said...
It's just hot-dogging.

hot-dogging;

1. to perform in a recklessly or flamboyantly skillful manner,
show off.

2. intended or done to draw attention; showy or sensational.


Although speed can be traded for altitude,
you won't get as much with this technique
or as much opportunity to pick a crash site.


Barnyard, the boy and I discussed this technique tonight.
he is of the opinion that it may be the desired way to effect a
takeoff in the BD5.
He said that it is surprising but the wheels should be
raised/retracted as soon as possible after liftoff. The BD5 sees an
immediate jump in speed of 20 knots when the wheels come up.

holding the aircraft low to the ground and accelerating in level
flight does two things.
it gets you to a safer climbout speed faster.
if the engine does quit you avoid the spine destroying thump into the
ground.

most of us have been flying what I'll call FAR23 type aircraft all our
lives. The BD5 is quite a different handling aircraft and needs to
approached with techniques evolved from flying the actual aircraft not
from past FAR23 experience.

Pete has a number of wood strakes along the underside which are an
inch high by half inch wide. he has accidently landed the BD5 with
wheels up and in the slide along the runway the inboard end of the
flaps got ground away and the strakes became half inch by half inch
where they took the rubbing on the bitumen. there was no other damage
and he didnt feel any jolts to the spine.
if he had been low to the ground he might have worn away the strakes
and the lower skin but he would have been spared the spinal injury.

I called it hot dogging because we would all know what I meant but it
may just be the safest way to takeoff in a BD5.

btw his fuel injection is a single point injector not a per cylinder
injection system. he says it usually works well and it solved the
surging problems experienced with the marvel schleber carby he tried
previously.

Stealth Pilot

"Stealth Pilot" wrote ...
holding the aircraft low to the ground and accelerating in level
flight does two things.
it gets you to a safer climbout speed faster.
if the engine does quit you avoid the spine destroying thump into the
ground.

That wouldn't help on the BD-5. The BD-5 is a very poorly designed airplane
and your friend had the quintessential BD-5 accident. There have been
several accidents and deaths along these lines. These usually happen early
in the testing program. The pilot is new to the airplane and the airplane
has an engine cooling problem. That's inherent in the design and the
designer never solved the problem. The pilot taxis out to the runway as the
engine compartment overheats causing a new problem in the fuel system. Once
on the runway, the pilot applies power pouring more heat into the
compartment. The engine lasts long enough to get in the air and the engine
quits. On the BD-5 all the big weights are down low. The fuel is on the
bottom of the airplane, the pilots center of gravity is low and the engine
is fairly low. That makes the airplane center of gravity low but the thrust
line is up at that top of the airplane. The high thrust line wants to push
the nose down so the pilot has to compensate with aft stick. Now the engine
stops. The clutch disengages the engine and the prop and the prop sits out
there windmilling. A windmilling prop is like a parachute, now trying to
pull the nose up. The airplane controls are commanding nose up already so,
between the controls and the prop, up the nose goes. If the pilot's not
spring loaded to shove the nose down, it won't go down. It will pitch up
violently and the g-loading will go up. This causes the wing skins to
wrinkle and that destroys the wing aerodynamics. The airplane does a high
speed stall and, without altitude to recover, it slams into the runway. If
the pilot's lucky. If not, the airplane stalls asymmetrically and
half-snaps to the inverted position and slams into the runway with generally
fatal results. Your friend was lucky.

Rich

In a previous article, "Richard Isakson" said:
bottom of the airplane, the pilots center of gravity is low and the engine
is fairly low. That makes the airplane center of gravity low but the thrust
line is up at that top of the airplane. The high thrust line wants to push
the nose down so the pilot has to compensate with aft stick. Now the engine
stops. The clutch disengages the engine and the prop and the prop sits out
there windmilling. A windmilling prop is like a parachute, now trying to
pull the nose up. The airplane controls are commanding nose up already so,
between the controls and the prop, up the nose goes. If the pilot's not
spring loaded to shove the nose down, it won't go down. It will pitch up
violently and the g-loading will go up. This causes the wing skins to

The Lake Amphibian, and probably most boat-hull type amphibs, have that
same problem. The weight and drag are down near the hull, and the thrust
comes from that engine mounted on a pylon above.


--
Paul Tomblin http://blog.xcski.com/
If I have pinged farther than others, it is because I routed upon
the T3s of giants.
-- Greg Andrews

On Thu, 24 May 2007 11:13:47 -0700, "Richard Isakson"
wrote:

"Stealth Pilot" wrote ...
holding the aircraft low to the ground and accelerating in level
flight does two things.
it gets you to a safer climbout speed faster.
if the engine does quit you avoid the spine destroying thump into the
ground.

That wouldn't help on the BD-5. The BD-5 is a very poorly designed airplane
and your friend had the quintessential BD-5 accident. There have been
several accidents and deaths along these lines. These usually happen early
in the testing program. The pilot is new to the airplane and the airplane
has an engine cooling problem. That's inherent in the design and the
designer never solved the problem. The pilot taxis out to the runway as the
engine compartment overheats causing a new problem in the fuel system. Once
on the runway, the pilot applies power pouring more heat into the
compartment. The engine lasts long enough to get in the air and the engine
quits. On the BD-5 all the big weights are down low. The fuel is on the
bottom of the airplane, the pilots center of gravity is low and the engine
is fairly low. That makes the airplane center of gravity low but the thrust
line is up at that top of the airplane. The high thrust line wants to push
the nose down so the pilot has to compensate with aft stick. Now the engine
stops. The clutch disengages the engine and the prop and the prop sits out
there windmilling. A windmilling prop is like a parachute, now trying to
pull the nose up. The airplane controls are commanding nose up already so,
between the controls and the prop, up the nose goes. If the pilot's not
spring loaded to shove the nose down, it won't go down. It will pitch up
violently and the g-loading will go up. This causes the wing skins to
wrinkle and that destroys the wing aerodynamics. The airplane does a high
speed stall and, without altitude to recover, it slams into the runway. If
the pilot's lucky. If not, the airplane stalls asymmetrically and
half-snaps to the inverted position and slams into the runway with generally
fatal results. Your friend was lucky.

Rich


the differences between these aeroplanes and the originals are subtle
and many. I just have not had the opportunity to discuss the comments
with the two guys. soon hopefully.
Stealth Pilot

Stealth Pilot wrote:

holding the aircraft low to the ground and accelerating in level
flight does two things.
it gets you to a safer climbout speed faster.
if the engine does quit you avoid the spine destroying thump into the
ground.

Stealth Pilot

Take-offs in a Dyke Delta requires the same technique. It doesn't want
to climb out solidly until it reaches 80mph. If you try to pull it out
of ground effect to early, the drag increases to the point that
acceleration stops. Pulling the gear up gives you 20mph. I'm to
understand that there have been accidents where the pilot ran out of
runway, trying to pull the craft into the sky without enough speed, or
enough power to overcome the drag.

Lift off into ground effect at 60, and hold level as the gear comes up.
Accelerate to 100 to get solid control authority, then head for the
heavens.

"Barnyard BOb" wrote in message
...
On Thu, 24 May 2007 03:28:10 GMT, cavelamb himself
wrote:

Morgans wrote:
"Stealth Pilot" wrote

maybe the hotdog method of achieving liftoff then maintaing low level
horizontal flight and accelerating like hell before climb out is a
better way of flying them.
interesting.


You may have finally made a positive point for hot-dogging. Anyone
think of
a down side?

Not a one.

Richard
-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Yes, and I'm surprised there is no rebuttal.
If it was better, it wouldn't be called 'hot-dogging.' ;-)

For openers...
The FAA is not known to support 'hot-dogging'.
Neither do legit aircraft manufacturers, AFAIK.

Why?
Like has been said...
It's just hot-dogging.

hot-dogging;

1. to perform in a recklessly or flamboyantly skillful manner,
show off.

2. intended or done to draw attention; showy or sensational.


Although speed can be traded for altitude,
you won't get as much with this technique
or as much opportunity to pick a crash site.


Blast away.
Nomex union suit - ON.


- Barnyard BOb -



Ok, but this is not enough to require Nomex--much less a real, industrial
strength, asbestos suit over it. ;-)

My disagreement is only with calling it Hot Dogging. What Stealth Pilot
suggested, and called Hot Dogging, was really just a soft field take off
without the soft field. Accelerate in ground effect, retract the wheels as
appropriate, and begin climbing at the normal climb speed. I have read that
the proceedure was strongly advised for some low powered retractables, such
as the early Swifts, to reduce the risks during the early part of the
climb--although that had to do with maintaining a usefull climb angle over
obstacles, rather than a possible loss of power.

FWIW, there may be some additional lessons regarding regarding a formation
take off, especially using dissimilar aircraft--which I will leave to those
with the required experience.

Peter

Peter Dohm wrote:

maybe the hotdog method of achieving liftoff then maintaing low level
horizontal flight and accelerating like hell before climb out is a
better way of flying them.

My disagreement is only with calling it Hot Dogging. What Stealth Pilot
suggested, and called Hot Dogging, was really just a soft field take off
without the soft field. Accelerate in ground effect, retract the wheels as
appropriate, and begin climbing at the normal climb speed. I have read that
the proceedure was strongly advised for some low powered retractables, such
as the early Swifts, to reduce the risks during the early part of the
climb--although that had to do with maintaining a usefull climb angle over
obstacles, rather than a possible loss of power.

Peter
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Peter,

If what was meant by Stealth is as you describe...... establishing
NORMAL climb speed similar to a soft field T.O., I'm with you.

However, if climb out is NOT established at NORMAL
climb speed as soon as practical....

I gotta stick by my original guns. :-)

P.S. All this discussion is rather moot for me,
after reading Rich Isakson's comments.


Barnyard BOb - the devil's in the details