Downdraft at 12,000 feet

"James Robinson" wrote in message
. ..
Pilot reported heavy downdraft over Lancaster, CA, resulting in crash.

http://www.orovillemr.com/news/chico/ci_4917367

Can somebody explain what he did right/wrong?

I used to own a 35 model Bonanza and it was unstable in roll and would
easily enter a "death spiral". Perhaps the 36 model is the same.

Danny Deger

Danny Deger wrote:


I used to own a 35 model Bonanza and it was unstable in roll and would
easily enter a "death spiral".


No certificated GA plane is unstable in roll.

Newps writes:

No certificated GA plane is unstable in roll.

This conflicts with other claims I've read in this group from time to
time, to the effect that all GA planes are unstable, IIRC.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Recently, Mxsmanic posted:

Newps writes:

No certificated GA plane is unstable in roll.

This conflicts with other claims I've read in this group from time to
time, to the effect that all GA planes are unstable, IIRC.

Two different issues, I suspect. No planes are stable indefinitely, while
others are quite sensitive and will behave as described.

Neil

Newps,

No certificated GA plane is unstable in roll.


Define unstable.

--
Thomas Borchert (EDDH)

"Thomas Borchert" wrote in message
...
Newps,

No certificated GA plane is unstable in roll.


Define unstable.


If the pilot does nothing, the disturbance (e.g. pitch or roll) will
increase.

Danny Deger

"Newps" wrote in message
. ..


Danny Deger wrote:


I used to own a 35 model Bonanza and it was unstable in roll and would
easily enter a "death spiral".


No certificated GA plane is unstable in roll.

I simply disagree. A GA plane, if put it a small roll can have the roll
increase if the pilot does nothing. The 35 model Bonanza is unstable in
roll. Go rent one and see for yourself. If you put it in a 30 degree bank
and let go of the stick, the roll will increase until you are in a death
spiral. That is why so many Bonanzas end up in one compared with other
airplanes. As far as I know, all Cessnas are stable in roll, i.e. without
pilot intervention they roll back to wings level.

I have a Masters in Aerospace engineering and my thesis was how to certify
light aircraft. The regs clearly state unstable in roll is acceptable.
They must be stable in pitch, but not in roll.

Danny Deger

Danny Deger wrote:


No certificated GA plane is unstable in roll.

Go rent one and see for yourself.

I own one.


If you put it in a 30 degree bank
and let go of the stick, the roll will increase until you are in a death
spiral.


Yours was rigged wrong. When put in a coordinated bank it will stay in
that bank.



That is why so many Bonanzas end up in one compared with other
airplanes. As far as I know, all Cessnas are stable in roll, i.e. without
pilot intervention they roll back to wings level.

I had a 182 for seven years and they will act the same as my Bonanza.
Put them in a coordinated bank and it will stay there.

On Thu, 04 Jan 2007 11:27:52 -0700, Newps wrote:



Danny Deger wrote:


No certificated GA plane is unstable in roll.

Go rent one and see for yourself.

I own one.


If you put it in a 30 degree bank
and let go of the stick, the roll will increase until you are in a death
spiral.


Yours was rigged wrong. When put in a coordinated bank it will stay in
that bank.

One of you is talking about a *stabilized* turn, the other it talking
about rolling into a 30 degree bank They are two different animals.
The Deb and Bo will keep right on going if you just roll into a 30
degree bank and let go. They will both happily fly a stabilized 30 or
45 degree banked turn hands off.

Roll mine into a 45 degree bank and dowwwwwnnnn we go. Roll into a 45
degree stabilized turn and trim and I know it'll do a 720 with so
little altitude variation you can barely see it.




That is why so many Bonanzas end up in one compared with other
airplanes. As far as I know, all Cessnas are stable in roll, i.e. without
pilot intervention they roll back to wings level.

I had a 182 for seven years and they will act the same as my Bonanza.
Put them in a coordinated bank and it will stay there.


Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

No certificated GA plane is unstable in roll.

Uh, even an Archer is unstable in roll. I went out and tried it myself.

Are you using a different definition of "unstable"? Here's what I did:
I went up on a calm night, trimmed for straight and level flight, and
let go of the controls. The plane flew nicely for about a minute or
three, by which time the aircraft had gotten itself into about a half
standard rate turn, which kept tightening. It took a good few minutes
to get to that point, but it did so every time (and not always in the
same direction). So, on the larger scale, it is unstable in roll,
albeit not =very= unstable in roll. Small excursions lead to larger
excursions. It does require active attention to fly it.

Do you mean something else?

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.