Bonanza crash caught on video

On Sat, 01 Sep 2007 21:54:03 -0600, Newps wrote:



Roger (K8RI) wrote:



"I think" meaning I don't know for sure, that flaps slow the
acceleration enough that nothing is gained in distance by using them.

It reduces ground roll by 20%.

It might get me into ground effect a bit earlier, but the end result
would take more distance to clear thatl 50 foot obstical.




One interesting characteristic of a soft field take off is if the up
elevator pressure is not eased off as the nose gear comes off the
plane will rotate into ground effect early and then settle back down
to never lift off again unless back pressure is eased off considerably
to allow the place to accelerate.


Uh, what? That has not been my experience. I have done numerous touch
and go's of this sort where I let it settle back on the runway as I was
accelerating on takeoff due to poor technique on my part. No doubt I

Yes, it would be due to poor technique, but unless the back pressure
is reduced the Deb will just go on down the runway, riding on the
mains, nose high.

slightly increased my takeoff distance but just leaving the controls
where they are the plane will takeoff just fine.

Even with 260 HP and a 3-blade prop, I have to let the nose down after
it settles or it won't acellerate enough to get back up.

Roger

On Sun, 02 Sep 2007 07:58:12 -0600, Newps wrote:



Morgans wrote:
"Newps" wrote


For the takeoff in the video no flaps was correct.


Could it be considered helpful to get off the ground quicker, so you could
suck up the gear and accelerate while still in ground effect?

The POH and the Air Safety Foundation say to leave the gear down until
past any short field object. The reason being under Vy it makes
little difference in climb ability while the gear doors cycling add a
lot of drag. So if it's a close in obstacle you leave the gear down on
a Bo.


He did get in the air but climbed too fast for the conditions. Once in
the air a clean airframe is better than a dirty one.

I'd say once Vy has been reached according to the above.

Roger





Of course, if you had to call it that close, the decision to take off with
all of the weight would be the wrong decision, anyway, so it goes back to no
flaps being correct.

I have heard of some people doing the takeoff run with no flaps, and
slightly before rotation, pop the first notch of flaps down, then milk them
up once speed and climb is obtained.

That is only beneficial for close in obstacles.

"Roger (K8RI)" wrote

The POH and the Air Safety Foundation say to leave the gear down until
past any short field object. The reason being under Vy it makes
little difference in climb ability while the gear doors cycling add a
lot of drag. So if it's a close in obstacle you leave the gear down on
a Bo.

Yep, I forgot to consider the gear doors.
--
Jim in NC

"RST Engineering" wrote

They are the support poles for the obstruction lights so we don't hit the
trees at night. I guess hitting a 4" steel pole is better than hitting
the top of a Douglas fir, eh? And not that we couldn't do a little tree
climbing and mount the light to the top of the tree so the light would
grow along with the tree? Naaaaaah.

Don't you DARE suggest anything that makes sense!

What color are the lights (red I suppose) do they blink, and how far apart
do they put the poles?
--
Jim in NC

RST Engineering wrote:
This picture was taken before the pigstickers were put up. If you can
imagine six steel spikes spaced every 500' at the treeline on the left side
of this picture 20 feet above the trees, you've got it about right.

Jim

Hmmm, and here I thought the red/white poles barely visible in the
Airnav picture showed them. Yikes. It's been a long time...two years
maybe...since I've flown into KGOO.

Roger (K8RI) wrote:

Could it be considered helpful to get off the ground quicker, so you could
suck up the gear and accelerate while still in ground effect?

The POH and the Air Safety Foundation say to leave the gear down until
past any short field object. The reason being under Vy it makes
little difference in climb ability while the gear doors cycling add a
lot of drag. So if it's a close in obstacle you leave the gear down on
a Bo.

Generally speaking unless otherwise stated in a specific airplane's
POH; leaving the gear down after rotation and under Vy is a good
practice and I heartily agree with ASF on this issue.
This is even more pronounced on higher performance airplanes with big doors.
On the Mustang, the fairing doors cause a ton of drag as they retract
(the suckers are as big as sails :-) and leaving the gear down as you
rotate has very little effect on acceleration below Vy so the accepted
procedure is NOT to retract the gear until firmly established with a
positive ROC but not to exceed 160 indicated to retract(for the 51).
The fairing doors on the P51 are about as huge as the spinnaker on a 12
meter racing yacht. :-))


--
Dudley Henriques

Roger (K8RI) wrote:

On Sat, 01 Sep 2007 21:54:03 -0600, Newps wrote:



Roger (K8RI) wrote:



"I think" meaning I don't know for sure, that flaps slow the
acceleration enough that nothing is gained in distance by using them.

It reduces ground roll by 20%.


It might get me into ground effect a bit earlier, but the end result
would take more distance to clear thatl 50 foot obstical.

That is not the case. You clear 50 feet sooner with flaps than without.
A lot sooner, 33% in fact. A Bonanza with a 520 at 2800 pounds,
5000 feet and 32 degrees gets these results: Flaps 20...Lift off in 876
feet and thru 50 feet in 1200 feet. No flaps...Lift off in 944 feet and
thru 50 feet in 1600 feet. There will be minor differences among the
various Bonanza models but all will perform basically the same.

john smith wrote:

In article ,
"Roger (K8RI)" wrote:


The POH and the Air Safety Foundation say to leave the gear down until
past any short field object. The reason being under Vy it makes
little difference in climb ability while the gear doors cycling add a
lot of drag. So if it's a close in obstacle you leave the gear down on
a Bo.


Not to mention that Vx and Vy with the gear down are about 10 kts lower
than with the gear up.




Vx and Vy are about 23 knots lower with gear and flaps down.

Morgans wrote:

"Roger (K8RI)" wrote


The POH and the Air Safety Foundation say to leave the gear down until
past any short field object. The reason being under Vy it makes
little difference in climb ability while the gear doors cycling add a
lot of drag. So if it's a close in obstacle you leave the gear down on
a Bo.


Yep, I forgot to consider the gear doors.




The Bo in the crash had the 28 volt electrical system so his gear cycle
time is 4 seconds. Very minor added drag. The 12 volt planes have a
gear cycle time of 8-12 seconds. On a 4 second bird I would put the
gear up in a situation like this.

Newps wrote:


Roger (K8RI) wrote:

On Sat, 01 Sep 2007 21:54:03 -0600, Newps wrote:



Roger (K8RI) wrote:



"I think" meaning I don't know for sure, that flaps slow the
acceleration enough that nothing is gained in distance by using them.

It reduces ground roll by 20%.


It might get me into ground effect a bit earlier, but the end result
would take more distance to clear thatl 50 foot obstical.

That is not the case. You clear 50 feet sooner with flaps than without.
A lot sooner, 33% in fact. A Bonanza with a 520 at 2800 pounds, 5000
feet and 32 degrees gets these results: Flaps 20...Lift off in 876 feet
and thru 50 feet in 1200 feet. No flaps...Lift off in 944 feet and thru
50 feet in 1600 feet. There will be minor differences among the various
Bonanza models but all will perform basically the same.

Yes, a few knots less takeoff speed pays huge dividends in distance.

Matt