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Tue Oct 13, 2009 5:03 am

mate who cares what he is doing if it is not approved in the AFM - that's my point.

I doubt if he will have the P-51 from which the pic was taken in formation doing a Cuban 8....

I've seen this aircraft looped and rolled.

Again it is not whether a sharp guy can do it, it is whether you are allowed to do it!

* I had a pilot who worked for me loop and roll a Baron 58 too. Did it OK except he was seen from the ground and I fired him...

Tue Oct 13, 2009 5:25 am

Towpilot wrote:Trust me, the A-26 in that picture is NOT on the top of a loop, but just about to gently turn rubberside down again on top of a half cuban eight! I know this for a fact!


The stress put on the aircraft in a Cuban 8 are the same as those put on the aircraft in a loop -- it's just going 2/3 of the way around the loop before it unloads and performs the half roll to upright.

How is that any "better" than the loop? You still put the highest G of the maneuver on the aircraft in the first 1/4, and you still have to pull the aircraft over the top with the lowest airspeed of the entire maneuver.

Something I'm missing here?

Tue Oct 13, 2009 5:28 am

Randy correct - aeros 101

Tue Oct 13, 2009 8:57 am

Randy Haskin wrote:
Towpilot wrote:Trust me, the A-26 in that picture is NOT on the top of a loop, but just about to gently turn rubberside down again on top of a half cuban eight! I know this for a fact!


The stress put on the aircraft in a Cuban 8 are the same as those put on the aircraft in a loop -- it's just going 2/3 of the way around the loop before it unloads and performs the half roll to upright.

How is that any "better" than the loop? You still put the highest G of the maneuver on the aircraft in the first 1/4, and you still have to pull the aircraft over the top with the lowest airspeed of the entire maneuver.

Something I'm missing here?


I would take this correct answer even a step further Randy :-))

A Cuban either straight or reversed involves a higher entry speed than a loop and a half roll which in an aircraft like the A26 where the nose can't be pinned throughout the half roll, puts the whole new issue for the possibility of asymmetrical angle of attack between the two wings as the half roll is attempted, the inevitable energy bleed occurs as the aircraft is rolled and a dished rolling pullout is attempted.
Such a situation can easily place asymmetrical g on the aircraft further complicating the maneuver as relates to stress.

Dudley

Tue Oct 13, 2009 9:13 am

http://napoleon130.tripod.com/id250.html

http://napoleon130.tripod.com/id510.html

We all know how the Biggin Hill event ended...

Image

Tue Oct 13, 2009 9:32 am

The other complicating factor no one is mentioning here is that it has 2 engines.

If you lose one while going up into the top of a loop, or cuban, you're below Vmca I strongly suspect, in an A-26, and at an airshow you're not very high.

Quite out of options -- if you pull the power back you stall, and if you don't you roll uncontrollably, and probably spin. At low altitude.

This is what nailed that Mosquito in England a few years back, as I understand it.

Dave

Tue Oct 13, 2009 11:03 am

Dave Hadfield wrote:The other complicating factor no one is mentioning here is that it has 2 engines.

If you lose one while going up into the top of a loop, or cuban, you're below Vmca I strongly suspect, in an A-26, and at an airshow you're not very high.

Quite out of options -- if you pull the power back you stall, and if you don't you roll uncontrollably, and probably spin. At low altitude.

This is what nailed that Mosquito in England a few years back, as I understand it.

Dave


The video clip of the accident crossed our display safety work group some time ago and was carefully studied in stop sequence. I could write a book on just what I saw improperly done with the roll let alone considering the regulating authority factors that failed leading up to the roll being attempted.
One can point in several directions in assigning a cause for this unfortunate incident.
What I found simply from the display pilot's viewpoint was that this aircraft by design simply bleeds too much energy during the initial pull into the roll set to handle the massive roll inertia problem and slow roll rate encountered as the roll is initiated.
In other words, even if forward pitch is used between the first knife edge position through inverted and through the second knife edge position, the A26 doesn't retain enough energy to cancel out the extreme nose down pitch rate through inverted the aircraft will experience as the aircraft is rolled.
This scenario of high drag rise into the roll set, high roll inertia, and slow roll rate would be enough for me anyway to recommend that the A26 NEVER be rolled during a display at low altitude.
The clip shows no high speed stall. The airspeed/g profile used by the pilot to initiate the roll in my opinion would have been ample to produce the predictable dishout and recovery from the roll at altitude, but initiated from a level 1 altitude, the roll was doomed to need more altitude than was necessary for the recovery.
Accidents like this one are especially tragic as they both can be abd should be avoided by the governing authority before the actual event is allowed.
Dudley Henriques

Tue Oct 13, 2009 11:28 am

Dudley,

The engine on that Mosquito quit, right?

Dave

Tue Oct 13, 2009 1:09 pm

Dave Hadfield wrote:Dudley,

The engine on that Mosquito quit, right?

Dave


You're referring to the Barton accident?
If so, the word we got at the time was that the evidence was inconclusive but was high indicative of a left engine power loss at the apex of an attempted wingover to the right.
Dudley Henriques

Tue Oct 13, 2009 3:55 pm

http://www.youtube.com/watch?v=5iayVNS20rc
Obviously he did not read the AFM, but dam I like the sound of the A-26 being put through its paces.

Tue Oct 13, 2009 4:05 pm

N3N

My point exactly. I cannot fathom the logic of those who argue the toss about operating outside of the published limits. Also note the number of accidents at airshows or doing just dumb things.

UK P-38/P-63/Hurricane in recent years to name a few.

Flying within the aircraft's and your own limits always is a must....

Tue Oct 13, 2009 4:19 pm

Obviously he did not read the AFM, but dam I like the sound of the A-26 being put through its paces.


The barrel roll and near vertical wing overs looked good.

Tue Oct 13, 2009 4:56 pm

Dudley Henriques wrote:
Dave Hadfield wrote:Dudley,
The engine on that Mosquito quit, right?

You're referring to the Barton accident?
If so, the word we got at the time was that the evidence was inconclusive but was high indicative of a left engine power loss at the apex of an attempted wingover to the right.
Dudley Henriques

We lost a couple of good guys in the Mosquito.

If you didn't study the AAIB report but just video, what's the point in publishing detailed highly researched and accurate reports if pilots won't read them? There was no 'inconclusive' about the power loss, or why.

In haste - [Sad rant]I'm continually saddened here at the number of pilots who a) are quick to generalise and criticise 'over there' and b) don't bother to actually research the facts which are instantly available after a 2 minute search.

It was DH Mosquito RR299 G-ASKH. Look up the AAIB report if you haven't. Dudley's analysis is not complete - therefore not accurate - without it. I'm disappointed that someone whose other comments are normally acute would lessen his authority and be so careless as to pontificate without bothering to research the matter with the material provided expressly for the purpose.

As a ground-bound reporter I'm sick of being told that 'here' we are better than 'there' as I travel the world. When 'here' features NO accidents that breathtaking ignorant arrogance may be justified.[/Sad rant]

Do better, gentlemen.

Tue Oct 13, 2009 5:08 pm

James, I don't see anything in his comments that are innacurate. He even caveated that the only thing he remembers was what they got word on at the time of the incident.

I fail to see how this diminishes his authority or he pontificated.

I would humbly submit that it is you who are diminishing his authority by making such statements without reading, in full, what is posted on the screen in front of you.

Tue Oct 13, 2009 6:16 pm

There are so many variables that come into play when doing acro that what you pulled off one day, then next day it might kill you. Density altitude, fuel loads, speeds call all kill you if you are not careful.
In the case of the A-26, the POH says NO aerobatics PERIOD, the Mosquito on the other hand does not have any restrictions other then not to do spins.

Acro is not the only killer in a airshow enviroment. When Harry Tope went in, he was not doing acro, but he did manage to stall and spin into the ground.

A2C Chris, You have never flown in a airshow enviroment, nor I bet have you even been to a airshow briefing, or a formation clinic and as such, you have no idea what it is like to fly in that envoriment. When I was flying with Carl at Oshkosh, I would have rather been in a wingmans slot as it would have been much less work then leading.
We did one flight where I did not quit moving or doing something for almost 90 mins. When we got on the ground I would have sworn we were up for 30 min or less because I was so busy, and I was not flying the plane.
I was approved to fly in the show by the head fed on the field because of my formation knowladge and the team Carl and I made. I did not have a pilots cert at the time, but I could fly formation, knew the radio procedures, and knew the formations and who was supposed to be where,as well as how to get them there, as well as a extra pair of eyes and ears, which came in handy on more than one occasion.
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