Didn't know the Skymaster was certified for aerobatics...

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oldtimer
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by oldtimer »

What happens to the attitude indicator in a roll?
Would you want to enter IMC after some yoyo has been rolling the airplane?
If he has done it once, how many other times has he done this.
If I were in a management position (which I am not) I would have fired his sorry ass out the door immediatly.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by CpnCrunch »

cgzro wrote:
Also the pre-flight for an aerobatic flight includes a few more items such as loose items checks etc. which likely have never been done in a non aerobatic plane and you risk getting hit in the head by something. I once got a mag-light right in the temple during a low roll and fire extinguishers have been known to come loose.. not fun so careful pre-flight is pretty important. We typically also usually have redundant seat belts because well ... its not pretty when you come loose.
In the video it looks like there's a cellphone and a metal can flying around the cockpit.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by co-joe »

oldtimer wrote:What happens to the attitude indicator in a roll?
....
Pretty sure that for every roll to the left you do, you have to do one to the right to undo it.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by trampbike »

DanWEC wrote:Why not? Heck didn't Tex Johnson do it in a 707? I'm not an aero pilot, am I naming the wrong type of roll?
As cgzro said, even for an aileron roll you'd need more than 1G to initiate the maneuver and to recover.

Tex Johnson did an aileron roll, which is also what that Skymaster driver did.
An aileron roll is a rotation around the longitudinal axis of the aircraft. Some pitch-up will be required initially for slow rolling machines, otherwise the resulting nose-low attitude after the completion of the roll could be a problem. In a fast rolling aircraft, you can pretty much just use ailerons to complete the roll.

A barrel roll requires a G-loading that is higher than 1G throughout the maneuver (or less than -1 if you want to do it inverted...). The flight path is shaped like a corkscrew. Think of it as the blending of an aileron roll with a loop. You're pulling on the stick while also rolling the aircraft.

Hope this helps.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by rigpiggy »

There was a paraplegic aerobatic performer used these in the 90s. Steve soper if i recall
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by cgzro »

[quote]What happens to the attitude indicator in a roll? /quote]

If its mechanical/gyroscope based I guess its a bit hard on it. The Extras that have gyro packages come with quick disconnects so you can slide out the gyro instruments prior to aerobatic flight but modern stuff uses solid state gyros which I doubt are harmed by rolling.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by goingnowherefast »

Go to the 2:00 mark.
https://www.youtube.com/watch?v=jLFwJlPVYyY

Pretty sure these guys aren't Bob Hoover.

Also, from CAR 101.01
"aerobatic manoeuvre means a manoeuvre where a change in the attitude of an aircraft results in a bank angle greater than 60 degrees, an abnormal attitude or an abnormal acceleration not incidental to normal flying"

You aren't going to break the airplane doing a proper roll, but it's still illegal.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by digits_ »

goingnowherefast wrote:Go to the 2:00 mark.
https://www.youtube.com/watch?v=jLFwJlPVYyY

Pretty sure these guys aren't Bob Hoover.

Also, from CAR 101.01
"aerobatic manoeuvre means a manoeuvre where a change in the attitude of an aircraft results in a bank angle greater than 60 degrees, an abnormal attitude or an abnormal acceleration not incidental to normal flying"

You aren't going to break the airplane doing a proper roll, but it's still illegal.
So if we all start doing loops -and thus redefine 'normal flying'- we will all be legal !
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by redlaser »

It boils down to this, aerobatic type aircraft are built to whitstand higher wing loads, whereas Normal or utility aircraft do not, I have see Cessna aircraft come back with bent ailrons after a student pilot or pilot have pushed the structure beyond its limits in doing aerobatic manoeuvres, So before doing a snap.barrel, or ailron roll check your POH to see if any of these manoeuvres are authorised, Normal cat. Aircraft are not.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by DanWEC »

Thanks for the info on the rolls. I was fairly sure I knew the difference between an aileron and barrel roll, but when you hear someone refer to a 1g barrel roll is that just an incorrect term, or loose approximation as opposed to blowing the shit out if it?

So next, is it not feasible for an average pilot to do a roll and stay well within the structural envelope? (Ignoring the contingency g for recovery from a botched maneuver, that's good info btw.)
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by trampbike »

DanWEC wrote:Thanks for the info on the rolls. I was fairly sure I knew the difference between an aileron and barrel roll, but when you hear someone refer to a 1g barrel roll is that just an incorrect term, or loose approximation as opposed to blowing the shit out if it?
Those "1G barrel rolls" are more like "lazy aileron rolls", IMO.
DanWEC wrote:So next, is it not feasible for an average pilot to do a roll and stay well within the structural envelope? (Ignoring the contingency g for recovery from a botched maneuver, that's good info btw.)
It sure is. You're operating out of your aircraft CoA, but it can easily be done (it doesn't mean it should, though!)

Cheers,
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by PilotDAR »

So next, is it not feasible for an average pilot to do a roll and stay well within the structural envelope?
If the pilot has been properly trained, yes.

But, an error in a roll becomes very unsafe quickly. If the axis of the roll becomes downward through pilot inattention, incompetence, or fear, the pilot may well find them self descending inverted toward earth, with speed and G building up quickly. Once in this situation, it's going to end badly. I well flown roll is within the structural limits of a normal category light aircraft. However, a botched roll will exceed these limits. A botched roll probably is within the limits of an aerobatic certified aircraft.

Like many things in piloting, the maneuver itself is basically simple, but the numerous things that can go wrong create the risk, and need for competent training.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by cgzro »

So next, is it not feasible for an average pilot to do a roll and stay well within the structural envelope?
In a slow rolling plane odds of success would be poor.
Faster rolling much easier better odds.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by JasonE »

cgzro wrote:
So next, is it not feasible for an average pilot to do a roll and stay well within the structural envelope?
In a slow rolling plane odds of success would be poor.
Faster rolling much easier better odds.
Want to come teach me to roll my Cherokee?? (just kidding, I'm saving for a 2nd acrobatic plane...)
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by CLguy »

First a 337 cannot be considered as a slow rolling airplane. An aileron roll done properly will put less stress on the airframe than most steep turns and there will be no negative G's or shit floating around the cockpit. I'm willing to bet that there is more stress put on those airframes on a daily basis by those newbies trying to land them in a crosswind. You get too see some crazy shit at times!
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by AuxBatOn »

Depends what you define as "slow". Anything less than 180 degrees a second for me is slow.

It's not about stress on the aircraft. It's about certification. The airplane was not certified to do this. It was likely never flight tested. No need to test it yourself...
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by AuxBatOn »

Just to show the importance of certification for the experts, look here: https://www.youtube.com/watch?v=WMG_G9ostt0 fast forward to 1:45 for the interesting part. If you don't flight test an area of the envelope, you cannot know the behavior of the aircraft in that part of the envelope. An aircraft that was designed for exactly this kind of maneuvers did not behave so well. It lead to a limitation of max 1 roll at full deflection.

What is the 337's behavior while rolling? What are its limitations?
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by lownslow »

What does the placard say under the registration? Looks like it starts with "Do not" and I hope it ends with something like "do anything dumb in this airplane."
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by co-joe »

I still say that the manoeuvre voided the c of a until maintenance performs a detailed inspection and signs off on it in the journey log. Not just while it was being performed. Does an overweight landing only void the c of a as the wheels touch and then everything's ok as long as the legs don't fall off? We only saw one roll. Who's to say the first 10 didn't go so well?
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by PilotDAR »

It's about certification. The airplane was not certified to do this. It was likely never flight tested.
It's not about getting in, but getting out, particularly if things go wrong. A well flown roll is hardly stressful on a plane, but a recovery can be if the roll was not well flown. If spinning a plane would make you nervous, then so should rolling it. I've posted this before, to remind viewers that certification testing is done to assure that pilots don't have to be test pilots, if they fly within the box.

[youtube]https://www.youtube.com/watch?v=zjB_q7AIvDo[/youtube]

The spin testing went exactly as planned. I temporarily installed a G meter, so I knew what I was doing TO the plane during recovery. I did 2.5 to 2.8 G's at or near Vne, ten times that day. The number which I found un-nerving, and casual aerobat pilots also might, was that each recovery dive at 2.5 G and near Vne, also peaked at more than 9000 FPM down - in a Caravan.

Those who fly certified planes presumably do so to benefit from the confidence that the aircraft has proven itself during certification testing. So why fly it outside those limitations?
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by cgzro »

Just as an aside, interesting things can happen at full aileron deflection. For example some RVs will exhibit a worrysome aileron buffet if you roll them at full aileron and in fact you need to not use full aileron to get maximum rate im some ac. Also some aircraft need substantial rudder to counteract the adverse yaw of full aileron and that can vary as the speed decreases going up and increases comming back down. Non trivial stuff to do safely every single time.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by AirFrame »

cgzro wrote:For example some RVs will exhibit a worrysome aileron buffet if you roll them at full aileron and in fact you need to not use full aileron to get maximum rate im some ac.
I haven't measured the exact roll rate, but it feels like the RV-6 rolls faster with the ailerons deflected just short of the point where they start to buffet. The buffeting is also speed dependent... At a slower entry speed you can go to full deflection without getting any buffet.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by lownslow »

co-joe wrote:I still say that the manoeuvre voided the c of a until maintenance performs a detailed inspection and signs off on it in the journey log.
Maybe, but what inspection? I doubt the maintenance manual has an inspection for intentional rolls and figuring out exactly what needs to be done is probably as vague a process as figuring out whether or not it was in any way okay in the first place.
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by LousyFisherman »

cgzro wrote:
So next, is it not feasible for an average pilot to do a roll and stay well within the structural envelope?
In a slow rolling plane odds of success would be poor.
Faster rolling much easier better odds.
I'll play the role of average, possibly below average pilot.
I have six hours aerobatics. At the time, 18 months ago I would have been allowed to do solo rolls and loops :) I do not "fly" the roll, I mechanically execute the appropriate procedure for the plane, in this case a Citabria .

Always at least 2000' feet AGL, my choice would be 4000'
Dip 5 degrees to build speed, 120mph if I recall correctly, fairly quick transition to 5 degrees up.
QUICK co-ordinated FULL rudder, FULL aileron, HOLD until just before level again :)
Not slam, but QUICK.

I know I wouldn't want to be there, unexpectedly, below 2000 AGL.
Without the training I wouldn't want to be there at all. Too many distractions.

YMMV
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Re: Didn't know the Skymaster was certified for aerobatics..

Post by AirFrame »

Is there a chance that the military's version of the 337 was built/certified differently? Does the military even have many small aircraft that aren't aerobatic?
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