Loopy in a Tommie?

[foxmoth]

With the ailerons on the Tommy I think rolling it is definitely not a manouvre I would want to try

[fireflybob]

There was a case in the UK many years ago where a private owner had a reputation for looping his own Piper Navajo.

Sadly he perished when both engines detached from the airframe at some stage on the way round a loop. I recall the engines were separate from wreckage of the rest of the aircraft. The AIB were able to compute the amount of "G" that was pulled which was well beyond the normal limits.

Piper Navajo break up in flight

NEVER do aerobatics in an aircraft which is not approved to do such maneuvers.

[B2N2]

Rolling a Pa38........

THE ACFT WAS OBSERVED TO ENTER A SPIN FROM APRX 3000 FT AGL. THE ACFT CONTINUED THE SPIN TO GROUND CONTACT WHICH WITNESSES STATED OCCURRED AS THE ACFT SEEMED TO LEVEL OFF. WITNESSES ALSO REPORTED SEEING THE ACFT PERFORM AEROBATICS, WHICH INCLUDED LOOPS, PRIOR TO THE ACCIDENT

ASN Aircraft accident 05-MAY-1985 Piper PA-38-112 N2475L

[Pilot DAR]

owner had a reputation for looping his own Piper Navajo

Indeed, casual aerobatics in aircraft clearly not intended for aerobatic flight is very foolish. The lesson obviously is just don't.

In the case of the Navajo (and I know nothing of this event, other than the referenced report) though I agree that it would appear obvious that the aircraft was dramatically oversped, It is much more likely that this was a result of a botched roll than loop. (And this is intended as the warning part of the message here).

A botched roll or wingover is the fastest way to get in trouble with an aircraft which will build up speed quickly, and this would seem to prove that. A loop is a bit of a different maneuver, and actually a bit more resistant to overspeeding, but also not appropriate in a Navajo (if even possible).

It is a mixed blessing to our industry that amazingly skilled pilots like Bob Hoover demonstrate aerobatics in non aerobatic types. It's great to see the skill, but it creates an "I can do that too" attitude, which is very likely unfounded for everyone else.

There are a very few special pilots, who can achieve these maneuvers with a margin of safety and thus success. Everyone else should not try!

[A and C]

I agree with DAR A badly flown Barrel roll is a killer in terms of overspeed and altitude loss, one only has to look at the list of airshow crashes that have been a result of mishandeled rolls.

[treadigraph]

In the case of the Navajo, it was a company pilot who crashed the aeroplane rather than the owner (Colin Chapman/Lotus Cars).

Had he got away with it, another poor sod flying it with passengers might have discovered the hard way that it had been overstressed.

[Pilot DAR]

discovered the hard way that it had been overstressed.

Though "overstressed" could lead to structural failure, it is more likely to do so right away, not later on. It is certainly possible for an aircraft to be overstressed, damaged, and land safely. If this were the case, a maintenance inspection would turn this up right away. I recall the report saying that that Navajo had just come from maintenance. If so, I would expect any wrinkles would have been noticed.

On the other hand, fatigue will crete a risk of structural failure from very difficult to see damage. Fatigue, however, is not the product of a few irresponsible unusual maneuvers, it is the product of prolonged flight in rough conditions, which is very likely over the life of an aircraft which has been flown completely within it's "normal" flight regime.

I think it much more likely that irresponsible pilots crash aircraft from poorly executed aerobatics, than suffer a structural failure as a result of some other pilot's poorly executed maneuvers.

Once you've looped it, would you mind posting the registration so the rest of us can avoid that particular machine. Thanks in advance.

If, during a walk around, you see a wrinkle, or other defect, it's up to you to get an inspection done before you fly it - might be nothing, might be something. For semi monocoque aluminum GA aircraft, if it has no wrinkles, unlikely it's been damaged during unusual maneuvering, so as long as you don't. you're fine. On a walk around, the only evidence of fatigue which you might see would be a crack in structure (obviously warrants inspection!), but there's lots of structure you'll never be able to see which could have that crack.

So if you're intent on leaving the plane in top shape for the next occupants, certainly don't aerobat it, but equally important, minimize it's exposure to low level turbulence too! That's the more insidious risk over the very long term of normal operations.....

[n5296s]

I'm certainly not going to disagree with PilotDAR, who knows far more about these things than I ever will, but I will throw into the discussion an anecdote I heard. There was a certain Pitts pilot who regularly used to take his plane to 9G - the Pitts is rated for 6G which means that nothing important will fall off up to 9G, but you may do damage anyway (the 1.5 over-G tolerance is true for any certificated type, in the US anyway). The people who used to do his annuals said they would regularly find damaged ribs and so on.

And of course one day something important DID come off, and that was the end of him.