STRUCTURAL FAILURES IN ALL AEROBATIC AIRCRAFT

If I may, I would like to continue the thread of the letter by Dan Bierly, “Success of Edge speaks for itself,” in the Oct. 19 issue, a bit further and shed some historical information that I feel paints a more accurate picture of airframe integrity in our unlimited aerobatic aircraft.

The truth is that there have been structural failures in almost all of the Unlimited aerobatic aircraft types in use today. Patty (Wagstaff) does a great job with her Extra and has done so in competition, as well as air shows. Her plane, as well as her previous Extras, have served her well. That having been said, the Extra has had its share of structural compromises. Fuel tank, rudder pedal, control stick and rear fuselage longeron failures have occurred in this aircraft type over the years. The CAP 232 has suffered a wing/fuselage separation in flight with fatal results. The CAP 231 has experienced some wing delaminations, although I do not believe these have caused the loss of an aircraft.

When I was U.S. team trainer in 1996 I witnessed a fatal wing failure/separation on a new (5.2 hours total time) Sukhoi 31 at a relatively low ‘G’ condition. And the Edge has had structural failures. One recent fatality in California found an aileron in one location and the rest of the aircraft in another. Only two months ago a pilot I was helping prepare for our U.S. National Aerobatic Competition experienced a complete failure/separation of the middle aileron hinge on the right wing while performing a full aileron deflection roll to the right. That aileron stayed on the aircraft, but it was jammed in a deflected position with a broken spar (the aileron’s, not the wing’s). The pilot was able to land the aircraft, but it was a near run thing. I would probably have jumped in the same situation.

At the end of the day we should keep in mind that these aircraft are used for unlimited competition, and unlimited means just what it says. Some are stronger than others, but the truism that “…there are no limits of any kind on any aircraft if you do not need to complete your flight or use the plane again” has not been repealed.

JOHN MORRISSEY

Greatplanes Aerobatics

Lee’s Summit, Mo

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