Flap Overspeed Inspection

[NealRomeoGolf]

I was looking through some Piper maintenance manuals expecting to find an inspection procedure for what to do if flaps are deployed outside the white arc, but I could not find anything. Not saying I am the best maintenance manual reader, but I could only find prop overspeed stuff. Am I looking in the wrong place? Are there no official procedures for inspecting flaps that were deployed outside the white arc?

I guess I did find this in the PA32 manual: 3-6 Overlimits: If the airplane has been operated so that any of its components have exceeded their maximum operational limits, check with the appropriate manufacturer.

So you have to call Piper?

Related question: what stress is caused by deploying flaps early? Stress on the skin? Stress on the control rods?

Pipers in question would be a PA28 or a PA32.

 

[GRG55]

Only flap problem I've had with my Pipers is fatigue cracking of the bracket on the flap that the actuating rod attaches to. No idea if that is from repeated overspeed deployment by prior owners. I suspect just part of an aging airframe. But something to be taken seriously.

 

[Craig]

The inspection books for the model aircraft should have the info for various time and condition inspections. They may be located within another manual, so a little hard to find.

Overspeed damage potential will vary by aircraft configuration, flight regime and operating conditions at the overspeed. Ours drill down to aircraft configuration, overspeed amount and activity at the point of overspeed. Ie. a straight, level 1 g, 10 knot overspeed inspection is way different than a 3 g, 50 knot overspeed with 5 stations loaded.

 

[Witmo]

Another variable is the amount of flap deflection when oversped. The flap deployment airspeed is based on full flap deflection in light airplanes. You're much less likely to hurt anything if you have 30 knots of excess airspeed at ten degrees of flap than at forty degrees of flap. A close visual inspection by an A&P should determine if anything is amiss after a light airplane flap overspeed.

 

[Bell206]

So you have to call Piper?

Yes. Some OEMs prefer this route as there can be too many variables to write a single inspection process. But this can be a gray area on the compliance side for a Part 91 aircraft. Regardless, if you call Piper they will want a boat load of info on the aircraft and what the operating parameters were at the time of the exceedence.

 

[Daleandee]

Another variable is the amount of flap deflection when oversped. The flap deployment airspeed is based on full flap deflection in light airplanes. You're much less likely to hurt anything if you have 30 knots of excess airspeed at ten degrees of flap than at forty degrees of flap.

Good point. Flying into Tennessee a few years ago with a friend that had a plane very similar to mine (he had a bit less HP) he was having a difficult time keeping up until he realized he'd forgotten to retract the 10º flaps he used on departure. Inspection found no issues with his plane.

 

[Larry in TN]

Unless you had high g-loading, with the flaps extended above Vfe, damage is unlikely. At 1g, you'll need a LOT of excessive airspeed to cause damage.

What are the load limits with flaps extended? +2.5? -x? Whatever they are, the structure can take those g-loads AT Vfe.

 

[CRQFlier]

I'd venture to guess that literally every PA28 used for training or in a club has experienced mild to moderate overspeed flap extension. Many times. As such, if this were a significant problem I'd expect many many reported issues. Not saying be careless or dont inspect, just thinking real world.

Sent from my SM-G960U1 using Tapatalk