Gear Up Landing Rub Strips

[ErikC]

I have been given the responsibility of the design/analysis/testing of our fuselage gear up landing rub strips. These parts are too be designed for the 3g gear up landing with mu = 0.5 with the ground per 14 CFR 23.561(c). My questions are, has anyone here had experience with what the FAA requires for testing/substantiation? Can we utilize small element tests using similar contact pressures and coefficients of friction to determine the wear rate? Or will we need to simulate a full aircraft gear up landing situation? Are there any AC's which I need to be aware of?

Thank you in advance.

Erik

 

[plasgears]

You will not be able to avoid the full scale test. Your results will be so much more acceptable.

The problem is not so much in the rub strips as the strength of the structure above the rub strips. Ribs above the strip will need to support the load without catastrophic failure.

 

[ErikC]

Agreed, the test plan already calls out for full-scale static testing of the support structure in flight, emergency landing and crash conditions. I was wondering how to substantiate the ability of the rub strips not to wear away completely in a gear up landing configuration. Is it acceptable by analysis, coupon testing or will we need to take a full structure, accelerate it up to landing speed, and let it skip down a test track? I sincerely hope that the final option is not what other companies have had to do.