The Full-Scale Structural Testing Lab recently began structural fatigue tests on a Liberty XL2.

During production of this particular aircraft, parts of the composite fuselage were intentionally manufactured with defects. Liberty Aerospace is requesting the tests to determine how long the aircraft will remain safe and flyable with these various composite delaminations.

The fuselage of the Liberty XL2 is constructed from carbon fiber and the welded tubular 4130 steel chassis takes the primary loads of the engine, nose gear, main gear and wing attachment. It also carries the control system assembly, fuel tank system and seat harness attachments.

During the test, the aircraft will be inspected every 1/10 of a lifetime for crack growth using NDI equipment. Significant crack growth will be measured and noted during each inspection.

The Liberty tests began in mid-July and will extend until the aircraft has sustained three simulated lifetimes (an equivalent of about 15,000 flight hours).

Results from the test will be used to develop guidelines for Liberty XL2 maintenance manuals.