Composite Airframe Outlasts Metal Testing Rig

It may not be the prettiest piece of hardware ever to come from Bend, OR... but a Columbia airframe -- complete with more than 100 sites of deliberately inflicted unrepaired damage, a host of structural and nonstructural repairs plus as many as 25 intentional manufacturing defects -- was recently subjected to a punishing fatigue analysis equivalent to 25,000 flight hours at loads exceeding the Columbia’s Utility Category certification levels.

The result was astounding, representatives with the planemaker told attendees at this week's Lakeland Fly-In. The Columbia airframe absorbed the loads, stress and punishment while the testing fixture, made of high-strength steel, was beginning to fail due to metal fatigue.

“This test should unequivocally quell any lingering misconceptions that somehow a composite airframe isn’t as durable as an aluminum airframe,” said Columbia Aircraft Manufacturing Corporation Vice President of Engineering Tom Bowen. “The load spectrum applied to the Columbia airframe during the test was 20% - 40% greater than what would have been required to simulate the same test on a Normal Category airframe. As far as we know, no other personal aircraft airframe, composite or aluminum, has ever successfully completed such an exhaustive and severe fatigue testing program.”

Listen To Bowen's Comments On Composites Durability Testing Here

Bowen pointed out that the 25,000 hours simulated by the test program is equivalent to 123 years of aircraft life if flown an average of 200 hours per year, twice as many as has been documented by the known competition. The test was originally intended to simulate 12,500 flight hours, but once the airframe achieved that milestone with no signs of fatigue, the test engineers decided to start the test cycle again and go a full 25,000 hours. Upon arriving at 25,000 hours, it seemed pointless to continue the test.

“We were curious to know just how far this airframe could be pushed,” said Jake Ruhl, lead structural test engineer for the project. “This test provides irrefutable evidence that the Columbia can go far beyond the designed service life even under extreme conditions with countless flaws, repairs, and damage while demonstrating no signs of fatigue or wear. In my mind, this test program -- equivalent to 166,695 cycles -- shows that the Columbia 350 and 400 airframes are likely the strongest, most damage tolerant and robust in the industry.”

FMI: www.flycolumbia.com