Pushing the Envelope of Flight Test Safety

In this time of high-energy research and testing, we need to learn from every example where planning and execution fell short of safety expectations. I am grateful to the U.S. Air Force for publishing its legal investigations of major mishaps. This month, we see a flight test mishap involving an AC-130J special operations aircraft.

This aircraft test flight story explores handling qualities at the edge of controllability under aircraft sideslip, or yaw. I encourage you to look beyond the military aircraft mission. Consider your process of test design, approval and conduct when people are at risk or Class A project hardware is being qualified for flight. When is exposure to risk needful and when does it become needless? How many data samples yield high confidence while sensibly managing risk exposure to crew? In this case, the crew had to explore the edge of an aircraft’s yaw envelope 183 times — on the final time it departed controlled flight and flipped inverted, yet fortunately held together to carry its crew to a safe landing — but the overstressed airframe was a total loss.

Does your test planning equip operators and crew to react to serious and possible off-nominal scenarios? Are there important safety data that exist but are hidden beyond your reach by a contract or proprietary agreement?