Safe Flight Instrument has been granted a U.S. patent for a system that aims to prevent tailstrikes, and resulting aircraft damage, on takeoff or landing. Tailstrike damage might be readily apparent, in some cases causing extensive structural damage, or could remain latent until a future incident, the company said.

Rather than focusing on pitch angle, Safe Flight’s Tailstrike Warning System uses ground clearance and angle of attack (AoA)—a relationship that can even alert pilots of the potential for a tailstrike caused by unstabilized approaches before an unsafe attitude is achieved. In addition, using the ground clearance-AoA relationship automatically accounts for variables such as runway slope and landing gear strut compression.

Since AoA is already being managed during takeoff and landing, this provides tailstrike protection without increasing piloting complexity, according to Safe Flight. The system can be integrated with existing primary flight displays to provide an indication of how close the aircraft was to a tailstrike for each takeoff and landing, it added.

The Tailstrike Warning System is based on the company's Speed Command of Attitude and Thrust (SCAT) system, which is already FAA certified on the RC-135, the military designation for the Boeing 707. It plans to certify the Tailstrike Warning System for air transport aircraft and bizliners.