In the midst of all the business being done last week during NBAA’s Business Aviation Regional Forum at Mineta San Jose International Airport (SJC), Attendees stopped to focus on the number-one priority for business aviation: safety. Two education sessions presented at the July 14 event focused on critical safety issues for the industry, aircraft icing and tire care.
Focus on Icing in Advance
The session on icing was presented by Dr. Earl Weener, a member of the National Transportation Safety Board (NTSB), who leads the board’s focus on general aviation (GA) safety. Weener presented more than half a dozen case studies of GA accidents and incidents caused by icing, showing simulations of what happened to the affected aircraft in flight and sharing the NTSB’s lessons learned from each investigation.
“None of these accidents that I’ll talk about today occurred because the airplane got so loaded up with ice that it couldn’t be propelled through the air,” said Weener. “They all occurred because of a loss of control.” Weener’s advice focused on what actions pilots should take before they fly into icing conditions, such as activating the deicing boots when entering such conditions rather than waiting for ice to build up on the wing.
“Use the deicing boots just like they vote in Chicago,” said Weener, “early and often.”
Weener also discussed the risks of super-cooled large droplets (SLD), a focus for the NTSB after the 1994 fatal crash of an American Eagle ATR-72 near Roselawn, IN. While the airplane was in a holding pattern, SLD formed on the trailing edge of the wing, where it was difficult to detect and where the deicing boots offered no protection. The SLD buildup caused the ailerons to deflect, resulting in an uncontrolled roll and a stall at higher airspeed than normally expected.
Based on lessons learned from the Roselawn accident, Weener advised that pilots must be alert to the significant changes in aircraft handling that can be caused by even a small buildup of ice. To deal with this, pilots may want to consider hand-flying the aircraft during icing conditions, as using the autopilot can mask aircraft handling changes.
The Importance of Tire Safety
Another critical issue that has led to fatal GA accidents is tire safety, said Keat Pruszenski of Michelin North America, citing the infamous 2008 crash of a Learjet 60 in Columbia, SC that killed four of six people aboard. The NTSB identified tire under-inflation as the cause of the accident: the severely under-inflated tires blew out during the takeoff roll, leaving the pilot without enough time to abort the takeoff.
“Aircraft tires are special,” said Pruszenski. “We make them very small to carry a very high load at very high speeds, and that puts a lot of pressure on the material they’re made of, making them very susceptible to under-inflation and foreign objects on the runway.”
According to Pruszenski, the two most common – and preventable – causes of tire events are under-inflation and foreign object damage (FOD). He recommended checking the tire pressure whenever the aircraft rolls out of the hangar, and ensuring that they are inflated to the top of the allowable range, or 105 percent of operating pressure. He also recommended flight departments and airport personnel schedule regular “FOD walks” to clear the runway of objects that can damage tires, such as hooks and pins, luggage clasps and crumbled hunks of concrete.