Solve this Aviation Safety Calculus: Little Device, Big Price, High Benefit

Share this article: FacebooktwitterlinkedinFacebooktwitterlinkedin

The Air & Space magazine with the headline, This Little Device Could Save Pilots’ Lives, highlighted the value of an Angle of Attack indicator. Why all of this talk about this instrument?

The NTSB has increasingly focused on Loss of Control as a cause of GA accidents; so much so that LOC made its 2015 Most Wanted List. Specifically it found that “between 2001 and 2011, over 40 percent of fixed wing GA fatal accidents occurred because pilots lost control of their airplanes.” In that annual list, the NTSB added the following possible solution: “Airplane owners should consider installing an AOA indicator, which, coupled with pilot understanding and training on how to best use it, can enhance situational awareness during critical or high-workload phases of flight.”

The Air& Space article reviewed the comments of participants at the October 14, 2015 NTSB sponsored Forum: Humans and Hardware: Preventing General Aviation Inflight Loss of Control.


Wendell Griffin, FAA Director of Accident Investigation and Prevention, emphasized the safety importance of AOA indicators by declaring that they are “the biggest win for us so far” in helping to prevent LOC accidents. Another agency representative added that these instruments do not have standard indicators; Dennis Beringer, a research engineering psychologist with the FAA’s Human Factors Research Group, translated that observation into regulatory context, when he declared, “We need to put into place display standards for these things to make sure they are effective across the board.”

University of North Dakota research Associate professor Jim Higgins converted masses of flight data monitoring program (115,000 annual flights of the university’s fleet of 120 aircraft) into an impressive conclusion, when he commented:

“On the base-to-final turn, the aircraft nose would typically drop about 0.7 degrees more on airplanes equipped with AOA indicators than on those without. ‘One interpretation would be that pilots are responding to the angle of attack awareness and lowering the nose when turning final.’”


The value of AOA to safety was emphasized by NTSB Member Earl Weener, when he mentioned that the NTSB recently added a checkbox on its accident report forms to indicate whether aircraft were equipped with an AOA system at the time of an accident. That is a strong endorsement of that instrument as essential equipment.

Those were a few of comments encouraging the installation of AOAs on GA aircraft.

Thomas Turner of the American Bonanza Society added a telling observation—that some of the AOA’s calibration steps may exceed the capabilities of an average GA pilot. To rely on the indicator after it has been installed, the testing procedures require may involve “precise flying that may be beyond the skills of some.”

One of the persons quoted flagged the cost of the AOA instruments as a deterrent to pilots adding them to planes. The representative of National Association of Flight Instructors (NAFI), Sean Elliott complained that even basic systems are currently in the $2,000 range. “I think the cost/benefit is still out of whack,” he said. “If you could make the price tag in the hundreds of dollars and not in the thousands, you would see wide adoption.”

The FAA announced in 2014 that it had simplified the design approval requirements for an AOA indicator cockpit instrument installation. That will reduce the overall cost of adding an AOA to GA airplanes, but according to NAFI the cost of the equipment is still prohibitive.

That is an argument which AOPA has used against the ADS-B equipage. The FAA’s counter has been that by mandating the installation of the NextGen essential (?) instrument, the manufacturers’ unit costs should be reduced. Would increasing the market size of AOA sales decrease the price to make it acceptable to GA pilots.

On the one hand, the NTSB has placed LOC on its Most Wanted List and indicates that 40% of the GA accidents might benefit from improved instrumentation. On the negative side (1) American Bonanza Society worries about whether calibration is a serious problem and (2) NAFI thinks that the AOA fails the cost/benefit quotient.

Should the FAA require GA pilots to install these instruments which will lower LOC accidents?


ARTICLE: This Little Device Could Save Pilots’ Lives

Share this article: FacebooktwitterlinkedinFacebooktwitterlinkedin

Be the first to comment on "Solve this Aviation Safety Calculus: Little Device, Big Price, High Benefit"

Leave a comment