NTSB Safety Study Targets Experimental Aircraft

Board's safety recommendations aim to reverse the high accident rate of amateur-built airplanes.


The NTSB held a fascinating meeting at its Washington headquarters on Tuesday morning that explored in detail the poor safety record of experimental amateur-built aircraft and produced a laundry list of solutions aimed at stemming the problem. The raw data presented in the NTSB’s study of experimental aircraft safety was wholly absorbing in and of itself, but it was the compendium of safety recommendations the Board put forward – 16 in all – that provide at least a glimmer hope that an abysmal safety record can indeed be improved.

Attended by the full NTSB Board, the meeting presented accident data culled from the available statistics in the last decade, as well as a closer examination of last year, which saw 224 accidents of experimental amateur-built (EAB) airplanes, 54 of them fatal. Most surprising looking at the data was that the number one cause of EAB accidents involved engine failure or loss of engine power, usually on the very first test flight or one of the first test flights, and often caused by disrupted fuel flow. The second leading cause of EAB accidents was loss of control, but here again there was a surprise in the data: Unlike loss of control accidents involving certified aircraft, which usually happen in the traffic pattern during the landing phase, most EAB loss of control accidents happened on takeoff and initial climbout.

Another big issue the study addressed is training. While experimental airplane builders as a group tend to have more flying experience than other general aviation pilots, those who were involved in accidents usually had very little time in type. Because of FAA rules that require flight instructors to obtain “letters of deviation” before they can conduct paid flight training in their experimental airplanes, getting adequate training isn’t always easy. And in single-seat models, it’s impossible.

In producing its safety study, the NTSB worked closely with the FAA and the Experimental Aircraft Association. The EAA conducted an online survey of owners and builders last summer, receiving about 5,000 responses from members who identified themselves as current builders, those who have built an aircraft, or those who have purchased one used. Of all the respondents, 76 percent had built an airplane. Interestingly, the median age of those who had built their airplanes was 62; the median age of those who were currently building one was 56; and the median age of those who had purchased one used was 60. The majority listed their occupation as “retired."

The average time to build an aircraft, according to survey respondents, was 2,000 hours. Considering there are 2,080 hours in one work year, it’s not surprising that most homebuilders are retired. The biggest investment is the time, with some builders saying it took them 10 or 15 years to complete their aircraft. The sad irony is that it took a builder more than a decade to build the airplane of his dreams, only for him to crash it and be killed on first flight or very soon after.

The most common types of kitbuilt airplanes were produced by Vans Aircraft, Lancair, Glasair and Zenith Aircraft, in that order. Of airplanes built from plans, the most common model was the Rutan LongEZ.

No surprise, the study found that amateur-built aircraft account for a disproportionate number of accidents compared with certified airplanes. Between 2001 and 2010, on average there were 213 accidents of EAB aircraft and 55 fatalities annually.

One of the eye-opening stats was that most accidents involving EAB aircraft happen very early in the airplane’s life, often on the very first flight, and early into that flight. Pilots who survived EAB crashes often said the engine quit or lost power, or that pitch control on takeoff or climbout was not what they anticipated. Another interesting statistic was that accidents caused by weather and CFIT were much less common in EAB aircraft than in certified airplanes.

Looking specifically at accidents stats from 2011, a total of 34 crashes occurred during Phase I flight testing. More than half of the accidents involved aircraft that were purchased used, again with crashes often happening shortly after the the airplanes were bought. About 10 percent of all EAB accidents in 2011 happened on very first flight, the NTSB said.

Based on the raw data, as well as the survey responses and experimental amateur-built rules in force in other countries, the NTSB made 16 safety recommendations, 12 of them directed at the FAA and four reserved for the EAA.

In a nutshell, they include: defining procedures for completing an aircraft fuel system functional test before the start of Phase I flight testing; requiring EAB applicants to submit a flight test plan before start of Phase I flight testing; applying incentives for builders to complete flight test training prior to start of Phase I flying; clarifying the circumstances in which a second qualified pilot could be allowed to fly during Phase I testing; requiring submittal of an Aircraft Flight Manual prior to start of Phase II flying; promoting the use of electronic data recording devices during Phase I flight testing for the creation of an Aircraft Flight Manual; making flight instruction in EAB aircraft easier; forming a coalition of kit makers and builder groups that would formulate incentives for flight training; creating provisions for modifying aircraft and returning them to Phase I flight testing if needed; and standardizing make, model and series data to meet ICAO specifications.

To the EAA, the NTSB made the following recommendations:

Formulate incentives to encourage builders and owners to complete training; work with members, aircraft manufacturers and avionics makers to develop standards for flight data recording; create and publish repository of flight instructors who are letter of deviation holders.

I’d take it a step further and abolish the whole letter of deviation practice when it came to EAB training. There should be no additional hoops to jump through for a pilot who wants to receive flight instruction in kitbuilt airplanes. I would also recommend that kit plane manufacturers add angle-of-attack indicators to the basic list of avionics they sell with their airplanes. It’s no secret that many homebuilders choose their models specifically because they want to fly on the edge of the flight envelope in a fun airplane. An AOA indicator would go a long way to allowing a pilot-builder to define and stay within that envelope. Finally, I would encourage makers of PC-based flight simulators to develop highly accurate models of all the most popular kit planes so that builders can experience the differences between the airplanes they learned to fly in and the airplanes they are building in a safe learning environment.

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