Transition to homebuilts: 'This is test flying'

Air Safety Institute makes safety case at NTSB seminar

September 18, 2013

Buying and flying an amateur-built aircraft is a venture into test flying, but do new owners give that consideration the respect it deserves?

The safety record, pitfalls, and safety strategies were spotlighted by the Air Safety Institute during an experimental aircraft safety seminar at the National Transportation Safety Board’s training center in Ashburn, Va. David J. Kenny, Air Safety Institute manager of aviation safety analysis, led about 60 pilots and aviation safety experts through the presentation, "Transitioning into a homebuilt: This is test flying," which provided an overview of who is buying used amateur-built aircraft, who is selling, and what the safety record says about the participants and the transactions. Other presentations at the Aug. 24 seminar focused on case studies and safety trends for amateur-built aircraft.

Buyers, in particular, must do their homework about specific aircraft to be purchased and about flying experimental aircraft generally, because for some, it is a  new ballgame.

"Buyers are often coming in from outside the homebuilder community, and may not have an appreciation of what they’re getting into," Kenny said.

That lack of information has been known to compromise safety if a pilot flies a newly purchased aircraft without taking pains to learn its systems thoroughly and spend time documenting its flight characteristics and performance. Variance from expected performance can be wider than with a production aircraft—or there may be little data available depending on how much testing was performed and documented by the seller.

A pilot should learn through careful testing how much aerodynamic warning to expect from the aircraft as it approaches a critical angle of attack. Incipient-stall behavior should be explored before attempting a recovery from a full stall.

Note that a builder/seller’s intimate knowledge of an aircraft’s construction may not translate to expertise about how it flies. Also, you may not buy your amateur-built aircraft from its builder. Approximately 55 percent of amateur-built aircraft accidents involved second or later owners, Kenny said.

Buyers and sellers

The ideal buyer’s scenario is to purchase the aircraft from its builder and learn firsthand what design concepts and performance goals applied to the project. 

Even better, Kenny said, is if the seller/builder has extensive experience in flight instructing and aerobatics. If the seller lacks those traits and qualifications, next best  is for the buyer to possess them.

Usually, however, they are absent on both sides of the deal.

Typically, the seller might be a 225-hour private pilot who has owned the aircraft for several years, did not build it, and  has only flown it occasionally because “he never learned to fly it well enough to feel confident in its cockpit.”

"Guess why he’s selling," Kenny said.

The presentation examined accidents highlighting errors or omissions such as a  buyer rushing through a checkout or declining additional training before departing in the aircraft. In one case, a new owner had not flown the 20-year-old homebuilt  in 11 months since buying it. The owner had made high-speed taxi tests, and had "expressed concern with ground-handling characteristics." Still, the owner opted to take off—resulting in losing control during the takeoff run, with an uncontrolled climb, crashing from 150 feet agl.

What’s a better way?

Don’t be in a hurry to buy and fly. Find the best instructor you can; if the CFI needs some familiarization training in the aircraft first, make that a priority. Then thoroughly review systems and procedures on the ground until you can pass what Kenny calls the "blindfold test."

His reminder to avoid hurrying includes how to conduct that first flight: Don’t make turns until reaching a safe altitude. Explore the flight envelope "cautiously, systematically, and thoroughly." Unless recoveries from full stalls have been performed during a demonstration flight, do not assume that stalls are recoverable: "This is something else that is not guaranteed with an experimental aircraft, although most well-known kits have reasonable stall characteristics when built and assembled according to the maker’s directions," Kenny said.

Air Safety Institute to produce transition course

In 2014, the Air Safety Institute will produce an online course for pilots on transitioning to other makes and models. It will include amateur-built and experimental aircraft.

One reason buyers transition into the experimental-aircraft market is to acquire more performance at a lower price than may be possible in the certified-aircraft market. But Kenny said buyers of experimentals should understand that "neither the aircraft nor its performance is going to be as predictable as a certified aircraft."

The experimental-category designation "is supposed to tell people that essentially they are investigating and flying this aircraft at their own risk";  there is "no representation" that it meets the airworthiness standards of Part 23 regulations.

"We see a lot of variation in how seriously builders and owners take the whole test-flying stage," he said.

A scarcity of instructors who are qualified to teach in some high-performance experimental aircraft can compound difficulties of pursuing familiarization training. Pilots seeking guidance on how to mount a test-flying program may find little source material available, although Kenny said the nonprofit National Test Pilot School  has expressed interest in addressing that problem in the near future.

Dan Namowitz

Dan Namowitz | Aviation Writer

Dan Namowitz is an aviation writer and flight instructor. He has been a pilot since 1985 and an instructor since 1990.