One of the books we have sitting in inventory is a book reporting to a community of test pilots the latest developments in the field. It is from an annual symposium held in Los Angeles, in this case back in 2003. It is bound pamphlet that was circulated to the participants as a handout at the symposium, and contains technical information and notes about the presentations made. It is a hard to find copy.

As we flip through it, we realize that we are in a different world from that of the calm, orderly and quiet world of the tranquil bookseller. We are reading about altitude and airspeed, hydraulic flows, throttles, handling characteristics and so on. Because this is not the world of books, rather it is the ultimate adrenaline ride, the testing of experimental planes. And not ordinary experimental craft that people build in their garages with kits, but rather full fledged high-speed multi-Mach-speed machines that move faster than bullets in flight.

While one of the greatest fears of a bookseller is a paper-cut from wrapping paper, we look here at the issues involved in testing an aircraft, and we have to wonder about the paragraph in italics below that outlines deliberately trying to force a plane into a unstable flight pattern to simulate control recovery in the worst case situation. Here's a photo of the cover with a link:


By comparison, we get excited when we used to push planes through their paces in a flight simulator software game. It is hard for us to imagine with the multiple complexities of three dimensional movement  at high speed in real life trying to recover from a deliberate test of having an airplane spin out of control and then hopefully, try to recover before the plane crashes.

Not our idea of a day in the office. We put a You-Tube video below with a deployed spin-chute for an X-29 test aircraft to give you a quick demonstration of what a spin chute is and how it works. The paragraph from our book talks about a design modification due to design/cost consideration that would eliminate the parachute from the test during a simulation of a test condition to simulate the circumstances that had caused a number of operational planes to crash.

Here is a short  mid-presentation discussion to the test pilots about removing one of the primary safety features for revamping a change to eliminate the high speed "falling leaf" failure that had caused the plane to oscillate and lose altitude drastically while swaying back and forth from side to side. This was the F-18 Hornet that is used by the Navy for flight operations.

The EMD is the test environment and backups that were used during the Engineering and Manufacturing Development phase when the plane was originally prototyped with special testing backups to avoid having the plane crash during testing.

Life Without a Spin Chute

Since the test plan involved intentionally putting the aircraft into out-of-control flight, a spin chute was originally considered to mitigate the risk of not returning to controlled flight. The original spin chute from the Hornet EMD days was long gone, and a proposal to adapt the Super Hornet chute used in EMD to the smaller aircraft was considered. That effort although simple in premise involved extensive structural modifications, extensive testing, and shortening of the chute riser length that drove the cost prohibitively high. The mere presence of a spin chute can also have an effect on the data of the flight test. Risks of non-recoverable out-of-control motion were therefore mitigated in other ways during the test program.