The Unfortunate Experimental Aircraft

The National Transportation Safety Board concluded that the pilot lost control of the experimental aircraft as his attention was diverted due to canopy opening in flight.

It is not clear at what point the canopy opened completely.

According to witness accounts the airplane was oscillating sharply in pitch and rocking from one side to other during takeoff roll. It shows that the pilot was trying to close the canopy as the aircraft continued to roll.

Just after takeoff, the experimental aircraft made a sharp 180 and was flying almost parallel to the runway. The pilot made an attempt to turn quickly back to the runway and the aircraft was banked almost 90 degrees and started descending.

The wingtip hit the ground and the pilot was killed instantly after the impact.

The runway on which this accident happened was 10,000 feet long. The pilot started his roll at the intersection; still there was 7,500 feet for him to takeoff.

This is enough length to stop, close the canopy and takeoff with the same clearance.

So what went wrong?

What looks like, the pilot thought he can close the canopy with his left hand while control the aircraft with his right hand.

A look at the Experimental aircraft

The aircraft in question was a homemade Rutan VariEze which was granted license in 1992. This airplane was used by the pilot, a minister to fly to different congregations.

The airplane was purchased only 8 months before the unfortunate accident happened. In its tenure of operation, the aircraft had crossed nearly five pair of hands.

Just like other Rutan canard designs, the VariEze are not an easy plane to stall. The nose rises when the stick if pulled full back, but it falls back gently as the air flow separates. The main wing do not stall even in full roll.

These are important points when we try to find out the reasons for accident.

When a conventionally configured aircraft drops out from a tight turn it indicates a stall-spin. In case of VariEze, the aircraft that cannot stall, this only indicates that the pilot was at complete failure to control the experimental aircraft.

Now the Canopy Part

The canopy of VariEze is attached to the right upper edge of the fuselage tub. It slides up to open. A cable behind the headrest of pilot prevents it from getting in contact with the right wing.

Almost all the VariEzes are equipped with one-piece bubble canopies. However there was a two-piece variant in the accident airplane. There were separate sections that covered the rear and front seats.

The windshield forms an integral part of the canopy in both the versions.

The latching system pulls the canopy downwards with the help of three linked hooks. The canopy is prevented from being released accidently by the foremost hook that engages the latch.

Earlier Similar Accidents

A similar kind of fatal accident occurred in 1979. The pilot did not latch the canopy and it opened as he took off and the airplane control was lost.

The fact that VariEze can be controlled in case the canopy opens indicates that the problem is not with aerodynamics.

A previous owner of this aircraft used to fly it for air-to-air photography. He used to intentionally keep the canopy open and never faced any problem flying that way.

However, he used goggles while doing so. Without a windshield, the strong winds will make it very difficult for the pilot to fly the airplane.

Even after wearing glasses the eyes will still be filled with tears and the vision will be blurred. When it is combined with disorientation and startle can lead to loss of control.

Disorientation and startle are enough in many cases even when the blast of wind is not there. Door pop up has crashed even certified airplanes, even though it is difficult to detect the change in behavior with this occurrence.

The Solution

The first concern of the pilot should be to fly the airplane when confronted with unexpected events like these. Regardless of what happens during the flight, it is not important enough that can replace the need to fly.

After the accident in 1979, a compulsory modification to the design of canopy was published by RAF. The builders were asked to install a backup latch, following on the principle followed by a hood latch in a car.

In case the canopy is left unsecured it will only rise an inch or two and the back latch will hold it in place. From the photographs that were taken minutes after the crash, it appears that the VariEze was not equipped with this safety feature.

VariEze are not certified planes and there is no airworthiness directive published by FAA. It is because of this reason the important modification is not mandatory. In case the airplane was inspected by an A&P the failure would have been detected.

Unfortunately, for homebuilt experimental aircraft there is no such mechanism. For such airplanes, the owner is the official inspector.

The problem with the unfaithful experimental aircraft was that it had gone through several hands. Even if there had been Canard Pushers in the original aircraft, they would have gone astray in the long operation period of aircraft.

It is quite likely that the unfortunate pilot had never heard of the backup latch. He would have never imagined that the canopy can open up during the flight or else there would have been some preventive measure.

Even in case the canopy does open, he would have considered it simple and easy to close it back. Experimental aircrafts are of much greater risks to pilots who had not build that aircraft on their own.

Such pilots, often, do not check all the newsletter notices or do careful inspections. These pilots do not have enough experience to ascertain as to when to carry out repair and inspection and at times ignore the notices as well. It is the builders who know exactly how their aircraft perform and what are the shortcomings.

Four conclusions came out from this fatal accident.

  • The canopy of the aircraft was not equipped with a backup latch.
  • Pilot did not locked the canopy properly before rolling down the runway
  • The pilot continued with the takeoff roll and tried to fix the problem while flying
  • The pilot lost focus from flying the airplane first and reach a safe altitude before fixing the problem.

These four steps show four opportunities and none of them was picked up.

One thought on “The Unfortunate Experimental Aircraft

  • September 3, 2017 at 1:56 pm
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    I am glad to be a visitant of this consummate website ! , thankyou for this rare information! .

    Reply

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