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Power Loss - A southeastern VariEze crashed into trees after power loss on it s first flight. The power plant was a conversion of a Chevy Corvair automobile engine. The aircraft was destroyed. The pilot was not injured.
Known Icing conditions/fuel management - A midwest VariEze pilot began an extensive
trip in IFR and icing conditions. His flight was a classic condition of many things going
wrong - in combination. He reluctantly accepted an altitude assignment in known icing
conditions, only 1000 ft above the MEA. The pilot became quite busy as ice was building,
switching the single Nay to identify intersections then noting an impending failure of the
gyro horizon - nose high at normal airspeed. Also, he reported a Nav problem and center
lost radar track of him. They were talking to him but did not know his position. At 40
minutes from takeoff the engine abruptly quit cold. He descended through the clouds
breaking out at about 500 ft AGL and put it in a freshly plowed field approximately 30
miles off course, carrying a large amount of airframe ice. The pilot received a fractured
vertebra. The aircrafts wing, belly, landing gear and canopy received major damage.
Investigators found the fuselage tank empty, speculating that the pilot had departed on
the fuselage tank and the engine failed due to fuel exhaustion. Probably the pitot-tube
had iced up resulting in his thinking the speed was ok and the gyro horizon was failing.
His airspeed was thus too low to allow a restart even when main fuel was selected during
the power-off descent through the clouds (windmilling not maintained).
Many builders, including this one, have modified the positioning of the fuel valve on the VariEze, defeating it s feature of reminding the pilot (by interference with his right wrist) that the fuselage tank was selected. There have now been two accidents caused by a combination of incorrect fuel management and defeating the interference design feature of the valve handle.
As you know from reading the
Canard Pusher, we report a synopsis of each accident and make recommendations to
builders/operators on any item that we feel should be changed or emphasized to decrease
the probability of reoccurrence. We have reviewed the data available, and have found one
factor that is significant. A high percentage of the accidents (minor and serious) have
occurred within the first few flights after a new owner has bought the airplane from a
previous owner. Statistically, you are far more likely to have an accident flying a
homebuilt built b someone else. This is true for experimentals, not just or VariEzes. For
example, an all-metal type that recently was grounded for a series of structural failures
- all the failures occurred after non-builders had bought the airplanes.
The factor may be a combination of inadequate familiarity with the airframe and systems, inadequate checkout and inadequate transmittal of documentation. Putting things in perspective, it is important to note that the builder is an aircraft manufacturer. As such, he may be responsible to a buyer for the quality of the machine and for properly educating the buyer in its safe use and the extent of his flight test program. We at RAF provide builder support to our customers - those who may need assistance or have questions on how to interpret the plans to build or how to interpret the Owners Manual to fly the completed aircraft. But, if you sell your airplane to another person you cannot expect that we can support him. He must go to you, the aircraft manufacturer. For example, if he needs to do a fiberglass repair, but does not have the plans and educational material he will not know how to do the job. He needs to get that information and documentation from the manufacturer.
Homebuilt accident record statistics were reported for a three-year time period by The Aviation Consumer last year. They show an overall accident rate for VariEze of 2.59 (1.55 fatal) per 100 aircraft during the 3 years. Average for all homebuilt aircraft was 3.93 (1.O7 fatal). We are not happy with this result, as we had expected the VariEze to be significantly better than the average homebuilt due to its strong structure and good stall characteristics. Structurally, the fiberglass VariEze has a perfect record - no inflight airframe failures in 100,000 flight hours, Also, there have been no fires either in operation or due to accident impact.
Data published by one source show that flying amateur-built aircraft is statistically a very risky sport, with an accident rate (per individual) higher than that for racing cars.