Accidents and Incidents
October 1989
A New York VariViggen crash landed in the Piconic Bay shortly after take-off when the engine quit. The pilot, an experienced Viggen flyer attempted two re-starts but could not get it to run. He then turned into the wind and executed a near perfect gear up water landing. The Viggen floated and the pilot was quickly rescued by some pleasure boaters. The Viggen was towed to the beach and, after spending some 20 hours in salt water, was returned to its hangar. The left wing root was heavily damaged and the builder probably will not rebuild. The pilot was bruised and shaken up but not seriously hurt. The cause of the engine failure was traced to the mixture outer cable attach point near the carburetor. This attachment had been perfect for seven years and almost 600 hours but failed at 600 feet over the bay shortly after take-off. This failure was such that the mixture lever arm on the carburetor was pulled to the idle cut-off position.
The pilot was unable to richen the mixture, or even to move the mixture at the carburetor, in spite of his best efforts. What can we learn from this accident? Engine controls are every bit as important and critical to flight safety as flight controls are. Check you engine controls for correct travel and try to imagine what you could do to make sure that no matter what fails, the mixture fails to full rich and the throttle fails to full power. The opposite result is simply unacceptable. A spring that pulls mixture and throttle arms to full rich and full power could prevent such a problem. At least with full power you could use the cockpit mixture lever to regulate power (it works just like a throttle) or even the mag switches to cut power off to facilitate a landing. Using mag switches to regulate power is not as good as using the mixture control. Above all, check that the clamp that secures your throttle outer cable and mixture outer cable are as near perfect as your ability and skill allows. A failure here is not acceptable.
--------------------------------------------
"Dear Burt,
I regret to inform you that VariEze Serial No. 235, N13EG, "Old Dog's New Trick", was destroyed in a landing accident at Blackhawk Airport, Cottage Grove, WI on Saturday, July 29, 1989. After planning to fly to Oshkosh on Thursday, the weather wasn't reported as good until Saturday when the Washington FSS allowed as how it was good weather all the way to Oshkosh so I took off and flew to Findlay, Ohio, planning a fuel stop there. When I got to Findlay, they were giving Special VFR clearances from the FSS there. I called the FSS and when they answered my transmitter went out so I could not reply to them. So I flew on to Putnam County Airport about 30 miles west of Findlay, landed and called the FSS on the phone and explained the situation.
As Oshkosh did not want you to talk to them, I decided to press on as I could receive very well. I then flew to Porter County Airport at Valparaiso, IN. Findlay FSS also gave me a good forecast for my route. After refueling at Porter County, I proceeded to the Peoria VOR and took up a 3370 heading to miss the Chicago TCA. When I reached the town of Marengo, IL, I was due south of Oshkosh so took up a 3600 heading. I had not been able to go higher than 3500 MSL after leaving Putnam County and the ceiling now started dropping. Soon it started to rain and I did a 180 and ran out of it again. Deciding that sitting it out on the ground would be the best idea, I started to look for airports on my chart and spotted Blackhawk about ten miles east of Madison. was tuned to the Madison VOR and was on the 900 radial. According to my chart, there was a super highway running near Blackhawk so I flew until I spotted the highway and turned west, as I got onto base leg the rain started again. I could see all right out of my canopy except for the critical lower front area where I needed to see the runway.
On my first pass, I could see that I was too low so I released the landing brake, added power and started a go-around. Just then I heard and felt a thump but the airplane kept on flying and climbed out. I checked what I could from the cockpit and discovered that the front of my left winglet had a crushed area about the size of my hand just above opposite the top of the rudder. The only thing I can figure was that I had hit a big bird as I was flying over a cornfield and there were no trees or poles in the field. climbed out and then tried to land the other way. This time I was all set up but had closed the air vent to keep the rain out of my face and just as I came down final the canopy steamed up so it was another go-around. On my final pass I tried Runway 27 again. I was set up well and as the runway was 2600 feet I was trying for the numbers. I could see that I was to the left of the runway so I banked right to line up, just as I banked left again, I felt it hit.
What I hadn't seen in the rain was that Runway 27 had a 275' displaced threshold because of a mound with a cornfield and a road that was about two feet higher than the end of the runway. The main gear and the left wingtip hit the edge of the road and separated from the airplane. The fuselage then skidded across the grass and up the runway, stopping just on the right edge of the runway just before the displaced threshold markings. was completely unhurt so unbuckled my harness, opened the canopy and stepped out into the rain. The ELT worked because even thought the radio was tuned to 119.3 the sound of the ELT signal could be heard. The destruction was almost total, the only thing that could have been salvaged was the canard and that had some tip damage. The left wing had been torn from the center section spar. The left side of the center section spar outboard of the fuselage had been torn off separately,. The center section spar with the engine mount, engine, and fuselage tank had ripped loose from the fuselage and the fuel strakes, the only thing keeping it with the fuselage was the aileron torque tube.
The right wing attach fitting was wrenched both at the wing and the center section spar. The fuselage lower aft cover was ripped off when the gear separated. It had the all glass gear tabs according to CP 14 and the tabs stayed in the airplane, although the gear legs did delaminate between the tabs. The nose gear failed to the right and crushed a small section of the lower nose. The belly of the airplane was surprisingly unscathed, just some paint scratches, at no point was the fiberglass abraded through. The engine sustained some damage, the main thing was the air intake pulled the carburetor with the intake spider attached loose from the case, breaking one bolt and cracking the boss where the other bolt was attached. The carburetor and intake spider stayed with the carcass held on with the fuel line. When the left wing separated, it swung in and dented the valve covers on cylinders I & 3. The propeller was shattered and the spinner had a few dents. I was lucky that it was raining as the center section spar coming loose dumped all the fuel into the engine compartment. The lower cowling and wheel pants disintegrated.
What should I have done? The first two things were lapses of memory. When I was getting the airplane ready for the trip I had planned to put RAIN-X on the canopy after polishing it but I left the RAIN-X home. The second item was that I forgot my handheld radio when I started on the trip. I'm sure that the canopy would have been easier to see through with RAIN-X and the handheld radio would have allowed me to go into a controlled field with long, wide runways. Next, when I ran into rain again I should have headed south again until I was well in the clear, there was plenty of fuel on board, having flown less that 2 hours on full tanks. Also I could have dialed up 7700 on my transponder and gone on ten miles to Truax Field which has an ARSA, I was definitely in an emergency situation. To what do I attribute my luck in being unscathed? First of all to a great design, the one witness to the accident stated that the airplane came apart just as it was supposed to,. The fuselage cocoon ended up intact. The seat belt and shoulder harness helped. Also had TEMPER FOAM cushions, even though the airplane hit with such force that it broke the bracket on the back of the radio stack the cushions absorbed the impact so that I could not feel it. I'm sure that the TEMPER FOAM saved me from serious back injury. Such is my sad tale and is the reason that I did not see you at Oshkosh this year.
Sincerely
James 0. Eggleston"
Many thanks, Jim, for this accurate and honest accident report. We can all learn from an accident like this. Rain-X is a great idea when flying into rain, and carrying a hand held radio for emergency use is another. ED.
--------------------------------------------
A Florida Long-EZ was heavily damaged during a landing attempt on a grass strip. Reportedly, the aircraft drifted off the edge of the runway area during the landing roll and struck two concrete culverts. The pilot sustained serious leg injuries and had to be cut out of the airplane. There was no fire and the pilot, who never lost consciousness, was able to talk with the firemen and medics who were helping to get him out. We are hoping to receive a report from this pilot when he has fully recovered. If he agrees, we will publish it in the CP at that time.
--------------------------------------------
An Alaska Long-EZ struck the top of a tree and crashed, fatally injuring the builder pilot. The pilot was apparently practicing night landings and got too low on final, crashing into the tree. This kind of accident is by no means confined to homebuilt aircraft, in fact, it is unusual in homebuilts. Night landings, especially at a country airport with few lights around, can be demanding and require lots of proficiency and extra care. A California VariEze crashed during an attempted go-around after landing and drifting off the runway. The aircraft struck several landing lights then hit a 10 foot high earth berm and crashed into a fence. The aircraft caught fire and was completely destroyed. The pilot was severely burned and is in critical condition. His passenger was killed. The pilot was not the builder of the VariEze.
He had recently purchased the airplane and had his instructor with him to help him get comfortable in the aircraft. It was only his fourth flight in his newly acquired airplane. The FAA has not concluded their investigation as yet but at least for now, it does not appear that there was anything amiss with the airplane. A VariEze crashed in Southern California recently and both occupants were killed. There was one eye witness who reported observing the VariEze performing some aerobatic maneuvers before it abruptly lost power and fell to the surface of a wet salt pan. The VariEze hit the surface essentially flat with little or no forward motion and was inverted. These very unusual circumstances called for a full investigation. Two representatives from RAF assisted the FAA in trying to determine what might have caused this tragedy. The investigation team was forced to use a helicopter to examine the crash site since it was not possible to walk across the muddy salt pan which was many feet deep in places.
It was obvious from 300 feet above the crash site that the VariEze had impacted inverted, with little or no forward or lateral velocity. This was evidenced by the mud splash marks radiating out from the center of impact. The RAF representatives returned to the crash site several times over the next three days and many photographs were taken, and there was much discussion and theorizing. While the exact cause may never be know for absolute certain, it is our belief, based on our knowledge of the VariEze design as well as our previous experiences examining several crash sites somewhat similar to this one, that this aircraft fell essentially vertically onto the surface of the salt pan. It struck the salt crust in a nose low, wings level, but inverted attitude. There was no evidence of a spin, no sign of rotation at the time of impact. The engine was not developing power and, most probably, was not even windmilling. Two of the eight large wing attach taper plugs were missing.
We believe they departed the airplane in flight, as did the AN-4 bolt and nut that secures them in place. When the remaining six taper plugs were removed, they were easily removed without having to drive them out. All three AN-4 bolts had had the length of threads increased to about 3/4" using a threading die to cut these additional threads. All three bolts showed evidence of elongation of the threaded area where they had stretched possibly due to being over-torqued. We theorize that possibly the forth bolt was over-torqued to the point of failure, or almost failure. During this last flight, and probably aggravated by the acrobatic maneuvers, this bolt failed. None of the taper plugs fitted very well into the tapered holes in the wing fittings.
For this reason, we believe that the two forward plugs on the left wing worked their way out of the tapered holes after the bolt broke, thus allowing the left wing to pivot aft on the aft two tapered plugs. There are marks on the left wing attach fittings which clearly show that the wing pivoted aft as much as 15 degrees. The wing swinging aft by itself would not have caused this accident, however the winglet mounted on the end of the wing swinging 150 left would create a powerful yaw with perhaps four times the authority of the rudder alone. Such a huge yaw angle would immediately drive the aircraft into a drastic departure from controlled flight. The airplane would flip over and experience heavy negative "G" forces which would cause the engine to starve of fuel, whereupon it would quit.
Apparently, this tumbling departure occurred at a rather high speed because the enormous negative, as well as positive "G" forces over-stressed the aluminum wing fittings as evidenced by the considerable elongation of the taper plug holes in the outer plate, both top and bottom, of each wing. The inner plates of each wing fitting, top and bottom, showed much less evidence of elongation, leading us to conclude that the home made taper plugs did not perfectly fit into the tapered holes. It is probable that the left wing, swept aft, may have caused the airplane to fall in a somewhat stable inverted spiral (as described by the eye witness). Flight experience and NASA testing have shown that a normal VariEze cannot maintain an inverted developed spin. There is no evidence to suggest that there was any inflight structural failure of any composite parts. Every single part of this aircraft (with the exception of the two wing attach taper plugs and the securing bolt) were found at the impact site.
--------------------------------------------
IMPORTANT
All VariEze builders and flyers should be aware of the Seriousness of this situation. If you know of anyone flying a VariEze who may not be receiving the Canard Pusher, please pass on the following critical information: A mandatory inspection of the long AN-4, 1/4" diameter bolts and nuts that secure the steel tapered plugs into the wing fittings. There are four (4) of these bolts, each must be removed and carefully examined for any evidence of over-torquing (stretched threads, necked down diameter anywhere on the length of the bolt). Double check to see that the threads on each bolt are not bottoming in the threaded lower taper plugs. You may have to use thin shim washers under the head of each bolt to assure a proper fit with no bottoming of threads.
Check that the jam nuts have at least 1-1/2 to 2 threads showing after they are tight. If you purchased your VariEze wing fitting from Ken Brock Manufacturing, you will notice that the AN-4 bolts have a longer than standard thread. These threads as they are on any AN bolt are not cut threads, they are rolled threads. If you see any evidence of the threads having been cut with a threading die, discard them and install new bolts. Look for any corrosion on these bolts. Any corrosion should be carefully cleaned off and the bolts should be greased before re-installing them. Excessive corrosion is cause to discard the bolts. If you did not personally install the bolts, you may have to assume that they might have been over-torqued. Any suspicion of over-torquing is cause to discard these bolts.
If your wing attach fittings were not manufactured by Ken Brock Mfg., you will need to carefully inspect the tapered plugs for perfect fit in the tapered holes. If in doubt, you may have to carefully lap each plug into its tapered hole, checking for perfect fit with engineering blue. Check to be certain that the tapered plugs do not go too deeply into the tapered holes. The top of the plugs must not go below flush with the top of the wing fittings. The design of a wing fitting such as the VariEze calls for the tapered steel plugs to take all flight loads. The AN-4 bolts should never see flight loads. All they are for is to retain the tapered plugs. If the tapered plus are a perfect fit, these bolts will require only a very light torque to snug the plugs into their respective holes.
Three (3) foot/lbs. (36 inch/lbs.) of torque are all that should be required. If you need more torque to pull the tapered plugs into their tapered holes, your tapered plugs do not fit correctly. Do not fly until you have corrected this situation. Two people have died because of improperly fitting wing attach taper plugs. Do not take this lightly. Your life depends on these wing attach fittings. You owe it to yourself and your passengers to do absolutely the very best work you are capable of here. This is especially true if your wing fittings are homemade. The Brock fittings are very accurately machined and all the tapered plugs are hand lapped and fit perfectly. Once you have installed a pair of tapered plugs and torqued the bolt (3 ft./lbs), as a double check, remove the bolt and check for a tight fit of each taper plug. It should take a sharp blow with a wood drift to loosen each plug. It the plugs fall out or are not tight, they do not fit correctly. Fix this problem before next flight.