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Prior to a recent flight, when on the ground and during preflight check, the
nose gear could be retracted and extended normally using the standard manual
gear installation, in place since 1979. Because of CG balance, and as is
somewhat usual in the VariEze, the force necessary to lift the nose on the
ground with gear extended is minimal. For safety, either a weight is placed on
the pilot’s seat or a weight (battery) is hung from the nose gear so that the
plane will not fall backward onto its prop and winglets when not attended,
especially when sightseers are around feeling and touching. When at a remote
location, the same safety has been achieved by lowering the gear slightly so
that more force is required to upend the fuselage. Until now, I have not been
in the habit of fully retracting the gear and placing the nose on the steel skid
for very short parking periods.
Recently, at a washstand, this method was used.
Leaning over the canopy and inadvertently applying body weight while washing the
plane in this position, I noted the nose dropped several degrees. I attributed
this to a spontaneous gear retract handle rotation, the gear not having been in
the over center position. Holding the nose level then, the gear could be
retracted and extended with no problem.
The gear retract mechanism was inspected visually
through the battery panel opening, retracted and extended multiple times and the
plane was flown several times with no difficulty thereafter.
During a recent flight, the gear was retracted manually after takeoff on
crosswind leg and noted to remain in mid position. Attempts thereafter to raise
the gear fully, or to lower the gear fully, failed. The gear remained in mid
position dangling in the slipstream while attempts to lower it were
unsuccessful. These attempts included slowing to full stall at 60-70 mph, high
G turns while cranking furiously, rapid pitch changes and vocal epithets. When
nothing worked, the tower was called and notified of the problem and equipment
was placed on standby.
The approach used was slow and controlled with
touchdown on the numbers at 75-80 mph. The canard was held up with full back
stick and trim and with no braking. Because of ground effect, lowering of the
nose did not occur until less than 50 mph while in this stick position. Then,
possibly because the gear was still in mid position before it collapsed, the
nose skid did not touch the asphalt until about 35 mph. A short and pleasantly
controllable skid, with minimal braking, occurred until stop some twenty or
thirty feet later.
After exiting the plane, I lifted the nose and was
surprised to note that I could easily rotate the gear handle to a solid over
center gear down position, got back in and taxied to the hangar. Once again,
the nose gear could be raised and lowered without any problem unless pressure,
similar to the wind effect, was applied to the faceplate in front of the wheel
at which time slipping was noted.
After removing the canard, the worm gear assembly was inspected and no obvious problems were seen. However, when looking at the cast iron gear cogs near the spiral gear with a mirror, the wear was very apparent.
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The entire assembly was replaced. With the exception of some paint scrapes, there was no damage to the plane. The photos below reveal how difficult it can be to inspect the cogs from topside with the assembly in place.
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Several factors have been learned as a result of this incident. I will no longer “rest” the nose in mid position while the gear is in mid position even for short periods. It will be either up or down (this is an obvious benefit of the Strong or other electric nose gear retract systems on some EZE’s, wherein this parking position is possible without fear of damage). Inspection of the retract mechanism will include a mirror and bright light. During conditional and other inspections, I’ll ask a friend or bystander to apply pressure to the faceplate during testing.
This shows the area of slip on the worm gear.
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