Somebody brought this to my attention at Sun N Fun.

NTSB Identification: CHI08LA274
14 CFR Part 91: General Aviation
Accident occurred Wednesday, September 03, 2008 in Findlay, OH
Probable Cause Approval Date: 3/23/2009
Aircraft: Sadler Vampire, registration: N333SV
Injuries: 1 Minor.

The airplane was an experimental amateur-built airplane that was a
prototype for light sport aircraft certification. The flight test was
conducted by the engine manufacturer, who also provided a pilot to fly the
airplane. The pilot had not received flight instruction or a checkout in the
airplane. The pilot learned to fly the airplane on his own by taxiing and
performing local flights in the airport area. The pilot also had no training
or experience in aircraft flight test. A larger radiator had been installed
onto the airplane due to noted high engine temperature during previous
flights. Prior to the accident flight, the pilot performed two taxi tests
during which he performed short hops on the runway to get familiar with the
aerodynamic forces that would be encountered during takeoff and landing. The
engine temperature was reported as normal during this time. The pilot then
attempted a takeoff for a flight that was to remain in the airport traffic
pattern. Just after takeoff the airplane lost total engine power. The pilot
attempted an engine restart without success, during which he did not hear
the engine turn over. The pilot then executed a forced landing into a quarry
located about 0.6 miles from the departure end of the runway. An examination
of the reduction drive assembly needle roller bearing sidewall revealed a
combination of wear and high temperatures leading to overstress.
Circumferential wear marks on the separated cage sidewall and the presence
of metallic debris suggested impingement of the rollers on the sidewall
during engine operation. Heat tinting of the outer raceway in the vicinity
of the failed sidewall and the cam that served as the inner raceway was also
noted. The needle bearing malfunction could be attributed to misalignment of
the needle bearing and insufficient lubrication.

The National Transportation Safety Board determines the probable cause(s)
of this accident as follows:
A total loss of engine power due to the failure of the reduction drive
assembly as a result of excessive wear and high temperatures. Contributing
to the accident were the pilot's lack of total experience in the airplane
and the unsuitable terrain for a forced landing.



CHI08LA274

On September 3, 2008, at 1257 eastern daylight time, a Sadler Vampire,
N333SV, received substantial damage on impact with terrain during a forced
landing and a post crash fire. The airplane experienced a total loss of
engine power after takeoff from Findlay Airport, Findlay, Ohio. Visual
meteorological conditions prevailed at the time of the accident. The 14 CFR
Part 91 flight test was not operating on a flight plan. The pilot sustained
minor injuries. The local flight was originating at the time of the
accident.

The airplane was certified as an experimental amateur-built airplane and
was used as a prototype toward seeking certification as a light sport
aircraft by its manufacturer.

The pilot stated the engine previously experienced "slightly" high engine
temperatures that had been reduced to the "normal operating range" with the
installation of a larger radiator onto the airplane.

The airplane was fueled from a portable fuel tank in the back of a pickup
truck. This fuel tank did not have any sump drains or fuel filtration
available. The pilot stated that there were no fuel sump drains available on
the airplane and Federal Aviation Administration (FAA) inspectors did not
note the presence of any fuel sump drains during their post accident
examination of the wreckage. Additionally, the provided airplane checklist
did not mention the sumping of fuel to check for contamination.

The pilot performed a low speed taxi followed by a high speed taxi. He
performed "short hops" to get used to the aerodynamics of the airplane for
takeoff and landing. He then "felt confident" that everything was operating
"well" enough to fly the airplane one time in the airport traffic pattern.
The pilot used runway 07 (5,883 feet by 100 feet, asphalt) for the takeoff.
He applied full throttle and obtained an engine speed of 5,100 revolutions
per minute (rpm). He rotated the airplane at 65 miles per hour (mph),
maintained 75 mph, and obtained a climb rate of about 200 feet per minute.
He turned crosswind approximately 500 feet agl, and in the turn to the
downwind leg, the engine experienced a loss of engine power while over Main
Street. He attempted an engine restart but did not hear the engine turn
over. He then turned his attention to executing a forced landing. He pitched
the airplane to obtain 85 mph, which reportedly was the best glide speed. He
stated that the glide ratio was "very poor" and knew that he could not
return to the airport. He saw a quarry that he thought was his best option
for a landing area because of the commercial area adjacent to the airport.
Once he knew that he could reach the quarry, he allowed the airplane speed
to increase to about 95-100 mph. As the airplane descended, the ridges in
the lower part of the quarry, where he wanted to land, came into view. The
airplane inadvertently touched down on the first ridge and bounced. The
pilot wanted to avoid a stall so he pitched the airplane nose down. He then
impacted a second ridge with trees and the airplane yawed left. He was
unable to realign the nose of the airplane with the direction of travel. The
airplane touched down and slid to a stop.

According to the Findlay Police Department Report, the airplane's main
landing gear wheels touched down on an upper ledge of the quarry and bounced
off the edge before striking two small trees and a lower ledge in the
quarry. The airplane's nose landing gear then struck the bottom of the
quarry. The airplane travelled westbound an additional 135 feet before
coming to rest. The pilot exited the airplane, and the airplane then caught
on fire.

The airplane wreckage was located approximately 0.6 miles north from the
departure end of runway 36.

The pilot, age 24, held a commercial pilot certificate with single-engine
land, multiengine land, and instrument airplane ratings. He was issued a
flight instructor certificate in May 2008. He accumulated a total flight
time of 455 hours, 6 hours of which were reported in the make and model of
accident the airplane. The pilot stated that he was hired by his
brother-in-law, who was the engine manufacturer, as a test pilot which was
also a way for him to accumulate flight time. The pilot stated that he did
not receive an airplane checkout in the accident make and model airplane but
learned to fly the airplane on his own. He stated that he got used to the
airplane on airport taxiways and on flights limited to the airport area. The
pilot had no previous aircraft flight test training or experience.

The aircraft manufacturer stated that the airplane fuel system consisted of
a single-fuel tank with a sump drain located on the gascolater, which was
the low point in the fuel system. There was a metal to metal fuel shutoff
valve, and excess fuel was ported back to the fuel tank near the fuel tank
vent. The fuel cap was not vented.

Cockpit engine water temperature indication is sensed at the outlet side of
the engine cooling system prior to entering the radiator.

The airplane was powered by a Rotamax 1300CG engine at the time of the
accident. The model and serial number of the engine were obtained from
company provided records that stated the engine was serial number 5,
manufactured on October 15, 2007, and accumulated 52 hours. However, the
Affidavit of Ownership for Experimental Aircraft, AC Form 80850-88,
identifies the engine as a Rotamax R700, serial number 2-DC-R-S-N-G-004. The
engine manufacturer stated the Rotamax 1300CG was the correct engine model
for the airplane.

Post accident disassembly of the installed Rotamax 1300CG engine and
reduction drive assembly was conducted under the supervision of the Federal
Aviation Administration. During the disassembly of the reduction drive
assembly, multiple bearing failures were noted. The reduction drive assembly
was then shipped to the National Transportation Safety Board Materials
Laboratory for metallurgical examination.

The metallurgical examination revealed one end of the rotor bearing journal
exhibited a dark and discolored surface relative to the opposite rotor
bearing journal on the shaft. Light colored lines from the needle rollers
were visible on the surfaces of both rotor bearings. There were no
indications of deformation (brinnelling) by the rollers on the inner
raceways. Closer examination of the discolored rotor bearing journal
revealed metal transfer on the bearing surface and pitting on one location.
Similar light colored lines from roller bearings were noted on the main
bearing journals.

The complete circumference of one of the sidewalls had separated from the
rest of the needle bearing cage. Upon removal of the sidewall, four needle
rollers fell out of the cage due to damage and plastic deformation to which
the cage had been subjected. It was not apparent whether this damage
occurred before or after the sidewall separated from the cage. Small shards
of metal were found on the rollers and the outer raceway. The outer housing
was discolored on the side with the fractured cage sidewall and around the
oil hole in the middle. A piece of metal debris was found inside the oil
hole.

The needle rollers showed signs of abrasive wear and damage to the ends of
the rollers. A typical needle roller exhibited abrasive wear by third body
particles at an end which was adjacent to the fractured cage sidewall. The
diameter of the needle roller on this end is also reduced relative to its
opposite end. A random sampling of five rollers produced an average
reduction in diameter of 0.0064 inch +/- 0.0007 inch. The ends of the
rollers next to the fractured cage sidewall were concave in profile with
buildup of material around the edge. The opposite end of the roller ends
possessed rounded edges.

The fractured sidewall of the cage had concentric abrasion marks coincident
with the location of the needle rollers. In between the rollers it appeared
that two fractured ribs had been plastically deformed and pressed against
the cage sidewall. In another location, there appeared to be buildup of
metal debris on the fracture cage sidewall.

Two ball bearings within the assembly had seized. The balls in one raceway
of the double row ball bearing were clustered together creating an
approximately 120 degree included angle of raceway in which there were no
balls. There was no readily visible evidence that would explain the seizure
of these bearings. Most of the bearings, once wiped of residue showed, a
typical lightly scratched finish with some discoloration from heat from post
crash fire.

End of NTSB report.

Rumors at the time said it was a disconnect failure of the gear box to the
prop.

The NTSB frequently gets things wrong so in this case they start talking
about the gearbox and then jump to the roller bearings in the engine like
that was the cause of loss of power. We had long discussions on the
viability
of the rotor needle roller bearings with Eric Barger. It appears I was
proved
right as Midwest engineers warned me about that. The rotor needles were
lubed
by oil injected into the intake as this engine uses a charged cooled rotor.
The attached picture is the roller bearing that Eric used.

The NTSB report did not say where the two ball bearings were located.
They could have been main bearings or they could have been in the gear box.
Must likely they were in the New Zealand (as I recall)  built gear box.
Kind of  a strange failure as gear boxes usually give a bit of warning.

This is still a mystery as far as I am concerned because I am still lacking
details on the RPM of the engine, the prop dimensions and the gear ratio
used in the gear box. Effective oiling also appears to be an issue

Can you help me out Eric?

Paul Lamar



Paul,

Is that a gravity feed oil system feeding the gearbox?

Mark S.

I am not sure how it was done.

Paul Lamar