LAX95LA149

NTSB accident investigation · Bulsky Skybolt · Goodyear, AZ · March 31, 1995

Accident · No injuriesLimited investigationFinal report
Date
March 30, 1995, 18:05 local (Mar 31, 1995, 01:05 UTC)
Place
Goodyear, AZ
Injuries
2 uninjured
Damage
Destroyed
Phase of flight
Enroute
Aircraft
N94BVBulsky Skybolt
Weather
Visual (VMC) · Day
Status
Completed · report August 23, 1995
Report
Approved by Office Director
FAA report
19950330006449A
Case key
29064

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

fuel starvation due to the partial failure of the fuel pump caused by the broken crankshaft idler gear attachment screw lockplate. The unsuitable terrain and trees were factors in this accident.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(partial) - mech failure/malfCruise
Fluid,fuel - starvationCause
Engine assembly,gear - loose part/bolt/nut/clamp/etcCause
Fuel system,pump - disengagedCause
Forced landingDescent - emergency
Terrain condition - none suitableFactor
In flight collision with objectDescent - emergency
Object - tree(s)Factor

Analysis

During the local area flight, the engine crankshaft idler gear lockplate broke which allowed the attach screws to back out. The idler gear became loose and its gear teeth were damaged. A partial failure of the engine-driven fuel pump, which is operated by the idler gear, can allow the engine power to suddenly reduce to idle. During the subsequent emergency landing, the airplane collided with some trees and bushes.

Factual narrative

On March 30, 1995, at 1805 hours mountain standard time, a Bulsky Skybolt experimental airplane, N94BV, collided with some trees and bushes during an emergency landing about 8 miles southwest of Phoenix Goodyear Municipal Airport, Goodyear, Arizona. The emergency landing resulted from a sudden loss of engine power. The pilot was conducting a local visual flight rules personal flight. The airplane, registered to and operated by the pilot, was destroyed. Neither the certificated commercial pilot nor his passenger was injured. Visual meteorological conditions prevailed. The flight originated at the Phoenix Goodyear Municipal Airport about 1715 hours.

The pilot told National Transportation Safety Board investigators in a telephone interview conducted on March 31, 1995, that he was returning to the departure airport when the engine power reduced to idle. The pilot immediately executed an emergency landing to a dirt road. During the landing rollout, the airplane wing struck a cactus bush and nosed over. The pilot also said the airplane had " . . . a lot of fuel . . . ."

The pilot repeated his telephone statement in the accident report. He added, however, that the terrain was covered with rocks, trees, bushes, and "big cactus." During the emergency landing, he intentionally struck the trees to absorb the initial impact energy.

On April 20, 1995, maintenance personnel disassembled the engine, a Lycoming IO-540-T4A5, for examination at Air Transport, Phoenix, Arizona. A Federal Aviation Administration (FAA) airworthiness inspector from Scottsdale (Arizona) Flight Standards District Office supervised the examination.

The inspector reported that the oil screen contained ferrous and nonferrous metal. The crankshaft idler gear, part No. LW-10290, was found loose and damaged. The inspector said that two screws, part No. STD-1838, that attach the crankshaft idler gear shaft to the engine case, were "backed-out". The lockplate, used to safety the attachment screws, was broken into several pieces. The pieces were found in the oil pan.

The inspector reported that the fuel pump is operated by the crankshaft idler gear.

Aircraft

Registration
N94BV
Reported as
Bulsky Skybolt
Category
Airplane
Serial number
1
Airframe hours
160
Engine
Lycoming IO-540-T4A5, 260 horsepower, reciprocating
Damage
Destroyed
Flight
Personal · Part 91
Registered owner
Kaelberer, Gunther
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Annual · May 26, 1994 · 40 hours before
Departed
GYR

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
39
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Rear
Flight hours
6,683 total · 45 in this make and model · 6,200 as pilot in command · 98 in the last 90 days · 58 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
170° at 5 knots
Visibility
50 statute miles
Lowest ceiling
None
Temperature
75 °F
Altimeter
29.00 inHg

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.