NTSB Factual Report

HISTORY OF FLIGHT

On Tuesday, July 20, 1993, at 1530 eastern daylight time, N3722Q, a Beech C33A, operated by C & D Enterprises of Nashville, Tennessee, and piloted by Milton Cashion of Nashville, collided with runway 13 while on final approach during a power-off forced landing at Combs Field, Paintsville, Kentucky. Visual meteorological conditions prevailed and an Instrument Flight Rules (IFR) flight plan had been filed. The certificated commercial pilot was fatally injured. The aircraft was destroyed . The flight was conducted under 14 CFR 91 and originated at 1422 hours in Westfield, Massachusetts and was destined for Nashville.

According to FAA provided transcripts of communications, when the airplane was at cruise flight of 10,000 feet above mean sea level, and 10 miles southwest of Paintsville, the pilot reported, " I just lost an engine and need an airport." Indianapolis Air Route Traffic Control Center controller gave the pilot vectors to Combs Field Airport, Paintsville. The pilot reported the airport in sight and that he would attempt a landing on runway 31. The airplane impacted on runway 13 about 500 feet from the approach end, and was destroyed by impact forces and a post impact fire.

A witness who was in his backyard across the street from the runway reported that, "he saw an airplane coming down the runway as to make a normal landing, but we noticed the propeller was not turning." He stated that the airplane make a steep right turn, then it fell to the ground. The airport is situated in a mountain valley with 500 foot hills on both sides.

The accident occurred during the hours of daylight, at 37 degrees 44.76 minutes North and 82 degrees 46.74 minutes West.

PERSONNEL INFORMATION

The pilot held a commercial pilot certificate with single engine and multiengine land ratings. According to FAA records, the pilot's total flight time listed by him on his last FAA medical certificate was " over 4000 hours."

AIRCRAFT INFORMATION

The 1967 year model Beech C33A airplane, serial no. CE129 was equipped with a Continental IO 520BA engine, serial no. 121210 6 BA. According to the engine log book, the airplane had accumulated over 2497 hours of total flight time. This time was recorded on the last 100 hour inspection that was completed on August 18, 1992. The engine had accumulated over 1600 since major overhaul.

METEOROLOGICAL CONDITIONS

The 1454 hours surface weather observation for Julian Carroll Airport, about 25 miles west of the accident site was as follows:

Sky condition, 2500 feet scattered; visibility, 10 miles; temperature, 89 degrees (F); dew point, 67 degrees (F); wind condition, 290 degrees at 6 knots; and altimeter, 30.10 inches.

WRECKAGE AND IMPACT INFORMATION

The airplane impacted the runway separating the right tip tank. Examination of the accident site revealed the scatterpath was oriented on a magnetic bearing of 105 degrees. The initial ground scar was 500 feet from the threshold of runway 13. The scar was two feet in length and about 18 inches wide. Small fragments of green glass were found in the scar along with fiberglass fragments of white and red paint. About 22 feet from the initial impact point (IIP) was a one foot deep crater about two feet in diameter.

The main wreckage was found about 56 feet from the IIP. Most of the airplane had been consumed in the post-crash fire. The airframe remained intact with all the major components in place, with the exception of the right tip tank which was located near the left tip tank, and the propeller forward of the engine.

Both wings were damaged by fire. The left tip tank remained attached to the wing. The right tip tank had separated and was outside the area of the fire. About 1 gallon of fuel was found in the right tip tank. The empennage was intact. Flight control cable continuity was established to the left aileron in the left wing and to the right aileron bellcrank in the right wing. Continuity was also established to the rudder, both elevators, and both elevator trim tabs in the aft fuselage. The left elevator trim tab actuator measured 36 mm which according to Beech Aircraft engineering data corresponded to a trim setting of 4.6 degrees tab down. The right actuator measured 35 mm which corresponded to a trim setting of 3.3 degrees tab down.

The landing gear actuator was consumed by fire. The position of the landing gear retract rods relative to the position of the actuator shaft indicated that the landing gear was extended at impact. The position of the roller in both the left and right inboard flap tract indicated the flaps were fully extended. Both flap actuators were consumed by fire. The melted aluminum on both actuators indicted that the flaps were extended. The forward fuselage and instrument panel were destroyed by fire.

Examination of the engine revealed it had separated from its mounts. The engine was removed to a hangar at the airport where a teardown was completed under the supervision of the NTSB. The top spark plugs were removed and appeared grayish with the drive coupling intact. Both magnetos produced spark when rotated by hand. When the crankshaft flange was rotated by hand, the accessory drives, camshaft, #1 and #2 pistons revealed evidence of restriction. The crankcase was disassembled. The #2 main bearing was missing, and some of its fragments were found inside the crankcase. Marks on the crankshaft indicated that the #2 main bearing shifted aft. The crankshaft had separated aft of the #2 main journal at the offset for the #2 piston. The two parts of the crankshaft and all the bearings and bearing fragments were removed and sent to the NTSB Lab in Washington, DC for further examination. The examination revealed that the crankshaft failed as the result of fatigue cracking initiating on the surface of the aft radius of the #2 main journal. Details of the crankshaft examination is attached to this report.

MEDICAL AND PATHOLOGICAL INFORMATION

A Medical Examination was done by the State of Kentucky Office of the Medical Examiner on July 21, 1993. According to the Medical Examiner's report, the pilot died as a result of the injuries received in the accident. Toxicological tests did not detect alcohol, drugs, or carbon monoxide.

ADDITIONAL INFORMATION

The wreckage was released to Ms. Edna Cashion, the Executrix of the pilot's estate on September 22, 1993.

NTSB Probable Cause

1) FATIGUE FAILURE OF THE ENGINE CRANKSHAFT AT THE NUMBER 2 MAIN JOURNAL DUE TO UNDETERMINED REASON (S) WHICH RESULTED IN THE TOTAL LOSS OF ENGINE POWER, AND 2) THE PILOT NOT MAINTAINING AN ADEQUATE AIRSPEED WHICH RESULTED IN AN INADVERTENT STALL/SPIN. A FACTOR IN THIS ACCIDENT WAS INADEQUATE ALTITUDE FOR THE PILOT TO RECOVER FROM THE STALL/SPIN.