NTSB Factual Report

HISTORY OF FLIGHT

On September 11, 2005, about 1545 Pacific daylight time, a Cessna 152, N6565L, collided with terrain in Lakewood, California. Aviation West Flight School was operating the airplane under the provisions of 14 CFR Part 91. The certified flight instructor (CFI) and the student pilot sustained fatal injuries; the airplane was destroyed. The local instructional flight departed Daugherty Field, Long Beach, California, and had been airborne about 1 minute. Visual meteorological conditions prevailed, and no flight plan had been filed. The approximate global positioning system (GPS) coordinates of the primary wreckage were 33 degrees 49.79 minutes north latitude and 118 degrees 976 minutes west longitude.

According to the Federal Aviation Administration (FAA), the airplane departed runway 25 right at Daugherty Field. About 30 seconds later, the pilot reported poor climb performance, and requested to return to the airport.

Numerous witnesses observed the airplane. They reported that it was low, and appeared to be going slow. The engine maintained the same sound; it was not coughing, sputtering, or backfiring. It sounded like it was at a low rpm (revolutions per minute). They reported that the nose was up as high as 45 degrees, the wings were rocking, and the tail was moving back and forth. It appeared that the airplane was turning back to the airport. The right wing then dropped about 90 degrees, and the nose went nearly straight down. The airplane came to rest behind a building. Pilot witnesses reported that they believed the airplane stalled during the turn.

PERSONNEL INFORMATION

CFI

A review of FAA airman records revealed that the first pilot held a commercial pilot certificate with ratings for airplane single engine land, multiengine land, and instrument airplane. The pilot had a certified flight instructor certificate with ratings for airplane single engine land and instrument airplane.

The pilot held a first-class medical certificate issued on December 14, 2004. It had the limitations that the pilot must wear corrective lenses.

An examination of the pilot's logbook indicated an estimated total flight time of 793 hours. He logged 92 hours in the last 30 days.

Student Pilot

The primary flight student did not hold any FAA pilot certificate. No personal flight records were located for the student pilot.

AIRCRAFT INFORMATION

The airplane was a Cessna 152, serial number 15284440. The logbooks contained an entry for an annual inspection dated June 28, 2005. The tachometer read 3,300 at the annual, and the total airframe time was 9,351 hours. The last inspection was a 100-hour inspection on August 15, 2005, at a tachometer time of 3,400 hours, and total time of 9,451 hours.

The engine was a Textron Lycoming O-235-L2C, serial number RL-19242-15. Total time recorded on the engine at the last 100-hour inspection was 2,762.5 hours. Work performed included an oil and oil filter change, a check of the exhaust system, gapping of the spark plugs, a check for compliance with airworthiness directives, and a notation that compression was 70/80 or better. The manufacturer's recommended time between overhauls is 2,400 hours.

WRECKAGE AND IMPACT INFORMATION

The National Transportation Safety Board investigator-in-charge (IIC) and an FAA inspector examined the wreckage at the accident scene.

The first identified point of contact (FIPC) was a ground scar on an asphalt parking lot. The FIPC was about 25 feet from power lines that the IIC estimated were 30 feet high. The power lines were nearly perpendicular to the debris path, which was along a magnetic bearing of 040 degrees. The IIC did not observe any damage to the power lines.

The airplane came to rest about 45 feet from the FIPC. The orientation of the fuselage was 030 degrees; the engine pointed 070 degrees. There was a post crash fire, and portions of the upper cabin area were not identifiable.

The right wing was under a truck, and the truck's front left wheel was on top of the right horizontal stabilizer. The right side of the fuselage and the vertical stabilizer rested against the truck's front bumper.

The propeller flange was deformed, and the propeller separated. One blade was bent aft 90 degrees just past midspan. It twisted clockwise about 45 degrees, and buckled along the trailing edge. The other blade exhibited a sweeping bend beginning about 2/3 of the span toward the tip; it bent aft about 70 degrees.

MEDICAL AND PATHOLOGICAL INFORMATION

The Los Angeles County Coroner completed an autopsy on the occupants. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological testing of specimens of the pilots. Analysis of the specimens contained no findings for carbon monoxide, cyanide, volatiles, and tested drugs for the student. Analysis of the specimens contained no findings for volatiles and tested drugs for the CFI; they did not test for carbon monoxide or cyanide.

TESTS AND RESEARCH

The FAA, Cessna, and Textron Lycoming were parties to the investigation.

Investigators examined the wreckage in detail at Aircraft Recovery Service, Littlerock, California, on September 16, 2005.

Investigators removed the engine, and slung it from a hoist. They removed the spark plugs. All spark plugs were clean with no mechanical deformation. The top spark plug electrodes were gray. Three electrodes were massive electrode type, and the center electrodes were oval shaped. The fourth plug was of the fine wire type. The bottom spark plugs were all the massive electrode type; they were oval shaped, wet, and oily. The Lycoming representative noted that the top spark plug electrode for cylinder number 3 indicated mid-service life; all of the other electrodes were worn beyond service limits.

A borescope inspection revealed no mechanical deformation on the valves, cylinder walls, or internal cylinder head.

Investigators manually rotated the crankshaft. The crankshaft and gears in the accessory case rotated freely. Thumb compression was obtained on all cylinders in firing order except for cylinder number 4. All of the valves moved approximately the same amount of lift in firing order except for the number 4 exhaust valve. The Lycoming investigator noted that it was heat soaked, and stuck in the open position. After he removed the push rod, spring pressure closed the valve.

Fire damaged both magnetos, and they could not be tested.

The vacuum pump drive gear melted, and the vacuum pump would not turn.

The oil sump was breached; the sump screen buckled, but was clean. The oil filter sustained mechanical and thermal damage. The oil pump exhibited some damage and scoring, which the engine representative said was consistent with extended life.

Investigators disassembled the engine.

All of cylinder number 1's rings moved freely, and they were shiny around their entire circumference.

The oil control ring for cylinder number 2 would not move. The top compression ring fractured in several locations, and a portion of it melted in the ring land. Part of the ring had heavy coking; another part was shiny. Piston material was missing at one edge of the fractured ring piece. This scarf gap was 1/8-inch wide at the edge of the piston face, and widened to 1/2 inch at the top compression ring. The scarf gap continued through the ring groove and into the material between the top two compression rings. The Lycoming investigator noted that this allowed combustion blow-by (blow torching) to consume the piston material. The third compression ring also fractured.

The top compression ring for cylinder number 3 fractured and separated into two pieces. Part of the ring had heavy coking; another part was shiny.

All of cylinder number 4's rings moved freely.

There was false brinnelling on the camshaft and followers. It was extensive on the face of the cylinder number 1 exhaust camshaft follower and the cylinder number 3 exhaust lobe of the camshaft.

The fuel selector valve was in the ON position.

Ash covered the instrument panel, and investigators could not read all of the panel's markings. The Cessna investigator determined that the ignition switch was in the right position. He measured the flap actuator at 0.1 inch, and reported that this corresponded to the full up position. The elevator trim measured 1.8 inches, which equated to 7-8 degrees tab up. He established partial control continuity from the rudder, elevator, and elevator trim tab control surfaces to the cable ends, which were cut during recovery, protruding from the tailcone. He was unable to verify aileron or flap continuity due to fire damage.

ADDITIONAL INFORMATION

The IIC released the wreckage to the owner's representative on September 16, 2005.

Pilot's Operating Handbook (POH)

The normal procedures section of the POH discussed a magneto check before takeoff. It instructed the pilot to move the ignition switch to the LEFT and RIGHT positions and note rpm drop. The pilot was to return the switch to the BOTH position at completion of the test. Another subsection discussed the takeoff, and noted the importance of checking full-throttle operation early in the takeoff run. It stated that any sign of engine roughness or sluggish engine acceleration was good cause for discontinuing the takeoff. It continued by indicating that, during a full static run up, the engine should run smoothly and turn approximately 2,280 to 2,380 rpm with carburetor heat off and the mixture leaned to maximum rpm.

The emergency procedures section of the POH discussed rough engine operation or loss of power. Among the topics in this section were discussions on spark plug fouling and magneto malfunction. It noted under spark plug fouling that this condition could be verified by turning the ignition switch momentarily from BOTH to either the LEFT or RIGHT positions. An obvious power loss in single ignition operation was evidence of spark plug or magneto trouble. If unable to determine the source or clear the problem, the pilot was to proceed to the nearest airport using the BOTH position of the ignition switch unless extreme roughness dictated the use of a single ignition position. Under magneto malfunction, it noted that sudden engine roughness or misfiring was usually evidence of a magneto problem. Switching from BOTH to the LEFT or RIGHT ignition switch positions would identify the malfunctioning magneto. If continued operation in the BOTH position was not practicable, the pilot should switch to the good magneto and proceed to the nearest airport.

NTSB Probable Cause

the certified flight instructor's failure to maintain an adequate airspeed resulting in a stall and loss of control. Also causal was the engine's loss of partial power due to inadequate maintenance, worn spark plugs, worn pistons, and broken piston rings.