NTSB Factual Report

On May 7, 2002, at 1230 Pacific daylight time, a Cessna 182P, N425Q, initiated a forced landing after a partial loss of engine power during the initial climb out from runway 15 at the Boulder City Municipal Airport (61B), Boulder City, Nevada. The airplane was being operated by Skydive Las Vegas as a skydiving flight under the provisions of 14 CFR Part 91. The airplane sustained substantial damage. The commercial pilot and four skydivers were not injured. Visual meteorological conditions prevailed for the local area flight, and no flight plan had been filed.

The airplane had been modified in accordance with a supplemental type certificate with the installation of a Continental O-550 engine and a 3-bladed propeller.

The pilot said in a written statement that during his run-up, the magneto check was not within acceptable limits. He attempted to fix what he thought was spark plug fouling, but the magneto check was still not within acceptable limits. He returned with his passengers to the ramp and shut the airplane down. Approximately 10 minutes later, he rechecked the magnetos and they passed the check. Approximately 15 minutes later, the pilot loaded himself and his passengers and proceeded toward runway 15 for takeoff. He configured and checked the airplane prior to takeoff: 10 degrees of flaps; full brakes; full power and static rpm; and all gages "in the green." As he released the brakes and started rolling there was no apparent problem.

As the airplane climbed out, the engine was not developing enough power, and the pilot initiated a shallow turn toward runway 9R. During this turn, the pilot was verifying that the throttle and propeller controls were full forward, and he noticed the mixture setting, which he had leaned for taxi and takeoff. He twisted the mixture control about two turns to richen; however, at that point the airplane lost all of its ability to climb. As he leveled the airplane, he executed a forced landing in the desert because of power lines between the airplane and the runway.

The National Transportation Safety Board investigator-in-charge (IIC) interviewed the pilot. The pilot stated that he had leaned the engine during the taxi and takeoff. His procedure for leaning was to bring the mixture back until the engine began to run rough, and then turn the mixture control knob two times until the engine was running smoothly again. During touchdown for the forced landing the airplane bounced. The pilot stated that either himself or a passenger "hit the throttle," and as he was attempting to pull the power back he noticed a ditch. The airplane came to rest on the far side of the ditch, shearing the nose gear and one of the main landing gear and bending the propeller blades.

The IIC interviewed Skydive Las Vegas' mechanic and two jumpmasters, who were onboard during the accident. The mechanic stated that under the supervision of the Federal Aviation Administration, he removed four spark plugs, rotated the engine, and removed the gascolator. He stated that the spark plugs appeared to have normal wear on them. When he manually rotated the engine, it turned smoothly with no binding, and he heard the impulse coupling for the magnetos clicking during the rotation. He stated that there were about 20 gallons of fuel on board, and that they found fuel in the fuel line to the engine. The mechanic also stated that he heard the pilot tell the owner of Skydive Las Vegas that he had leaned the airplane for takeoff due to density altitude. However, he had not readjusted the mixture control setting when it became apparent that the engine was not developing power.

The two jumpmasters, who were passengers in the airplane, stated that the pilot did not conduct a run-up or magneto check prior to takeoff. They also noted that the angle of attack was "steep," and that the airspeed was slow. Both jumpmasters stated that the engine did not sputter. They also stated that the engine sounded normal, but that it didn't seem like it was running at full rpm. One jumpmaster stated that he was in a position to look at the gages during the flight and noted that the airspeed was 65 miles per hour, the rpm was 2,250, and the manifold pressure was "slightly" above the green arc (above 20 inches).

Weight and balance calculations by the pilot for the flight determined that the airplane's gross weight was 2,883 pounds; the maximum certified gross weight for the airplane was 2,950 pounds. Examination of the weight and balance records indicated that the lubricating oil weight was not accounted for on the worksheet supplied by the operator. Recalculations revealed the weight and balance to be within acceptable limits.

The Pilot's Handbook of Aeronautical Knowledge, AC 61-23C, states that operation with a lean mixture may result in a loss of engine power.

NTSB Probable Cause

the pilot's failure to lean the mixture properly resulting in a partial loss of power.