NTSB Factual Report

On June 7, 2005, at 1545 central daylight time, a Cessna 182TR, N4978T, sustained substantial damage when the main landing gear collapsed during landing on runway 16 (5,000 feet by 150 feet, asphalt) at the Palwaukee Municipal Airport (PWK), Wheeling, Illinois. The commercial pilot was not injured. The 14 CFR Part 91 business flight departed Danville, Virginia, about 1135 eastern daylight time en route to PWK. Visual meteorological conditions prevailed at the time of the accident. The flight was on an instrument flight rules (IFR) flight plan.

The pilot reported the airplane was at a cruise altitude of 20,000 feet for about 30 minutes when the attitude indicator failed. He continued to his destination without the attitude indicator and with the autopilot off.

When he neared his destination, air traffic control (ATC) cleared the airplane to descend to 3,000 feet mean sea level. The pilot reported that he slowed the airplane to 110 kts. He reported that when he was 10 miles from the airport, he put in ten degrees of flaps and lowered the landing gear switch. He reported seeing a green light on the gear position indicator. He reported that the primary altimeter (electrically powered) was inoperative and was stuck at 2,900 feet. The pilot set 29.83 in the secondary altimeter's Kollsman window. He reported that ATC gave him radar vectors to intercept the localizer for landing on runway 16.

ATC instructed the pilot to switch the radio frequency to PWK's tower frequency. The pilot reported that when he tried to contact PWK tower, he realized that the primary and secondary radios had failed. The pilot reported that he took out his hand-held radio and contacted PWK tower on it and reported to ATC that he had a radio failure. He reported that he realized that the airplane's HSI was inoperative and his portable Garmin 290 GPS had "turned itself off due to an interruption of electrical supply from the plane, due to the auto off feature when external power is discontinued." He turned the Garmin 290 back on and used the "direct to" feature to help him locate the airport. The pilot reported that he recognized that the airplane's GPS/radio/VOR receiver had powered down and was "recycling through the power-up check and was providing no radio or guidance information."

The pilot reported: "As I descended to the runway, I pulled the power, added full flaps, and continued down the PAPI glideslope. Just prior to touchdown, I heard the controller comment that the wheels were not down. I pulled back on the yoke and saw that neither the amber nor green gear lights were on. As the plane was about to settle, I put the nose back down. I did not add power for a go around as it appeared that the full flaps setting and potentially my inability to retract the flaps might lead to my inability to climb sufficiently to do a go around. Additionally, the gear was hanging down below the plane and would have added further drag. I did not believe that I could pull the breaker and pump the gear into place in time, while still maintaining control of the aircraft."

The pilot reported that he landed the airplane as "softly and slowly" as possible. The airplane landed on its fully extended nose wheel and partially extended main landing gear. The airplane rolled onto its right wing and horizontal stabilizer and skidded to a stop on the runway.

The airplane was taken to a maintenance facility where it was put on jacks in order to check the landing gear system. When the landing gear handle was put in the up position, the landing gear retracted normally. When the gear handle was put in the down position, the landing gear extended, but did not extend to the fully down position. The landing gear hydraulic reservoir was checked for hydraulic fluid. The mechanic who performed the inspection reported that the fluid level was below the pick-up point of the electrically activated hydraulic pump. However, there was enough hydraulic fluid available in the reservoir for the emergency manual gear extension to operate. The mechanic added 6 to 8 ounces of hydraulic fluid. After the hydraulic fluid was added, the landing gear was cycled 4 to 5 times and the landing gear retracted and fully extended normally. The mechanic reported that the emergency gear extension procedures were followed to pump the landing gear down and the landing gear went to the fully extended position.

The inspection of the battery revealed that it was weak and required recharging.

The airplane was repaired. The maintenance logbook entries indicated that the maintenance facility serviced the aircraft's battery, serviced the hydraulic system with MIL-5606 hydraulic fluid, replaced the engine drive vacuum pump, checked the vacuum system check valves, replaced the vacuum regulator filter, adjusted the regulator for 5 inches of mercury at 2,100 RPM, and replaced the auxiliary radio antenna.

NTSB Probable Cause

The pilot failed to verify that the landing gear were fully extended and failed to perform the emergency landing gear extention procedures. Factors to the accident included the low hydraulic fluid level, and the weak battery that resulted in a partial electrical failure.