Aviation Accident Summaries

Aviation Accident Summary CEN13LA141

McKinney, TX, USA

Aircraft #1

N6195P

PIPER PA-24-250

Analysis

The pilot stated that he attempted to contact the air traffic control tower for a landing clearance but was unable to. He circled in the area to troubleshoot the problem and determined that the radios were not transmitting. The air traffic controllers in the tower saw the airplane circling and radioed that the pilot was cleared to land. The pilot turned toward the airport, at which time a total loss of electrical power occurred. The pilot and passenger, who was the airplane owner, were unable to identify the cause of the electrical failure. The pilot selected the landing gear to the down position, and the passenger performed the landing gear emergency extension checklist. The pilot reported hearing the gear extend and asked the passenger if the gear appeared to be down and locked; the passenger replied yes. The landing gear collapsed when the airplane touched down, and the airplane slid about 200 feet before coming to rest. A postaccident visual examination of the landing gear did not reveal any mechanical failure or malfunction that would have prevented the gear from locking in the extended position. An annual inspection of the airplane had been completed about 1 month before the accident flight during which new bungee cords were installed on the landing gear, in accordance with an airworthiness directive. The landing gear system, including the emergency extension system, was reportedly operationally checked during the annual inspection without any anomalies noted. Due to damage sustained in the accident, the landing gear could not be functionally tested; therefore, the reason for its collapse could not be determined. Although the airplane battery did not hold a charge during postaccident testing, the alternator functioned properly. Electrical power should have been available from the alternator once the engine was running, regardless of the condition of the battery. The reason for the electrical system failure could not be determined.

Factual Information

On January 23, 2013, at 1200 central standard time, a Piper PA-24-250, N6195P experienced a landing gear collapse on landing at the Collin County Regional Airport (KTKI), McKinney, Texas. The airline transport pilot and passenger were not injured. The airplane was substantially damaged. The airplane was registered to and operated by private individuals under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed. The flight originated from Grayson County Airport (KGYI), Denison, Texas at 1135. The airplane departed KTKI and was flown to KGYI where a touch and go was performed followed by a full stop landing for fuel. The pilot reported that while en route back to KTKI he was unable to contact the air traffic control tower. He circled the area and subsequently determined that the radios were not transmitting. The control tower saw the aircraft circling and radioed that they were cleared to land. The pilot stated they turned toward the airport at which time a total loss of electrical power occurred. The pilot and passenger attempted to identify the cause of the electrical failure, which included checking the circuit breakers, without success. The pilot reported he moved the landing gear handle down position and the passenger followed the landing gear emergency extension checklist. The pilot heard the gear extend and reported that it appeared as if the landing gear were down by looking in the left wing tip mirror. The pilot reported he continued the landing approach and was cleared to land by the control tower via a light gun signal. The landing gear collapsed when the airplane touched down and the airplane slid approximately 200 feet prior to coming to rest. The firewall was damaged. Following the accident, the master switch was turned on and indications in the cockpit revealed electrical power was produced. After about one minute, the electrical power went off. The landing gear could not be functionally tested due to impact damage. A visual inspection did not reveal any mechanical reason to have prevented it from locking in the extended position. An electrical capacity test was performed on the airplane battery. The battery failed 13 minutes into the 60 minute test. The alternator, voltage regulator, over voltage control, and capacitor tested normal. The aircraft owner reported the airplane had not been flown since October 2012; however, the battery was placed on a charger before the flights. The mechanic who performed the annual inspection stated that he did not perform an electrical capacity check on the battery during the inspection. The last annual inspection on the airplane was performed on December 13, 2012. Records indicate that a landing gear swing and operation check of the emergency extension was conducted during the inspection.

Probable Cause and Findings

Collapse of the landing gear for reasons that could not be determined because visual examination did not reveal any mechanical malfunction or failure that would have prevented the gear from locking in the extended position and postaccident damage precluded functional testing.

 

Source: NTSB Aviation Accident Database

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