Casualties unknown

2002-12-17: Hawker Siddeley DH-125 (N55RF) — Seattle, WA

Seattle, WA, US

On December 17, 2002, a Hawker Siddeley DH-125 (registration N55RF) was involved in an aviation accident near Seattle, WA. Investigators recorded the probable cause as: The landing gear down and locked was not verified prior to landing. The checklist was not followed, and an inoperative landing gear warning horn were factors. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

During landing, the landing gear was not extended, resulting in touchdown on flaps and keel. Investigation revealed a faulty horn relay but no gear extension issue.

Approach and Landing

The co-pilot was the pilot flying during the approach, with the captain providing directions. The captain reported that he extended the flaps and the landing gear. However, when the aircraft touched down, the landing gear was not extended. The co-pilot stated that she looked at the landing gear lever and saw "three green lights" during the approach.

Cockpit Voice Recorder Transcript

Analysis of the cockpit voice recorder indicated that the co-pilot directed the captain to call inbound. The captain acknowledged and stated "fifteen flaps." The co-pilot then said "fifteen flaps, before landing." The captain did not respond but made a radio transmission. Shortly thereafter, the captain stated he was extending the flaps to 25 degrees. Another radio transmission to the tower occurred when the co-pilot said "final, sync, ignitions." The captain responded "ignitions on." Full flaps were then extended. The captain continued to give the co-pilot directions for heading, speed, and altitude. At approximately 300 feet, the captain stated, "yaw damper's off, air valves are off, ready to land."

Post-Accident Actions and Inspection

The captain reported that it was obvious touchdown occurred on the flaps and keel. He raised the flaps, shut down the engines, and confirmed that the landing gear handle was down. During a subsequent gear swing test, the landing gear cycled several times without difficulty. All red and green lights illuminated at the proper positions. However, it was found that the gear-not-extended warning horn did not function when the gear was retracted, flaps were fully extended, and power levers were at idle. Further investigation revealed a bad set of contacts in the relay. When the relay was bypassed, the horn sounded.

Damage Assessment

Inspection of the aircraft damage showed that the outer rims of both main landing gear tires exhibited scrape marks around the circumference. The outer surfaces of the gear door fairings were scraped, and the flap hinge fairings were ground down.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20021220X05625. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.