Aviation Accident Summaries

Aviation Accident Summary CHI96LA162

FARGO, ND, USA

Aircraft #1

N229AM

Swearingen SA226TC

Analysis

While on short final to land, the pilot-in-command landed with the nose landing gear still in the uplocked position. The maintenance logbook indicates several undetermined nose gear uplock conditions that the flight crews had to lower the nose gear by free falling it. All flights were uneventful up until this flight. A transcript of the cockpit voice recorder (CVR), indicated that the before landing checklist was not completed correctly. The landing gear challenge and reply checklist was recorded as saying landing gear coming down, with a horn beeping in the background. The Pilot's Operating Handbook (POH) says, landing gear--down, with no report of three green down and locked lights.

Factual Information

On May 17, 1996, at 0815 central daylight time (cdt), a Swearingen SA-226TC, N229AM, operated by Airvantage, Inc., of Minneapolis, Minnesota, received substantial damage when its nose gear did not retract into the down and locked position on landing roll on runway 17 (9546' X 150' dry/asphalt) at the Fargo Municipal Airport, Fargo, North Dakota. The pilot-in-command reported that he had 3 down and locked indications on the landing gear prior to landing. The 14 CFR Part 135 flight had been on an IFR flight plan. Visual meteorological conditions prevailed at the time of the accident. The pilot-in-command and copilot reported no injuries. The flight departed Minneapolis, Minnesota, at 0649 cdt. According to the pilot-in-command's written statement, he said they were on base leg for landing on runway 17 at Fargo Municipal, with half flaps selected and three green down and locked gear indications verified by the copilot. On final approach, after being cleared for landing, the pilot-in-command selected full land flaps with no unsafe gear horn indications. After landing rollout the nose dropped to the ground and the engines were secured after they struck the runway. A Federal Aviation Administration (FAA) Principal Maintenance Inspector (PMI) represented the NTSB during the on-scene investigation. The PMI reported that during a gear retraction test conducted on May 17, 1996, the gear was selected up with all three landing in the up and locked position. The landing gear selector was placed in the down position, and only the two main gear came out of the wheelwell and went to the down and locked position. The nose gear stayed up and locked in the nose wheelwell. The two main gear transit lights came on while the mains were in transit light and the two green down lights came on when the main gear were down and locked. The nose gear transit light did not come on. When the emergency gear extension handle was pulled, the nose gear up lock released and the nose gear extended to the down and locked position. The nose gear transit light worked properly and the green down and locked light came on. The landing gear was cycled three more times, and the landing gear operated normally. The PMI could not find what caused the nose gear to remain up and locked when he tried to extend the gear the first time. All retractions were normal after the PMI used the emergency gear extension to lower the nose gear. According to the maintenance log book that the pilot-in-command signed, on May 10, 1996 on a flight to Minot, North Dakota, a different flight crew had the same problem with the nose gear. That crew used the emergency gear extension to lower the nose gear. The corrective action was to perform an operational check and adjust the nose gear actuator. After the adjustment the nose gear operated properly. On May 13, 1996 a different flight crew entered a discrepancy that the nose gear would not indicate up and locked. The corrective action was to rebuild the nose gear actuator, replace over center bellcranks and springs. The airplane was test flown and the gear worked properly. A transcript of the cockpit voice recorder (CVR) was conducted on November 13, 1996 by the NTSB's Engineering and Computer Services Division. A transcript was prepared of 09:16 minutes of the 30:29 minute recording which is enclosed with this report. At 0813:17 on the cockpit microphone one, "gear down, before landing checks." At 0813:18 on cockpit microphone two, "K gear in transit sshhhh. before landing, landing gear's coming down, prop sync off, speed lever are high. lights?" That was the last recording of the landing gear position with a beeping horn in the background. The Pilot's Operating Handbook (POH) states for the before landing challenge and reply checklist in the following order," No Smoking/Fasten Seat belt Sign--On, Speed Levers--High RPM, Propeller Synchronizer--Takeoff-Landing, Landing Gear--Down, Flaps--As Required, Cabin Differential Pressure--Check Zero, Ignition Mode Switches(if installed)--As Required."

Probable Cause and Findings

the flight crew did not comply with the gear down and lock checklist. The factors were a jammed nose gear and inattentive preflight planning/preparations by the pilot-in-command.

 

Source: NTSB Aviation Accident Database

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