# NTSB IAD01IA009: Raytheon 400A, N792TA, Morristown, NJ, October 23, 2000 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: October 23, 2000, 15:20 local (19:20 UTC) - Place: Morristown, NJ - Location: 40.7966° N, 74.4773° W: Placed by OpenAirDocs: center of Morristown, NJ, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=40.7966&lon=-74.4773&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report December 18, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 50530 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=IAD01IA009 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/50530/pdf - Page: https://openairdocs.org/ntsb/IAD01IA009 ## Probable cause The failure of several relays on the roll trim control printed circuit board, which caused an uncommanded aileron trim input. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, descent - electrical system,electric relay - failure (cause) ## Analysis During a descent in preparation for landing, the left wing of the airplane experienced an uncommanded aileron trim input to the up position. Attempts to raise the right wing through the use of the roll trim select switch were unsuccessful on both the pilot and copilot sides of the airplane. The left wing continued to trim up until the left and right trim tabs were fully deflected in opposite directions requiring both pilots to physically control the airplane with full left control column input. The pilots declared an emergency and as airspeed was reduced, controllability improved and an uneventful landing was made. Examination of the roll trim control printed circuit board revealed that the relays on the board had developed a 'time lag,' causing them to stick in the closed position. As of the date of this report, the manufacturer was in the process of redesigning the circuit board. ## Factual narrative On October 23, 2000, about 1520 Eastern Daylight Time, a Raytheon 400A, N792TA, operated by Raytheon Travel Air, was not damaged when it experienced an uncommanded aileron trim input while descending through 12,000 feet, 20 miles south of Morristown, New Jersey. There were no injuries to the two certificated airline transport pilots and two passengers. The flight departed the Charlottesville-Albemarle Airport (CHO), Charlottesville, Virginia, and was destined for the Morristown Airport (MMU), Morristown, New Jersey. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed for the executive transport flight conducted under 14 CFR Part 91. According to the Raytheon Travel Air Incident Report Form, during the descent, at 250 knots, the left wing began to trim up. The pilots were able to stop it initially, and attempted to use the roll trim select switch to raise the right wing. The attempt failed on both the pilot and copilot sides. The left wing continued to trim up until the left and right trim tabs were fully deflected in opposite directions requiring both pilots to physically control the aircraft with full left control column input. The pilots declared an emergency with the MMU tower, and requested vectors direct to MMU for landing on Runway 05. As the airspeed was reduced for landing, the controllability improved, and an uneventful landing was made with 30 degrees of flaps. According to a representative of the operator, several relays on the airplane's roll trim control printed circuit board experienced a malfunction during the flight. The circuit board was removed from the airplane and functionally tested after the incident. The test revealed no abnormalities. Further testing of the relays on the circuit board revealed that a "time lag" had developed, which caused them to stick in the closed position. The "lag" occurred after power had been applied to the circuit boards for more than 10 minutes. As of the date of this report, the manufacturer was in the process of redesigning the roll trim control printed circuit board. ## Aircraft - Registration: N792TA (not matched to a registry record) - Reported make and model: Raytheon 400A - Category: Airplane - Serial number: RK-264 - Airframe hours: 616 - Engines: P&W JT15D-5 2900 lbs thrust turbo fan - Damage: No damage - Flight: Executive/Corporate, Part 91 - Registered owner: Rcm Corp - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, October 16, 2000, 16 hours before - Departed: CHO, CHARLOTTESVILLE, VA - Destination: MMU, NJ - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 6,630 total, 589 in this make and model, 4,746 as pilot in command, 94 in the last 90 days, 37 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 5 knots - Visibility: 6 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 66 °F - Altimeter: 29.00 inHg - Observed at: MMU, 20 nm away From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.