# NTSB MIA00LA091: Beech F90, N101ET, Monroe, GA, February 9, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 9, 2000, 09:05 local (14:05 UTC) - Place: Monroe, GA - Coordinates: 33.782501, -83.692779 - Nearby events: https://openairdocs.org/map.md?lat=33.7825&lon=-83.6928&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 30, 2003 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 48637 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA00LA091 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/48637/pdf - Page: https://openairdocs.org/ntsb/MIA00LA091 ## Probable cause chafed wiring that resulted in an electrical short which initiated the landing gear retraction cycle when cabin heat was activated, resulting in the main landing gear retracting during taxi. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Gear retraction on ground, taxi - to takeoff - air cond/heating/pressurization,cabin temp control - activated - electrical system,electric wiring - chafed (cause) - electrical system,electric wiring - shorted (cause) - gear retraction - inadvertent activation ## Analysis The pilot stated that while taxiing for takeoff he selected max ground heat, and immediately experienced main gear retraction. The tail dropped suddenly, impacting the ramp, and the airplane slid about 30 feet before coming to rest. An FAA inspector and a manufacturer's representative examined the airplane, and found that a partially spiral wrapped wiring bundle, tied in the vicinity of the aileron control cables and turnbuckle, had some wires which had chafed. The wiring insulation had been removed due to friction exerted against either the turnbuckle, or the cable. The manufacturer's representative stated that two of the wires which had chafed through electrically shorted together when the pilot selected max ground heat, activating the landing gear's relay, and initiating the landing gear retraction cycle while the aircraft was on the ground. ## Factual narrative On February 9, 2000, about 0905 eastern standard time, a Beech F-90, N101ET, registered to and operated by Avondale Mills Inc., as a Title 14 CFR Part 91 business flight, main landing gear retracted while taxiing for takeoff from Monroe County Airport, Monroe, Georgia. Visual meteorological conditions prevailed at the time, and an instrument flight rules flight plan was filed. The aircraft was substantially damaged, and the private-rated pilot was not injured. The flight was originating at the time of the accident. The pilot stated that while taxiing for takeoff the cabin was cold so he selected max ground heat and immediately experienced main landing gear retraction. He said that the moment he activated the max ground heat switch, the tail dropped suddenly, impacting the ramp, and the airplane slid forward for about 30 feet before coming to rest. An FAA inspector, along with a Raytheon representative examined the accident airplane and removed the splash curtain, inspecting the wiring to the J107 connector, located in the right main landing gear wheel well. They noted that several wires had chafed through the insulation. The chafing was in the area where the wires were tied to the aft wheel well compartment wire bundle, where the bundle made a 180-degree bend. At the end of the bend, four wires had chafed through the insulation, along with other wires which had partially chafed through. According to the Raytheon representative, the wires had chafed on the side, against the plastic spiral wrap, placed to protect the wire bundle connected to the J107 connector. The chafed side of the wires appeared to have rubbed against the right aileron control cable turnbuckles, which ran through the back of the compartment. The wires in the bundle which were affected are as follows: Wire # G8A22 Pin M - main landing gear motor (arcing) Wire # H39A22 Pin U - heat switch (arcing) Wire # H76A22 Pin V - heat switch Wire # D10A22 Pin F - landing gear position (arcing) Wire # G21A22 Pin H - not associated The Raytheon representative stated that wires G8A22 and H39A22 electrically shorted together when the pilot selected max ground heat to warm the cabin, and voltage from wire # H39A22 (heat switch), activated the landing gear's up relay, in landing control box K100, initiating the landing gear retraction cycle, while the aircraft was on the ground. Due to the weight of the airplane and the direction of nose gear movement during retraction, the nose gear remained down and locked. ## Aircraft - Registration: N101ET (not matched to a registry record) - Reported make and model: Beech F90 - Category: Airplane - Serial number: LA172 - Airframe hours: 4620 - Engines: Pratt & Whitney Canada PT6-135 750 horsepower turbo prop - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: Avondale Mills Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, December 9, 1999, 33 hours before - Departed: D73, MONROE, GA - Destination: AIK, AIKEN, SC - Flight plan: IFR - Airport: D73, Monroe-Walton County ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 3,534 total, 1,285 in this make and model, 2,239 as pilot in command, 60 in the last 90 days, 20 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 53° at 5 knots - Visibility: 3 statute miles - Lowest ceiling: none - Temperature: 41 °F, dew point 30 °F - Altimeter: 30.29 inHg - Observed at: AHN, 20 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20000209004379A](https://openairdocs.org/incident/20000209004379A), Feb 9, 2000: Beech F90, Monroe, GA, No damage. (-23) This investigation follows accident involving a Beech F-90, serial number LA-172 aircraft, whose landing gear retracted during taxi operation when the… 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.