# NTSB LAX94LA105: Rockwell AC-112, N1084J, Modesto, CA, January 23, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 23, 1994, 13:50 local (21:50 UTC) - Place: Modesto, CA - Location: 37.6258° N, 120.9544° W: Placed by OpenAirDocs at MODESTO CITY-COUNTY-HARRY SHAM FLD (MOD), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=37.6258&lon=-120.9544&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report November 14, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 28646 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94LA105 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28646/pdf - Page: https://openairdocs.org/ntsb/LAX94LA105 ## Probable cause the worn/chafed landing gear wire which provided intermittent electrical power to the hydraulic pump. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Main gear collapsed, taxi - from landing - electrical system,electric wiring - chafed (cause) - landing gear,gear locking mechanism - pressure too low (cause) ## Analysis THE PILOT WAS TAXIING TO HIS HANGAR AFTER PRACTICING TAKEOFFS AND LANDINGS. WHILE ON THE TAXIWAY, THE LANDING GEAR WARNING HORN SOUNDED AND THE RIGHT MAIN LANDING GEAR LIGHT WENT OUT. MOMENTS LATER, THE RIGHT MAIN LANDING GEAR COLLAPSED. EXAMINATION OF THE AIRCRAFT DISCLOSED THE WIRING FROM THE RIGHT MAIN LANDING GEAR TO THE HYDRAULIC PUMP WAS WORN AND CHAFED WHICH RESULTED IN INTERMITTENT OPERATION OF THE PUMP. ## Factual narrative On January 23, 1994, about 1350 hours Pacific standard time, a Rockwell Aero Commander AC-112, N1084J, right landing gear collapsed while taxiing to the hangar after landing at Harry Sham Field, Modesto, California. The pilot was completing a visual flight rules (VFR) local personal flight. The airplane, registered to and operated by the pilot, sustained substantial damage. The certificated private pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at Harry Sham Field at 1330 hours. The pilot submitted a Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2. He indicated in the report that he made two takeoffs and landings on runway 10R. After completing the second landing, he made a right turn off the runway and taxied toward his hangar. While taxiing between 3 and 4 miles per hour, the landing gear warning horn sounded and the right main landing gear down light went out. The pilot immediately shut down the engine and then the right main landing gear collapsed. The pilot also did not indicate in the aircraft accident report when the last annual inspection was completed. Nor did he indicate the total flight hours on the airframe and the total flight hours since the last annual inspection. Mr. Tom Rouch, Top Gun Aviation, Inc., Harry Sham Field, said in a telephone interview conducted on June 6, 1994, that he repaired the airplane. During the maintenance repair, he found the right main landing gear wiring considerably worn and chafed. He said the wiring was the original wiring. This condition caused an intermittent operation to the hydraulic pump. During normal operation, the hydraulic pump maintains pressure to the landing gears when they are extended. ## Aircraft - Registration: [N1084J](https://openairdocs.org/deregistered/N1084J-2018-05-30), registration cancelled 2018-05-30, S/N 84, built 1973 (OpenAirDocs) - Reported make and model: ROCKWELL AC-112 - Registry model: [Aero Commander 112](https://openairdocs.org/model/aero-commander-112) (registry code 0144701) (OpenAirDocs) - Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 84 - Engines: LYCOMING IO-360 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: King, Gregory W. - Airworthiness certificate: Standard, Normal - Airport: MOD, Harry Sham Field ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 454 total, 150 in this make and model, 395 as pilot in command, 60 in the last 90 days, 12 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 6 knots - Visibility: 40 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 46 °F - Altimeter: 29.00 inHg - Observed at: MOD ## 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 19940123002149A](https://openairdocs.org/incident/19940123002149A), Jan 23, 1994: Gulstm 112, Modesto, CA, Substantial damage. During taxi to ramp gear horn sounded. Right main collapsed. Found gear wiring worn and chafed. Hydrulic interupted. 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.