# NTSB CHI94LA087: Piper PA-44-180, N190ND, Grand Forks, ND, February 13, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 13, 1994, 14:33 local (20:33 UTC) - Place: Grand Forks, ND - Coordinates: 47.909843, -97.069419 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.9098&lon=-97.0694&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report November 14, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 9469 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA087 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9469/pdf - Page: https://openairdocs.org/ntsb/CHI94LA087 ## Probable cause the improper maintenance installation (cotter pin) by other maintenance personnel. Factors were main landing gear scissors not safetied properly and extension of landing gear not possible by pilot-in-command (CFI). ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Gear collapsed, landing - flare/touchdown - landing gear,main gear strut scissors - not safetied (contributing factor) - maintenance,installation - improper, other maintenance personnel (cause) - gear extension - not possible, pilot in command(cfi) (contributing factor) ## Analysis WHEN THE LANDING GEAR WAS EXTENDED FOR LANDING, THE RIGHT MAIN LANDING GEAR LIGHT BEGAN FLASHING AND AN UNSAFE GEAR WARNING WAS RECEIVED. SEVERAL ATTEMPTS WERE MADE TO ASSURE THE LANDING GEAR WAS EXTENDED INCLUDING REPEATED ATTEMPTS AT NORMAL AND EMERGENCY GEAR EXTENSION. UPON LANDING THE RIGHT MAIN GEAR COLLAPSED. SUBSEQUENT EXAMINATION REVEALED THAT A COTTER PIN ON THE RIGHT MAIN LANDING GEAR SCISSORS HAD BEEN OPEN AND CAUGHT A WIRING BUNDLE IN THE WHEEL WELL WHICH PREVENTED THE DOWN LOCK FROM ENGAGING. ## Factual narrative On February 13, 1994, at 1433 central standard time, a Piper PA- 44-180, N190ND, registered to University of North Dakota, and operated by a flight instructor and student, experienced a collapse of the right main landing gear on touchdown at the Grand Forks International Airport, Grand Forks, North Dakota. The airplane sustained substantial damage. The occupants reported no injuries. The 14 CFR Part 91 flight was operating in visual meteorological conditions. No flight plan was on file. The local instructional flight departed Grand Forks, North Dakota, at 1345. The instructor pilot stated that when the landing gear was extended the right main landing gear light began flashing and an unsafe gear warning light was illuminated. Several attempts were made to assure that the landing gear was extended including repeated attempts at normal and emergency gear extension. Maintenance personnel were contacted by radio in an attempt to alleviate the problem. A low pass was made over the airport to attempt to determine if the gear appeared to be extended. The tower reported that the gear appeared to be down. Upon landing the right main landing gear collapsed. A subsequent examination revealed that a cotter pin on the right main landing gear scissors was open and caught a wiring bundle in the wheel well which prevented the down lock from engaging. ## Aircraft - Registration: [N190ND](https://openairdocs.org/deregistered/N190ND-2019-11-01), registration cancelled 2019-11-01, S/N 4495002, built 1989 (OpenAirDocs) - Reported make and model: PIPER PA-44-180 - Registry model: [Piper PA-44-180](https://openairdocs.org/model/piper-pa-44-180) (registry code 7104402) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 4495002 - Airframe hours: 2351 - Engines: LYCOMING O-360-A1H6 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: University Of North Dakota - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, February 7, 1994, 17 hours before - Airport: GFK, Grand Forks Intl., runway 17L, 3,900 × 75 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 24; commercial; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: right; flight hours: 1,417 total, 120 in this make and model, 1,251 as pilot in command, 106 in the last 90 days, 70 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 14 knots - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft overcast - Temperature: 7 °F, dew point 1 °F - Altimeter: 27.00 inHg - Observed at: GFK, 1 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 19940213001999A](https://openairdocs.org/incident/19940213001999A), Feb 13, 1994: Piper PA44180, Grand Forks, ND, Substantial damage. Unsafe right gear on extension unable positive lock. Gear collapsed landing. Cotter pin on scissors caught wires. ## Other investigations on N190ND (1) 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. - [NTSB GAA16CA377](https://openairdocs.org/ntsb/GAA16CA377), Jul 7, 2016: Piper PA 44 (N190ND), Keene, NH, substantial damage. Probable cause: The flight instructor’s failure to use carburetor heat during the approach while operating in atmospheric conditions that were conducive to carburetor icing, which resulted in a loss of engine power… 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.