# NTSB FTW98LA060: Piper PA-24-250, N6661P, Lubbock, TX, December 1, 1997 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: November 30, 1997, 18:42 local (Dec 1, 1997, 00:42 UTC) - Place: Lubbock, TX - Coordinates: 33.590793, -101.850303 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.5908&lon=-101.8503&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report November 6, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 20492 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA060 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20492/pdf - Page: https://openairdocs.org/ntsb/FTW98LA060 ## Probable cause The inadequate maintenance of the landing gear assembly by maintenance personnel resulting in a partial gear extension, and the pilot's misjudgment of a proper touchdown point to intentionally shut down the engine resulting in the airplane landing short of the runway. A factor was the soft terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, approach - landing gear,normal retraction/extension assembly - binding(mechanical) (cause) - maintenance,annual inspection - inadequate, other maintenance personnel (cause) - Main gear collapsed, emergency descent/landing - terrain condition - soft (contributing factor) - engine shutdown - intentional, pilot in command - proper touchdown point - misjudged, pilot in command (cause) ## Analysis During the initial takeoff departure climb, the gear would not retract and the pilot returned to the airport where a mechanic examined the gear, serviced the struts, and performed a retraction test (gear were extended and retracted 3 consecutive times). Subsequently, the flight departed on the cross country flight with a planned refueling stop. During the approach, the gear would not extend. The pilot maneuvered in the area and performed the emergency gear extension procedures; however, the gear would not go beyond 1/2 extension. During the final approach to the runway, the pilot shut down the engine and the airplane landed short of the runway. The FAA inspector and a mechanic found that the 'slide tubes on the main gear had accumulated a lot of dirt causing some binding on their normal operation. This binding consistently caused the gear electric motor circuit breaker to pop.' The gear could be extended manually by the FAA inspector and the mechanic. Flight time since the last annual inspection was 57 hours. ## Factual narrative On November 30, 1997, at 1842 central standard time, a Piper PA-24-250, N6661P, owned and operated by a private individual under Title 14 CFR Part 91, the gear collapsed while landing short of runway 35L at the Lubbock International Airport, Lubbock, Texas. The commercial pilot and the passenger received minor injuries, and the airplane sustained substantial damage. The airplane, operating on an IFR flight plan, encountered visual meteorological conditions prior to the accident. The flight departed San Antonio, Texas, at 1215. During a personal interview, conducted by the investigator-in-charge, and on the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot reported that during the initial climb from San Antonio, the gear would not retract. He returned to the airport where a mechanic examined the gear, serviced the struts, and performed a retraction test (gear was extended and retracted 3 consecutive times). Subsequently, the flight departed San Antonio for Colorado Springs, Colorado. En route the flight encountered headwinds and the pilot decided to make a refueling stop at Lubbock. During the approach at Lubbock, the landing gear would not extend. The pilot maneuvered in the area and performed the emergency gear extension procedures for 2 hours trying to get the gear extended; however, it would not go beyond 1/2 extension. During the final approach to runway 35L, the pilot shut down the engine to try to save the propeller. The airplane landed short of the runway in soft terrain. The FAA inspector and a mechanic examined the airplane at Lubbock. Structural damage occurred to the firewall, engine mounts, and fuselage. The mechanic, a previous owner of a PA-24-250 airplane, has over 20 years of maintenance experience working on equivalent equipment. The mechanic found that the "slide tubes on both the main gear had accumulated a lot of dirt causing some binding on their normal operation. This binding consistently caused the gear electric motor circuit breaker to pop." The gear could be extended manually by the FAA inspector and the mechanic. A review of the maintenance records by the FAA inspector revealed that the last annual inspection was completed on April 30, 1997. Flight time since the annual inspection was 57 hours. ## Aircraft - Registration: [N6661P](https://openairdocs.org/deregistered/N6661P-2013-04-12), registration cancelled 2013-04-12, S/N 24-1784, built 1960 (OpenAirDocs) - Reported make and model: Piper PA-24-250 - Registry model: [Piper PA-24-250](https://openairdocs.org/model/piper-pa-24-250) (registry code 7102404) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-1784 - Airframe hours: 5151 - Engines: Lycoming O-540-A1C5 250 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Robert L. Zimmerman - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 30, 1997, 57 hours before - Departed: SAT, SAN ANTONIO, TX - Destination: LBB - Flight plan: IFR - Airport: LBB, Lubbock International, runway 35L, 11,500 × 150 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 79; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 3,865 total, 3,862 in this make and model, 3,830 as pilot in command, 50 in the last 90 days, 11 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 46 °F, dew point 43 °F - Altimeter: 29.00 inHg - Observed at: LBB ## 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 19971130035869A](https://openairdocs.org/incident/19971130035869A), Nov 30, 1997: Piper PA24250, Lubbock, TX, Substantial damage. Acft landing gear would not extend, and acft landed short of the rwy. Lubbock, TX. (.4)during the initial takeoff departure climb, the gear would not retract… ## Other investigations on N6661P (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 CEN13CA005](https://openairdocs.org/ntsb/CEN13CA005), Oct 5, 2012: Piper PA-24-250 (N6661P), Colorado Springs, CO, substantial damage. Probable cause: The pilot’s failure to maintain airspeed during the landing with known structural icing, which resulted in the airplane’s stall. Contributing to the accident was the pilot’s failure to divert to an… 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.