# NTSB ANC99LA152: Maule ML-4, N4623T, Anchorage, AK, September 24, 1999 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 24, 1999, 13:06 local (21:06 UTC) - Place: Anchorage, AK - Coordinates: 61.159111, -149.989654 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.1591&lon=-149.9897&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report May 17, 2001 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 47539 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC99LA152 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47539/pdf - Page: https://openairdocs.org/ntsb/ANC99LA152 ## Probable cause The improper (reversed) connection of the elevator control cables by the owner/pilot-mechanic, and the failure to have the installation inspected by another mechanic. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, takeoff - roll/run - flt control syst,elevator control cable/rod - reversed (cause) - maintenance,rebuild/remanufacture - improper, owner/pilot mechanic (cause) - maintenance,inspection - not performed, other maintenance personnel (cause) - Nose over, takeoff - roll/run ## Analysis The pilot was beginning the first postmaintenance check flight after rebuilding the airplane. As the airplane began to fly off the runway, the pilot pulled aft on the yoke, and the airplane nosed over. Postaccident inspection revealed the elevator cables were connected backwards. The pilot, who is also a certificated aircraft mechanic, told the NTSB investigator-in-charge that he bought the airplane as a project and rebuilt it. He stated he hooked up the elevator cables backwards, and did not recognize the error during his inspection. He added that he did not have anyone else inspect his work. ## Factual narrative On September 24, 1999, at 1306 Alaska daylight time, a Maule ML-4 airplane, N4623T, sustained substantial damage when it nosed over during takeoff from the Lake Hood Strip, Anchorage, Alaska. The solo airline transport pilot received minor injuries. The airplane was being operated as a visual flight rules (VFR) postmaintenance check flight under Title 14, CFR Part 91, when the accident occurred. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed. According to the FAA inspector who interviewed the pilot, and inspected the airplane at the scene, the pilot was beginning the first flight after rebuilding the airplane. The pilot indicated to the inspector, that as the airplane began to fly off the runway, he pulled aft on the yoke, and the airplane nosed over. A postaccident inspection revealed the elevator cables were connected backwards. The pilot, who is also a certificated aircraft mechanic, told the NTSB investigator-in-charge (IIC) during a telephone interview on September 27, that he bought the airplane as a project, and rebuilt it. He stated that during the rebuild he hooked up the elevator cables backwards, and did not recognize the error during his inspection. He added that he did not have anyone else inspect his work. He indicated that he was beginning the takeoff on the first test flight, and as soon as he pulled aft on the yoke, the airplane nosed over. The airplane came to rest inverted, and sustained substantial damage to both wings, the vertical stabilizer, and the left wing lift-strut. ## Aircraft - Registration: [N4623T](https://openairdocs.org/aircraft/N4623T), registered now, S/N 91 (OpenAirDocs) - Reported make and model: Maule ML-4 - Registry model: [Maule M-4](https://openairdocs.org/model/maule-m-4) (registry code 5460104) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 91 - Airframe hours: 1334 - Engines: Continental O-300A 145 horsepower reciprocating - Damage: Substantial damage - Flight: Part 91 - Registered owner: Jack E. Corey - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 23, 1998, 0 hours before - Departed: Z41 - Airport: Z41, Lake Hood Strip, runway 31, 2,200 × 70 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine sea, multi-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 15,000 total, 2 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft broken - Temperature: 52 °F, dew point 34 °F - Altimeter: 29.00 inHg - Observed at: ANC, 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 19990924027829A](https://openairdocs.org/incident/19990924027829A), Sep 24, 1999: Maule M4, Anchorage, AK, Substantial damage. (.19) On September 24, 1999, at 1306 Alaska daylight time, a Maule ML-4 airplane, N4623T, sustained substantial damage when it nosed over during takeoff from… ## Other investigations on N4623T (3) 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 ANC90LA081](https://openairdocs.org/ntsb/ANC90LA081), Jun 1, 1990: Maule M4 (N4623T), L. Susitna Riv, AK, substantial damage. Probable cause: THE PILOT'S FUEL MISMANAGEMENT IN NOT HAVING SUFFICIENT FUEL TO REACH HIS DESTINATION. - [NTSB SEA83LA200](https://openairdocs.org/ntsb/SEA83LA200), Sep 3, 1983: Maule M-4 (N4623T), Monroe, WA, substantial damage - [NTSB DEN79DTE39](https://openairdocs.org/ntsb/DEN79DTE39), May 26, 1979: Maule M-4 (N4623T), Englewood, CO, substantial damage 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.