# NTSB DEN03LA076: Swearingen SA226TC, N229AM, Denver, CO, April 16, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 15, 2003, 20:41 local (Apr 16, 2003, 02:41 UTC) - Place: Denver, CO - Coordinates: 39.858333, -104.666946 - Nearby events: https://openairdocs.org/map.md?lat=39.8583&lon=-104.6669&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report November 25, 2003 - Report: Approved by Office Director - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 56897 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN03LA076 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/56897/pdf - Page: https://openairdocs.org/ntsb/DEN03LA076 ## Probable cause The failure of the landing gear system and the flight crew's failure to ascertain that the landing gear was down and locked. A contributing factor was the inadequate maintenance inspections performed by maintenance personnel. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, approach - gear extension - performed, pilot in command - landing gear,normal retraction/extension assembly (cause) - maintenance,inspection - inadequate, company maintenance personnel (contributing factor) - Wheels up landing, landing - flare/touchdown - gear down and locked - not verified, flightcrew (cause) ## Analysis The flight was following a heavy jet on landing approach. The crew agreed to fly the approach at a slightly higher altitude than normal to avoid any possible wake turbulence. The first officer, who was flying the airplane, called for the landing gear to be lowered. When the captain placed the gear handle in the DOWN position, he noted red IN-TRANSIT lights. He recycled the landing gear, but got the same result. He consulted the emergency checklist and thought he had manually extended the landing gear because he "heard the normal 'clunk feel' and airspeed started to decay." In addition, when power was reduced to FLIGHT IDLE, the GEAR UNSAFE warning horn did not sound. The first officer agreed, noting 2,000 pounds of hydraulic pressure. The airplane landed wheels up. Propeller blade fragments penetrated the fuselage, breaching the pressure vessel. Postaccident examination revealed the nose gear had been partially extended but the main landing gear was retracted. The crew said the GEAR UNSAFE indication had been a recurring problem with the airplane. The problem had previously been attributed to a frozen squat switch in the wheel well. ## Factual narrative On April 15, 2003, at 2041 mountain daylight time, a Swearingen SA226TC, N229AM, operated by Superior Aviation, Inc., of Kingsford, Michigan, as flight HKA 1813, was substantially damaged during a wheels-up landing on runway 35L at Denver International Airport, Denver, Colorado. The airline transport certificated captain and commercial certificated first officer were not injured. Visual meteorological conditions prevailed, and an IFR flight plan had been filed for the nonscheduled domestic cargo flight being conducted under Title 14 CFR Part 135. The flight originated at Gunnison, Colorado, approximately 2000. The following is based on the accident report and a written statement submitted by the captain. The flight had been radar vectored behind and was following a heavy jet for an approach to runway 35L. As a result, it was mutually agreed that the approach would be conducted at a slightly higher altitude than normal to avoid any possible wake turbulence. The first officer, who was flying the airplane, called for the landing gear to be lowered. When the captain placed the gear handle in the DOWN position, he noted red IN-TRANSIT lights and remarked to his first officer, "It's happening again. The nose is not coming down." He recycled the landing gear, but got the same result. He consulted the emergency checklist and extended the landing gear manually. He felt confident that the landing gear was down and locked because he "heard the normal 'clunk feel' and airspeed started to decay." In addition, when power was reduced to FLIGHT IDLE, the GEAR UNSAFE warning horn did not sound. He wrote, "In the past, when there was no green indication in this aircraft with the use of the emergency extension system, the gear remained down and locked." He felt the wheels contact the runway, but the airplane continued to sink and then he heard the propellers striking the pavement. The first officer's statement corroborated that of the captain's. He added, "Sometimes, the squat switch in the wheel well for the position lights freeze and are showing red when they should be green or out." Following the emergency checklist, the landing gear was manually extended and he noted 2,000 pounds of hydraulic pressure. This made him feel confident that the landing gear was down and locked. According to an FAA aviation safety inspector who examined the airplane, the nose landing gear was partially extended, but the main landing gear was not. Propeller blade fragments penetrated the fuselage and breached the pressure vessel. ## Aircraft - Registration: [N229AM](https://openairdocs.org/deregistered/N229AM-2003-07-17), registration cancelled 2003-07-17, S/N TC305, built 1979 (OpenAirDocs) - Reported make and model: Swearingen SA226TC - Registry model: [Swearingen SA226TC](https://openairdocs.org/model/swearingen-sa226tc) (registry code 8780404) (OpenAirDocs) - Registry engine: [AiResearch TPE331 series](https://openairdocs.org/engine/airesearch-tpe331-series) (registry code 01514, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: TC-305 - Airframe hours: 31643 - Engines: Garrett TPE 331-34 840 horsepower turbo prop - Damage: Substantial damage - Flight: Part 135 - Registered owner: Superior Aviation, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, April 3, 2003, 26 hours before - Departed: GUC, Gunnison, CO - Destination: DEN, Denver, CO - Flight plan: IFR - Airport: DEN, Denver International, runway 35L, 12,000 × 150 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: serious; commercial, flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; last flight review November 21, 2002; seat: left; flight hours: 4,565 total, 2,179 in this make and model, 4,244 as pilot in command, 124 in the last 90 days, 70 in the last 30 days, 3 in the last 24 hours - Co-pilot; age 39; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; last flight review January 3, 2003; seat: right; flight hours: 2,517 total, 1,400 in this make and model, 1,094 as pilot in command, 139 in the last 90 days, 4 in the last 30 days ## Weather - Conditions: Visual (VMC), Night/dark - Wind: 240° at 26 knots, gusting 31 - Visibility: 10 statute miles - Lowest ceiling: 3,000 ft broken - Temperature: 45 °F, dew point 25 °F - Altimeter: 29.54 inHg - Observed at: DEN ## 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 20030415009089A](https://openairdocs.org/incident/20030415009089A), Apr 15, 2003: Swrngn SA226TC, Denver, CO, Substantial damage. (-23) PIC landed on runway 35L with the main gear in the retracted position and the nose gear partilly extended but not locked. The investigation is ongoing at… ## Other investigations on N229AM (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 CHI96LA162](https://openairdocs.org/ntsb/CHI96LA162), May 17, 1996: Swearingen SA226TC (N229AM), Fargo, ND, substantial damage. Probable cause: the flight crew did not comply with the gear down and lock checklist. The factors were a jammed nose gear and inattentive preflight planning/preparations by the pilot-in-command. 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.