NTSB CAROL · Event
Event DEN03LA076
Registry · N229AM
FAA Aircraft Registry record.
Make / Model
BELL HELICOPTER TEXTRON CANADA 407
Year of manufacture
2011
TCDS
H2SW · BELL HELICOPTER TEXTRON CANADA LTD
Engine
ROLLS-ROYC 250-C47B (650 hp)
Seats / Engines
8 seats · 1 engine
Last airworthiness date
20110711
ADS-B equipped
Yes — Mode-S A2027C
Registrant of record
FIRST CITIZENS BANK & TRUST CO
Source: FAA Aircraft Registry (releasable master file).
Aircraft involved
Probable cause & findings
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.
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. 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. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_2003_DEN03LA076.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
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Related research
What the literature says.
Academic papers and agency reports matching this event's aircraft type or causal vocabulary (wake turbulence, turbulence, maintenance). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
- NASA NTRS 2019 · Conference Paper
Aircraft wake turbulence minimization by aerodynamic means
The paper reviews NASA's efforts on wake vortex turbulence minimization by aerodynamic design or retrofit modifications to large transport aircraft.
- NASA NTRS 2019 · Conference Paper
Wake Turbulence Mitigation for Arrivals (WTMA)
The preliminary Wake Turbulence Mitigation for Arrivals (WTMA) concept of operations is described in this paper. The WTMA concept provides further detail to work initiated by the Wake Vortex Avoidance…
- NASA NTRS 2019 · Conference Paper
Aircraft wake turbulence avoidance
Aircraft wake turbulence /trailing vortex systems/ avoidance during flight, describing procedures for pilots and tower operators
- NASA NTRS 2019 · Conference Paper
Aircraft wake turbulence progress and plans
Aircraft wake turbulence and trailing vortices, investigating physical characteristics, hazard potential and avoidance techniques
- Embry-Riddle Scholarly Commons 2025 · Journal article (JAAER)
Political Turbulence and Aviation Safety: A Cross-National Analysis of Political Stability's Effects on Aviation Accidents
To what extent does political stability affect aviation safety? This research aims to link domestic political conditions and public safety through the consideration of aviation accident frequency.
- SKYbrary (Eurocontrol) 2023 · SKYbrary article
Wake Vortex Turbulence — SKYbrary Knowledge Base
SKYbrary wake vortex turbulence comprehensive article — generation mechanics, dissipation factors, separation standards (ICAO LIGHT/MEDIUM/HEAVY/SUPER + recategorisation RECAT-EU).
Browse the full corpus — academia portal ↗