DEN03LA076

NTSB accident investigation · Swearingen SA226TC · Denver, CO · April 16, 2003

Accident · No injuriesLimited investigationFinal report
Date
April 15, 2003, 20:41 local (Apr 16, 2003, 02:41 UTC)
Place
Denver, CO
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N229AMSwearingen SA226TC
Weather
Visual (VMC) · Night/dark
Status
Completed · report November 25, 2003
Report
Approved by Office Director
Parties
FAA Flight Standards District Office
FAA report
20030415009089A
Case key
56897

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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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

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Airframe/component/system failure/malfunctionApproach
Gear extension - performedPilot in command
Landing gear,normal retraction/extension assemblyCause
Maintenance,inspection - inadequateCompany maintenance personnelFactor
Wheels up landingLanding - flare/touchdown
Gear down and locked - not verifiedFlightcrewCause

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 Postaccident examination revealed the nose gear had been partially extended but the main landing gear was retracted.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
Reported as
Swearingen SA226TC
Category
Airplane
Serial number
TC-305
Airframe hours
31,643
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
39
Injuries
Serious
Certificates
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
Role
Co-pilot
Age
39
Injuries
None
Certificate
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.

Other investigations on N229AM · 1

Matched to the same aircraft by N-number and date.