- Date
- April 8, 1986, 13:19 local (19:19 UTC)
- Place
- Chicago, IL
- Injuries
- 1 minor, 113 uninjured
- Damage
- Substantial damage
- Phase of flight
- Landing
- Aircraft
- N9054UBoeing 737-222
- Weather
- Visual (VMC) · Day
- Status
- Completed · report January 25, 1988
- Report
- Approved by Office Director
- Case key
- 13252
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
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.
Analysis
The left main landing gear collapsed moments after touchdown. Winds as reported by the twr were from 350 degs at 19 KTS gusting to 29 KTS. The captain and copilot reported the touchdown was normal. The 3 flight attendants said the aircraft landed hard and started shaking very badly. The flight attendants also reported that the previous 2 landings had brought a great deal of vibrating/shaking to the aircraft. The left main landing gear tee bolt was found separated. Metallurgical examination of the tee bolt showed the fracture emanated from a shallow preexisting crack in the drag brace bearing surface radius that the metallurgist found to be sharper than desired. The collapse of the landing gear is considered related to the fractured tee bolt. The safety board is unable to determine whether other events, circumstances or conditions were present that contributed to the tee bolt failure in this instance. The operator has amended their repair specifications for the tee bolts.
Aircraft
- Registration
- N9054U
- Reported as
- Boeing 737-222
- Category
- Airplane
- Serial number
- 19935
- Airframe hours
- 32,714
- Engine
- P&W JT8D-9, 14,500 lbs thrust, turbo jet
- Damage
- Substantial damage
- Fire
- On-Ground
- Flight
- Part 121
- Operator
- United Airlines
- Registered owner
- United Airlines
- Airworthiness certificate
- Standard, Transport
- Departed
- OMA · Omaha, NE
- Flight plan
- IFR
- Airport
- ORD · Chicago-O'Hare Int'L, runway 27R, 7,416 × 150 ft, asphalt
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
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 53
- Certificate
- Airline transport
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--w/ waivers/lim
- Seat
- Left
- Flight hours
- 11,400 total
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 300° at 15 knots
- Visibility
- 15 statute miles
- Lowest ceiling
- 3,500 ft broken
- Temperature
- 54 °F, dew point 28 °F
- Altimeter
- 29.00 inHg
- Observed at
- ORD