- Date
- June 22, 1987, 20:39 local (Jun 23, 1987, 03:39 UTC)
- Place
- Los Angeles, CA
- Injuries
- 83 uninjured
- Phase of flight
- Standing
- Weather
- Day
- Status
- Completed · report November 28, 1989
- Report
- Approved by Office Director
- FAA reports
- 19870622055262A19870622055261A
- Case key
- 25616
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
Failure of the qualified mechanic to insure the operation of the aircraft brakes prior to taxiing and his failure to utilize the emergency brake system to prevent the collision. Contributing to this accident was the decision of airline maintence supervisors to allow a non qualified mechanic to perform right seat/flight engineer panel duties. Also contributing was the qualified mechanics failure to use the aircraft's inertial navigation system for cross reference to taxi speed.
Failure of the qualified mechanic to insure the operation of the aircraft brakes prior to taxiing and his failure to utilize the emergeny brake system to prevent the collision. Contributing to this accident was the decision of airline maintenance supervisors to allow a non-qualified mechanic to perform right seat/flight engineer panel duties. Also contributing was the qualified mechanics failure to use the aircraft's inertial navigation system for cross reference of taxi speed.
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
A Boeing 747SP collided with the tail of a Boeing 737. The 737 was lined up on a parallel taxiway awaiting departure. The 747 was taxiing from a terminal gate to maintenance. The 747 was being operated by two mechanics. One of the mechanics was not qualified to taxi the 747. No. 4 eng hung start and was not running during taxi. The no. 4 eng hyd sys was switched off. The no. 4 hyd sys is the primary power for the acft brake sys. The 747'S inertial nav sys (ins) is required to operate while taxiing for speed reference. The ins was also switched off. The 747 speed became excessive on parallel taxiway. When mech attempted to stop there was no brake power. He did not activate the emer brake sys powered by no. 2 eng hyd sys. The mech swerved the 747 to the left. The 747 r wing collided with tail of 737. The airline maint supervisor of 747'S was aware of mech non-qual and of the no. 4 eng not operating. Decision was made to let the acft taxi contrary to procedures.
A Boeing 747SP collided with the tail of a Boeing 737. The 737 was lined up on a parallel taxiway awaiting departure. The 747 was taxiing from a terminal gate to maintenance. The 747 was being operated by two mechanics. One of the mechanics was not qualified to taxi the 747. No. 4 eng hung start and was not running during taxi. The no. 4 eng hyd sys was switched off. The no. 4 hyd sys is the primary power for the acft brake sys. The 747'S inertial nav sys (ins) is required to operate while taxiing for speed reference. The ins was also switched off. The 747 speed became excessive on parallel taxiway. When mech attempted to stop there was no brake power. 747 r wing collided with tail of 737. The airline maint supervisor of 747'S was aware of the mech non-qual and the no. 4 eng not operating. Decision was made to let the acft taxi contrary to procedures.
Aircraft · 2
- Registration
- N184AW
- Reported as
- Boeing 737-277
- Category
- Airplane
- Serial number
- 22651
- Airframe hours
- 13,290
- Engine
- P&W JT8D-15, 20,550 lbs thrust, turbo fan
- Damage
- Substantial damage
- Flight
- Part 121
- Operator
- America West Airlines
- Registered owner
- America West Airlines
- Airworthiness certificate
- Standard, Transport
- Destination
- PHX · Phoenix, AZ
- Flight plan
- IFR
- Airport
- LAX · Los Angeles Int'L
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.
- Registration
- N141UA
- Reported as
- Boeing 747SP
- Category
- Airplane
- Serial number
- 21023
- Airframe hours
- 52,233
- Engine
- P&W JT9D-7, 40,000 lbs thrust, turbo fan
- Damage
- Substantial damage
- Flight
- Part 121
- Operator
- United Airlines, doing business as United Airlines
- Registered owner
- First Security Bank Of Utah
- Airworthiness certificate
- Standard, Transport
- Airport
- LAX · Los Angeles Int'L
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, aircraft N184AW
- Age
- 31
- Certificates
- Commercial, Airline transport, Flight instructor
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--no waivers/lim.
- Seat
- Left
- Flight hours
- 6,271 total · 1,320 in this make and model · 266 in the last 90 days
- Role
- Pilot, aircraft N141UA
- Age
- 46
- Medical
- Unknown
- Seat
- Left
Weather
- Conditions
- Day
- Wind
- 250° at 8 knots
- Visibility
- 8 statute miles
- Temperature
- 64 °F, dew point 63 °F
- Altimeter
- 29.00 inHg
- Observed at
- LAX
FAA reports on this event · 2
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.