Boeing 737-300 N12318

Summary

On 17 March 1989 at about 20:00 local time, a Boeing 737-300 registered N12318 was involved in an accident near Oakland, California, United States. 69 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

17 March 1989 at 20:00

Classification

Accident

Location

Oakland, California, United States

Nearest airport

Oakland Intl (OAK)

Coordinates

Not recorded

Aircraft

Boeing 737-300

Registration

N12318

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Denver

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

DCA89MA034

Nobody was injured.

IGNITION OF PUDDLED FUEL FROM A BLOCKED COMBUSTOR DRAIN LINE, AND A SLOW START DURING WHICH FUEL WAS MISTED AND BLOWN OUT THE TAIL PIPE. AN EXISTING TAILWIND AT THE GATE ALLOWED THE FUEL TO WET THE TAIL SURFACES AND BE IGNITED DURING THE APU START. THE OPERATOR CONFIRMED USING RTV MATERIAL IN THE APU BUILDUP PROCESS AT THEIR FACILITY.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

THE CREW WAS NOT AWARE AN APU FIRE HAD OCCURRED AT THE GATE PRIOR TO STARTING THE MAIN ENGINES. AFTER DEPARTURE THE AIRPLANE EXPERIENCED SEVERE VIBRATIONS; AN EMERGENCY WAS DECLARED, AND THE FLIGHT LANDED WITHOUT INCIDENT. ABOUT 1/2 OF THE UNDERSIDE OF THE ELEVATOR & TRIM TAB WERE SEVERELY FIRE DAMAGED. THE TAIL CONE WAS CHARRED & BLISTERED OVER A 3 FT BY 3 FT AREA. FOUR GROUND SERVICE PERSONNEL HANDLED THE AIRCRAFT DURING PUSHBACK. THE APU COMBUSTOR CAP DRAIN LINE WAS FOUND CLOGGED WITH SEVERAL PIECES OF ROOM TEMPERATURE VULCANIZING (RTV) MATERIAL (POTTING COMPOUND) USED IN THE APU BUILDUP PROCESS. THE APU MANUFACTURER'S OVERHAUL MANUAL CAUTIONS OPERATORS TO USE RTV SPARINGLY, AND TO REMOVE ANY EXCESS PRIOR TO INSTALLING EXHAUST PIPE SHIMS TO PREVENT PLUGGED FUEL DRAIN FITTINGS AND TORCHING STARTS. IN ADDITION, THE ATOMIZER ASSEMBLY SHOWED STREAKING IN THE PRIMARY ORIFICES, AND EXAMINATION OF THE OIL PUMP REVEALED SLOW SEQUENCING (IGNITION AND FUEL INITIATION).

Quoted verbatim from the NTSB record.