ATL97LA078

NTSB accident investigation · Piper PA-31-350 · Sparta, TN · May 20, 1997

Accident · No injuriesLimited investigationFinal report
Date
May 20, 1997, 14:15 local (19:15 UTC)
Place
Sparta, TN
Injuries
6 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N4105QPiper PA-31-350
Weather
Visual (VMC) · Day
Status
Completed · report September 5, 1997
Report
Approved by Office Director
Case key
3852

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

A fire in the left engine started by a leak in the fuel pump.

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.

FireCruise - normal
Fuel system,pump - leakCause
Miscellaneous,engine - fire

Analysis

The airplane experienced an in-flight fire in the left engine that was first noticed by the pilot upon touchdown in Sparta, Tennessee. The pilot and his five passengers safely evacuated the airplane, and then used a hand-held fire extinguisher to put out the fire. The airplane incurred substantial damage to the left engine, including a buckled firewall, melted fuel lines, and separated throttle and propeller cables. Further examination of the engine revealed that the fuel pump had a leak, possibly precipitated by faulty gasket material, which allowed the fuel to ignite when in contact with the heated engine. A Service Bulletin has been released by the pump manufacturer urging close inspection of the attaching screws.

Factual narrative

On May 20, 1997, around 1415 central daylight time, a Piper PA-31-350, N4105Q, experienced an in-flight fire in the left engine which was first noticed by the pilot upon touchdown into Sparta, Tennessee. The airplane was operated by the pilot on a personal flight under the provisions of Title 14 CFR Part 91. The prevailing weather was visual meteorological conditions and an instrument flight plan was filed. The airplane sustained substantial damage. The commercial pilot and his five passengers were uninjured. The flight originated in Sarasota, Florida at 1215 eastern daylight time and was destined for Huntingburg, Indiana.

During cruise, the pilot noted higher than normal fuel consumption on the left engine which prompted him to divert to Sparta. The pilot stated he made a normal landing. On the landing roll-out, he noticed the left engine compartment was on fire and stopped the airplane. He evacuated the airplane, and extinguished the fire using a hand-held fire extinguisher.

Subsequently, an airworthiness inspector from the Nashville FSDO examined the airplane. He noted extensive damage, including melted fuel lines, throttle and propeller cables separated with concurrent evidence of heat damage, and a buckled firewall.

Representatives from Textron Lycoming, the engine manufacturer, and Lear Romec, the fuel pump manufacturer, were involved in the subsequent examination of the engine. It was determined, after pressurizing the fuel pump, that there was a leak in the fuel pump precipitated by a possible problem with the gasket material. The screws around the gasket loosened, allowing the leak to start. This leak allowed fuel to have contact with the heated engine, and it provided the fuel for the in-flight fire.

The fuel pump, part number RG9080J7A, was overhauled by D & G Fuel Supply in April. This overhaul shop was an approved facility which used the Lear Romec overhaul manual. Their last FAA audit was in March of 1997. There were no reports of problems with this facility. As per the overhaul manual, the torque on the fuel pump attaching screws was set, and then the pump was pressurized to 60 pounds per square inch (psi) to determine if there were any leaks. At this time, no leaks were noted.

Currently, the fuel pump manufacturer, Lear Romec, has released a Service Bulletin, number 101SB020, which recommends inspections of the torque on the attaching screws every 50 hours or 6 months, whichever comes first. According to an engineer from Lear Romec, this measure is a safety precaution to prevent further in-flight fires while the company attempts to determine the reason the screws are loosening.

Aircraft

Registration
N4105Q
Reported as
Piper PA-31-350
Category
Airplane
Serial number
31-8252029
Airframe hours
3,277
Engine
Lycoming TIO-540-52BD, 350 horsepower, reciprocating
Damage
Substantial damage
Fire
In-Flight
Flight
Personal · Part 91
Operator
Brad Mulzer
Registered owner
Mulzer Crushed Stone
Airworthiness certificate
Standard, Normal
Last inspection
Annual · January 7, 1997 · 30 hours before
Departed
SRQ · Sarasota, FL
Destination
HNB · Huntingburg, IN
Flight plan
IFR
Airport
SRB · Upper Cumberland Regional, runway 4, 5,003 × 75 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
32
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 3, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
2,353 total · 845 in this make and model · 2,184 as pilot in command · 49 in the last 90 days · 17 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
300° at 7 knots
Visibility
10 statute miles
Lowest ceiling
2,800 ft broken
Temperature
66 °F, dew point 54 °F
Altimeter
30.00 inHg
Observed at
CSV, 20 nm away