SEA06CA080

NTSB accident investigation · Pitrolo GL-25 · Worden, MT · April 21, 2006

Accident · No injuriesData collectionFinal report
Date
April 21, 2006, 16:30 local (22:30 UTC)
Place
Worden, MT
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N27EPPitrolo GL-25
Weather
Visual (VMC) · Day
Status
Completed · report August 29, 2006
Report
Approved by Office Director
FAA report
20060421004579A
Case key
63564

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 NTSB’s determination of the probable cause, and any contributing factors.

The loss of engine power due to failure of both electronic ignition systems. A contributing factor was the lack of suitable terrain for the forced landing.

Analysis

According to the pilot, the purpose of the flight was to "check out and become familiar with a recent instrument panel upgrade performed by the local avionics shop during the past several months." After about 90 minutes of flight time, the new digital horizon indicator "had an over temperature warning," which the pilot later found was set to warn when the "local environment (behind the instrument panel)" temperature reached 120 degrees F. Within a few minutes, the engine lost power. The pilot noted that the two 5-amp circuit breakers for the two electronic ignition systems had popped and could not be reset. During the ensuing forced landing in a wheat field, the main landing gear sank into the soft ground and the "landing gear sheared off." Examination by the pilot and avionics shop personnel revealed a "dead short in each electronic ignition module." These modules were installed on the cabin side of the firewall as per the manufacturer's recommendation. The reason for the short circuits in the modules could not be determined; however, the pilot suspected "a heat related issue."

Factual narrative

On April 21, 2006, about 1630 mountain daylight time, a Pitrolo GL-25 amateur built experimental airplane, N27EP, sustained substantial damage during a forced landing following a loss of engine power near Worden, Montana. The commercial pilot, the sole occupant, was not injured. The airplane was registered to and operated by the pilot. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight conducted under 14 CFR Part 91. The flight departed from Billings Logan International Airport, Billings, Montana, about 1500.

According to the pilot, the purpose of the flight was to "check out and become familiar with a recent instrument panel upgrade performed by the local avionics shop during the past several months." After about 90 minutes of flight time, the new digital horizon indicator "had an over temperature warning," which the pilot later found was set to warn when the "local environment (behind the instrument panel)" temperature reached 120 degrees F. Within a few minutes, the engine lost power. The pilot noted that the two 5-amp circuit breakers for the two electronic ignition systems had popped and could not be reset. During the ensuing forced landing in a wheat field, the main landing gear sank into the soft ground and the "landing gear sheared off."

Examination by the pilot and avionics shop personnel revealed a "dead short in each electronic ignition module." These modules were installed on the cabin side of the firewall as per the manufacturer's recommendation. The reason for the short circuits in the modules could not be determined; however, the pilot suspected "a heat related issue."

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.

Loss of engine power(total) - mech failure/malfCruise
Ignition system - failure,totalCause
Forced landingEmergency descent/landing
On ground/water encounter with terrain/waterEmergency landing
Terrain condition - soft
Terrain condition - none suitableFactor

Aircraft

Registration
N27EP
Reported as
Pitrolo GL-25
Category
Airplane, amateur-built
Serial number
3027
Engine
Lycoming IO-540, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Departed
BIL · Billings, MT

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
50
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2
Flight hours
1,500 total · 830 in this make and model · 6 in the last 90 days · 4 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.