Broomfield - Broomfield

The airplane was maneuvering to deliver fire retardant when its left wing separated. Aircraft control was lost and the airplane crashed into mountainous terrain. A witness on the ground took a series of photographs that showed the air tanker's left wing separating at the wing root and the remaining airplane entering a 45-degree dive to the ground in a counterclockwise roll. An examination of the airplane wreckage revealed extensive areas of preexisting fatigue in the left wing's forward spar lower spar cap, the adjacent spar web, and the adjacent area of the lower wing skin. The portion of the wing containing the fatigue crack was obscured by the retardant tanks and would not have been detectable by an exterior visual inspection. An examination of two other air tankers of the same make and model revealed the area where the failure occurred on the accident airplane was in a location masked by the airplane's fuselage construction. The airplane was manufactured in 1945 and was in military service until 1956. It was not designed with the intention of operating as a firefighting airplane. In 1958, the airplane was converted to civilian use as an airtanker and served in that capacity until the time of the accident. The investigation revealed that the owner developed service and inspection procedures for the airtanker; however, the information contained in the procedures did not adequately describe where and how to inspect for critical fatigue cracks. The procedures were based on U.S Navy PB4Y-2 airplane structural repair manuals that had not been revised since 1948.

Flight / Schedule

Broomfield - Broomfield

Registration

N7620C

MSN

66260

Year of Manufacture

1944

Date

July 18, 2002 at 06:40 PM

Type

CRASH

Flight Type

Fire fighting

Flight Phase

Flight

Crash Site

Mountains

Crash Location

Estes Park Colorado

Region

North America • United States of America

Coordinates

40.3364°, -105.5311°

Crash Cause

Human factor

Narrative Report

On July 18, 2002 at 06:40 PM, Broomfield - Broomfield experienced a crash involving Consolidated PB4Y-2 Privateer, operated by Hawkins %26 Powers Aviation, with the event recorded near Estes Park Colorado.

The flight was categorized as fire fighting and the reported phase was flight at a mountains crash site.

2 people were known to be on board, 2 fatalities were recorded, 0 survivors were identified or estimated. This corresponds to an estimated fatality rate of 100.0%.

Crew on board: 2, crew fatalities: 2, passengers on board: 0, passenger fatalities: 0, other fatalities: 0.

The listed crash cause is human factor. The airplane was maneuvering to deliver fire retardant when its left wing separated. Aircraft control was lost and the airplane crashed into mountainous terrain. A witness on the ground took a series of photographs that showed the air tanker's left wing separating at the wing root and the remaining airplane entering a 45-degree dive to the ground in a counterclockwise roll. An examination of the airplane wreckage revealed extensive areas of preexisting fatigue in the left wing's forward spar lower spar cap, the adjacent spar web, and the adjacent area of the lower wing skin. The portion of the wing containing the fatigue crack was obscured by the retardant tanks and would not have been detectable by an exterior visual inspection. An examination of two other air tankers of the same make and model revealed the area where the failure occurred on the accident airplane was in a location masked by the airplane's fuselage construction. The airplane was manufactured in 1945 and was in military service until 1956. It was not designed with the intention of operating as a firefighting airplane. In 1958, the airplane was converted to civilian use as an airtanker and served in that capacity until the time of the accident. The investigation revealed that the owner developed service and inspection procedures for the airtanker; however, the information contained in the procedures did not adequately describe where and how to inspect for critical fatigue cracks. The procedures were based on U.S Navy PB4Y-2 airplane structural repair manuals that had not been revised since 1948.

Aircraft reference details include registration N7620C, MSN 66260, year of manufacture 1944.

Geospatial coordinates for this crash are approximately 40.3364°, -105.5311°.

Fatalities

Total

2

Crew

2

Passengers

0

Other

0

Crash Summary

The airplane was maneuvering to deliver fire retardant when its left wing separated. Aircraft control was lost and the airplane crashed into mountainous terrain. A witness on the ground took a series of photographs that showed the air tanker's left wing separating at the wing root and the remaining airplane entering a 45-degree dive to the ground in a counterclockwise roll. An examination of the airplane wreckage revealed extensive areas of preexisting fatigue in the left wing's forward spar lower spar cap, the adjacent spar web, and the adjacent area of the lower wing skin. The portion of the wing containing the fatigue crack was obscured by the retardant tanks and would not have been detectable by an exterior visual inspection. An examination of two other air tankers of the same make and model revealed the area where the failure occurred on the accident airplane was in a location masked by the airplane's fuselage construction. The airplane was manufactured in 1945 and was in military service until 1956. It was not designed with the intention of operating as a firefighting airplane. In 1958, the airplane was converted to civilian use as an airtanker and served in that capacity until the time of the accident. The investigation revealed that the owner developed service and inspection procedures for the airtanker; however, the information contained in the procedures did not adequately describe where and how to inspect for critical fatigue cracks. The procedures were based on U.S Navy PB4Y-2 airplane structural repair manuals that had not been revised since 1948.

Cause: Human factor

Occupants & Outcome

Crew On Board

2

Passengers On Board

0

Estimated Survivors

0

Fatality Rate

100.0%

Known people on board: 2

Operational Details

Schedule / Flight

Broomfield - Broomfield

Flight Type

Fire fighting

Flight Phase

Flight

Crash Site

Mountains

Region / Country

North America • United States of America

Aircraft Details

Registration

N7620C

MSN

66260

Year of Manufacture

1944