Three dead after Large Air Tanker crashes while fighting bushfires in southern NSW

[Dennis Donovan]

9. Coulson Group is the largest aerial firebomber company - they operate 2 Martin Mars aircraft

https://www.coulsonaviationusa.com/fleet

for the crew.

This reminded me of a video of another C-130 firefighting aircraft that had major structural failure around the wing box (center section of fuselage where the wings connect) back in 2002:

https://en.wikipedia.org/wiki/2002_United_States_airtanker_crashes#C-130A,_Walker,_California

N130HP crash scene from NTSB report

Lockheed C-130A Hercules registration N130HP, call sign Tanker 130, was flying against the Cannon Fire, near Walker, California on June 17, 2002, when it experienced structural failure of the center wing section, causing both wings to fold upward and separate from the aircraft. The fuselage rolled and crashed inverted, killing the three crewmen on board. Unusually, the aircraft was being filmed during the retardant drop and at the moment the wings separated, providing valuable evidence for the subsequent investigation by the National Transportation Safety Board (NTSB).

Tanker 130 had departed the Minden, Nevada air attack base at 2:29 p.m. PDT loaded with 3,000 US gallons (11,000 L) of fire retardant for its sixth drop of the day with a pilot, copilot and flight engineer on board, and arrived at the fire at 2:45 p.m. The aircraft made an initial spotting pass over the drop zone, then flew back for the drop, which was to dispense half of the load of retardant. The drop run required the aircraft to make a perpendicular crossing of a ridgeline and then descend into a valley. A video of the accident shows the aircraft crossing the ridge and then pitching down to begin its drop of the retardant. Near the end of the drop, the nose of the aircraft began to pitch up to level attitude as the descent was arrested. The nose continued to pitch up past level attitude, and at the end of the drop, the right wing began to fold upwards, followed less than one second later by the left wing. Two debris fields were found, one 500 feet (150 m) in length and the other 720 feet (220 m) in length. A post-impact fire in the first debris field consumed major portions of the wing and engine components; there was no fire in the second debris field, which included the fuselage and empennage.

The aircraft, previously United States Air Force (USAF) Serial Number 56-0538, was one of the original C-130A production series and had been built and delivered to the USAF in 1957. It was retired from military service in 1986. In May 1988, the aircraft was acquired from the General Services Administration by the USFS, which in August that year sold it and five other C-130s it had acquired to Hemet Valley Flying Service, for conversion to an airtanker. Hemet then sold the C-130 to Hawkins & Powers. At the time of the crash, the aircraft had logged 21,863 flight hours.

The NTSB investigated the crash and determined that the accident was caused by a structural failure that occurred at the wing-to-fuselage attach point, with the right wing failing just before the left. The investigation disclosed "evidence of fatigue cracks in the right wing's lower surface skin panel, with origins beneath the forward doubler. The origin points were determined to be in rivet holes which join the external doubler and the internal stringers to the lower skin panel. These cracks, which grew together to about a 12-inch (30 cm) length, were found to have propagated past the area where they would have been covered by the doubler and into the stringers beneath the doubler and across the lap joint between the middle skin panel and the forward skin panel."

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Perhaps the 2002 crash will shed light on what happened with the C-130 in Australia?