At about 1922 Eastern Daylight-Saving Time on 16 February 2006, the pilot of a turbine PZL-Warszawa-Ockie M-18A, Dromader, registered VH-FVF, was fatally injured when the aircraft impacted terrain during fire-bombing operations approximately 20 km south-south-west of Cootamundra, NSW.
The pilot was an experienced agricultural pilot with previous fire-bombing experience. Although he had considerable flying experience on radial-engine Dromader aircraft, and in other turbine agricultural aircraft, his total flying experience in the modified turbine Dromader was 4.7 hours. Prior to commencing fire-bombing duties two days before the accident, the pilot had not recorded any fire-bombing flights in the previous 3 years.
The pilot's limited familiarity with the handling characteristics of the modified and heavily-loaded aircraft might not have allowed him adequate recognition of an impending stall. The pilot had not jettisoned the load of retardant when the aircraft stalled. The ensuing loss of control occurred at a height that did not permit recovery before the aircraft collided with the ground. The possibility that the pilot was distracted by a problem with the operation of the fire doors or some other activity could not be determined.
Subsequently, the state fire authority reviewed its minimum pilot experience levels for aerial fire suppression. The minimum aircraft type experience for fire-bombing pilots was made more specific to the type of aircraft. It also introduced a recency requirement for fire-bombing operations.
Preliminary report released 11 April 2006
A turbine-engined PZL-Warszawa-Okecie M-18A Dromader aircraft, registered VH-FVF (callsign Bomber 223), was conducting fire suppression operations on a bushfire in the vicinity of Mount Ulandra, near Bethungra, NSW. At 1921 Eastern Daylight- saving Time, the aircraft was seen by fire fighters to make a low pass over the fire ground area and commence a left turn. Another fireman reported seeing the aircraft in an almost vertical left bank before losing sight of it. None of the other firemen continued to watch the aircraft but, moments later, they reported that they heard a loud noise. When they looked again, the aircraft had hit the ground. The pilot was fatally injured and the aircraft was destroyed by impact forces. There was no fire.
The crew of a helicopter engaged in fire bucket operations on the same fire ground reported hearing the Dromader pilot broadcast that he was 'lining up for a drop'. A short time later, the helicopter crew reported that they heard the pilot transmit three short expletives. After unsuccessfully attempting to contact the pilot, they commenced searching and located the wreckage of the aircraft a few minutes later, where fire fighters were already in attendance.
The aircraft had impacted open, rising terrain in a nose-down, slightly right wing-low attitude. Examination of the impact marks and the wreckage indicated that the aircraft had been travelling at low forward speed and with a high rate of descent. The ground around the wreckage was covered with a considerable amount of chemical retardant from the ruptured hopper (Figure 1).
Figure 1: Aerial view of wreckage
The aircraft was manufactured in Poland in 1988 and placed on the Australian register in March 1999. In November 2003, the aircraft was modified from the original design in accordance with an approved Supplemental Type Certificate (STC), number SA09039SC, which permitted the replacement of the original reciprocating (radial) engine and the 4-blade propeller with a Garrett TPE 331-12U gas turbine engine and a Hartzell 5-blade constant speed propeller. The modification also incorporated other changes that included the replacement of the hopper with a larger, 800 US gallon (3,030 L) hopper. Additionally, servo tabs were added to the primary flight control surfaces, flap travel was increased and vortex generators were installed on the wings and tailplane.
The aircraft was operated in the restricted category 1 that permitted flight at weights up to 5,300 kg during agricultural operations, which was 1,100 kg in excess of the certified maximum aircraft weight. Flights at those weights restricted the aircraft's maximum speed and, during fire suppression operations, manoeuvring was limited to a maximum angle of bank of 30 degrees.
The pilot held a commercial pilot licence, endorsed for the aircraft type, and a valid Class 1 medical certificate. The pilot also held a Grade 1 Agricultural Rating and had been issued a Night Visual Flight Rules Agricultural Rating on 19 December 2004. The test for that rating met the requirements of the Aeroplane Flight Review, the biennial proficiency check required of pilots. The pilot had in excess of 4,000 hours in agricultural flying operations, of which 127 hours were flown in fire suppression operations over a period of six seasons. Although the pilot had only 4.7 hours on the aircraft type, he had flown over 400 hours on the unmodified radial-engine Dromader aircraft type, and had over 600 hours on other turbine-powered aircraft. The pilot had commenced fire bombing operations two days before and was reported to have been well rested and in good health.
The investigation is continuing and will include the following aspects:
- analysis of data downloaded from the aircraft's Global Positioning System navigation receiver to determine the actual flight path
- testing of the switches controlling the hopper gate
- examination of other aircraft components
- a review of maintenance documentation and records of modification made to the aircraft
- an appraisal of flight characteristics of the modified aircraft during operations at higher gross weights.
|Date:||16 February 2006||Investigation status:||Completed|
|Location:||20km SSW Cootamundra, Aero.|
|State:||New South Wales||Occurrence type:||Loss of control|
|Release date:||31 October 2007||Occurrence category:||Accident|
|Report status:||Final||Highest injury level:||Fatal|
|Aircraft manufacturer||PZL Warszawa-Okecie|
|Type of operation||Aerial Work|
|Damage to aircraft||Destroyed|
|Departure point||Wagga Wagga, NSW|
|Departure time||1853 ESuT|
|Destination||Wagga Wagga, NSW|
|Role||Class of licence||Hours on type||Hours total|