Aviation safety investigations & reports

Fletcher FU 24-950, VH-HTB, "Spring Valley" 2 km east of Frogmore NSW, 29 November 1989

Investigation number:
198900023
Status: Completed
Investigation completed

Summary

Download Final Report
[Download  PDF: 24KB]
 

The aircraft was engaged in superphosphate spreading operations. An aerial survey of the property had been conducted by the pilot in company with the property owner. Powerpoles in the valley ahead and to the left of the airstrip were marked. When operations started the wind was a light north-easterly and ambient temperature was 16 degrees Celsius. By the time the aircraft had refuelled and was ready for the thirty-sixth flight of the day, the ambient temperature had increased to 28 degrees Celsius and the wind direction had changed to a south-westerly. Shortly after takeoff, the aircraft was observed to sink after overflying the high-voltage powerlines between the marked poles. On the next flight the aircraft was observed to make a tight left turn and fly down the valley adjacent to the left marked powerpole. On the next and final flight, the aircraft was apparently attempting to follow the track of the previous flight. While crossing the powerlines south-west of the marked powerpole, the aircraft's landing gear and left wing tip struck the powerlines. With the broken powerline jammed behind the left aileron washout plate, the aircraft impacted the ground 100 metres beyond the powerpole. Ground impact forces destroyed the aircraft and reduced the cockpit area to non-survivable dimensions. On-site examination of the aircraft and subsequent laboratory examination and testing of components did not reveal any pre-existing mechanical defects or abnormalities which could be considered as factors in, or contributory to, this accident. Powerline impact marks on the aircraft were consistent with the aircraft being in a left banked attitude when it struck the wire. The investigation revealed that the loader driver's truck bucket load gauge had no conversion/calibration chart, and that the aircraft was being operated in excess of the maximum allowable weight for takeoff. It is considered probable that the pilot had elected to fly down the valley, (thus taking advantage of the downslope), to compensate for a degradation of aircraft performance whilst operating overweight in the changed ambient conditions. The absence of a superphosphate trail before wire impact indicates that the pilot did not dump any of the load and was either unaware of, or had forgotten about, the existence of powerlines to the south-west of the marked powerpole.

Download Final Report
[Download  PDF: 24KB]
 
 
 
General details
Date: 29 November 1989   Investigation status: Completed  
Time: 1150    
Location: "Spring Valley" 2 km east of Frogmore    
State: New South Wales   Occurrence type: Wirestrike  
Release date: 10 May 1991   Occurrence category: Accident  
Report status: Final   Highest injury level: Fatal  

Aircraft details

Aircraft details
Aircraft manufacturer Airparts NZ Ltd  
Aircraft model FU-24  
Aircraft registration VH-HTB  
Serial number 174  
Type of operation Aerial Work  
Damage to aircraft Destroyed  
Departure point "Spring Valley" NSW  
Departure time 1149  
Destination "Spring Valley" NSW