Erickson Aircrane accident Jericho, Victoria
Report out.
https://www.atsb.gov.au/publications...r/ao-2019-008/
Furthermore, the shape of the dam and surrounds of the site reduced the opportunity for recovery, and the aircraft impacted the water. The carriage of additional crew increased the risk of injury, while training for emergencies directly supported the crew’s survival.
https://www.atsb.gov.au/publications...r/ao-2019-008/
What the ATSB found
The ATSB found that the approach path to the dam was incrementally shortened over the course of the days’ operation. It is likely that the final tight approach path was at the upper margins of allowable speed and angle of bank, requiring a steep flare that contributed to the aircraft entering vortex ring state on approach.Furthermore, the shape of the dam and surrounds of the site reduced the opportunity for recovery, and the aircraft impacted the water. The carriage of additional crew increased the risk of injury, while training for emergencies directly supported the crew’s survival.
John E, I tend to think you are closer to the probable cause than the ATSB speculation. One thing I could add re the Crane’s engines. The engines transient response was slow. A very experienced Crane pilot at SA, Jim Kay,who did a lot of the certification and marketing flying, would refer to the JFTD-12 transient response as “pull and wait “. There was a lot of push-back from SA to P&W on this issue and the -5 engines were slightly better in that regard. The problem was that the engine was basically a J-60 turbo-jet redesigned to add a power turbine ( sorry,P&W for the oversimplification of what was,at the time,a spectacular effort ) and the control system mods were limited. It is not too unrealistic to propose the possibility that a crew in a hurry put themselves in a position where the slow transient response of the engines caught them. In either 1967 or 1968, when SA was doing commercial S-64 marketing demonstrations pretty aggressively,we had a 64 in Colombia supporting some oil business work,and a botched approach into the rig site where they were based resulted in a total loss and the death of the rear seat pilot ( head injury,no helmet-and that provoked fallout that you can imagine ). Similar circumstances to the one in discussion now: empty aircraft, crew perhaps in a hurry, good weather,no aircraft faults found after the fact.
Last edited by JohnDixson; 17th Apr 2020 at 14:31. Reason: Typo
John E, I tend to think you are closer to the probable cause than the ATSB speculation
- It was reiterated to pilots that, though aircrew work in close partnership and cooperation with aerial attack supervisors (AAS), AAS instructions are advisory. The pilot in command retains full authority to make decisions to ensure the safety of the aircraft and management support was available if escalation was required.
- Kestrel Aviation increased the frequency of contact with Erickson Inc. crews to provide safety management support, and reduce operational pressure.
Sounds better than: “I commanded a high rate of descent, while reducing my airspeed in an attempt to make my profile more acceptable. When I pulled in a lot of power to arrest the ROD (With little IAS) the AC predictably entered VRS” (Or far more common - .....When I pulled in a lot of power to arrest the ROD (With little IAS) the AC predictably lost RRPM. I reacted to the subsequent increased ROD by raising the lever......“)
Didn’t end well - “must have been VRS - nothing I could do!!”
It drives me nuts how often reports cite VRS as the cause when clearly there other more likely potential causes
Talking to the company pilot with whom the test flights were done in the following accident at no time were they able to enter VRS, and the ATSB chap occupying the other seat agreed. Once he got back to the office the story changed, so the report chapter on the testing would seem to be bollox. The conclusion reached in the testing was that the crew developed a high rate of descent in rearward flight. Remember getting the turbine endorsement in a UH-1B, one flight was a instructor demonstration of VRS at 14,000, wearing a parachute which was required for flight above 5,000, at our light weight we were unable to achieve the aim
https://www.atsb.gov.au/media/24791/199100126.pdf
The slow response time of the engines sounds very similar to those fitted in the RAF Puma Mk 1 - which had no anticipators. ISTR the crucial N1 figure was 85% and if you pulled pitch quickly below that figure the Nr would decay quickly, dropping the gennies off line and the AP.
As I suggested earlier Crab
