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Old 22nd Mar 2008, 18:40
  #19 (permalink)  
LOMCEVAK
 
Join Date: Sep 2001
Location: UK
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Most of the relevant aspects of spinning on the ETPS course have been covered above but here is a little more meat on the bones. The Tucano and Hawk both have an expanded spin envelope to allow spinning outside of the Release to Service cleared envelope. This allows deliberate control mishandling at spin entry, during the spin and during recovery. It also allows the Hawk to be spun with the airbrake out and in the Tucano power on (30%TQ) spins in addition to the erect, left 4 turn spins in the R to S. However, to perform these spins a safety pilot must be in the telemetry ground station and the spin panel must be selected on. The most critical item in the 'spin panel' is a voice alerting device which automatically gives a voice command to 'recover' at the minimum altitude and to eject if not recovered by the relevant altitude.

The Alpha Jets at Boscombe are ex German Air Force ones that were never cleared for spinning in service althoug spin trials were flown and they could have been cleared had there been a need. Perhaps they will be cleared for spinning at ETPS one day but until then the EPNER Alpha Jets are spun whenever possible during the course. Out of interest, a spin panel was installed along with the flight test instrumentation fit into two airframes, and these have yaw rate (rather than roll rate) lights as the aircraft does not have a turn needle.

The Hawk inverted spin incident is an interesting one. The airframe in question, XX343, had been landed with the right main landing gear stuck up in the late 1980s. Thereafter it had some slightly unusual spin characteristics, one of which was a tendency to enter an inverted spin when certain deliberate mishandling cases were evaluated. In particular, relaxing the full aft stick back to trim whilst maintaining full pro spin rudder or applying full outspin aileron when there was a roll rate hesitation (which was actually one of the inverted spin entry techniques in the Hunter). I had it start to go inverted several times but I used to watch the AoA gauge closely when making these inputs and if I saw it drop below 10 degrees I knew that it was going inverted so I would just centralise and recover. However, I had some students who did not catch it and it actually went inverted, although you could then centralise the controls without difficulty during the first half turn. It was only if you let in go past that point that the rudder overbalanced, and once stabilised in a fully developed inverted spin the foot load to centralise the rudder was about 250 - 300 lbs (based on USN T-45 spin trials). The incident that occurred was a student pilot and a student FTE together. The pilot moved the stick forward too rapidly with pro spin rudder and the aircraft stabilised in an inverted spin. He knew what he had to do but could only get the rudder back to about 1/4 in-spin which was not enough for recovery. Eventually adrenalin enabled him to centralise the rudder, possibly with some help from the FTE and, as I recall, rotation stopped around 6000 ft. the telemetry safety pilot could offer no help as the pilot in the aircraft knew what to do but just couldn't do it! Shortly afterwards we stopped solo students performing relaxed back stick spins!
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