Lemain
The report is compiled from many smaller reports prepared at various times by many different people as the investigation into all aspects of this incident were examined. The feed pipes to the ASI and altimeters were too disrupted to be able to come to any positive conclusion as to whether they were serviceable or not. However at least two separate investigations were undertaken into each separate instrument and the conclusion was that these instruments were essentially working and reading correctly, with the caveat that the left hand altimeter may have been sticking and under reading at times. This does not work in the pilot's favour.
Because these instruments were examined separately and presumably by two separate examining teams, at different times, it is only natural that the reports on the instruments condition will vary slightly.
One item that cropped up in the report is that the altimeter settings on both the left and right altimeters were not set to 1013 mbar which was the correct QNH and QFE setting for the day. That shows a lack of attention to detail on behalf of the pilot, although it could be argued that the instrument settings were altered in the crash or while they were being removed for examination. That is rather unlikely, but it remains a faint possibility.
Circumstantial evidence from earlier in the flight obtained from radar returns also suggests that the aircraft was maintaining the appropriate altitude and speed and that these instruments were therefore working correctly.
The instruments, although old, were designed to be read at a glance by military pilots operating under stressful conditions. Although there will be certain light angles that reflect off the instrument glass making them difficult to read, this situation is relatively rare and of very short duration when the aircraft is manoeuvering aerobatically.
I suggest that any wooliness in the report is simply to avoid pointing the finger of blame directly at the pilot, which it is not the AAIB's brief.
The down wind takeoff, display notes folded in a pocket, altimeters not set, display minimum altitudes busted, loop entry at too low a speed, full engine thrust not selected, a failure to recognise the apex of the loop was too low, and a failure to initiate an escape manoeuvre, all point towards one conclusion. Given that the aircraft was essentially airworthy and that no gross faults have been found to which the crash might be attributed, it is only possible to conclude that the pilot was at fault. The pilot held a class 1 medical at the time and incapacitation due to medical issues is thought unlikely. The holes in the cheese line up.