Icon A5 final report

[ozbear]

A trap for us all to remember not just over water many pilots have been killed flying up dead end valleys from the beginning of Aviation

 

NTSB Releases Final Report in Fatal Icon A5 Accident

 

 

[poteroo]

A trap for us all to remember not just over water many pilots have been killed flying up dead end valleys from the beginning of Aviation

ANSWER = plenty, and there'll be more.

 

 

But, I believe there's more to this than just running out of room in a dead end valley. It's likely that they were unable to utilise all of the space available, because, when they realised that it was the 'wrong' inlet - they were not flying close to the shoreline on the right hand side. In this case, they increased power aggressively and began a turn to the left. It's likely they might have made it had they been able to use all of the available distance from one shoreline to the other. That's why LL, (and mountain), pilots are trained to hug one side or the other to maximise 'room' in event of a reversal being required.

 

The other problem these unfortunate pilots had was that in flying low over water, they could not allow the nose to drop into the turn so as to shorten up the space needed. In a valley, you can always allow the nose to drop into the turn because you are turning out over the lowest land in the valley centre.

 

In another forum there was a lot of comment on the fact that this company promoted the A5 using several U-tube vids involving a lot of low level flying. It seems that they may not have followed their LL training principles in the heat-of-the-moment manoeuvring on this mission. I'd assume they were in fact trained to do this sort of flying? Hard enough being a test & demo pilot without adding to your risk by flying low as well. So needless.

 

 

[Warmi]

Low speed ( I think it was 50 knots ) was another contribution factor ...

 

 

[poteroo]

Low speed ( I think it was 50 knots ) was another contribution factor ...

Agree that this was one of their causal factors.

 

To minimise the radius of turn - the aircraft needs to be flown at the lowest possible IAS. They probably needed a 45 deg aob turn to avoid CFIT, and to do that from 50 kts would require a lot of power to accelerate it. My guesstimate is that it had a Vs of about 40-45 kts. So, they could not roll into a 45 turn until reaching at least 1.21 Vs (= 55 kts) Operating at less than 1.2 Vs requires a heap of power and acceleration as the aircraft is rolled into the turn - otherwise the aircraft will be at risk of stalling in the turn. Making entries into steep turns from low level requires a deal of instruction and lots of supervised practice. Even more important where the aircraft is already flying at only 1.3 - 1.4 Vs for operational reasons. I find it difficult to comprehend pilots flying so low, and slow, when in proximity to hills??