Originally Posted by
Juliette Alpha
Apparently the MI-17 was climbing fast to avoid AA fire,
Climbing fast in a helicopter at 12kft ?
What climb rate will be available at a reasonable weight at that altitude?
I feel pretty safe to assume that it will be <<5 m/s.
Climb rate of the Airbus will have been surely significantly higher.
Regarding the speeds I would consider the helicopter almost a stationary 'target'. (350-400kts TAS vs. <100kts). Assuming CAVOK you should be able to see a helicopter the size of a MI-17 at least 5 nm away. That would give you a time window of roughly 45s. In that period the helicopter will have climbed less than 200m. Climbing 5m/s at an approach speed of 200m/s gives you an angle of <1,5°. So if they were flying in a straight line and visibility was OK, climbing of the helicopter shouldn't have been much of a factor.
There must have been other factors involved.
Maybe they were in a turn or blinded by the sun. Otherwise it would be indeed a bit mysterious why they didn't see the helicopter. AoA of the Aircraft itself (3 - 5°) might have been a factor as well.
Will be interesting to see if we ever get an Accident Report on this one!?