Some reports are suggesting dual engine failure after take-off (DEFATO) That would help explain why there was a mayday call. It's something that is very noticeable to the flight crew, very quickly. If the plane had been incorrectly configured for take-off (as some have speculated - noting that flaps may have been incorrectly positioned and gear was still down) it's less likely the pilots would've figured out what was wrong in time to diagnose the problem and then communicate. The rule of thumb is: Aviate, Navigate, Communicate. There's also some suggestion that the RAT (Ram Air Turbine) was deployed, which would add weight to the DEFATO hypothesis.
A dual engine failure immediately after V2 would most likely occur due to birdstrikes. Other foreign object damage is possible, though less likely to affect both engines. It could also potentially be contaminated fuel, but there have been subsequent take-offs from that airport, so it's unlikely the source of fuel was the problem.
Dual engine failure at, or immediately after, V2. Startled pilots. No positive rate achieved so no "positive rate, gear up" call out and action. Begin the DEFATO checklist, which I suspect is mainly memory items due to the time critical nature of the fault. Continuing aviating. Issue mayday.
If it turns out to be this scenario then the sad reality is that the pilots simply did not have enough of three critical things. Time, altitude, speed. The nearest comparison would be US Airways Flight 1549. But Chesley Sullenberger and Jeffrey Skiles had nearly 4 minutes, 190kts and 3,000ft to play with.
My thoughts and sympathies go to all those affected.
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