Washington DC plane crash: Plane experts query how collision happened in ‘most controlled airspace’

Speaking to CNN, Cedric Leighton – a retired US Air Force colonel – said it was normal for that type of military aircraft to be training at night in the area, particularly to make sure pilots are proficient with using instruments needed to fly in the dark.

He said one of the unit’s duties is to transport high-ranking personnel around the capital – however, it is now known that only the crew was on board at the time of the collision.

The unit’s pilots are expected to be proficient at flying in DC’s busy airspace and “train in order to avoid incidents like this”, he added.

Mr Butterworth-Hayes said only experienced pilots would be able to train in such a busy section of airspace.

“Whether it’s training for new systems or equipment, we need to know what systems the pilot had turned on in the helicopter and whether they had all the safety systems on board, or whether they were trying a new procedure or new route.”

Speaking to BBC World Service’s Newsday programme, Australia-based aviation expert Neil Hansford said the collision raises specific questions for US aviation authorities and will likely lead to an overhaul of procedures.

He said it wouldn’t happen in Europe or Australia because there are tighter rules governing flight paths.

Another factor in the tragedy, says Mr Strickland, is the lower speed the jet was flying at because it was coming in to land.

“If any major shock happens, there isn’t really any time – even if the crew survives – to do anything.

“The aircraft has got a degree of vulnerability because of its speed. You can imagine that a similar outcome would have been likely even with a much larger aircraft.”