ITV News has been told that the squadrons have been working over-time and are having to cancel leave as they embark on back to back tours to Afghanistan and Libya.
The combination of stress and fatigue is potentially dangerous for those in charge of powerful fighter jets.
The causes of the crash are to be fully investigated in due course.
A vessel has gone out to the crash site to locate the wreckage ahead of a salvage operation.
More top news
The President has been removed from his post at the head of the ruling ZANU-PF party in a move that adds to pressure on him to stand down.
The deputy leader of far-right group Britain First has been arrested in London over a speech made at a rally in Belfast this summer.
A retired solicitor from Bristol has died after being swept overboard while competing in the Clipper Round the World yacht race.