If it appears to Her Majesty that national danger is imminent or that a great emergency has arisen, She may by order, signified under the hand of the Secretary of State, provide that airmen who would otherwise fall to be transferred to the reserve shall continue in air force service; and thereupon the last foregoing section shall apply to such airmen as it applies while men of the reserve are called out on permanent service.

Where an order has been made under subsection (1) above, the occasion thereof shall forthwith be communicated to Parliament.

An order in force under subsection (1) above may be revoked by order of Her Majesty signified as therein mentioned.