Expiration of Take-Off Clearance

[malecontrol]

How long is a take-off clearance valid? I hear it's 90 seconds, is that correct? What happens 90 seconds after issuing a take-off clearance if the pilot does not commence the take-off? Does it automatically expires and the pilot should request for a new clearance or does the controller have to cancel it him/herself? Or is it valid indefinitely?:rolleyes:

[Spitoon]

I don't recall ever seeing anything defined.

I would say that like any other clearance, unless there a specified 'clearance expiry', it's valid until the aircraft does it or the controller cancels it.

[ron83]

will agree with Spitoon it's valid until it's cancelled.

[Late Landing]

ICAO Doc 9870 refers to the 90 seconds in Chapter 4 regarding the 'Recommendations for the Prevention of Runway Incursion'.
Under the heading 'Pilots' it states "If lined up on the runway and held more than 90 seconds beyond anticipated departure time, pilots should contact ATC and advise that they are holding on the runway." Under the heading 'ATC' it states "Line-up clearance should not be issued to an aircraft if that aircraft will be required to hold on the runway for more than 90 seconds beyond the time it would normally be expected to depart."
Perhaps this has generated the confusion, and if the basis for this query.

[Jetjock330]

Abu Dhabi, OMAA, AUH, 10-1P 2, 3.2 declares take-off roll must done within 20 seconds.

I gather, that is the length of the clearance too???

OMAA/AUH +JEPPESEN ABU DHABI, UAE ABU DHABI INTL 1 APR 11 10-1P2 .Eff.7.Apr. AIRPORT.BRIEFING
3. DEPARTURE
3.1. START-UP, PUSH-BACK & TAXI PROCEDURES
3.1.1. START-UP & PUSH-BACK
Departing ACFT shall contact Delivery to obtain clearance between 30 min and 10 min prior requesting start-up and pass following information:
- ACFT callsign, - ACFT type, and for ACFT in the heavy wake turbulence category the word
"Heavy", - Parking stand, - Requested flight level, - ATlS information and QNH, - RNAV 1 or 5 status.
ACFT subject to a Departure Slot Time (DST) shall include a realistic airborne time.
Departing ACFT shall contact ABU DHABI Ground (South) when completely ready to start-up and/or push-back.
Push-back approval is valid for 1 min and shall therefore commence promptly after having obtained approval.
3.1.2. TAXIING
3.1.2.1. GENERAL
Cockpit and security checks shall be completed prior to reaching RWY holding point. ACFT shall be ready for departure on reaching RWY holding point, unless otherwise stated. Pilots are reminded to pay particular attention to conditional line-up clearances to avoid RWY incursions.
3.1.2.2. PRESIDENTIAL FLIGHT APRON
Unless otherwise instructed ACFT shall expect to exit via TWY E.
3.1.2.3. GENERAL AVIATION APRON
After receiving start-up clearance contact Abu Dhabi Aviation Operations (ADA) for taxi guidance on the General Aviation apron. Exit via TWY F5.
3.2. OTHER INFORMATION
ATC requires ACFT to commence its take-off roll within 20 sec of being cleared for take-off. However, in the interest of expediting traffic, a clearance for immediate take-off may be issued to an ACFT before it enters the RWY. On acceptance of such clearance, ACFT shall taxi out to the RWY and take off in one continuous movement. Non-compliance will result in ATC reporting the occurrence to the Authority for further action.