Extended diversion time operations (EDTO)
44.—(1)  An AOC holder must not operate a large aeroplane with 2 or more turbine engines on a route where the diversion time from any point on the route to an en‑route alternate aerodrome exceeds the threshold time except under and in accordance with approval granted by the Director‑General of Civil Aviation under the Air Navigation (98 — Special Operations) Regulations 2018 for that purpose.
(2)  For the purpose of paragraph (1) —
(a)if the aeroplane has 2 turbine engines, the diversion time is calculated in International Standard Atmosphere and still‑air conditions at the one‑engine inoperative cruise speed and the threshold time is 60 minutes; or
(b)if the aeroplane has more than 2 turbine engines, the diversion time is calculated in International Standard Atmosphere and still‑air conditions at the all‑engines operating cruise speed and the threshold time is 180 minutes.