Singapore legislation
Regulation 41
of Air Navigation (135 — Commercial Air Transport by Helicopters and Small Aeroplanes) Regulations 2018
Regulation 41
Take-off alternate aerodrome or heliport
Subregulation 1
An AOC holder must select, and specify in the operational flight plan, filed flight plan and preliminary flight plan (if applicable), a take-off alternate aerodrome for a flight of a small aeroplane if —
the meteorological conditions at the aerodrome of departure are below the AOC holder’s established aerodrome landing minima for that operation; or
it would not be possible for the aeroplane to return to the aerodrome of departure for other reasons.
Subregulation 2
Except in accordance with an approval granted under the Air Navigation (98 — Special Operations) Regulations 2018 for EDTO operations, the AOC holder must ensure that the take‑off alternate aerodrome selected in accordance with paragraph (1) is located —
within one hour of flight time of the aerodrome of departure at a one‑engine inoperative cruise speed, if the small aeroplane has 2 engines; or
within 2 hours of flight time of the aerodrome of departure at an all‑engine operating cruise speed, if the small aeroplane has 3 or more engines.
Subregulation 3
An AOC holder must select, and specify in the operational flight plan, a take‑off alternate heliport for a flight of a helicopter if the weather conditions at the heliport of departure are at or below the applicable heliport operating minima.
Subregulation 4
For the purposes of paragraph (2), flight time is calculated in International Standard Atmosphere and still air conditions using the relevant cruise speed as determined from the AOC holder’s Operations Manual and the aeroplane’s actual take‑off mass.