Singapore legislation
Regulation 79
of Air Navigation (91 — General Operating Rules) Regulations 2018
Regulation 79
Navigation equipment
Subregulation 1
An operator of a Singapore registered aircraft must ensure that the aircraft is equipped with a navigation system that enables the aircraft to proceed in accordance with the flight plan and the requirements of the appropriate air traffic services authority, except when navigation for a VFR flight is accomplished by visual reference to landmarks.
Subregulation 2
An operator of a Singapore registered aircraft must not operate an aircraft in an area where the appropriate air traffic services authority has specified a navigation specification for performance‑based navigation unless —
the aircraft is equipped with the capability of operating in accordance with the required navigation specifications; and
the operator has an approval granted by the Director‑General of Civil Aviation under the Air Navigation (98 — Special Operations) Regulations 2018 for that purpose.
Subregulation 3
An operator of a Singapore registered aircraft must not operate an aircraft in RVSM airspace unless —
the aircraft is equipped with the capability of —
indicating to the flight crew the flight level being flown;
automatically maintaining a selected flight level;
providing an alert to the flight crew when the altitude of the aircraft deviates from the selected flight level by more than 300 ft (90 m); and (iv)automatically reporting pressure altitude; and
the operator has an approval granted by the Director‑General of Civil Aviation under the Air Navigation (98 — Special Operations) Regulations 2018 for that purpose.