Joined: 11 Dec 2005
|Posted: Mon Apr 09, 2012 3:52 am Post subject: ETOPS
| Long Range Requirements and ETOPS:
The normal limit for a twin to be away from an adequate aerodrome is 60 minutes.
Under ETOPS (Extended-Range Twin-Engine Operational Performance Standards) the rule can be extended to as much as 180 minutes.
Long Range Twins Without ETOPS:
Without ETOPS approval a twin engined aeroplane must not be operated further from an adequate aerodrome than the distances listed:
• Performance Class A Aeroplanes of either 20 or more passenger seats or a MTOM greater than 45,360kg: a distance equivalent to 60 minutes flight time.
• Performance Class A Aeroplanes with a maximum approved passenger seating configuration of 19 or less and a MTOM less than than 45,360kg: the distance equivalent to 120 minutes flight time or for jets and with approval of the Authority, up to 180 minutes.
• Performance Class B or C aeroplanes: the lower of 300 nm or a distance equivalent to 120 minutes flight time.
The times are based on a one engine inoperative TAS.
Long Range Twins With ETOPS:
ETOPS can be authorised in the AOC after extended reliability trials of:
- Training systems.
- Operating procedures.
The still air time (rule time) can be extended from 60 to 90 to 120 to 138 and even 180 minutes from a suitable alternate.
The approval is incremental.
Each increment is based on a track record of successful operation at the shorter time.
A three or four engine aircraft cannot go further than 90 minutes unless it can sustain a double engine failure at the most critical point and make a landing.