ETOPS
 

Can a route be planned with the exact number of minutes required for a diversion?

i e. My fleet is approved for 120mins. A specific route is usually planned with a single diversion airfield (LIDO OFP) within the 90 mins circle. This doesn't require any extra ETOPS fuel. On certain days, actual weather conditions put the aircraft outside the 90 min circle, hence the need for another diversion airfield, which then requires significant extra fuel.

My question is: can I not plan using just the one diversion airfield with a 93 min circle, since it fits within my 120 min approval? Carrying 3 mins of diversion fuel may be a lot less than 30 mins for the 2nd diversion airfield.

Sounds like a planning policy issue. Ie the company is approved for 120 but have a policy to plan to 90. I don’t imagine you’d need any more fuel for 93 minutes anyway, unless you’re fuel is always driven by the ETOPS requirement?

Our company has 180 approval but the policy is to plan 120 if possible. I wouldn’t be ad how planning beyond 120 minutes against our policy, even though it’s all legal.

Curiously it is a fixed distance (your aircraft types speed for the designated number of minutes) that determines the requirement. The planning visual presentation of the rings will never differ whatever the weather. In the “ETOPS analysis” Your diversion time in the “flight time from ETP will be affected by winds (and frequently over the actual minutes you are authorised for).

Yes, the range rings are all nil wind. It surprised me when I first learned this but I think it would just be far too complicated to account for winds for each flight it would also make it difficult for airlines to schedule services near the ETOPS limit as on any particular day the range circles might not work out. Practicality wins.