EDTO

Question 1

Additional Fuel Considerations

Answer 1

Additional Fuel, if required, shall include the following:

• 5% contingency fuel (wind forecast errors)
• Fuel to account for a/c specific performance factor
• Fuel to account for APU fuel consumption
• Fuel to account for forecast icing penalty
• Fuel to account for CDL/MEL performance penalties

Question 2

Planning for the Critical Fuel Scenario ensures that at the planned aircraft weight, sufficient fuel to cover:

Answer 2

1. Departure and flight to most critical point of the route, assuming linear reduction in the contingency fuel
2. Failure of one engine, depressurisation or both, at the most critical point.
3. Descent to required flight level/altitude.
4. Cruse at the planned speed to ERA
5. Descent to 1500ft AAL at the ERA.
6. An approach and landing with minimum 15 mins fuel remaining calculated at 1500ft AAL consumption rate.

Question 3

EDTO definition?

Answer 3

Aircraft with 2 engines operating on a route that that contains a point further than 60 mins flying time in ISA and still air conditions, at the inoperative cruising speed, from an ERA.

Question 4

Can the take-off and/or destination aerodrome be considered as ERAs?

Answer 4

Yes.

Question 5

What does the EDTO max diversion time take into consideration?

Answer 5

The most limiting EDTO significant system, if any, and the cargo fire suppression system time limitation.

These limits are reduced by an operation safety margin of 15 minutes.

(i.e. 15 mins safety buffer added)

Question 6

Are EDTO ERA required to be specified on the filed ATS flight plan and the OFP?

Answer 6

Yes.

Question 7

A350-900 Approved EDTO Maximum Diversion time and distance?

Answer 7

240mins / 1691Nm

Question 8

A350-1000 Approved EDTO Maximum Diversion time and distance?

Answer 8

240mins / 1712 Nm

Question 9

How are the approved EDTO distances calculated?

Answer 9

One-enginge inoperative speed tables at MMO/VMO and still air conditions.

Credit for drift-down is considered.

Question 10

EDTO Fuel Requirements?

Answer 10

EDTO Critical Fuel Scenario must be considered and, if required, Additional fuel uplifted to cater for most limiting scenario.

Critical fuel calculations are based on planned aircraft weight. Forecast atmospheric conditions such as en-route winds, ISA deviation and icing shall be considered.

Question 11

EDTO Dispatch requirements

Answer 11

Planning minima to be used for nominated ERA shall meet the criteria specified in OMA. Planning Minima for EDTO.

Dispatch requirements also apply to departure and/or destintation airport that support EDTO.

Question 12

EDTO Planning Minima?

Answer 12

+/- 1 Hour anticipated time of landing
Weather conditions at or above planning minima for expected approach
Table D:
Precision Approach DA/H + 200ft / RVR/VIS + 800m
Non-precision approach MDA/H + 400ft / RVR/VIS + 1500m

For USA Aerodromes: Table B