EDTO Diversion Time

[Fltjh]

Hi guiys,

Got a question regarding EDTO, hope to get some clarification

To determine EDTO area of operation for 2 engine = one engine operative speed x max diversion time (example 180min) approved by state (still wind and standard condition)

Area of operation = 1250NM for example

During flight planning stage, the critical fuel analysis which take into consideration for wind, temp and other environmental condition calculate a diversion time of 220min for example but distance is still within 1250NM area of operation.

Can i say that, Actual diversion time may exceed the authorized diversion time as long as the flight is conducted within the authorized EDTO area of ops?

Please assist to advise

[compressor stall]

Yes... using your example... the actual diversion time on the day may be longer than 180min. but remember you still need the fuel for the 220min diversion plus the reserves/extras.

It's all about probability...

[Fltjh]

Thanks for the reply stall.

I also wonder if you able to point me to a document or advisory from ICAO or EASA or FAA that mention the actual diversion time in CFP may exceed authorized diversion time? I am looking for some explanation on this.

Regards

[swh]

Your diversion will be planned Vmo/MMO as that is the worst fuel situation but there is never any requirement to actually fly that, you save gas if you fly normal speeds.

”It should be noted that the speed/FL used for the determination of estimated time of use in either method is for flight preparation purposes only. The use of a speed/FL during flight preparation does not imply that the same speed/FL must be used in the event of a diversion. In other words, it is perfectly acceptable for the flight crew to select a more appropriate speed/FL for an actual diversion.”

from http://www.ifalpa.org/store/doc9976.pdf

[mgahan]

ICAO Doc 10085 has plenty of detail.

MJG