EDTO Diversion Time
Thread Starter
Joined: May 2018
Posts: 2
Likes: 0
From: Singapore
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
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

Joined: Feb 2000
Posts: 4,704
Likes: 589
From: 500 miles from Chaikhosi, Yogistan
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...
It's all about probability...
Thread Starter
Joined: May 2018
Posts: 2
Likes: 0
From: Singapore
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
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
Eidolon

Joined: May 2001
Posts: 2,244
Likes: 62
From: Some hole
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
”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




