View Full Version : D-TO (B737) ?
rsbessa
5th Aug 2014, 13:34
Hi guys...
Anyone knows what the D in "D-TO" stands for ?
It is just something that came up on a eqpt recurrent class...
babisiliop
5th Aug 2014, 14:09
Stands for Derate Take-off
Cheers
Depending on where you saw it it could be 'displaced' as in take-off point.
rsbessa
5th Aug 2014, 14:46
It appears on the TMD, whenever an Assumed Temperature is selected.
I believe that it doesn't stand for Derate, because when we do a DERATE, the TMD shows TO1 / TO2.
When a Derate is combined with an assumed temperature we have D-TO1 or D-TO2.
It's just for curiosity ! In case anyone knows, please share with us.
Our documentation doesn't say much else:
• TO – takeoff
• TO 1 – derated takeoff one
• TO 2 – derated takeoff two
• D-TO – assumed temperature reduced thrust takeoff
• D-TO 1 – derate one and assumed temperature reduced thrust takeoff
• D-TO 2 – derate two and assumed temperature reduced thrust takeoff
There are planes with different annunciations though:
• R-TO – reduced takeoff
• R-CLB – reduced climb
Note: R-TO does not indicate the type of reduced takeoff. The N1 limit may be reduced due to the entry of an assumed temperature, a takeoff thrust derate or a combination of both assumed temperature and takeoff thrust derate.
Can't speak specifically for the 737 but FWIW on the 777 and 747 "D-TO" was the correct annunciation when you were performing an assumed temperature take-off.
TO 1 or TO 2 was seen on the 744 when you performing a Reduced Thrust Take-off, something we'd (generally) only get involved with if performing a three engined ferry.
In any event surely the answer should all be in the appropriate FCOM 2.
( slow in typing - what Denti said!!)