View Full Version : Flex to Climb Gate before MCT (single engine)

18th Mar 2008, 22:04

I hope the title makes sense. I was told once (during my conversion training) that in the engine failure after take off scenario on the A320 there is a very good reason why the thrust lever is brought back into the CLB gate from the FLEX gate before selecting MCT i.e. not to select TOGA then MCT. I'm sure I understood the reason why at the time, but for the life of me I cannot remember now. Can anyone shed light again...I might write it down this time...!!



18th Mar 2008, 23:01
If you go fwd (into TOGA) then back with any flap extended, you will get SRS GA TRK which might not be what you want.

Always go back then fwd with the thrust levers. You will then get MCT on one eng without trashing your FD commands.


Reader not a writer
19th Mar 2008, 01:17
Hang On Guys

You might be getting some wires crossed here!

On take off you either have TOGA or FLEX/MCT selected, which in both cases is an "AUTOTHRUST ARMED" mode, effectively a fixed thrust setting depending on what has been set in the MCDU.

If you are unlucky enough to suffer an engine failure after take off you are still in "AUTOTHRUST ARMED" mode.

To get "AUTOTHRUST" to engage after an engine failure you must go from TOGA (if selected) or FLEX/MCT (if selected) back to CLIMB and then back to FLEX MCT.

Two Basic Principles Here:

TWO ENGINE ------ full AUTOTHRUST only available with CLIMB set.

SINGLE ENGINE---- full AUTOTHRUST only available with FLEX/MCT set.

Willing to be corrected !!!

Old Fella
19th Mar 2008, 02:20
Wasn't it just so simple when, for the most part, engine management was MANUAL with a Flight Engineer to look after systems management, fuel management, passenger environmental comfort, speed control and engine thrust for the majority of the flight as well being another set of eyes and ears on the flight deck. All we cost was a reasonable salary, a few sandwiches and coffee and we were often the "calming influence" when things got tense. Those were the days.

Down Three Greens
19th Mar 2008, 13:35
Fantom has got it in one. TOGA + Flap '1-4' => TOGA - SRS - GA TRK

19th Mar 2008, 15:20
To get "AUTOTHRUST" to engage after an engine failure you must go from TOGA (if selected) .....
..... back to CLIMB and then back to FLEX MCT.
Most incorrect.

There are 5 distinct thrust settings:

Actual N1 for day to day FLEX may be below or above the MCT value. Hence the designer decided to have a single DETENT for these two distinct settings. The only problem is, how do you tell EIU that you no longer want FLEX and need MCT when both settings are commanded by having TL in the same detent. Move out, move in. Once MCT (thrust setting, not detent) is selected, autothrust becomes active. This also applies for TOGA tkof. MCT from TOGA is commanded by retarding TLs one step to FLEX/MCT detent, no need to go back to CLB.

FD (the un-real)

19th Mar 2008, 17:44
..........another quite good reason to select TOGA after an engine failure. There is no choice but to come back one click to the MCT gate!


19th Mar 2008, 20:29
If you decide to use TOGA do it before leaving the SRS mode! i.e. below 'engine out accel alt/engine secure/10min'. Do not select TOGA in an attempt to speed up the acceleration during the level acceleration segment, or else you will go into the SRS again.
Going from FLEX to MCT after the clean-up by bringing the levers forward to TOGA briefly and then back will NOT give you SRS! Will you however remember this in the unlikely event for any reason the flap lever position is not at 0??
(it is flap lever position which makes the SRS available not the actual flap position)

My 2 ct: Keep it simple and cover the worst case scenario by always bringing the thrust levers back to go from FLEX to MCT instead of bringing them forward and making yourself vulnerable for mistakes.