Go around, thrust reduction altitude oei

[HazelNuts39]

Originally Posted by OPEN DES

EASA Air Ops, part CAT does not make any provisions for Performance class A in G/A for AEO nor OEI.

Not entirely correct:

CAT.POL.A.225 Landing — destination and alternate aerodromes
(a) The landing mass of the aeroplane determined in accordance with CAT.POL.A.105(a) shall not exceed the maximum landing mass specified for the altitude and the ambient temperature expected for the estimated time of landing at the destination aerodrome and alternate aerodrome.

For decision heights not less than 200 ft, the maximum landing mass specified in the AFM for the altitude and temperature is determined in accordance with the certification requirements of CS-25.119 (3.2% AEO) and CS-25.121(d). CS-25.121(d) requires a climb gradient of 2.1% OEI for twins at a speed not greater than 1.4 Vsr (typically minimum drag speed).

For decision heights less than 200 ft, the maximum landing mass must additionally comply with the certification requirement of CS-AWO 243.
CS-AWO 243 requires a climb gradient of 2.5% at VREF, typically 1.12 Vsr in the approach climb configuration.

P.S. Like all WAT-limit reqirements, the limiting gradient is a momentary gradient, for the quoted requirements at the pressure and temperature at airport level. That momentary gradient does not define the flight path to another altitude.

[Pugilistic Animus]

In the FARs the approach climb gradient restriction allows for OEI performance from the MAP...but landing climb configuration is still assumed AEO.

[ajd1]

Probably being dim here, but a couple of earlier posts refer to time limitations on TOGA thrust.

I fly Boeings and in all the FCOMS (73,75,76,77,78) I can only find references to Take Off Thrust time limits (5m or 10m); I can't find anything written about G/A Thrust time limitations.

I'm sure somebody will put me right.

[Ops_Room_Junkie]

It's a TOGA limitation. TOGA aka Take-Off // Go Around.

It is maximum,but time limited, thrust.
Levers fully forward. Airbus fly by wire is ltd to 5 mins all engines, 10 minutes one engine inop.

[ajd1]

Yes, I know what TOGA means; maybe it's just a Boeing/Airbus difference as I haven't seen a TOGA limit in the Boeing books.

[Ops_Room_Junkie]

TOGA limits

Sorry perhaps I am missing something here or we are talking at odds.
As far as I was aware TOGA thrust does not know if you are taking off or going around: it's just a maximum thrust setting you can select for either take off or go around (when you need maximum thrust). I have only worked on B737-300 with CFM56 and I was pretty sure TOGA was ltd to 5 mins...whether you are taking off or going around.
Sorry if I am missing something and/or being too simplistic about it.

[vilas]

ORJ
You are right.

[Denti]

According to boeings information for the 737 there is no time limit at all on G/A thrust, but there is of course a time limit on TO thrust (in our case always 10 minutes). However, that applies only to unreduced TO thrust, if reduced TO thrust is used check against MCT and if it is higher apply the time limit. To make it operationally easier my company has decided to always apply the time limit, although thrust reduction is in all truth a thrust increase in more than 99% of all cases.

[rudderrudderrat]

Hi Denti,

According to boeings information for the 737 there is no time limit at all on G/A thrust, ........ although thrust reduction is in all truth a thrust increase in more than 99% of all cases

Do you set a reduced GA thrust which is less than MCT? If not, then why do you think there is no time limit?

[Denti]

Simple, there is only a time limit for unreduced TO thrust in the limitations chapter, none for GA thrust, and yes, GA thrust is usually reduced as well, although my comments in the previous post were about reduced take off thrust.

[vilas]

Denti
The following 737 technical website gives 5 Miniute limitation for GA as well
http://www.737.b737.org.uk/powerplant.htm
I didn't fly 737 but I think there should be a limit. Just check.

[rudderrudderrat]

Hi Denti,

there is only a time limit for unreduced TO thrust in the limitations chapter, none for GA thrust,

Errrrrr, what does MCT stand for?
So if your thrust (during the Take off or GA or Climb or during level flight or whatever) is greater than MCT, how long do you think your procedures allow you to keep it there?
What other name would you prefer to give to a thrust setting above MCT?

[underfire]

Quite a few variables thrown around here. There is also MCL-max climb vs MCT max continuous.

Thrust rating is based on EGT for 5 mins at sea level and ambient temp of 35 degrees C for hot weather ops with no penalty. The cycles and conditions on the engine will decrease the EGT margins, thus decreasing time limits.

Specific procedures are designed, with different thrust time limits, for high-altitude airports or cold weather ops.

I seem to remember a few tricks, with AT on/off when sel TOGA, especially when OEI (and the double press).