British airways flex or assumed

[colartkit 4]

Hi allReading a thread recently on assumed/flex and de-rated take-offs and trying a search here and on web, I was wondering if anyone knows what British Airways uses. Is it a combination of both or one of them?Thanks in advance EDIT: The title should read British Airways flex/assumed or de-rated

[Samwise 1]

I seem to remember hearing that BA commonly use TO2 plus whatever flex is required.

[G-CIVA 62]

BA 744s operating during normal line operations have their Take Off Performance Calculations usually calculated by a system based at Compass Centre near London Heathrow called 'CARD' using info entered by the crew using the centre CDU in ACARS mode. CARD allows better performance and higher take off weights vs the manual calculations from the Performance Manual which tend to err on the conservative side.CARD/ACARS spits out the figures which are then printed & entered into THR REF & TAKE OFF REF pages in the CDU/FMC...these are then checked against the final loadsheet which is sent to ACARS normally following the pushback, any changes which fall outside of the original CARD numbers (higher ZFW?) may require a new CARD take off calculation prior to arrival at the holding point.BA SOP is that all Packs are set to OFF for every take off above 300t, the rationale here is that this helps to keep engine temperatures slightly cooler thus preserving engine life. Packs are selected back to 'ON once CLB thrust is set after departure.Engine Thrust mode is normally 'TO' with (or without) an assumed temperature unless at very light weights, where TO-1 or TO-2 with/without an assumed temp may be used - such as an empty aircraft departing EGLL for Cardiff for maintenance or vice versa.TO-1 & 2 are fixed derates at 5 & 15% reductions in total thrust, BA do not normally use these unless recomended by CARD, prefering to opt for Full TO Thrust with or without an assumed temperature as stated above. The rationale is that if an ENG Fail occurs after V1 a futher press of the TOGA Switches will cancel any assumed temperature and command full TO thrust. Do the same with TO-1 or TO-2 with an assumed temperature and you will only get the maximum rated TO-1 or TO-2 thrust.CLB 1 is normally set once the aircraft is 'clean' & accelerating towards the ECON CLB SPD (calculated by the FMS against a CI of 0 for the climb).All of this info is from a RW source, albiet now 3 years old & forms part of our FCOM & SOPs used at BAV, somone with more current RW info might chip in.

[colartkit 4]

Thanks Sam & Steve.Steve, great info. Very much appreciated.

[Samwise 1]

Thats a great bit of info Steve, it answers the OP's question pretty thouroughly :(

[G-CIVA 62]

No worries - glad to help.

[scandinavian13 5,192]

Awesome post Steve.Also, keep in mind:FLEX is purely an Airbus term.De-rate and assumed temp are what you're looking for.

[colartkit 4]

Awesome post Steve.Also, keep in mind:FLEX is purely an Airbus term.De-rate and assumed temp are what you're looking for.

Does that mean that boeing use the term ASSUMED which is FLEX for Airbus. The reason I ask is that in TOPCAT I am able to tick "allow assumed/flex temp take off" or "allow derated take off" or "allow combination of both". I use allow assumed/flex temp take off only, as Steve above says that BA do not usually allow derated take offs unless empty. I know this is a question for the TOPCAT forum :( but since we are on the subject...

[G-CIVA 62]

Allan,Assumed Temp & Flex could be seen as one & the same.With regard to TOPCAT it depends on how you want to have do your TOPCAT calculations...as I only fly the 747-436 for BAV only the "allow assumed/flex temp take off" box is checked. If I need to do a MX flight to/from Cardiff with an empty aircraft I'll just go into the TOPCAT Aircraft file & make the changes for that flight, reverting to the above afterwards.Steve

[colartkit 4]

Thanks Steve. Thats how I've been doing things. Good to know I'm on the right track. Cheers.

[SpeedbirdA320FO 27]

They're all the same thing. On the Airbus we use flex, just the Airbus term for de-rated or assumed, on the FMGC perf page we have a box for Flex, and the throttles are set to the respective gate! Flx temp is different based on conditions/airport though.Sam.