Airbus FMGS holding logic
Doees anyone on here understand the intricacies of how the A320 FMGS calculates holding patterns ?
My particular query relates to losing a specific amount of time during an enroute/approach hold. For example, an ATC instruction like "7 min delay required, adjust the holding pattern to depart at time 52".
Logic says I would allow for 2 x 2min turns and make each holding leg 1.5mins. Having sad that, every time I have tried it, it has never worked. Principally due to the timing of the turns not being predictable. I have seen every variation of turn from 1.5 to 3 mins, making it difficult to compute. (Its seems to depend on altitude - we usually hold somewhere near FL180-FL250).
FCOM is vague on a lot of this information.
Does anyone have any hints/tips/tricks on how to accurately manage a holding pattern to make sure it terminates as close as possible to a set time ?
Thanks !
Last edited by SumFingWong; 17th Jan 2013 at 00:49.