Cheju
14th Feb 2013, 13:49
Hi, I'm just about to start my training on long haul operations and I wasn't 100% sure about the concept of "depressurization critical point" - what's the concept of it? And why do we have that on flight plan?
My "limited"understanding is lets say.. U hav got depress'n crit point between A(company designated ERA) and B(destination) and company added mandatory fuel because if you have depress'n at or after crit point and you divert to that ERA, it require more fuel than continuing destination. I mean..is this the concept of the depress crit point? Ie greater fuel/time requirement beyond crit point etc? Similar to ETP concept in some way?
Second question is, if you require diversion to random(other than company specified: no mand fuel) ERA following depress'n event, how would you estimate fuel required by manipulating FMC? Ie put fl140 or 10000 ft all the way? I heard there is a simple formula can be used for quick estimation: ie use prog page 3,put ERA destn, get the dist, then dist X3 plus 3? Or something like that..can anyone help? Im on -400 and Appreciate any comments. cheers
My "limited"understanding is lets say.. U hav got depress'n crit point between A(company designated ERA) and B(destination) and company added mandatory fuel because if you have depress'n at or after crit point and you divert to that ERA, it require more fuel than continuing destination. I mean..is this the concept of the depress crit point? Ie greater fuel/time requirement beyond crit point etc? Similar to ETP concept in some way?
Second question is, if you require diversion to random(other than company specified: no mand fuel) ERA following depress'n event, how would you estimate fuel required by manipulating FMC? Ie put fl140 or 10000 ft all the way? I heard there is a simple formula can be used for quick estimation: ie use prog page 3,put ERA destn, get the dist, then dist X3 plus 3? Or something like that..can anyone help? Im on -400 and Appreciate any comments. cheers