FlightDetent
3rd Mar 2004, 21:19
Our fleet is equipped with ASI-and-speedtape conf.
However, although there never were any commonality issues as it is the only Boeing model we have had and all aircraft are produced to the same standard, SOPs exclude the use of -F bugs for flap retraction.
More than that, eversince the beginning, for flaps 5 TO (99,9%) the speed schedule is alterned to SOP's 170, 190, 210. That is, flaps are brought to 1 not at Vref+15, but at 170 kt.
On our typical (scheduled short haul Europe) weights, this makes us fly on flap 5 setting 10 to 15 knots faster than necessary (ASI), or 15-20kt (speedtape) and about 10-15 kt faster on flaps 1 (speedtape only). My understanding is such, that this degrades climb performance. These effects come to my mind:
- higher fuel consumption (longer time-to-climb)
- increased wear to flap track mechanism (higher aerodynamical loads)
- enlarged noise pattern (lower climb-out profiles)
I would be very pleased to hear your comments on my reasoning, and more importantly, I'd like to ask, how do YOU fly the aeroplane. If you feel free to post so, I would also be happy to associate the procedure to a specific Operators name.
I understand fully, that in the early 90's the initial batches of pilots had been trained in Seattle and later on, some by Air France instructors. These pilots formed and created the first verison of our procedures that have insisted on this revised speed schedule eversince the beginning.
It may then be the case, there's a perfectly valid and economicaly viable reason to it and the case is that simply no one remembers. There are no commonality benefits in not using the speed tape. There are no unification benefits with flaps 15 TO schedule, as we make less than 5 a year (my guess), whereas the fleet is 20+ strong with about 120 departures a day.
Thanks for your views and info
FD.
PS: How can my typing be so bad that instead of "views" I always end up with "wives"? :eek: :E :mad: :ouch: :ooh:
However, although there never were any commonality issues as it is the only Boeing model we have had and all aircraft are produced to the same standard, SOPs exclude the use of -F bugs for flap retraction.
More than that, eversince the beginning, for flaps 5 TO (99,9%) the speed schedule is alterned to SOP's 170, 190, 210. That is, flaps are brought to 1 not at Vref+15, but at 170 kt.
On our typical (scheduled short haul Europe) weights, this makes us fly on flap 5 setting 10 to 15 knots faster than necessary (ASI), or 15-20kt (speedtape) and about 10-15 kt faster on flaps 1 (speedtape only). My understanding is such, that this degrades climb performance. These effects come to my mind:
- higher fuel consumption (longer time-to-climb)
- increased wear to flap track mechanism (higher aerodynamical loads)
- enlarged noise pattern (lower climb-out profiles)
I would be very pleased to hear your comments on my reasoning, and more importantly, I'd like to ask, how do YOU fly the aeroplane. If you feel free to post so, I would also be happy to associate the procedure to a specific Operators name.
I understand fully, that in the early 90's the initial batches of pilots had been trained in Seattle and later on, some by Air France instructors. These pilots formed and created the first verison of our procedures that have insisted on this revised speed schedule eversince the beginning.
It may then be the case, there's a perfectly valid and economicaly viable reason to it and the case is that simply no one remembers. There are no commonality benefits in not using the speed tape. There are no unification benefits with flaps 15 TO schedule, as we make less than 5 a year (my guess), whereas the fleet is 20+ strong with about 120 departures a day.
Thanks for your views and info
FD.
PS: How can my typing be so bad that instead of "views" I always end up with "wives"? :eek: :E :mad: :ouch: :ooh: