Originally Posted by
sailingfun
Generally they don't make daily or even monthly adjustment to the block. Its normally seasonal. The number you need to look at for the 747-400 would be what they are blocking it at today. If its blocked at 11:40 today they should not have any problems with the 330 for the summer. If however the switchover to summer block times is done on 15 May as a example then there may be a issue. If the 400 has been making it in the winter under 12 hours however there should not be a problem with the 330 making it under 12 hours in the summer. The good news is the FAA is all over Delta on this issue since they have pushed it in several markets. The rule is that the flight must come in under 12 hours 70 percent of the time to remain with a 3 man crew. The Delta flight planning system does not give the company the ability to fudge the numbers. It is very accurate on flight times. The varible is taxi time. Delta has been known to get special taxi clearances for flights that look like they will go outside the 70 percent rule to speed things up. Moscow-Atlanta on the 767ER is a example. You also get arrival priority on that flight. They don't grant exemptions so if you only make it 69% of the time you have to drop the route or add the 4th crewmembers or bunks.
NW has changed block times within their published timetable when they think it saves them money. NWALPA won a grievance years ago that the company had to pay us based on their published public timetable. This kept them from padding the times for On Time performance but paying us a lot less than the padded time.
As far as summer flying is concerned, the A330 may or may not make it in under 12 hours. It depends on the flight path. Our dispatchers have sent us on very southern routes for turbulence avoidance (i.e. not NOPAC). For the week that the A330 replaces the 747-400 on LAX-NRT service, the 747 scheduled block time is 11:40 (winter winds)