I'm trying to cruise at altitudes greater than FL350 and cannot do so. I just cannot climb above this altitude no matter what I try, even at lighter weights than 110k. Is there a an OPT CRZ FL determined by the FMC as it is in other Boeings or is the 737 FMC really that cut down as compared to the -800 and other Boeings?Right now my Wife is on a SWA 737-700 @ FL390 about to descend into Tampa (even though flying West from KPVD...)Tim

I'm pretty sure even a 737-400 FMC computes OPT CRZ level. Dreamfleet's does.Lee Hetherington (KBED)

I have no problem with getting to cruise-level greater then fl 350. I usual fly at fl 410. But you could fly at fl 350, and after a while step to a greater altitude when you have burned some fuel.Marius

>I have no problem with getting to cruise-level greater then>fl 350. I usual fly at fl 410. But you could fly at fl 350,>and after a while step to a greater altitude when you have>burned some fuel.>>MariusOne other thing - because the FMC does not (yet) model cost index, it will not properly calculate your optimum cruize altitude - it will always default to FL350.Be sure and set your preferred cruise altitude on the PERF INIT or CRUISE pages and you shouldn't have a problem, assuming you're not too heavy.

I just climbed a -600 to FL390. I was using MAX RATE climb, but at FL380 at M.755 I was still climbing at 1100fpm. At top of cruise, my GW was 112,000lbs.Lee Hetherington (KBED)