Information on STEP CLIMBS

[Guest Popo]

Hi everyone,In flight planning for B747-400 I am having difficulties in determining where the step climbs are supposed to be and how to set them in the FMC. For example I am planning to fly 35,000 ft how do I then sequence the step climbs? I assume there must be a procedure that determins this. Is there an article or link that can help me know and learn the ABC's about this? It may sound dumb, but that is what I am facing.Thanks for your assistance in advance.Cheers,Popo.

[downscc 1,327]

No dumb questions here.The FMC does the step climb calcs for you (close enough for most of us). Set the STEP value to 2000 for RVSM airspace such as NATS (the default I think is 4000). Look on the cruise VNAV page, it tells you optimum, maximum and distance to next step automatically once you are on your way. There is no pre-programming when the steps will occur, and it will not recommend a step if there is less than 500 nm remaining for that step.I am usually too heavy to get to FL350 directly, so my FMC cruise altitude is maybe FL290 or FL310. The first step usually occurs somewhere between 800 - 1200 nm depending mostly on weight. The FMC will provide miles to step and it is displayed on the ND as a small circle with SC next to it.To execute the step smoothly, I change to ALT HLD, increase the MCP ALT and the FMC cruise altitude, then use V/S to climb in the step at 400 fpm. Once there, I put it back in VNAV although that is just habit. I prefer doing it manually to not disturb the folks watching the movie.

[FLEX1978 373]

[To execute the step smoothly, I change to ALT HLD, increase the MCP [ALT and the FMC cruise altitude, then use V/S to climb in the step [at 400 fpm. Once there, I put it back in VNAV although that is just [habit. I prefer doing it manually to not disturb the folks watching [the movie.His Method works very well. Another option is to remain in VNAV select a higher alt on the MCP and push the ALT knob. This will also update the FMC with the new ALT.Rob

[Guest nilisvd]

It is also possible to approximate the step-climbs on forehand. By using your take-off weight you can use the table at the bottom of page 2-9 in the manual to determine the optimum flight level. In the same table the last column gives you the 'time to burn wt'. This gives you an estimate of the time it will take to burn as much fuel for the next optimum flight level. Another, probably more exact way of determining step climbs is described in the manual written by Craig Read, see http://www.speedbirdonline.co.uk/downloads..._1.0_206648.zip. The method describe over there makes use of the tables presented on page 2-10 and 2-11 of the manual.Be aware that the tables are for a Mach .86 cruise.

[cavaricooper 2,614]

Popo:The only thing I would add, is that when flight planning, make sure your PERF page is correct (close to proper fuel load) and make sure your waypoint winds have been entered. That way you will have a complete picture of the flight profile before departure. The FMC really is the best place for final flight planning, and with the 2000 STEP entered, you will be able to see if you need to lower your initial CRZ altitude, to allow the vertical profile to more closely sync with the OPT altitude.Dan's method of dialing in the new ALT and then going to VS 400+ allows the champagne and foie-gras in first to remain undisturbed. Rob "freight dog" Prest's method works fine for pallets of Asparagus enroute to the market. Either way, pushing the ALT knob on the MCP will allow the FMA to return to SPD VNAV PATH.Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 | 2 x APC UPS | Coolermaster Stacker 830 SE | Gigabyte P35 DS3R | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Creative X-Fi Fatal1ty | 2 x 1 GB Corsair XMS2 | 2 x 320GB WD Caviar RAID 0 | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |

[FLEX1978 373]

Your right Carl, never had a box complain once! :) Rob

[Guest Popo]

Gentleman,Many thanks for all your advises. I will follow the steps advised and see it fairs. Shoudl I still fail I will come back you guys again.It is wonderful to have such kind of assistance from fellow simmers.Great guys and cheers.Popo

[Guest Popo]

Gentlemen,Many thanks for all your guidance on going about the step climbs. I will try it out and see how I fair.One thing is correct, is that one needs to do some good reading of the manuals to get the basic understanding and the obviously practice, practice, practice.Cheers Popo

[cavaricooper 2,614]

>Your right Carl, never had a box complain once! :) >>RobThere's something to be said for freight! Interesting destinations, higher ZFW and MLW and nary a crisis at FL330. I do enjoy flying "Jet-Lift" every so often. ;)Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 | 2 x APC UPS | Coolermaster Stacker 830 SE | Gigabyte P35 DS3R | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Creative X-Fi Fatal1ty | 2 x 1 GB Corsair XMS2 | 2 x 320GB WD Caviar RAID 0 | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |