User needs help understanding Step Climb

[Leffe 4]

You are mistaken. Check FCOM Vol.2, page 11.42.22

I admitt that I was wrong about this FL380 instead of step of 2000 feet, which i thought.I guess I read it wrong in the other manual then, and that I usually always do my steps manually./ LeffeI´m curious if you got an answer why you couldn´t climb then?Also I understood it had something to do about wind/fuel etc but as you saidyou set up an average of Cruise wind from ASE so I don´t either understand what oneshould change that./ Leffe

[Mike Ionas 5]

The predicted wind was entered in the PERF page, while the CRZ page was using actual wind for its calculations. I was able to climb when the time came, the calculation was wrong.

[Leffe 4]

The predicted wind was entered in the PERF page, while the CRZ page was using actual wind for its calculations. I was able to climb when the time came, the calculation was wrong.

Ok, good to know./ Leffe

[janpitor 2]

I had/have a different Issue, of FMC suggesting me a Flight Level of FL362 on a 25 Min' route (79nm), totally not realistic to climb that high for such short route.if any one knows how to over come this, it would be amazing.

The FMC doesn´t calculate it based on the route lenght. Only on weight/fuel consumption etc.

[Akila 39]

The FMC doesn´t calculate it based on the route lenght. Only on weight/fuel consumption etc.

that is strange.based on what I was told, it should, I just could never find that "trip" altitude that everyone kept mentioning to me.

Well first of all, it's not called OPT Altitude - but "trip" altitude. And the page I'm speaking of is the INIT REF page 1.

FMC will Calculate it for you. It's called trip altitude, and is shown on the INIT REF page 1 in the FMC. It do however require you to enter basic information: Origin, destination, CI and Weights

Here is from the manual:

Trip altitude is automatically computed and displayed whenever entries have been made for the ORIGIN, DEST, GROSS WT, and COST INDEX. Otherwise, the field is blank.Trip altitude is the predicted minimum cost altitude determined by operator constraints. Provides crew a reference for selecting a planned cruise altitude.

there are flights that short in real life (i do them all the time in real life - as a passenger)example LLBG - OJAI, well Royal Jordanian uses ERJ for that route , but it could easily be an NG.you will see those short distances more often in south east Asia, like Philippines or Indonesia when it's Island hopping,long enough to justify a flight (as cursing it in a ferry would take a long time), but it is actually a very short distance/flight.or in places that there are no roads (crossing the rain forest) and only by flight you may reach there (e.g. Sentani/Jayapura - Papua , Indonesia to the baliem valley, must be done by air, even thoughthe distance is very short) - done by Merpatti commercial Airline & Lion Air, and guess what Lion air were the 1st to have the NG900 in the world at 2006/7.Another example I used to use those flights in the Philippines, when the roads conditions are very bad and a ground ride would take you like 8hr or so, there is an alternative of taking it by Air, e.g. Puerto Princesa <-> El Nido (Palawan).I use those short flight many times in the FSX/NGX. for me it is crucial to have that calculated.

[willywonka 36]

Also Emvaos is right, found that in FCTM/ Leffe

Haha, he would have to be; he programmed the damn thing! :D

[Mike Ionas 5]

The STEP calculation does not work with simplistic optimal altitude vs weight calculation (only) but mainly with fuel saving. That includes speed scheme, wind and ISA to begin with. The FMC recalculates an entire "test" RTE in parallel to the actual route and compares fuel at arrival. In your pictures the ACTUAL WIND values between STEP inquiries change considerably. Perhaps so does ISA DEV. Different input, different output. It is a solver not a table interpolation method.In case of a MOD RTE or STEP scheme displayed in the CRZ page you can actually edit R3 and enter your own wind forecast. The header will change from ACTUAL WIND to EST WIND.

Dear Vangeli,I tried the step climb using estimated winds instead of actual as you suggested but the problem remains.This time the flight was from LGAV to LHBP following NEVRA UZ507 TSL UL617 MAKED UP36 RAXAD UL617 PARAK UY554 ABONY. Initial FL F360 with a step climb to F380 a little bit later.After reaching cruise level I selected the CRZ page and entered the new FL and the estimated wind:The s/c was calculated correctly and then I selected the PROG page:Everything normal again and the s/c was calculated a little bit before MAKED wp:However, after a few minutes when selecting the CRZ page for a second time, the initial calculations disappeared:and the step point changed to NOW:and when selecting PROG page the s/c time remained correct while the distance changed to a negative 6 digit value:although in the ND the s/c was displayed at the same position as before:Afterwards I returned to the CRZ page, deleted the STEP CLIMB value and upon re-entering it it was again calculated correctly regardless of actual or estimated winds. However when i visited the CRZ page again after a few minutes the same problem occurred.Therefore the first time the step climb is always calculated correctly. However if after sometime I visit the CRZ page again the problem occurs.Is this only happening to me?MikeP.S. It seems somebody changed the subject of this topic from "step climb problem" to the one displayed now...