I have a question concerning the proper method of changing FL. If you are cleared by ATC to climb to FL200. You reach that FL and for whatever reason you stay at that FL for a short bit. Finally you are cleared by ATC to climb to your filed cruise altitude of FL360. You dial 36000 into the MCP and...

 

What is the proper procedure to get the 737 to begin its climb to FL360? Is it press LVL CHG than reengage VNAV or do you dial press ALT INTV?

Hi

 

ALT INTV would be the way it's done. Pressing it will reset your FMC cruise altitude to the MCP selected altitude.

 

Keep in mind LVL CHG and VNAV are independent of each other. VNAV flies the vertical profile you have programmed in your route while LVL CHG pitches to maintain a climb at your specified speed. When pushed, It will annunciate "N1" on the speed mode and "MCP SPD" on the pitch mode for a climb at your MCP selected speed. Hope that helps.

 

Cheers

That does, thank you Paul.

I think you can also do it via CRZ page on CDU.

CRZ page on the CDU? Not as far as I am aware. If your cruise ALT was, for example FL360 and you are currently at FL360, you may then use the CRZ page to enter a higher ALT such as FL380. If you enter that into the CRZ page then dial the MCP to 38000 the NGX will start the climb with VNAV.

 

However, in my hypothetical question ATC only cleared you to FL200 for whatever reason. Your CRZ page on the FMC has FL360 from when you entered it on the ground before departure. Your MCP has FL200 because that was the last altitude you were cleared for. You are currently at FL200 and have been for a few minutes waiting for clearance to resume climb. Now ATC is clearing you to climb and maintain FL360. What is the correct way to get the NGX to resume the climb after you dial 36000 into the MCP?

CRZ page on the CDU? Not as far as I am aware. If your cruise ALT was, for example FL360 and you are currently at FL360, you may then use the CRZ page to enter a higher ALT such as FL380. If you enter that into the CRZ page then dial the MCP to 38000 the NGX will start the climb with VNAV.

 

This is the method I normally use for step climbs.

 

You are currently at FL200 and have been for a few minutes waiting for clearance to resume climb. Now ATC is clearing you to climb and maintain FL360. What is the correct way to get the NGX to resume the climb after you dial 36000 into the MCP?

 

I had a situation last week when ATC on VATSIM only cleared me to FL350 instead of my planned FL370 due to traffic just ahead of me also at FL370. After about 10 mins I was cleared to FL370 so I put 37000 into the MCP and pressed ALT INTV while in VNAV to climb and that worked OK. I did notice that the RESET MCP ALT message popped up on the FMC when I leveled out at FL350.

Thank you, Michael.