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Flaps30

FMC Won't Hit Target Altitude

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I decided to fly Fred Clausen's tutorial ver. 2 from KJFK to KORD with the 737-700. I've tried several times, but can't seem to get her to make the 200/5000 restriction at PAPPI. I followed the directions exactly, but no dice. It calls for hitting Decend Now about 30 nm before the top of decent point, which it begins nicely. The decent profile shows up on the display, but the decent never increases above 1000fpm. The decent profile then disappears. It arrives at PAPPI at about 22000 ft rather than 5000, and at a speed above 200. I made sure I hit exec on the fmc but still no. I'm in VNAV and LNAV and there are no VNAV disconnects. Has anyone tried this flight before? Any ideas? Thanks. Tom

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The expected behavior is to descend at 1000 fpm until the VNAV profile then follow the VNAV profile down at whatever rate it commands. You didn't provide enough info to figure this out, such as when the VNAV profile disappears, the cruise altitude from which you started the descent. Is 5000 at PAPPI the only constraint? Are you on the SAYRS2 arrival? It has a constraint at GHOST of 10000 and none at PAPPI... so I can't figure out what your arrival flight plan was either. Sorry I can't help yet.


Dan Downs KCRP

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Hi Dan,First of all, thanks for helping me. Sorry for not including more info, I didn't realize what you would need. Turns out, I think I solved my own problem. Seems the tutorial never mentioned one important step - to hit the exec. key on the FMC. Not thinking, I typed in exactly what it said, and didn't realize it probably didn't lock in the command. For the record, here is the flight plan and the exact instructions:KJFK-COATE-J36-FNT.PMM4-KORDEnter 5000 into the MCP ALT WindowOpen up the FMCPress the LEGS pagePress NEXT PAGE until you see PAPPI displayed on the FMCEnter 200/5000 into the scratch pad, and then press the LSK on the right side that corresponds to the PAPPI intersection.Press the DES buttonPress DES NOWPress EXECPress DEP ARRPress LSK 2RPRess NEXT PAGE until you see DILS27LPress LSK 2R to select the WAVIE transition Press EXECAs you can see, the EXEC command comes after the DES NOW instruction. Apparently this is only for the DES NOW commnad and not the 200/5000 restriction also. I noticed this and hit EXEC right after the 200/5000 entry and it worked beautifully. Thanks again. Tom

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