Return to cruise

[sandpatch 9]

I have searched in the forums but without success.

 

I tried flying a tactical mission with the poseidon where I climbed to a cruise altitude, descended on the tactical area, flew around and would return. I wasn't able to get the plane to return to climb/cruise mode. Is there a procedure to reset the system so it will accept climbing again?

[scandinavian13 5,192]

 

 

Is there a procedure to reset the system so it will accept climbing again?

 

Re-enter a cruise altitude on the CRUISE page. Start the climb in FL CH with the intended cruise alt (or initial cleared alt) in the alt window to get you into a climb. Once you re-enter a cruise altitude in the FMC, you should be able to switch back to VNAV.

[sandpatch 9]

Yeah, I thought so too but when I entered a new cruise altitude it would jump back to the descent page...

[scandinavian13 5,192]

Yeah, I thought so too but when I entered a new cruise altitude it would jump back to the descent page...

 

Even when you're climbing in FLCH with an altitude higher than your current?

[sandpatch 9]

Yeah, that was the way I remembered it so I did it. I can try again soon and I'll report back

[scandinavian13 5,192]

Yeah, that was the way I remembered it so I did it. I can try again soon and I'll report back

 

It may require you to climb in FLCH or V/S back to a cruise altitude such that you're at the altitude in the window in ALT HOLD before you can go back to re-set the cruise alt. I'm not looking at the manual right now.

[sandpatch 9]

Hmm, when I retried this I totally broke the left FMC. I only accepted a single letter in the scratchpad and it didn't show me warnings. I did come to some rte finishes since I pretended to be on a patrol mission and I did stretch the FMC to it's capabilities. It feels as if I have come further than any beta tester so I will just give up here. This is more than a quick fix to solve.

[scandinavian13 5,192]

Hmm, when I retried this I totally broke the left FMC. I only accepted a single letter in the scratchpad and it didn't show me warnings. I did come to some rte finishes since I pretended to be on a patrol mission and I did stretch the FMC to it's capabilities. It feels as if I have come further than any beta tester so I will just give up here. This is more than a quick fix to solve.

 

That's interesting. If you come across it again and have a set of steps to reproduce it, we'd be grateful. It would help us chase it down if it's an issue.

[Tino 81]

Hi Kyle, 

 

Found this issue about 30 minutes ago. Currently flying KIAD - KLAX. Wanted to step climb, so I entered "34000" in the CRZ page since I was stepping up from FL320. Once I hit execute, the descent mode activated. I held off the decsent by hitting ALT HOLD. I manually flew up to 34000. When holding at FL340, tried entering the new altitude in the CRZ page and it just goes directly to the DES page again. Now, I'm also noticing single digits when trying to enter "any" information in the L FMC. I have to currently use to R FMC in order to enter information. 

 

I don't usually need to use step climbs in the NGX, so I can't say I've done it before. Here's how I was going to initiate the step climb: Enter FL340 in the CRZ page, reset MCP ALT to 34000 and hit FLCH. maybe I'm doing something wrong here? As of right now, I'm in ALT HOLD at FL340, with SPD Intervention armed at .79 Mach since VNAV wants to reduce power for decsent. Funny thing is CRZ is still showing on EICAS screen. 

 

Thanks for your time.

 

Sante-

[scandinavian13 5,192]

Thanks for your time.

 

Steps to reproduce?

 

What was set on your PERF INIT page as the cruise altitude? Be as specific as possible so that I might be able to try and reproduce what you're seeing.

[Tino 81]

Steps to reproduce?

 

What was set on your PERF INIT page as the cruise altitude? Be as specific as possible so that I might be able to try and reproduce what you're seeing.

 

Steps to reproduce would be to start the flight at KIAD with exact weight\fuel figures. Step climb would be roughly 30 minutes after departure up to FL340. Using the 737-900WL latest version. 

 

Also, If you have ASN, I have been using LIVE weather from Dec, 6th. 2015, in case you need to use historical. 

 

CRZ ALT was at 32000 in the PERF INIT Page. This information was provided to me by PFPX, exported directly to the NGX. (In case you'd like to reproduce).

 

********************************************************************************

                    F O R   I N F O R M A T I O N   O N L Y

********************************************************************************

UNITED AIRLINES FLIGHTPLAN - IFR  UAL1073B  N32404  KIAD-KLAX 

--------------------------------------------------------------------------------

ALL WEIGHTS IN POUNDS (LB)                                       STD 06DEC/1850Z

--------------------------------------------------------------------------------

OFP 1 - PREPARED 06DEC/2222Z BY SANTE SOTTILE  

 

1073B/UAL1073B      N32404/B737-9ERW CF                   ROUTE:          (AUTO)

 

DEP: KIAD/IAD 19R   ELEV   313 FT   MACH:       M.81      TTL G/C DIST:  1986 NM

ARR: KLAX/LAX 25R   ELEV   128 FT   INIT ALT:   FL320     TTL F/P DIST:  2006 NM

                                    FUEL BIAS:  100.0%    TTL AIR DIST:  2211 NM

                                                          AVG WIND CMP: HD042 KT

ALT: KLGB/LGB 30    ELEV    60 FT   27 NM

--------------------------------------------------------------------------------

CONFIG      DOW  PAX   CARGO   TOTAL   ULOAD LIM             ZFW     TOW     LDW

STANDARD  94600  153    7417   36429    2048 TOW     MAX  136100  174700  157300

                                                     PLN  131029  172652  140999

                                                     ACT  ......  ......  ......

 

               FUEL    CORR    ENDUR

TRIP       31653  ........  04:51 

CONT 5%        1583  ........  00:19

ALTN KLGB      1026  ........  00:08

FINAL RESV     2443  ........  00:30

HOLD           2460  ........  00:30

MIN T/O       39165  ........  06:18       .....................................

EXTRA          2458  ........  00:30       CAPTAINS SIGNATURE  (....)

TAXI            250  ........  00:10       

RELEASE       41873  ........  06:58       I ACCEPT THIS OFP AND I AM FAMILIAR

                                           WITH THE PLANNED ROUTE AND AERODROMES

 

FUEL TANK CAP 46057 LB / MAX EXTRA FUEL 2048 LB LIM BY TOW

TRIP CORR FOR 3000 LB TOW INCR: +313 LB / 3000 LB TOW DECR: -466 LB

2000 FT LOWER:  +900 LB / EET 04:47  CLB: 250/280/78  DES: 78/280/250

 

--------------------------------------------------------------------------------

KIAD  STD 18:50Z/13:50L  ETD 18:50Z  ACT OFBL ....  EST T/O 19:00Z  ACT T/O ....

KLAX  STA 00:30Z/16:30L  ETA 23:56Z  ACT ONBL ....  EST LDG 23:51Z  ACT LDG ....

          05:40              05:06   TTL BLCK ....                  TTL FLT ....

--------------------------------------------------------------------------------

 

ATC ROUTE: N0474F320 BUNZZ3 RAMAY J149 EYTEE J6 COLNS J134 STL J110 RSK J64 TBC J128 PGS RIIVR2

 

Let me know what other information you'd like. I can't see what was in my PERF INIT now since it's still showing a descent profile.

 

Thanks,

 

Sante-

[scandinavian13 5,192]

Let me know what other information you'd like. I can't see what was in my PERF INIT now since it's still showing a descent profile.

 

This is all well and good - the weights would help me get the plane into a similar weight state, and the route helps me get an idea of where you were going - but I need the button presses and procedure. Clearly, the airplane got into a state that was confused. I need to know how you get it into that state. Might you have set the cruise altitude too high - say FL360 - on the PERF INIT page such that when you were cruising at FL320, and wanted to change to FL340, 340 was actually a descent from 360...? Somehow the plane got into a situation where it saw 340 as a descent. That's what I need.

 

See if you can get it to do it again, and then let us know what exact steps are required.

[Tino 81]

This is all well and good - the weights would help me get the plane into a similar weight state, and the route helps me get an idea of where you were going - but I need the button presses and procedure. Clearly, the airplane got into a state that was confused. I need to know how you get it into that state. Might you have set the cruise altitude too high - say FL360 - on the PERF INIT page such that when you were cruising at FL320, and wanted to change to FL340, 340 was actually a descent from 360...? Somehow the plane got into a situation where it saw 340 as a descent. That's what I need.

 

See if you can get it to do it again, and then let us know what exact steps are required.

 

That makes sense! It could have been a much higher number in the PERF INIT page at the gate. I might have skipped over it by mistake and assumed PFPX was inputting that information automatically. I will re-visit the flight in the future and see if that was the culprit. 

 

Thanks for your time, Kyle.