Possible T/D bug with the 777-200LR SP1b

[Wothan 173]

I´m flying from EKCH (Copenhagen) to OMDB (Dubai) with the following route (Calculated by PFPX):

 

EKCH RWY 12

SID: SIME7B

SIMEG-Z491-KEKOV-N195-XIMBA-M860-CRM-UL852-VAN-UG81-BONAM-UL124-UMH-UL223-LAGSA-T217-LAM-G666-ORSA-B416-DESDI

STAR: DESD6D

OMDB RWY 30R

 

The FMC predicted a setpclimb from FL390 to FL410 at waypoint KAVIL on airway UL223, 383nm from Dubai.

But approximately 1045 nm from Dubai I got the T/D marker on the ND and an FMC announcement to "RESET MCP ALTITUDE".

On the FMC predicted altitude was shown to be FL390 for the next 873 nm. Step climb seems to have been canceled on the FMC.

The VNAV Vertical deviation scale is shown on both the PFD and ND, but centered (as expected since I´m predicted to be at FL390 the next 873 nm).

 

I find it weird to see T/D allready 1045 nm from my destination, as well as the stepclimb being cancelled.

 

I use ASN and update current winds and Descend forecasts every ½ hour.

 

Otherwise the flight has been smooth with no hickups, pause or other issues, using both ASN and RC4.3

 

 

Finn Jacobsen

[Haleo 3]

Could be a problem with a pre SP1 panel state ? 

[Wothan 173]

Could be a problem with a pre SP1 panel state ? 

 

Nope..

I don´t have any custom saved panelstates.

 

I simply build the flightplan with PFPX+ASN

Started FSX

Selected EKCH

Selected the PMDG 777-200LR

Started the sim

Setup passenger, cargo and fuel loads as noted in the PFPX flightplan

Loaded flightplan via the FMC + SID and STAR

Setup Performance and Take off pages

Started the flight

 

No inbetween saving

No Time acceleration

 

I paused the sim for appr. 40mins, but after resuming flight, the step climb and proper T/D point was indicated on the FMC correctly the next hour flying, but then changed as explained.

 

Here is the content from the PMDG 777 flightplan .rte file:

 

Generated by PFPX 09 Aug 2014 10:03 UTC

 

57

 

EKCH

1

DIRECT

1 N 55.6179 E 12.6560 17

-----

1

0

 

1

17

-

-1000000

-1000000

 

SIMEG

5

Z491

1 N 55.2500 E 13.5012 0

0

0

0

 

TELMO

5

Z491

1 N 55.0546 E 14.1163 0

0

0

0

 

KEKOV

5

N195

1 N 54.9494 E 14.4412 0

0

0

0

 

KOLOB

5

N195

1 N 54.8231 E 14.9442 0

0

0

0

 

ELPOL

5

N195

1 N 54.6064 E 15.6339 0

0

0

0

 

OGRES

5

N195

1 N 54.0106 E 17.0153 0

0

0

0

 

UNDUK

5

N195

1 N 53.5761 E 17.9764 0

0

0

0

 

NASOK

5

N195

1 N 53.0919 E 19.0064 0

0

0

0

 

SORIX

5

N195

1 N 52.6953 E 19.8200 0

0

0

0

 

XIMBA

5

M860

1 N 51.6558 E 21.4278 0

0

0

0

 

EGLON

5

M860

1 N 51.4167 E 21.9847 0

0

0

0

 

ROLKA

5

M860

1 N 50.4042 E 23.8256 0

0

0

0

 

KOVUS

5

M860

1 N 50.1422 E 24.2414 0

0

0

0

 

GORKU

5

M860

1 N 49.6053 E 25.0722 0

0

0

0

 

PEMIR

5

M860

1 N 49.2822 E 25.5550 0

0

0

0

 

INROG

5

M860

1 N 48.4147 E 26.8128 0

0

0

0

 

ERADA

5

M860

1 N 47.4392 E 28.2028 0

0

0

0

 

NETED

5

M860

1 N 47.1144 E 28.6492 0

0

0

0

 

KIV

5

M860

1 N 46.9260 E 28.9045 0

0

0

0

 

ANEDO

5

M860

1 N 46.3633 E 29.6919 0

0

0

0

 

DIGAM

5

M860

1 N 45.2583 E 31.1117 0

0

0

0

 

BOMKI

5

M860

1 N 44.5350 E 32.0300 0

0

0

0

 

NEVKA

5

M860

1 N 44.1575 E 32.4764 0

0

0

0

 

TUNSA

5

M860

1 N 43.9233 E 32.7583 0

0

0

0

 

ABRAN

5

M860

1 N 43.6172 E 33.1222 0

0

0

0

 

KUGOS

5

UM860

1 N 42.7806 E 34.0878 0

0

0

0

 

SIN

5

UM860

1 N 42.0223 E 35.0768 0

0

0

0

 

CRM

5

UL852

1 N 41.2655 E 36.5489 0

0

0

0

 

SEHER

5

UL852

1 N 40.5061 E 38.5736 0

0

0

0

 

BALON

5

UL852

1 N 40.0917 E 39.6083 0

0

0

0

 

ARKIN

5

UL852

1 N 39.9514 E 39.9167 0

0

0

0

 

ULGAN

5

UL852

1 N 39.6417 E 40.6925 0

0

0

0

 

NEGOL

5

UL852

1 N 39.4764 E 41.0792 0

0

0

0

 

KESIR

5

UL852

1 N 39.3153 E 41.4514 0

0

0

0

 

VAN

5

UG81

1 N 38.4661 E 43.3252 0

0

0

0

 

ZELSU

5

UG81

1 N 38.2656 E 43.7831 0

0

0

0

 

BONAM

5

UL124

1 N 38.0489 E 44.2997 0

0

0

0

 

TUDNU

5

UL124

1 N 37.8561 E 44.7217 0

0

0

0

 

UMH

5

UL223

1 N 37.6872 E 45.0844 0

0

0

0

 

SNJ

5

UL223

1 N 35.2389 E 47.0078 0

0

0

0

 

KRD

5

UL223

1 N 33.4351 E 48.2891 0

0

0

0

 

DELBU

5

UL223

1 N 32.7278 E 48.9064 0

0

0

0

 

ALTAX

5

UL223

1 N 32.1472 E 49.3983 0

0

0

0

 

MESVI

5

UL223

1 N 31.4889 E 49.9503 0

0

0

0

 

KAVIL

5

UL223

1 N 29.8056 E 51.2844 0

0

0

0

 

DAXOT

5

UL223

1 N 29.1461 E 51.8267 0

0

0

0

 

DASDO

5

UL223

1 N 28.8550 E 52.0631 0

0

0

0

 

LAGSA

5

T217

1 N 28.4947 E 52.3353 0

0

0

0

 

LAM

5

G666

1 N 27.3728 E 53.1840 0

0

0

0

 

LVA

5

G666

1 N 26.8121 E 53.3559 0

0

0

0

 

DATUT

5

G666

1 N 26.5589 E 53.5939 0

0

0

0

 

ELIRA

5

G666

1 N 26.3514 E 53.7506 0

0

0

0

 

ORSAR

5

B416

1 N 26.0750 E 53.9583 0

0

0

0

 

PEBAT

5

B416

1 N 25.8647 E 54.3992 0

0

0

0

 

DESDI

5

DIRECT

1 N 25.6008 E 54.7083 0

0

0

0

 

OMDB

1

-

1 N 25.2528 E 55.3644 62

-----

0

0

 

1

62

-

-1000000

-1000000

 

 

Finn Jacobsen

[3-2-1-Now 126]

 

 

The recommended altitude is set to the CRZ ALT when within 500 nm of the T/D.

 

It will also cancel any further step climbs. Did you clear any route discontinuities or anything like that? I suspect something is not right with the flight plan as you entered it.

 

Best regards,

Robin.

[Wothan 173]

It will also cancel any further step climbs. Did you clear any route discontinuities or anything like that? I suspect something is not right with the flight plan as you entered it.

 

Best regards,

Robin.

 

I´m 110% sure that there where no discos anywhere on that plan.

 

I loaded the flightplan via the FMC, entered SID & STAR and ran through the entire flightplan - removing any Discos.

I also checked the entire route in Plan mode.

 

Step climbs and T/D was indicated correctly from the start and well into the flight.

 

The only thing I have done is to update winds and forecast during the flight.

 

So my only theory is that there might have been som error in the wind data from ASN, but calculated fuel and estimated time to arrival has not changed more than a couple of decimals/minutes.

 

 

Finn Jacobsen

[Wothan 173]

I just landed at Dubai.

 

The flight went smooth apart from the TD/D issue and I executed a full LAND 3 autoland.

 

I did not reset my MCP altitude before the LEGS page told that the next waypoint was below FL390.

 

But the issue still feel weird.

 

 

Finn Jacobsen

[ZKOKQ 984]

I deleted all panel states Finn, that is including PMDG default ones. Try deleting all panel states, re install SP1B and try the flight again, Or any flight and see if it happens again.

[PeterAmsterdam 0]

Hello,

 

Just an idea but take a look at your flightplan in PFPX. Sometimes due to airway restrictions you have to descent to a lower flightlevel. After exiting the airway you are allowed to climb again to your desired altitude. I've had this once with a flightplan from EHAM to OMDB.

 

Peter Aertssen

Amsterdam EHAM

[Wothan 173]

What I saw was an altitude restriction at FL130A, but that was 873nm ahead of me.

 

I have now deleted the old panelstates and re-installed SP1b and saw that the dates are newer, so maybe that could be a reason.

It could also be a single hitchup, maybe introduced by faulty winddata from ASN.

 

Let´s see how the comming flights will evolve!

 

 

Finn Jacobsen