What did I do wrong?

[J D ADAM]

Flight RJAA/VHHH Everything satisfactory until TOD (VNAV/LNAV).
Noticed whilst descending that VS was 400fpm,and although I knew this was incorrect I left it like that to see what happened. Of course by he time I reached Hong Kong I was far too high for approach so went into a holding pattern at TONIC(very odd reproduction on the Nav display) . Then for approach. Well, firstly the ILS did not record DME and the glide slope would not capture (Cat2).Then whatever I did including lowering the flaps and wheels the yellow under speed warning to the left of the FD would not drop.
I know that I should have gone flight change after realizing the discrepancy after TOD, but wanted to see the result of VNAV.
So the landing! was a complete ballsup!
What did I do wrong?

Derek
NZAA

[Jeroen Hoppenbrouwers]

Do you have a situ file?

[ScudRunner]

A very wild guess...

Some sort of pitot/static/Air data problem (relating to the speed tape issues)

Scud.

[Tom]

My guess, if you have throttle hardware, all 4 levers need to manually return to the full idle position otherwise the auto-throttle will "assume" HOLD, but the throttles will be producing more power than needed keeping you high on VNAV.

[John H Watson]

Perhaps a combination of factors.

Were your engines at idle during the descent? Perhaps your joystick throttle was out of idle? VNAV Idle descent allows manual thrust input without disconnecting the auto throttle, but at some point, you should get a DRAG REQUIRED message if you stray too far above the descent profile. Did your PFD show that you were on the descent profile? (vertical deviation indicator was centered)

Were there any abnormal height restrictions in the STAR?
Did you get your FMC weights incorrect at the start of the flight or did you make a wrong entry on the APPRoach page for approach speeds? (or none at all)

Were there no EICAS messages?

Not all ILS's have associated DME's, although I would have thought VHHH should have had the latest equipment.

Rgds
JHW

[J D ADAM]

Were your engines at idle during the descent? Perhaps your joystick throttle was out of idle? VNAV Idle descent allows manual thrust input without disconnecting the auto throttle, but at some point, you should get a DRAG REQUIRED message if you stray too far above the descent profile. Did your PFD show that you were on the descent profile? (vertical deviation indicator was centered)

Thank you for your replies Gentlemen
You could be correct in saying that my throttles were not in the idle position, but this has occured often when flying autos due to stupidity but on all other times this has had no effect.  

 

Were your engines at idle during the descent? Perhaps your joystick throttle was out of idle? VNAV Idle descent allows manual thrust input without disconnecting the auto throttle, but at some point, you should get a DRAG REQUIRED message if you stray too far above the descent profile. Did your PFD show that you were on the descent profile? (vertical deviation indicator was centered)

Were there any abnormal height restrictions in the STAR?
Did you get your FMC weights incorrect at the start of the flight or did you make a wrong entry on the APPRoach page for approach speeds? (or none at all)

Were there no EICAS messages?

Not all ILS's have associated DME's, although I would have thought VHHH should have had the latest equipment.

No drag required message!
Weights were correct based on PSPX and showed  an expected 14 tonnes on arrival

Cannot answer on the descent profile
No drag required message although I instituted drag.
DME answered shortly

Do you have a situ file?

Only at push and start

Some sort of pitot/static/Air data problem (relating to the speed tape issues)

Buggered if I know!!!

My guess, if you have throttle hardware, all 4 levers need to manually return to the full idle position otherwise the auto-throttle will "assume" HOLD, but the throttles will be producing more power than needed keeping you high on VNAV

Answered above.


Finally I thought i would set up a situ at LIMES which is prior to TONIC. Set a hold at TONIC and CAT2 land at VHH.

Worked perfectly. Profile of hold represented perfectly on the nav display, DME came up

My feeling is that the computer had a minor heart attack  

Any way onwards to learn all the complexities of PSX

Cheers

Derek

[Jeroen Hoppenbrouwers]

Next time, push the EVENT REC button when you have a "wuk?" moment. That will give you the opportunity to pick up the situ file saved at that moment and reconstruct later.


Hoppie

[J D ADAM]

Hi Guys,
re flew RJAA/VHHH and no problems all so must have been a computer glitch!

 Well not quite no problems  except visitors arrived just prior to descent and I had to put the aircraft on a sky hook for an hour #$$%%$#

I had surgery 2 weeks ago and PSX has been my savior  during my convalescence.

Thanks Hardy

Cheers
Derek