BMI Baby decomp, 3rd sept

[blue up]

On the way home from ZTH we expedited a descent after a Baby called for an Em descent to fl100 in the London TMA. Last we heard was him being cleared below Fl250 for further. Very clear voice comms (?) and sounds of the cabin alt 'bong-bong' in the background.

Anyone know what the final score was?

I'm still writing our winter refresher course on pilot incap this week and wondering if there is anythig worth adding to my course content.

[AltFlaps]

All turned out well ...

Was caused by an engine bleed trip off, and subsequent climbing cabin.

Handled well, landed uneventfully in BHX

AF

[blue up]

Orphanage unharmed and all hospitals narrowly avoided!

Case closed.
(..although not aware how easy it is for 73 bleed loss to cuse cabin alt warning)

[Tail-take-off]

Unfortunately it happens all too often on the older 737s that when one bleed fails you find out that the other is not up to the job on it's own:uhoh:

[fireflybob]

(..although not aware how easy it is for 73 bleed loss to cause cabin alt warning)

Perhaps they had dispatched with a pack u/s to start off with? (Although this means max FL250)

[Flight Detent]

Wonder why they didn't push the "Horn Cutout" switch as a first response to the alert!

Cheers...FD...:confused:

[AltFlaps]

They did not dispatch with one pack U/S ...
The crew were very surprised by how quickly the cabin began to climb with one bleed/pack tripped ...

[preferboeing737]

I had this happen once while on the jumpseat of a 737-800. The good pack wouldn't hold pressurizion even though it should have. I found out later that mx discovered that the remaining pack had a pack valve that was frozen shut and not supplying any air. They didn't know how long it had been inop. as it was only discovered when the other pack failed. Needless to say I'm not very impressed with their mx. department.

[stevehudd]

dont want to play devils advocate but why does it always happen on a 73?

[PAXboy]

stevehudd A non-expert answer/guess would be: There are more 737s in the world so are likely to have more incidents through sheer weight of numbers. How many times a day to Ford motor cars break down around the world and how many Fords are in existence?

I sit to be corrected.

[ironbutt57]

It's all about sectors and numbers.....who flies the most and under what conditions....and it doesnt always happen on a 737...just happened to me on a plastic french jet...:yuk:

[boyband]

All I can say is - Thanks to the the professionalism of these pilots who handled this situation superbly. They clearly aren't paid enough for the job they do.:ok:

[get a bigger hammer]

Pack problems are notoriously difficult to isolate on the Classic 737. Its a mature system now but the FIM that maintenance guys have to work to although exhaustive is not practical to use. Practically every engineer I know type rated on the 737 would like to see a vast improvement in its reliability.

Poor pack operation on one side can easily be disguised when operating on two packs. When the good one lets go the cabin altitude will climb. Any aircraft that has to be released on single pack operation should have an assurance check performed prior to dispatch (MEL dependent). This is also a scheduled maintenance task carried out at differing times dependent on operator. It checks both the integrity of the pack and of the hull to maintain that pressure.

So next time before being critical of maintenance think of the wider picture, Its not just pilots that are under pressure percieved or other wise.

[FE Hoppy]

Funny how in the old days any FE worth his salt would know which aircraft in the fleet leaked more than others and which packs were good or bad by monitoringcabin rate changes when packs were switched on or off. Just another unlisted task that has fallen by the wayside.