A320 Emergency Descent
 

Airbus guidance prior to commencing the descent is “communication establish”. Can I get some feedback of different airline philosophy regards heatset ON/OFF after donning the O2 mask? .

I see a lot of different crew turning cockpit speaker OFF before engine start, however I have always assume assumed the Airbus policy of setting the speaker volume to 1 o’clock position ( during cockpit preparation) had something to do with emergency descent scenario. i.e Mask on and Int On is enough to establish comms?

In the cruise, you are normally headset off, loudspeaker 1 o clock’ position. So in case of emergency descent, you first put the mask, then your headset. The other way around might be difficult and uncomfortable especially if you were big headset, you won’t be able to put the oxy mask on top of it. You can experiment it. We don’t rely on loudspeakers during emergency descent. We do a quick « intercom check » then intercom back to off to avoid the noise created while you breath in the oxy mask. Only turn the intercom On when you need to talk.
We always set loudspeaker to minimum in my company while using headset as otherwise it creates an annoying echo. We are using the TELEX 850.

And be aware that after a rapid decompression you may be rendered deaf until the pressure differential across your ear drum clears.

In my opinion, turning the speakers off or anywhere below audible is a silly idea.

As an aside I would say beware. I always use noise cancelling headsets. I have never got round to measuring the actual level, but the A320/321 ventilation and airstream noise of some I have flown is quite loud - especially if the filters are blocked. 6-8 hours or more of that every day could damage your hearing. A330 is quieter, but I still normally keep my ANR headset on. If your hearing gets damaged there is no cure - it can’t be fixed.

Generally EMER DES is executed in a unnecessary hurry. EMER DES should be understood as two parts exercise. The EMERGENCY part and RAPID DESCENT part. Emergency is from possible hypoxia and this gets over when O2 mask is put on. In establishing communication one can definitely spend some seconds to ensure whatever it takes. Passenger masks have taken care of their O2 requirement. Now what is left is a rapid descent. Aircraft pitches down only at 1g, banks and turns at certain rate which doesn't increase no matter how fast one rotates the buttons. So just do it the way one does for normal descent except in select speed VMO/present speed and use speedbrakes. Rest is read and do.That's all there is to it.

Uplinker

Agreed 100%. The cockpit isn’t quiet enough for me to have it off as a rule.

Does anyone have a reference about the maximum altitude from which you would not execute an emergency descent, just a rapid descent without reaching for the oxygen mask. I seem to recall somewhere in the region 16,000ft to 20,000ft, you would arrive at 10,000 in a couple of mins. Am I making this up or have I read that somewhere?! Thanks

The Abnormal procedure for “excess cabin altitude” uses 16000’. I.e Below 16000 descend. Above 16000 emergency descent. Refer to the FCOM PRO ABN CAB PR.

Procedure at my airline is mask on, headset on, select intercom and then a brief “I’m on comms” from both pilots to establish that 1) they are alive and 2) microphone/audio is correct. Then PF calls “emergency descent” and starts memory item flows. Speaker is normally on anyway but putting headset on as SOP should improve being able to hear your colleague and ATC

I believe the masks are set for deployment above a cabin altitude of 16000 ft for high altitude opperations and 14000 ft for normal ops if they have not been deployed earlier by the pilot. i also understand that oxygen is very limited, Round 12 minutes.
It is worth noting that a normal mix of passengers are not all young and healthy and although many passengers can tolerate some degree of hypoxia others have conditions which may push them into the area of the oxygen–hemoglobin dissociation curve that severe and possible complications can occur,
Yes the procedure should not be rushed but the descent to 10000 ft or other elevation that is required by terrain should be complete within that 12 minutes from the loss of pressure,

Qwark

Not an Airbus driver, but if it had to do with the emergency descent scenario, the MEL would make reference to it as alternative procedures would have to be established. Like with PA. But I would say intercomm and headset are the primary means of communication, as they are the most clear/clean options.

Purely personal point of view:
From a physical point of view (common for all commercial jets I would say) emergency descents are like any emergency, all fine in the simulator and in the books, but reality will always be a bit of a surprise. Speakers work fine in a "noise clean" environment, but can be really annoying when noise levels start to increase, because noise will become a stress factor. It's a lot easier to rely on the headset, block the outside noise and control "inside headset noise" yourself, than having to curse your collegue because he just slammed the speaker on full. Reality can lead to some funny comms situations, especially when oxygen masks are involved :-).

Some think speakers are nice backups, but if she/he doesn't react to something, and you think there is a comm problem, just tap her/his shoulder... gently is enough and works like a charm :-)

There's a straight forward procedure. Declare, put the mask on, wear headset, check interphone receiver on and volume adjusted, hot Mic on and check with the PM. Execute the first step. The hot Mic may be put off if breathing sound becomes too loud. Ask for ECAM actions. According to Airbus Second step is done with ECAM. Some airlines have a little variations.
Descending at VMO/MMO with speed brake half full it takes 4mts and covers 40miles to reach 10000ft. from 39000ft. If at less speed due to damage then may be 8 to 10mts.

Not in our SOPM, but in the FCOM: You can use the Expedite push button if you aircraft has it installed to initiate the emergency descent; It will go down faster:
FCOM: PRO-Normal Procedures-FMS- Expedite Descent.

Its being removed and it will pitch down slightly faster rest is same. Won't make difference of more than a few seconds.

pineteam

The trouble with going straight for the expedite button is that it will target a descent speed of 340 kt or M 0.8, which may not be appropriate if you have structural damage. Open descent with selected speed gets the aircraft going down, while giving you a moment to think about your strategy.

Ah yes! Thank you Qwark. Knew I'd seen that somewhere before :)