hot cabin on the grd in a B738
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hot cabin on the grd in a B738
What would you do in the following, using your corporate policy of
Safety
Comfort
Sched
Economy?? and CRM skills
You are in command of a B738. You have had a 20 minute taxy in high outside temps to the departure runway. All tempurature selectors on full cold, with the temp gauge in the fwr and aft cabin around 30 C.
The maintenance log has previous entries that the cabin temp gets hot on the grd, but temperature control in the air in normal.
The Purser calls after about 15 minutes of taxi saying that the cabin is very hot. You advise the temperature controllers are in full cold, and that the cabin will cool in the air. You are now 2nd in the queue.
You and the purser (and FO) have two different native tongues. Commmmunication is not easy.
The majority of pasengers native tongue is of the pursers (and FO), not yours.
As you are cleared to line up, the purser advises that she is no longer able to control the pasengers, some are standing up as the cabin is very hot.
Not wanting to limit your choice of answer, but would you consider:
1) Returning to the gate,
2) Making a commanding PA advising you are now ready for takeoff and that if everyone does not take to their seats you will return to the gate and call the authorities,
3) Taxi off the runway to give time for the cabin crew to hand out wet towls, loose your place in the queue, and reenter the departure sequence (about 5 acft ahead of you for departure).
Thanks for your interest.
IBT
Safety
Comfort
Sched
Economy?? and CRM skills
You are in command of a B738. You have had a 20 minute taxy in high outside temps to the departure runway. All tempurature selectors on full cold, with the temp gauge in the fwr and aft cabin around 30 C.
The maintenance log has previous entries that the cabin temp gets hot on the grd, but temperature control in the air in normal.
The Purser calls after about 15 minutes of taxi saying that the cabin is very hot. You advise the temperature controllers are in full cold, and that the cabin will cool in the air. You are now 2nd in the queue.
You and the purser (and FO) have two different native tongues. Commmmunication is not easy.
The majority of pasengers native tongue is of the pursers (and FO), not yours.
As you are cleared to line up, the purser advises that she is no longer able to control the pasengers, some are standing up as the cabin is very hot.
Not wanting to limit your choice of answer, but would you consider:
1) Returning to the gate,
2) Making a commanding PA advising you are now ready for takeoff and that if everyone does not take to their seats you will return to the gate and call the authorities,
3) Taxi off the runway to give time for the cabin crew to hand out wet towls, loose your place in the queue, and reenter the departure sequence (about 5 acft ahead of you for departure).
Thanks for your interest.
IBT
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IBT, as a Purser on the 737 my eye was caught by your threadtitle. Obviously I will never be in command of a 737, so perhaps I should refrain from answering........
But I won't.
Horrid situation for all concerned, and tricky with the different languages. Seems to my like a good example of an instance where the captain should rise to the occasion and be Captain with a capital C.
You're the one who knows all the facts, and you're the one who can decide to take the shortest way out of this agony.
Take off ASAP!
I suspect & hope you went for option 2.
Once in the air and with tempers & temperature cooled, a chat with the FO first and then a joint one with the purser to smooth any ruffled feathers?
Looking frwrd to reading the rest of your story.
But I won't.
Horrid situation for all concerned, and tricky with the different languages. Seems to my like a good example of an instance where the captain should rise to the occasion and be Captain with a capital C.
You're the one who knows all the facts, and you're the one who can decide to take the shortest way out of this agony.
Take off ASAP!
I suspect & hope you went for option 2.
Once in the air and with tempers & temperature cooled, a chat with the FO first and then a joint one with the purser to smooth any ruffled feathers?
Looking frwrd to reading the rest of your story.
IBTheseus, unfortunately I have had a similar experience, although not to the degree of having passenger problems. My decision was to take off, however the cabin temperature did not decrease in flight, which resulted in a return to departure airport.
Thus from my experience I suggest that a crew should put the aircraft tech until, the full nature of the problem is understood and if necessary rectified.
As a passenger who hates hot cabins, I can well imagine the cabin crew loosing control of the situation. Heat is a significant physical and mental stressor, which will affect the crew as well as passengers, this is a threat to a safe operation, and good CRM requires the crew combat it. There is the classic opportunity for error – “it will be alright if I get airborne”, I made such an error that exacerbated the threat. The crew and I were exhausted after a short hot flight.
In addition to safety, any adverse passenger reaction of the operation due a hot cabin may not be any worse than a delayed flight; better to arrive safely (and cool) than on-time in a sweat.
Thus from my experience I suggest that a crew should put the aircraft tech until, the full nature of the problem is understood and if necessary rectified.
As a passenger who hates hot cabins, I can well imagine the cabin crew loosing control of the situation. Heat is a significant physical and mental stressor, which will affect the crew as well as passengers, this is a threat to a safe operation, and good CRM requires the crew combat it. There is the classic opportunity for error – “it will be alright if I get airborne”, I made such an error that exacerbated the threat. The crew and I were exhausted after a short hot flight.
In addition to safety, any adverse passenger reaction of the operation due a hot cabin may not be any worse than a delayed flight; better to arrive safely (and cool) than on-time in a sweat.
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In the instance/example quoted by IBTheseus the tech crew knew that once in the air it would cool off quickly. I would have gone for option 2 but made sure that engineering were aware that I was going to log the faults on arrival. A short burst of discomfort followed by a normal, comfortable flight with a on time arrival will keep the pax happy, a return to the gate with a 'delay undetermined' will make them very unhappy and they will not forget in a hurry. My only proviso is that you must be satisfied that there are no airworthiness or safety implications, just a bit of discomfort.
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Flapsforty
Glad you didn't hold back
Option 2 was chosen, and yes the cabin returned to normal temperatures airborne.
The departure sequence was also complicated slightly because of a landing aircraft dropping spare parts on the runway that needed removal. Never sure how long this will take.
Coming into a new culture, and corporate culture I was puzzled by the Chief Pilots attitude that more should have been done (as acft taxied onto the runway) to comfort the pax on the ground. His solution (#3) was to taxi off the runway, lose your place in the queue and ask the flight attendents to pass out wet towls. then take off. Extra time with a hot cabin!!
alf5071h, I can certainly see your point (and experience). Were it not for previous maitanence reports, would do the same.
BlueEagle, aggeed and what was done.
For me it is either return to the gate, or TO asap. Personally have trouble with delaying the takeoff to hand out wet towls.
Glad you didn't hold back
Option 2 was chosen, and yes the cabin returned to normal temperatures airborne.
The departure sequence was also complicated slightly because of a landing aircraft dropping spare parts on the runway that needed removal. Never sure how long this will take.
Coming into a new culture, and corporate culture I was puzzled by the Chief Pilots attitude that more should have been done (as acft taxied onto the runway) to comfort the pax on the ground. His solution (#3) was to taxi off the runway, lose your place in the queue and ask the flight attendents to pass out wet towls. then take off. Extra time with a hot cabin!!
alf5071h, I can certainly see your point (and experience). Were it not for previous maitanence reports, would do the same.
BlueEagle, aggeed and what was done.
For me it is either return to the gate, or TO asap. Personally have trouble with delaying the takeoff to hand out wet towls.
This brings up something I've always wondered about. I understand that in flight the packs mix outside cold air with bleed air to obtain the desired temperature. But on the ground, since there is no cold air, is a compressor-type airconditioner employed? Since I am only a FakePilot, I can understand the AC controls and how they apply for air mixing. However, I don't see any controls there necessary for a "conventional" air conditioner. ?
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Sorry, will take it off topic for a moment:
Fake pilot:
<I understand that in flight the packs mix outside cold air with bleed air to obtain the desired temperature.>
No, all the fresh air originates as bleed air. This is then conditioned.
On the ground to provide cool air, hot bleed air is taken from the compressor stages of the engines, passed through heat exchangers over which outside air is blown over. Therefore you now have pressurised near ambient temperature bleed air. A simplification but an easy way of understanding the principle is this: this air is next allowed to expand…in doing so pressure drops…and when pressure drops, temperature drops. Thus you have cold air. This can then be mixed with a controlled amount of hot air that hasn’t been cooled if required to bring the final output temperature up to that that is required. (This may also be mixed with filtered re-circulated air from the cabin).
To find out more about the cooling system search for ACM or air cycle machine. Its operation is a bit mind bending at first
All the best,
Tom.
Fake pilot:
<I understand that in flight the packs mix outside cold air with bleed air to obtain the desired temperature.>
No, all the fresh air originates as bleed air. This is then conditioned.
On the ground to provide cool air, hot bleed air is taken from the compressor stages of the engines, passed through heat exchangers over which outside air is blown over. Therefore you now have pressurised near ambient temperature bleed air. A simplification but an easy way of understanding the principle is this: this air is next allowed to expand…in doing so pressure drops…and when pressure drops, temperature drops. Thus you have cold air. This can then be mixed with a controlled amount of hot air that hasn’t been cooled if required to bring the final output temperature up to that that is required. (This may also be mixed with filtered re-circulated air from the cabin).
To find out more about the cooling system search for ACM or air cycle machine. Its operation is a bit mind bending at first
All the best,
Tom.
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On the ground the pack outlets often ice up. Hence the little and not so little lumps of the stuff that fly out of the vents at you. Try switching the packs to manual then "warm" this usually melts the ice and everything is well with the world again.
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If the company is not too fussy about APU fuel burn - you could let the APU feed both the packs till just prior to take-off.
APU does bleed a LOT more than the engines at idle thrust.
Just means you gotta shuffle around the Air Con / Press panel after start a lot more, and hope you don't screw it up !!
I wouldn't want to move my A/c with Pax standing. Guaranteed law-suite.
APU does bleed a LOT more than the engines at idle thrust.
Just means you gotta shuffle around the Air Con / Press panel after start a lot more, and hope you don't screw it up !!
I wouldn't want to move my A/c with Pax standing. Guaranteed law-suite.
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4MONU
I agree that leaving the APU to feed both packs on the ground does wonders to keep cabin temps down. As soon as I transfer bleeds across to the Eng, there is an immediate rise in Cabin temps.
I use this more often now, however the Co will not see the funny side of this. They are rather keen to reduce APU running time. Just about a failable item on a check, running the APU a second longer than necessary.
BTW, do you know where the temperature probs are for the overhead panel PACK L and R, and the three DUCT SUPPLY(s)?
Not sure the boeing diagrams give the detail I need.
I do see where the pack temps are above the DUCT SUPPLY. Not sure how this should happen?
Thanks
IBT
I agree that leaving the APU to feed both packs on the ground does wonders to keep cabin temps down. As soon as I transfer bleeds across to the Eng, there is an immediate rise in Cabin temps.
I use this more often now, however the Co will not see the funny side of this. They are rather keen to reduce APU running time. Just about a failable item on a check, running the APU a second longer than necessary.
BTW, do you know where the temperature probs are for the overhead panel PACK L and R, and the three DUCT SUPPLY(s)?
Not sure the boeing diagrams give the detail I need.
I do see where the pack temps are above the DUCT SUPPLY. Not sure how this should happen?
Thanks
IBT
