Please change the 737 Pressurisation System
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uniu.. the reason the NG is like this is for commonality with the classic.Too many operators flying a mixed fleet of classic and NG. You may know about the southwest NG's ,without a/t,lvl chg....
Jambo,what plane are you flying? It doesn't seem so complicated a system: bleeds on,packs on and pressure on AUTO. Do you really need some fancy pushbuttons?
Mistakes were made by no adherence with procedures.It can be done on all type of planes,no matter how advanced.Only the pilotless airplane won't do that.
Now you have something with the master caution sys...I suppose you would like ECAM more...
As I said above the number of 737 classic on the market is to high, so the NG should have the same procedures, for commonality.
The NG is an advanced airplane, it has more in common with the 777 than with the 737 classic ,under the skin. But on the outside should look and fly as close as posible as the classic.
You may know ,for ex , that although the pressurization sys looks the same,it's different in design and operation.
Jambo,what plane are you flying? It doesn't seem so complicated a system: bleeds on,packs on and pressure on AUTO. Do you really need some fancy pushbuttons?
Mistakes were made by no adherence with procedures.It can be done on all type of planes,no matter how advanced.Only the pilotless airplane won't do that.
Now you have something with the master caution sys...I suppose you would like ECAM more...
As I said above the number of 737 classic on the market is to high, so the NG should have the same procedures, for commonality.
The NG is an advanced airplane, it has more in common with the 777 than with the 737 classic ,under the skin. But on the outside should look and fly as close as posible as the classic.
You may know ,for ex , that although the pressurization sys looks the same,it's different in design and operation.
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Alexban, I fly the NG. These incidents happened! So it doesnt matter whether it was following procedure, not following procedure or whatever that caused it. One has to ask, will it happen again and if so how can we prevent it. In the case of A/c & Press it has happened many many times. So lets either take the option away from the pilot altogether, he cannot be trusted 100%. (sorry girls and boys its true). Or design a Y2K+ system (not 1967) that is ergonomically and systemically foolproof. That would involve some push buttons perhaps, a better MCS maybe EICAM yes that would be nice to have in a 1999 airplane, why not. Is Boeing still retricted to the 25% changes to type rule when they went for original certification? I dont know, but surely an improvement in safety such as this is not hard to make. (expensive yes). Put it this way, if my family were on the Helios flight, I have enough evidence to take Boeing to the cleaners under a product liability suit! And I would.
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The quickest solution is to simply add one essential item to the Boeing 737 current after takeoff checklist; and that is "Cabin Rate of Climb .....Check". If the outflow valve, bleed or pack switches are in an inappropriate positions, the cabin rate of climb will show aircraft rate of climb and thus alert the crew to a pressurisation problem. The relevant dial can be easily seen by both pilots whereas the pressurisation panel switches are not easily monitored from the left seat.
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Adding another item to the checklist will only mean there is another item that is potentially overlooked. To say that the NG is just like the 777 under the skin is only relevant to the PFD/ND dislplay. The pressurisation system is still reliant on the bleed switches being turned on at some point during the flight and physically connecting the bleed system to the pressurisation system. It should be fool proof but it isn't so Boeing need to come up with additional defenses to allow for the fools.
To say that it is simply a matter of good airmanship and the problem shouldn't exist is ignoring reality and the many examples of pilot induced pressurisation incidents.
To say that it is simply a matter of good airmanship and the problem shouldn't exist is ignoring reality and the many examples of pilot induced pressurisation incidents.
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Tee em, if you take off bleeds OFF, with the APU pressurising the cabin, the rate will be normal. Normal until about 20,000ft when it wont have enough blow and your cabin will keep sneaking up to meet you. Then wah, wah, wah, and you think youve got a CONFIG warning as youre already half hypoxic. No another item on the checklist is no use.
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Jambo - my input:
To all those who shout 'Airmanship' - yes you are right. We should NOT fail........
...but
................. as Captain SandL says - time for a change. Just because we SHOULD avoid these events does not mean that the system can not be designed better.
My vote - Yes
To all those who shout 'Airmanship' - yes you are right. We should NOT fail........
...but
................. as Captain SandL says - time for a change. Just because we SHOULD avoid these events does not mean that the system can not be designed better.
My vote - Yes
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Jambo, It depends on the leak rate. One of FRs got to just shy of FL310 before the cabin horn went off.
Interestingly, a Boeing Tech Rep came to visit our company for an annual road show. It was stated that since the Helios Crash that there were planned changes to the pressurisation system in the pipeline with "Voices and Flashing lights" instead of, and perhaps in conjuction with the Cabin/Config. horn.
As for airmanship this has happened to some very crusty old veterans on the 737 with time in type well in to the 10Ks. I certainly would never be so bold as to say it would never happen to me, although as a company we were extensively educated to the dangers and flaws of the system after our incidents. We have robust procedures now which if followed give about 8 opportunities to trap the error before one has painted oneself into a corner.
Interestingly, a Boeing Tech Rep came to visit our company for an annual road show. It was stated that since the Helios Crash that there were planned changes to the pressurisation system in the pipeline with "Voices and Flashing lights" instead of, and perhaps in conjuction with the Cabin/Config. horn.
As for airmanship this has happened to some very crusty old veterans on the 737 with time in type well in to the 10Ks. I certainly would never be so bold as to say it would never happen to me, although as a company we were extensively educated to the dangers and flaws of the system after our incidents. We have robust procedures now which if followed give about 8 opportunities to trap the error before one has painted oneself into a corner.
To say that it is simply a matter of good airmanship and the problem shouldn't exist is ignoring reality and the many examples of pilot induced pressurisation incidents.
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Sorry, Centaurus - I must disagree with you there. If the fix is simple why not do it? We do not seek 100% fool-proofing, just closing gaps where they can be easily closed. Where would you stop with the "disregard of the principles of good airmanship" - would you never have installed EGPWS - good pilots do not fly into terrain? Maybe disable the gear/flap warning horn - we ALWAYS put the gear down to land, don't we?
"If the checklists and scans had been followed etc etc " - 100% agreement, but they were not. Let's not have professional pride blind us to the need ALWAYS to move safety onwards, and let's never forget to remember the Lowest Common Denominator?
"If the checklists and scans had been followed etc etc " - 100% agreement, but they were not. Let's not have professional pride blind us to the need ALWAYS to move safety onwards, and let's never forget to remember the Lowest Common Denominator?
"Voices and Flashing lights"
a Boeing Tech Rep came to visit our company for an annual road show. It was stated that since the Helios Crash that there were planned changes to the pressurisation system in the pipeline with "Voices and Flashing lights" instead of, and perhaps in conjuction with the Cabin/Config. horn.
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I'm sure generating a horn sound in the 80's was much simpler than giving an aural warning saying "Cabin altitude! Cabin altitude!" but is it still that difficult to make it talk in the 21st century? I guess not. I don't see any technical reason why it couldn't do both, generate a horn sound (which might be mistaken for T/O config) and then yell "Cabin altitude!".
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Put it this way, if my family were on the Helios flight, I have enough evidence to take Boeing to the cleaners under a product liability suit!
Sue the manufacturer?
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We are getting confused here between this concept of 'legislation' and manufacturers' responsibilities - and commonsense. I know EXACTLY what Centaurus is saying, and I assume that 'legislation' is not what was meant, but the issue is:
Can things be improved - yes
Should they be - yes
Why should anyone disagree? 'permFO' has it in one. Would 100+ be alive if the Helios a/c had a clear, obvious and unambiguous pressurisation warning that crews were trained on and aware of? Leaving aside the other 'mysteries' of that accident, I know the answer is 'possibly' but we must not ignore the options.
Can things be improved - yes
Should they be - yes
Why should anyone disagree? 'permFO' has it in one. Would 100+ be alive if the Helios a/c had a clear, obvious and unambiguous pressurisation warning that crews were trained on and aware of? Leaving aside the other 'mysteries' of that accident, I know the answer is 'possibly' but we must not ignore the options.
