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B737 design flaw, pilot error induced by B737 design

luckytohaveajob

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Boeing has a flawed system design. Using the same non-descriptive horn to represent two separate functions is the problem, not giving pilots one more exception to the rule.


Boeing's insistence on it infallibility is Boeing's biggest failure. Boeing overall build a good product. But Boeing's over inflated sense of superiority is the reason Airbus has made the progress it has made in recent times.


AP
FAA renews, toughens warning to Boeing 737 pilots
Monday November 10, 5:39 pm ET
By Tim Klass, Associated Press Writer
FAA requires flight manual change to remind Boeing 737 pilots, 'Don't ignore warning horn'
SEATTLE (AP) -- The Federal Aviation Administration has toughened a requirement that Boeing 737 pilots be reminded not to ignore a cabin pressure warning horn, ordering preflight briefings as well as changes in manuals.if(window.yzq_d==null)window.yzq_d=new Object(); window.yzq_d['bN2ABNG_XLc-']='&U=13f40b4rv%2fN%3dbN2ABNG_XLc-%2fC%3d626899.12894134.13150363.1383221%2fD%3dLREC%2fB%3d5133107%2fV%3d1';

The airworthiness directive, issued Monday and effective Nov. 25, stems from a crash in which 121 people died on Aug. 14, 2005, when a Helios Airways 737-300 slammed into a hillside north of Athens, Greece.
Greek investigators determined that the pilots had lost consciousness because of a cabin pressure failure shortly after takeoff on a flight from Nicosia, Cyprus, and that the plane kept going on autopilot for two hours until it ran out of fuel.
Authorities say the cabin pressure control settings had been operated improperly and that an alarm went unheeded. Last Tuesday the attorney general of Cyprus said five people would face criminal charges for the crash.
The FAA's order applies to all Boeing 737s, the world's best-selling commercial jet with more than 6,000 orders since the model was launched in 1965 and 5,397 in use worldwide, and takes effect in 120 days. Public notice and comment requirements were waived "because an unsafe condition exists that requires the immediate adoption" of the directive, according to the notice.
Changes in the manuals must be made by each airline. The process is complex, varying by aircraft as well as the nature of the change, and new wording must be validated before it can take effect, FAA spokesman Les Dorr said.
FAA directives typically are reissued by civil aviation authorities in other countries.
Airlines with large number of 737s, according to the Web site http://www.airfleets.net, include Southwest with 541 planes, Continental with 259, Ryanair of Ireland with 168, United with 162, Alaska with 110, Air China with 107 and China Southern with 102. Southwest, Ryanair, Alaska and some smaller carriers have all-737 fleets.
Chicago-based Boeing Co. and FAA representatives said the cockpit warning horn serves a dual purpose. On the ground it indicates something is wrong with the plane's pre-takeoff configuration, such as the setting of the wing flaps. In the air it means a loss of cabin pressure, which can cause pilots to lose consciousness if they don't immediately put on oxygen masks.
The FAA directed on July 7, 2006, that flight manuals be changed to remind pilots to pay heed to the warning horn after takeoff, but "we have received continuing reports of in-service events involving failure of the flight crew to recognize and react property to valid cabin altitude (air pressure) warning horns," according to the latest directive.
Dorr wrote in an e-mail that between the Helios crash and the first directive, the FAA received four reports of pilots disregarding the alarm, all from U.S. carriers which he did not identify. Since then there have been three reports from carriers that were not identified by country, he added.
Such problems in other countries typically are reported to civil aviation authorities who then notify the manufacturer, in this case Boeing, which in turn alerts the FAA, Dorr said.
Before the Helios crash, Boeing was alerted to "some cases where flight crews were getting confused" about the alarm horn and advised airlines "to do a little crew training on that," Boeing spokeswoman Liz Verdier said.
After the FAA's initial directive, which largely incorporated Boeing's advisory note, the manufacturer began working on a change in the cockpit and flight deck design to incorporate a warning light that will provide a second indication of cabin pressure loss when the horn sounds, Verdier said.
"Within the next month or so," she said, Boeing expects to have the change ready to incorporate into production of current models, the 737-700, -800 and 900, followed by production of retrofitting kits for earlier models a few months after that.
The FAA may propose further action to "address the unsafe condition" once the warning light kits are available, according to the airworthiness directive.
 

Captzaahlie

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horn e article.....
 

Old School 737

NG's now and it is A OK!!
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Enough
Its only been that way since, oh, about 67. As in !967! Possibly earlier!!!! Now they say its unsafe???
 

Jim Smyth

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If you ever had this happen to you (especially the first time) you would know how distracting and confusing it may be. At low altitude or in the Takeoff segment its a real handful with everything else thats going on. Usually the ivsi on the pressurization panel is pegged at 4000 fpm. It also appears your in negative pressure since the needle is below zero. Then you question your self if its + or - 4000 fpm since its right in the middle of the very small gage. Best bet it to level off and don't climb anymore till problem is fixed or return to airport. But thats not what always happens and the horn gets disregarded for a Takeoff warning malfunction which is now way behind where your at on your flight segment profile. There should have been 2 different horns/tones/alerts from the beginning to eliminate this issue.
 

Furloughed80

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If you ever had this happen to you (especially the first time) you would know how distracting and confusing it may be. At low altitude or in the Takeoff segment its a real handful with everything else thats going on. Usually the ivsi on the pressurization panel is pegged at 4000 fpm. It also appears your in negative pressure since the needle is below zero. Then you question your self if its + or - 4000 fpm since its right in the middle of the very small gage. Best bet it to level off and don't climb anymore till problem is fixed or return to airport. But thats not what always happens and the horn gets disregarded for a Takeoff warning malfunction which is now way behind where your at on your flight segment profile. There should have been 2 different horns/tones/alerts from the beginning to eliminate this issue.

Agreed; until you have this happen to you in the heat of the moment you cannot appreciate just how confusing it can be.
 

another cfii

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One simple fix: Fly Airbus:) All it needs is an alarm clock to wake you up for the arrival.
 

radarlove

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I love the solution: everyone does it wrong, so do they change the warning system, or do they just emphasize that it's really, no I mean really really important that you not screw it up.

"management by memo not incentive". Duh. I can't believe Boeing hasn't had to pay out $100 million because of this stupid system. How much would it cost to have the GPWS say, "Cabin Pressure Warning. Cabin Pressure Warning".

No, instead they're going to issue memos and make stuff bold print. Nice.
 

AK737FO

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no NASA app required

Lets not make more out of this than needed. It's not that hard. If you get an intermittant horn, you only need to ask yourself one question. Am I on the ground? If yes, then its a Takeoff warning horn. If No, then grab the mask.
In the Air = grab the mask. Simple.
 

Old School 737

NG's now and it is A OK!!
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Lets not make more out of this than needed. It's not that hard. If you get an intermittant horn, you only need to ask yourself one question. Am I on the ground? If yes, then its a Takeoff warning horn. If No, then grab the mask.
In the Air = grab the mask. Simple.

Nicely put!!!!
 

luckytohaveajob

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Buzzing horns are useless human factors

How many people get out of their car with a horn buzzing? As they get out and walk away with the lights left on, some of them are asking a similar question you posed, What is that buzzing sound? Five hours later you realize what that buzzing sound was as you have a dead battery. How effective is the old gens landing gear horn? Not very! How conditioned are we to cut it out before we even consider its significants thereby conditioning ourselves to ignore horns.

So there you are 25 miles from the airport at 5000 feet, your told to slow to 190. The flaps come out to five. The plane is slowed. Then you are told to descend to 4000 feet.

HORN! HORN!

We all try to get to the cutout button as fast as possible because it is so annoying even though the horn is telling us something very important, PUT DOWN THE GEAR. Problem is, we are 25 miles from the airport!

Buzzing horns are useless warnings when applied to human factors engineering. And down right dangerous when the same horn has multiple needs depending on particular conditions.
 
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ImbracableCrunk

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Die-hard 737 fans: it's okay to love the plane and admit that the warning system isn't the best.

For the "it's not a big deal" group, tell that to the Helios families. I'm betting the group of people who have had this type event and the group who say it's not a big deal have very little carryover.
 

GuppyWN

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At WN we've had several crews climb with the take-off warning horn sounding. Didn't figure it out till the FA's called and told them the "gear" was down.

It's happened to every 737 operator out there. Why? Cause it's a stupid system. Who puts a dual use horn in an airplane? I mean really. We've got a box that can tell us to pull up. A box can tell us to go around. A box can tell us if we're going to hit somebody. Surely we can have a box tell us:

"hey dumbass turn the packs back on" or
"hey dumbass put the flaps out" or
"hey dumbass release the brakes before taking off"

Gup
 

ron burgundy

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If you ever had this happen to you (especially the first time) you would know how distracting and confusing it may be. At low altitude or in the Takeoff segment its a real handful with everything else thats going on. Usually the ivsi on the pressurization panel is pegged at 4000 fpm. It also appears your in negative pressure since the needle is below zero. Then you question your self if its + or - 4000 fpm since its right in the middle of the very small gage. Best bet it to level off and don't climb anymore till problem is fixed or return to airport. But thats not what always happens and the horn gets disregarded for a Takeoff warning malfunction which is now way behind where your at on your flight segment profile. There should have been 2 different horns/tones/alerts from the beginning to eliminate this issue.

Did ya hear it on the takeoff roll? NO? Are you above 10,000 ft? HMMMM...

I heard it on the takeoff roll and kept going..Then you know damn well what that horn is!

Did not hear it on the take off roll,uneventful takeoff,below 10,000 and the horn goes off,probably not gonna fall out off the sky or pass out from lack of o2. Level off and deal with it. once again, 50/50 chance of getting it right. Am I on the ground or in the air? Oh, and what do you mean by "especially the first time"? how many times has this happened to you?
 

Jim Smyth

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Did ya hear it on the takeoff roll? NO? Are you above 10,000 ft? HMMMM...

I heard it on the takeoff roll and kept going..Then you know damn well what that horn is!

Did not hear it on the take off roll,uneventful takeoff,below 10,000 and the horn goes off,probably not gonna fall out off the sky or pass out from lack of o2. Level off and deal with it. once again, 50/50 chance of getting it right. Am I on the ground or in the air? Oh, and what do you mean by "especially the first time"? how many times has this happened to you?

There have been many professional aviators that have gotten this scenario wrong over the years. Some have paid with there lives and had a bunch of people behind the cockpit door follow them to nirvana when the wrong decision was made.

I have had this problem multiple times over the last 26 years. At the Takeoff roll (bad takeoff warning horn), after breaking ground when the air/ground safety puts you in the air mode, before 10,000 feet, at cruise.........you name it. Its never a good feeling where ever it happens and it sometimes doesn't go by the book. What gets you is when its just after Takeoff, your in bad weather, at night with a brand new FO that just became frosty the snowman and it feels like your head is going to implode! Oh yea, ding,ding,ding........its the flight attendants wanting to know whats going on, was that a frequency change, Huh? What, Over, oh theres mountain's out there, what, huh? It can turn real fugly.....................fast!

Your turn will come and hopefully you will become Chuck Yeager when it does and you make the right decision.

http://www.youtube.com/watch?v=mNRXJEE3Nz8
 
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ron burgundy

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There have been many professional aviators that have gotten this scenario wrong over the years. Some have paid with there lives and had a bunch of people behind the cockpit door follow them to nirvana when the wrong decision was made.

I have had this problem multiple times over the last 26 years. At the Takeoff roll (bad takeoff warning horn), after breaking ground when the air/ground safety puts you in the air mode, before 10,000 feet, at cruise.........you name it. Its never a good feeling where ever it happens and it sometimes doesn't go by the book. What gets you is when its just after Takeoff, your in bad weather, at night with a brand new FO that just became frosty the snowman and it feels like your head is going to implode! Oh yea, ding,ding,ding........its the flight attendants wanting to know whats going on, was that a frequency change, Huh? What, Over, oh theres mountain's out there, what, huh? It can turn real fugly.....................fast!

Your turn will come and hopefully you will become Chuck Yeager when it does and you make the right decision.

http://www.youtube.com/watch?v=mNRXJEE3Nz8

I've already had my turn..It worked out fine. I got lucky again I guess.
 

pipe

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Did ya hear it on the takeoff roll? NO? Are you above 10,000 ft? HMMMM...

I heard it on the takeoff roll and kept going..Then you know damn well what that horn is!

Did not hear it on the take off roll,uneventful takeoff,below 10,000 and the horn goes off,probably not gonna fall out off the sky or pass out from lack of o2. Level off and deal with it. once again, 50/50 chance of getting it right. Am I on the ground or in the air? Oh, and what do you mean by "especially the first time"? how many times has this happened to you?

Great. It is an easy problem to troubleshoot.

There is no valid reason that it should have to be a troubleshooting event though. Change the damn horn!!! There is no excuse on planet earth that the NG aircraft (at the very least) don't just state "landing gear" "flaps" "pressurization", etc. Even the freaking MD-80 has been able to do most of that for a quarter of a century. Even 727's with RAAS can tell you what runway you're about to enter.

Boeing is wrong on this one. Problem is, I'd bet that their lawyers are concerned that fixing it will be viewed by other scumbag lawyers as an admission of guilt that will get them absolutely smoked in a bunch of liability suits.

The system could be fixed very, very easily. The problem is, you won't be able to blame the pilots any more if there is a pressurization problem resulting in an accident.

PIPE
 
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luckytohaveajob

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The system could be fixed very, very easily. The problem is, you won't be able to blame the pilots any more if there is a pressurization problem resulting in an accident.
PIPE

Unfortunately, Boeing's lawyers will point to the old facts and the new additional training and say the pilots should have known better. Then Boeing will hire expert witnesses who are over 60 who just medical ed out the likes of Ron Burgundy. All the jury will hear from Boeing is how incompetent the pilots are as opposed to what a flawed system Boeing has insisted on producing.

The American legal system will once again not provide justice. Boeing will once again claim its innocence and walk. Boeing has taken this approach countless times. Admitting there is a problem and taking responsibility is a major problem for Boeing. Boeing claims it is perfect so it must be. Haven't you read the slogans or heard the commercials?

Take the nitrogen systems in the fuel tanks. Installed but not activated. Those inactive systems will sit idle until every -200/-300/-500 is parked or the numbers are so few, the FAA doesn't care and requires the systems installations in order to put some little operator out of business.

Another example is the B737 rudder PCU actuator. After four fatal accidents, the FAA gave Boeing eight years to fix the problem. The last unmoded B737 are just getting the fix today. The entire time table was based on a statistical calculation it couldn't happen until the fixes could be installed during an eight year period. Thankfully no additional lives were lost with a known problem and fix.

System issues on the 6000+ B737 fleet are not about safety. Instead they are political. And until the body count motivates the politics, the B737's deficiencies will continue to be present.
 
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Singlecoil

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I agree, they should definitely change the horn. I should point out that the nitrogen systems are now being activated, however. I have flown at least one that was operational.
 
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