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In 2005, Helios flight 522 crashed into a Greek hillside. Was it because one man forgot to flip a switch?

Early on the morning of 14 August 2005, Alan Irwin, then 44, was with his partner, Donna, and their two young children in an apartment in Larnaca, Cyprus. It was a convenient base, only minutes from the airport. Irwin was an aircraft engineer; he had become obsessed with the technical aspects of planes as a young man in the Royal Air Force, following in the footsteps of his father, also an aircraft engineer and pilot. “I enjoy being around machines,” Irwin says. “If they’re broken, they’re… ( More...

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Highflyer1950 31
Every standard cockpit geographical check generally starts from the left seat over to the right seat and then down the centre console. At some point on an originating flight the first officer should have completed a manual/auto check of the pressurization outflow valve for proper indication and operation and at the end of the check the system would have been returned to auto and confirmed on the prestart checklist, again on the take-off checklist, again on the after take-off checklist (confirming the aircraft is pressurizing) and again while completing the 10,000’ and above checklist. If the engineer left the auto/manual switch in Manual it would mean the crew failed to do their required checks. If however, the first officer was interrupted while doing this check, he/she could have failed to finish the procedure by confirming the system was back in auto. Since two items can set off the same audio warning, one must eliminate the takeoff configuration warning because they are airborne, the other requires a glance up and a quick flick while reaching for the O2 mask. It’s called a type rating for a reason.
Robert Spruce 13
Did they not check the CVR or the DFDR? surely that would have shown whether or not they followed the checklist and confirmed the switch was set to auto. I agree with Highflyer1950, it is the ultimate responsibility of the flight crew to confirm that systems are nominal and correctly functioning.
My experience of over 16,000 hrs on DC9's tells me that sometimes a crew member will try to shortcut checklists. NOT ON MY WATCH!
Silent Bob 8
This was an older CVR that only recorded for 30 minutes, so it only caught the last portion of the flight right before it crashed. So my guess is the FDR didn't rec many parameters such as switch positions.

Obviously I can't speak for Helios in 2005, but our Before Start Checklist includes checking the press switch is set correctly (it may not be AUTO if there is an MEL item).

Even in this day and age it is common for the pilot responding to the checklist challenge to state the correct response without actually looking at the item in question. It was hammered into us pretty hard in initial training that when running a checklist the person reading needs to verify the response as well, not just the person responding.

The question you need to ask yourself is "Why are crew members shortcutting checklists?". Rather than blaming the person i.e. "NOT ON MY WATCH!", have a look at your HSMS.
Highflyer1950 3
When operating between 4 & 6 legs a day, crews eventually commit to memory checklist items. To me, the most intensive checklist is the “originating” checklist which should catch the most serious issues? Quick turn checks tend to get run very quickly but as I stated earlier the crew had a minimum of 5 opportunities to catch a switch in the wrong position and 3 chances to observe that the aircraft was not pressurizing during the climb? You might remember the Payne Stewart accident where there was a great deal of certainty that the O2 bottle may have not been turned on during the pre-flight which would have rendered O2 masks useless depriving the crew/passengers of O2. Sadly, we are all human and do make mistakes.
Ken Lane 11
I am dumbfounded how any reasonable person can find a party on the ground at fault for any incident short of a blatant attempt to carry out an act that is intended to interfere with the safety of flight. But, that can only apply to any control input that is not within reach or has an indicator provided to the flight crew.

So, that leaves one cause... failure to follow procedures and verify with the checklists from pre-start on forward.

This would not be the first time an incident took place because of checklist and procedural failure. Though they are much more rare there will likely be others regardless of how "safe" an airplane is designed and how "idiot proof" the engineers may try to make them.

The very last line of defense against any incident is... the human factor.

And, there is an issue when management places so much pressure upon the flight crew they are less likely to return when an issue appears in flight that cannot be resolved. Two things should always be the first option... to go around and after departure, put it back on the ground.
Jasper Buck 8
"So, that leaves one cause... failure to follow procedures and verify with the checklists from pre-start on forward."

That's exactly what the Helios Airways Flight HCY522 accident investigation report says.

"The cause was:

Non-recognition that the cabin pressurization mode selector was in the MAN (manual) position during the performance of the Preflight procedure, the Before Start checklist and the After Takeoff checklist.

The direct causes were:
• Non-recognition that the cabin pressurization mode selector was in the MAN (manual) position during the performance of the Preflight procedure, the Before Start checklist and the After Takeoff checklist.
• Non-identification of the warnings and the reasons for the activation of the warnings (Cabin Altitude Warning Horn, Passenger Oxygen Masks Deployment indication, Master Caution).

The latent causes were:
• Operator’s deficiencies in the organization, quality management, and safety culture.
• Regulatory Authority’s diachronic inadequate execution of its safety oversight responsibilities.
• Inadequate application of Crew Resource Management principles.
• Ineffectiveness of measures taken by the manufacturer in response to previous pressurization incidents in the particular type of aircraft."

IOW, the flight crew screwed up.

That said my former boss at the FAA once asked me why I was such a hard ass on type ATP type rating rides in the DC-9/MD-80/B-717.

My answer was always the same. The FAA's Airline Transport Pilot and Type Rating for Airplanes; Airman Certification Standards (the old Practical Test Standards)(FAA Order-FAA-S-ACS-11) says, in no less than 60 places, that the applicant must use an appropriate checklist to complete a task. In my case a checkride failure was almost guaranteed if the pilot repeatedly demonstrated a "Failure to follow appropriate checklists or procedures."

I point that out because I was a party to at least 3 accidents that were a result of the crew's failure in not using, in whole or in part, a checklist or proper checklist procedures. That includes:

--Delta flight 1141 in 1988, the NTSB found that there was inadequate cockpit discipline that resulted in the flight crew's failure to extend the aircraft's flaps and slats to proper take-off configuration, and (2) the failure of the plane's TOWS to sound and alert the crew that their plane was not properly configured for takeoff.

--Northwest 255 in 1987 The NTSB determined that the probable cause of the accident was the flight crew's failure to use the taxi checklist to ensure that the flaps and slats were extended for takeoff. Contributing to the accident was the absence of electrical power to the airplane takeoff warning system which thus did not warn the flightcrew that the airplane was not configured properly for takeoff. I was the FAA lead investigator.

--Air Florida Flight 90 in 1982 the NTSB determined that the cause of the accident was pilot error. The pilots failed to switch on the engines' internal ice protection systems, used reverse thrust in a snowstorm prior to takeoff, tried to use the jet exhaust of a plane in front of them to melt their ice, and failed to abort the takeoff even after detecting a power problem while taxiing and seeing ice and snow buildup on the wings.

Following a checklist regardless of the size and/or complexity of an aircraft is important.

As an aside note the first three latent causes. Sounds like a Lion Air and Ethiopian Airlines 737 Max scenario.


Capt J Buck

ATP DC-9 B757 B767
Flight Instructor
Ground Instructor
Aircraft Dispatcher
A&P Mechanic
Air Traffic Controller
FAA Aviation Safety Inspector (Ret.)
FAA certified accident investigator (Ret.)
ICAO Panel Member
joel wiley 2
That is harsh and hard. But then, so is the ground. Thanks for posting.
Ken Lane 1
I've watched a good many of the air accident investigation shows. They're written to be sensationalists and draw in the viewer. But, for the pilot watching there are some serious lessons in those shows.

And, the issue that comes up most often as the entire cause or a significant contributing factor... the human factor.

One was on DAL1141. Pilots pulled the alarm breaker so they could taxi on one engine at higher power and not hear the alarm. That act also kept the alarm from sounding when they departed with flaps retracted. The result was killing everyone on board except for one little girl.

Until Air France 447, the casual observer might think pilots are incredibly smart and well-trained professionals. If Wolfgang met those pilots on the other side, it was probably with a facepalm expression.
Grahame Budd 5
I was on that plane a few weeks earlier when it had the exact same issue. In this case the crew figured out the ambiguous warning, and correctly descended and returned. Subsequently I have followed the incident closely, and agree that if the crew had reacted properly, and if ground engineering has not ignored a suggestion to make the relevant check, there would not have been a crash. That time. But with the alert system was definitely an issue, which had been reported several times, and which was subsequently redesigned.
gilgraham 4
To answer the question in the headline - the answer is NO, ABSOLUTELY NOT. At least 3 people "forgot to flip a switch", and the crew failed again at 12,000+ ft. The man on the ground is the least responsible.
WhiteKnight77 6
One cannot help but feel bad for Irwin.

Procedures are in place for a reason. Follow the procedures properly and you mitigate chances for disasters such as this. Boeing should also have been more reactive to the warnings advanced by the airlines, that crash might not ever have happened.
LarryQB 3
So much unknown - perhaps the auto pressurization failed and the crew selected manual to directly control the outflow valve. One wonders if when the Captain left the cockpit, perhaps to consult with the F/As, the F/O failed to don his mask.

[This poster has been suspended.]

Highflyer1950 1
True, but only on the ground!
It’s called a type rating for a reason. perfect
David Beattie 1
Any experienced pilot knows that getting an airplane post maintenance requires a very thorough preflight of the cockpit. This switch is included in the cockpit preflight flow/checklist.

Secondly, the fact that the cabin altitude warning shares an alarm with the config warning is not a secret nor is it unusual. Just like the trim cutout switch was not a secret on the Max. This is another case of pilots who were ill trained or complacent about their studies. In addition to the aural warning, there is also a Cabin Altitude annunciator light which they missed. It is inconveniently located on the overhead but a master caution light would also illuminate to call attention to a problem on the overhead panel.
What a sad story feel for all these people !
Greg S -4
The Guardian is a rabidly anti-American rag. The narrative that Boeing bears significant blame is patently absurd. A warning horn that might have two meanings is perfectly adequate. Even a warning horn with a single meaning can still be ignored and silenced by a complacent or ineffective flight crew.
joel wiley 12
Your assertion is not supported by the story upon which you comment. If The Guardian is rabid about anything, it is reporting facts, which can be stubborn things, especially when they run counter to one's world view.
Greg S -3
My assertion is not based upon the story; no such assertion could be. It is based upon reading perhaps a thousand articles in the Guardian over the decades. Stating that the Guardian is "rabid about reporting facts" reveals the depths of your confusion. Isvestia from the Soviet Union also reported facts. Russia Today and PressTV report facts. The propaganda effect is achieved by editing. The narrative guides the story; facts that fit the narrative are included, out of context if necessary, and facts that contradict the narrative are excluded. That's how we get a story like this.
Joel Rugeno 7
Greg S your response suggests that anything anti American is verboten, you obviously didn’t read the entire article or you’d seen that Boeing knew about many previous such cases. Boeing isn’t entirely responsible for the crash but sure are complicit in the crash and the whole sordid episode afterwards
To me, it suggests that The Guardian should be read with a jaundiced eye, with extra scrutiny given to its columns that have an anti-America narrative. Doesn't mean the anti-America narrative is always wrong. But that extra skepticism is called for. That's what Greg S' comments sound like to me.
joel wiley 7
That 'jaundiced eye' is applicable to any and every news organization in this day and age.
Yes, but some more than others. I have, for years, said that Fox News should be required to broadcast with a laugh track so that the goobers that fixate on it know when the 'bullshit partisan hack bile' is flowing. Tucker Carlson was sued for saying some outlandish inaccurate crap. But he won the case. How did he do that? The judge basically said that he was not saying anything that was a demonstrable fact. He was LYING, and it being a LIE, he could say that because 'a rational person would realize that his show was all LIES, and BLOVIATION'.

So, Fox News LIES. They broadcast KNOWABLE LIES, and do not warn their viewers of that fact. So the story that ran in another, less disgusting cesspool media company, that proved that people that only watched Fox News were stunningly misinformed on what was going on in the Real World was totally true, and yet Fox News is the Pravda of the current White House.

'We lie, you decide'?

The UK had a long history of having a news media that was very confrontational, and not afraid of calling the ruling party of the day on their crimes, lies, and manipulations. It's changing there, but I'd trust the news of the BBC, and NHK, than any other. I'd lump 'RT' in with Fox, and OAN: Lying liars...
joel wiley 2
I have no idea what continent you are on. This source rates news articles on two scales, one a left-right lean and sourced facts - fact free prose. It is only rating American sources for the most part but does include the Guardian. Individual stories are rated and overall trends graphed.
This shot compares MSNBC, CNN, Fox
'This source' is BS!!!

They hide their methods, they obfuscate their methods, they refuse to show what they use for their ratings. So, a bullshit site claims to call other media bullshit? To call it foul gives them too much credit. It's as meaningless as Fox News telling viewers they are 'Aperica's most watched source'.

"Taking these factors into consideration, Ad Fontes Media and items it produces – even when taking into account some experienced members of its Advisory Board – are likely best understood as informed but also amateur in nature. This assertion is supported by a number of different observations of Ad Fontes Media’s website, including a lack of concise language in the methodology, some grammatical errors (suggesting it has not been reviewed by many people), and the existence of a merch page.

But even if all these factors were to be set aside, it remains possible that engaging in such analysis is a largely fruitless endeavour, a point outlined in the aforelinked article by Tamar Wilner in the Columbia Journalism Review, in which the Ad Fontes Media Chart is harshly assessed. Regardless, without the underlying data being made public and subject to scrutiny, the question of whether this chart was produced using conclusions from a rigorous, robust process cannot be definitively answered."
"In Adfontesmedia’s defense, getting rid of bias is *really, really hard*, and from a more personal perspective, they seem to be putting in a lot of hard work toward figuring out all of this difficult stuff. But they have not yet reached that critical milestone of being better than nothing at all."
joel wiley 3
Reasonable people can disagree reasonably. I disagree with your assertion of 'BS' that they 'hide their methods' and that your link refutes that position. They freely describe their methodology. They invite reviewers from a variety of perspectives - mind you, those reviewers by volunteering are a 'self selecting population'. Your quora reference appears to consist of 3 personal opinions, 2 for and one against. I guess adding yours to theirs its 2 & 2. I hardly see that a damning.

But media bias is off-topic for this thread which is a story about a plane crash.
WhiteKnight77 1
Years ago, UCLA did a study on the news media and found that most were left leaning, similar to what this chart shows. Sadly, they took that page down. It did not show whether or not news articles were factual or not, but how can anyone discern facts when talking heads put their own biases into a story nowadays? It all feeds hive minds as to who they think is believable or not. Sadly, news organizations will defend the same things that pols who are in their group think while castigating those they do not. The same goes for those who watch, or read, said news outlets.
Evidence suggests that a warning horn that might have two meanings is definitely not perfectly adequate.
joel wiley 5
A warning horn to alert the aircrew that 'something' needs to be addressed is perfectly adequate

to the accounting department.


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