Minutes of Cypriot Flight Are Described in a Greek Report
By IAN FISHER
Published: August 23, 2005
ROME, Aug. 22 - An exhausted-sounding man apparently worked to take control
of a Cypriot jetliner in the last 10 minutes of its flight, trying to
radio in a final distress call just two seconds before the plane crashed
last week in the mountains north of Athens, a preliminary report said
The report, by a chief Greek investigator, said
there were indications that the Helios Airways plane had suffered a problem
in its pressurization system that possibly incapacitated the two pilots.
But the final cause of the crash, on Aug. 14, was that the Boeing 737-300
ran out of fuel after flying nearly three hours, double the planned duration
from Larnaka, Cyprus, to Athens.
"There is proof that the engines of the plane
stopped working because the fuel supply was exhausted, and that this was
the final cause of the crash," the report said.
There were no survivors among the 115 passengers
and 6 crew members on the flight, bound for Prague after a stop in Athens.
After a string of major air crashes in the last
month, 136 French tourists refused Monday to board a charter flight from
Crete to Paris because of safety concerns. Agence France-Presse quoted
a passenger as saying that passengers were worried because the jet had
made a recent emergency landing in Milan and had been delayed twice for
technical reasons, and that one pilot was 21.
In the Greek crash, the man believed to have tried
to take control of the plane was a flight attendant, Andreas Prodromou,
who was learning how to fly small airplanes.
The report, which was read on Greek television
on Monday, said there were indications that someone had tried to take
control of the plane toward the end of the flight. The plane's voice recorder,
recovered after the crash, picked up the sound of a man, sounding "distressed
or suffering from exhaustion," yelling, "Mayday! Mayday! Mayday!"
10 minutes before the crash, then again two seconds before impact.
The radio was set to the wrong frequency, the report
said, and the call was not heard on the ground.
About 30 minutes into the flight, the pilot reported
problems with the air-conditioning. Autopsies on bodies from the flight
did not show any intoxication from fumes, adding to the theory that decompression
and a resulting loss of oxygen incapacitated those on the plane.
A former chief mechanic of Helios recently acknowledged
that the same plane lost cabin pressure on a flight in December because
a door was not properly closed. Helios, a low-cost airline, maintains
that its operations are safe.
From The Cyprus Mail:
"Tsolakis confirmed that they had asked for a recording of the captain’s
dialogue with the company just after takeoff
Larnaca when he contacted them to report a problem.
But they were told there was no such recording, the Greek investigator
The existence of a problem is further reinforced by reports that the black
box had shown that the alarm in Boeing’s cockpit sounded at 9.15am, just
before the German captain spoke to the company’s British chief engineer.
The alarm went off when the aircraft was flying at 14,500 feet.
It also transpired that the passenger oxygen masks had been deployed,
indicating that the aircraft lost pressure shortly after departure.
According to the reports, the German captain told the chief engineer that
he was having problems with the computer cooling system.
The engineer told him to shut it down and switch to the backup system,
followed by instructions regarding the location of the switches.
Reports insisted that the two men could not communicate: the engineer’s
last words were “word confuse”.
After that the communication was terminated with the engineer asking the
captain to put the co-pilot on so that he could speak to a Greek engineer.
But apparently those words never reached the plane, the reports said."
If this report in The
Cyprus Mail is correct then it becomes quite likely that the aircraft
was never pressurized to begin with. Consider that the aircraft took off
at 0907 and at 0915, only 8 minutes later, it was at 14,500' with the
cabin altitude warning (triggered passing 10,000' in the B737) annunciated.
14,500' in 8 minutes is just under 2000 fpm rate of climb, which is probably
about right, and the only way the cabin gets there that fast (as well)
is if there was no source of pressurization at all.
Additionally, without the packs there would have been no cooling air being
provided to the avionics, which would likely precipitate problems with
flight displays, FMC, and etc. Those problems occurring at the same time
as the pressurization warning might cause a crew to mis-attribute the
source of the warning to the avionics problem, and not the cabin pressurization.
If the computer cooling reset instructions received from the ground engineer
seemed to be having some effect, then it's possible that they decided
that continuing the climb was acceptable, still not recognizing that the
real source of the problem lay with the lack of an air-supply from the
packs, and not a failure of the avionics cooling system or ground/air
As the climb continued
without pressurization, the hypoxic effects would quickly become more
severe and the warning would continue to be ignored, having already been
attributed to the avionics cooling. With mental capacities decreasing
and pilot fixation still centered on solving the cooling problem, it's
quite possible the crew lost consciousness without ever realizing what
the source of their problems was. It's likely that the cabin crew were
informed about the reason for the interim level-off, and that would have
allayed initial F/A alarm about the rubber jungle having come down. They'd
have noted the aircraft continuing its climb and assumed all was well.
Only when the pax started dropping off into unconsciousness would they
have realized it wasn't...
It would seem to me that a +/- 2000 fpm cabin vertical speed should have
been noticeable to the crew, but then again at Alaskan Airlines there
was a very similar incident [Alaska Flt 506 on 20 Mar 2000 - link)
where a 737NG departed with both packs off and the crew failed to recognize
the condition until the alarm bells went off at 10,000' and the rubber
jungle made its appearance at 14,000ft. The pilots were later sacked for
pressing on to destination. ALPA took up their case.
If this latest report
is credible, then departing with the engine bleeds off ( a common practice
in runway/weight limited situations) or aircon packs off, has to be considered
another simple and plausible explanation for what happened to Helios Flight
ZU522 on 14 Aug 2005.
|A later deeper analysis
|MindSets, Mis-idents and Misinterpretations - the
Case of the dual function warning horn
As one pilot related:
have pointed out, warning horns can really
mentally incapacitate a flight crew into
a thinking paralysis if not cancelled in
Take the Birgen Air 757 Accident as an example.
They had a constant overspeed warning, which
could not be cancelled, right into the stall.
We train the same scenario once in a while
during simulator checks and I am still amazed
how many mistakes are made until the horn
is silenced (by pulling C/Bs).
Another example: A few years back I had
a fire bell during T/O. Just the bell -
no EICAS messages and no fire lights. And
worse, the fire bell could not be cancelled.
Again we made some mistakes until the bell
was silenced by pulling the aural warning
C/Bs. (It did require a full power down
to actually reset the glitch in the warning
So I would consider it possible, that while
the Helios crew was working on some technical
problems during departure they misinterpreted
the Cabin Alt Warning Horn as being the
take-off configuration warning horn that
they were totally familiar with - and were
immediately stressed out by the noise so
that they never realised where the warning
was coming from and how to react correctly.
It never occurred to them to press the horn
cancel button - so that is why that alarm
sounded throughout the flight.....above
10,000ft cabin altitude. Their attempt to
discuss their problem with a Helios engineer
didn't work out due to the Greek/German
language barrier..... and the enervating
uncancellable horn in the background wouldn't
have helped either.
A voice message clearly annunciating (twice)
the problem as "pressurization
/ Check cabin altitude" would
have avoided this accident - as would an
FMS automatic 90 degree turn off airways
and descent mode (after 3 minutes) if crew
had not retarded thrust levers for an emergency
Leaving engine bleeds off intentionally
for improved performance on take-off and
initial climb is a common tactic for crews.
Accidentally leaving aircon packs off can
also happen per the incident related below.
From a cabin crew point of view, once told
by the flight-crew that they were working
a problem, they'd not be surprised if the
rubber jungle of masks came down. They'd
tend not to query the crew about that, at
least not straightaway. They'd just tend
to the pax and assist them with their masks.
The F/A's would be unaware that the aircraft
was continuing its climb. Unfortunately
it would only take about 4 to 5 minutes
(in that cont'd climb) for the pilots to
succumb to the hypoxia. By FL340 they'd
So whether the lack of pressurization was
due to a leaky door seal or engine bleeds
or packs left off or an outflow valve left
at OFF (and not AUTO), the problem is the
same - and the same across all airplane
types also. If crews aren't schooled in
aviation medicine and have not had a hypobaric
chamber run and thus don't know their personal
hypoxia onset symptoms, then they are very
According to the reports, the German captain
told the chief engineer that he was having
problems with the computer cooling system.
The engineer told him to shut it down and
switch to the backup cooling system, followed
by instructions regarding the location of
Reports insisted that the two men could not
communicate: the engineer’s last words were
After that the communication was terminated
with the engineer asking the captain to put
the co-pilot on so that he could speak to
a Greek engineer.
But apparently those words never reached the
plane, the reports said."
warning horn issue
(A Ryanair Incident)
(FO turned packs off when reconfiguring the Pressurization
panel after a "bleeds off" take off.)
"At approximately FL240 the crew heard
what they understood to be the configuration warning
horn sounding. Checks on the aircraft take-off
configuration and reference to the Quick Reference Handbook
(QRH) failed to detect the cause of the warning. At
08.18Z, 612 asked ATC could he hold at FL 260? FL 270
was given, with a slight heading change. Cabin service
continued normally during this time, with the No 1 CCM
attending the cockpit on call from the Captain. However,
the crew were engrossed in the problem and the Captain
told her he would call her again shortly when the situation
was sorted. Trouble shooting continued, the FO
was concerned that the QRH held no rectification measures,
the Captain initially thought that there might be a
micro-switch problem on the thrust lever quadrant, closing
the thrust levers had no effect on the warning horn,
which continued to sound. Further re-assessment led
the crew to check the overhead panel where the Captain
noticed that the Packs were OFF. He immediately switched
both Packs ON and controlled the rate of repressurization
in Standby Mode. A check on the cabin altitude showed
approx 14,000 ft. The Captain instructed oxygen masks
on and as the FO read out the Rapid Decompression checklist
from the QRH, ........"
Further similar incident
makes instructive reading. Both a/c packs off and pilot doesn't
put on o2 mask - but does descend.
During climb-out from Stansted Airport (EGSS), the flight crew
experienced an illumination of the “Master Caution” indicating
“Overhead” on the main instrument panel. A short time later,
the “Master Caution” (Overhead) illuminated again, followed
by an additional warning light on the rear overhead panel, indicating
that the passenger oxygen masks had automatically deployed in
the cabin. Having reached FL 143, the aircraft was descended
to and levelled at FL 100, where further analysis by the flight
crew determined that the pressurisation system had not been
properly configured for flight. The aircraft returned to the
airport of departure, where it landed without further incident.
|Narrative: on passing FL 100 and as the normal Standard
Operating Procedures (SOP’s) were being carried out, the “Master
Caution” illuminated advising “Overhead.” Further analysis identified
that the passenger oxygen system had deployed in the cabin.
The cabin altitude aural warning horn, (which alerts the flight
crew that the cabin altitude is 10,000 ft above mean sea level)
did not sound on the flight deck. Having reached FL 113, the
aircraft was descended with clearance from ATC down to FL 100.
The SCCM was called to the flight deck to report on the status
of the cabin and she confirmed that the passenger oxygen masks
had in fact deployed. The SCCM was then informed by the Captain
that the pressurisation system had failed and that the aircraft
would be returning un-pressurised to EGSS. The Captain then
made a public address (PA) announcement to the passengers informing
then of the situation.
Prior to the commencement of the descent from FL 100 to EGSS,
the flight crew observed that the No 1
and No 2 Engine Bleed Air Switches were not selected to “On”.
When both Engine Bleed Switches were configured correctly, the
pressurisation system returned to a normal condition. It was
also noted by the flight crew that the circuit breaker for the
cabin altitude aural warning horn was found to be in the “Open”
position. The pressurised aircraft then continued its descent
to EGSS, where it landed without further incident at 1338 hours.
|See also the identical Alaska 506 incident
|Nightmare cruise at FL340: The fact that the
airplane climbed itself to and cruised at FL340, the pax all
nodded off and became brain-dead (as did the flt crew) - all
that is classified as merely the outcome - as is the fact that
some cabin crew members managed to stay conscious on portable
oxygen and finally access the cockpit. The F/A's would've been
frantically trying to assist pax in the cruise by running around
with their portable oxygen but once hypoxia sets in and consciousness
is lost, giving an unconscious pax a whiff of oxygen would become
clearly futile to the F/A's.
Once into the cockpit, the F/A's would've tried desperately
to revive the pilots with their own oxygen but probably would
not have been knowledgeable enough to select 100% or ensure
a good facial seal. Eventually they'd have removed the captain
to the rear to free up his seat for the attempt to fly a recovery.
The inability to transmit probably relates to the mikes being
diverted to the oxy-masks as much as still being on Nicosia
frequencies. The weak mayday calls heard on the CVR were possibly
made on intercom and/or just picked up by the cockpit area
mike (CAM). The F/A's may not even have been able to identify
the transmitter selector switch or the PTT (press-to-talk).
Hearkening back to the original problem, it could easily
have been the repeat of that Dec 04 door-seal (as it's alleged
to have been causing a hissing noise on the prior flight).
Equally it may have been a switch out of position. Use of
a WARNING HORN that they couldn't cancel was a sufficiently
mind-numbing distraction for the flight-crew that their minds
were oriented towards avionics cooling - as sometimes happens
on the ground - as evidenced by what they said to their maint
plus the fact that the horn was never cancelled - simply because
they'd completely forgotten about the deadly DUAL FUNCTION
of that warning horn.
It is after all, quite a simple scenario. Just more
holes in Swiss Cheese lining up and a below average crew getting
totally distracted by a misinterpreted blaring and uncancellable
warning horn (that's often heard on the ground but very rarely