Pre-Take-Off Checks

[Canary42]

Surely the flight deck pre-take-off checks include all systems switched on ?

Apparently not the cabin pressurisation system !

https://uk.yahoo.com/news/serious-incident-tui-plane-carrying-094935536.html      

 

[mushroom25]

this isn't the first time this has happened - google Helios Air 522......

[Old_Geezer]

Perhaps it will be included by that airline from now on.

[New Judge]

The full report is here:

https://assets.publishing.service.gov.uk/media/67335df9bac74dd6026bf2dd/Boeing_737-8K5_G-TAWD_11-24.pdf

I haven't read it properly yet but it seems checks on cabin pressurisation are included in the pre-flight check and it seems they were completed. A warning in the cockpit was also present after takeoff but I'm not sure what, if any, reaction there was.

The aircraft was at 15,000 feet when action was finally taken and that surprises me. Aircraft are pressurised to the equivalent  of around 6,000 feet and should never exceed 8,000 feet. I would have thought that before the aircraft reached an altitude of around twice the normal pressurisation level, crew members, if not passengers, would have noticed. I'll have a proper read.

I notice the same aircraft was involved in a serious incident just three days later. It suffered a  "catastrophic" landing gear  failure while landing at Leeds-Bradford Airport. The aircraft left the runway while it was landing during Storm Babet.

I'm not surprised incidents like that happen at Leeds-Bradford in strong winds. At an elevation of almost 800 feet it is the UK's highest commercial airport and apart from that its runway faces in the wrong direction,

[Peter Pedant]

big trouble for the pilots if they have not completed the  flight checks

the fella who landed on the river ( and saved everyone) was not allowed to fly again  as he had done action no 50 much much too early

https://en.wikipedia.org/wiki/Sully_Sullenberger

[New Judge]

You need to read up about that, Peter.

Chesley "Sully" Sullenberger did not retire until a year after he landed his aircraft on the Hudson River, when he reunited with his co-pilot on that day for his final flight before retirement, aged 59.

It was at first suggested that Sully was to blame for saving all 155 people on board his Airbus A320 when it lost both engines at less than 3,000 feet soon after takeoff, suggesting he should have diverted either back to La Guardia or to a nearby smaller airport, Teterboro.

However, when the NTSB performed simulations of that idea  only seven of the 13 simulated returns to La Guardia and one of the two to Teterboro succeeded. But these simulations were not realisic as they involved making an immediate diversion to one of the two locations. When a small amount of "thinking time" (as little as 30 seconds) was added, all simulations failed.

The situation of double engine failure so soon after takeoff was not included in the handbook and Sully and his first officer rightly received many accolades for their superb airmanship.

[THECORBYLOON]

I would have thought there would be a default position, physically preventing take-off unless every mandatory action had been taken.

[New Judge]

So, having read the report:

- The engine bleed switches were left in the “off” position following maintenance.

- This was not noticed during the pre-flight checks.

- The “after takeoff” checklist also included a check on the bleed switches but the fact they were off was not identified. Because of this the cabin did not pressurise.

- The aircraft continued to climb and the cabin altitude warning was triggered with the aircraft at approximately FL130 (13,000 feet). 

- The crew did not react instantly to this by donning oxygen masks as they believed they were at a low enough altitude for them to be unnecessary. 

- The aircraft continued to climb before the captain noticed the bleed switches (which are located on the co-pilot’s side of the flight deck)  in the “off” position. He ordered them to be switched on and the aircraft levelled off at 15,000 feet.

- Believing throwing the bleed switches would quickly rectify the cabin pressurisation failure, the crew continued their climb towards 28,000 feet. However, at 20,000 feet an air-conditioning pack failure light was noticed and, after consulting with ground engineers, the decision was made to return to Manchester.

So there is nothing to physically prevent the aircraft taking off with bleed switches off. Various avenues for the crew’s failure to notice they were off were explored, including fatigue, the fact that the copilot was delayed getting to the aircraft (with most of the checks being carried out by the captain), and the position of the switches.