July 2010 Archives

Both pilots and all four cabin crew on this brand-new Germanwings Airbus A319 began feeling "sleepy and unwell" after only a few minutes of flight, according to the report from the Irish Air Accident Investigation Unit. Donning oxygen masks provided almost instant relief from the symptoms.

The purser, the first to act on her awareness of what she saw and felt by calling the pilots on the interphone, may have saved the day by doing so. An "unusual number "of passengers were falling asleep and her attempt to attract the attention of a nearby cabin crew member failed. He was "unresponsive".

Her message jolted the pilots into the realisation that they, too, were feeling unwell. They declared a full emergency and returned to Dublin, landing just 24min after take-off.

An extremely thorough investigation into what happened checked out the aircraft and engines and found no evidence of any contamination.

What they didn't do - and that's a real pity - is to check out the passengers, except by interviewing them. Blood tests, even a few days later, may have provided the missing evidence of what happened.

The AAIU's principle recommendation was that Ireland's major airports should, as required by ICAO, have medical staff on hand. Dublin did not.

But it requires more than an available doctor. It requires crew and passengers who know they have been affected by some form of cabin air contamination to insist on having medical tests.

Well done the Purser. If the crew just quietly gone to sleep we could have seen a repeat of the Helios accident. That was caused by crew and passenger hypoxia following failure of the cabin to pressurise - not the case here. But the risk of subtly losing consciousness, however it happens, needs to be taken seriously. 

Having voiced concerns about the effect on pilot competence of high levels of automation, I am about to sing the praises of even more automation that Airbus is testing for its A350XWB, which is due in service in 2013. 

I was sitting with experimental test pilot Peter Chapman in a simulator which Airbus calls "A350 aircraft minus one", trying the new systems out, which is what that particular simulator is for.

Actually these new ideas are not a routine kind of automation, which is why I like them: they are more like applications that are available to use rather than a system that does everything for you while your skills fade and your brain dies. But the main thing is that these three applications address real problems.

The first is called "take-off securing". It's a FMS function that recognises take-off performance data that does not make sense when the pilots enter it, and all it does is warn them. They then have to check their own figures and enter the corrected data. In the last few years there have been plenty of incidents and some accidents that resulted from incorrect aircraft weight entry. These were not all specific to an aircraft type or manufacturer, but just today the UK AAIB has reported on one such incident involving an A340-600.

The second is an en-route function: if there is a failure that forces the aircraft to descend, such as loss of an engine or pressurisation failure, the FMS will provide the crew with drift-down data and, if the aircraft is over mountains, safe escape routes.

If the pilots specify a chosen diversion, the FMS will suggest a detailed flightplan and do all the calculations. If the pilots want to be mentally prepared for an eventuality, they can ask the FMS "what if" questions and review the proposed solutions.

Finally, there is the runway overrun protection system (ROPS). Runway overruns are the most common of all airline accidents, and this could put a stop to them.

Before or during descent to a destination airport, pilots can specify the runway in use, and review what the aircraft's landing performance will be under the current conditions.

The pilots are shown, on the navigation display, a graphic of the chosen runway with two magenta lines across it, the first showing where the aircraft would stop if it is dry, the second if wet. If the runway is too short a warning is generated.

The photograph below is the display being tested in an A380. The pilots have chosen the runway by moving the chevrons over the runway threshold - in this case Toulouse runway 14L - and clicking to designate it. Then you get the response you see here:

For a more complete narrative on ROPS, with more illustration, go to one of my earlier blogs here.

If Airbus can make take-off performance data entry safer, and reduce the risk of overruns, the future will see far fewer events in which aluminium gets seriously bent.

And if you do suffer an engine failure over the Himalayas one day, the new FMS function that shows the best escape routes during drift-down should be good for your blood pressure.