Thursday, September 22, 2011

System certification questions abound as leaky line story breaks: What the blazes is happening in the world of aircraft systems certification?

Last year, we learned that Honeywell Phase 3 liquid crystal displays are susceptible to EMI, a discovery made when Gogo's in-flight Wi-Fi system was being tested for STC on Boeing 737NG aircraft (and long after the systems had been installed on lots of 737NGs and 777s).

Now comes today's revelation that some leaky feeder cables on aircraft equipped with AeroMobile/Panasonic's eXPhone solution have not passed flam, and EASA is preparing paperwork! The cable, which provides a signal to passengers' mobile phones, is not hard to spot - it's what is running down the length of the aircraft. See this pic from AeroMobile's web site.

AeroMobile leaky.JPG

Below you can see AeroMobile's full rack. The AeroMobile equipment (three avionics units in this shot) is the equipment to the left of the orange boxes. The two thick black cables are the leaky feeder cables. I wonder how easy/difficult it is to pull these cables out and replace them. Please comment if you can shed some light on that MRO question.

AeroMobile leaky 2.JPG

So, how the devil did these systems receive certification?

It's a question that nobody in this industry likes to address on record. So back to sources I go.

Says a source: "The key takeaway from all of this stuff is that it doesn't matter if you put a system on board aircraft via STC or linefit. You need to do complete tests. You should do them on every single installation."

Is the system manufacturer or the airframer ultimately to blame?

"There could be fault on both sides. Was the equipment fully qualified and was all relevant testing done by the manufacturer and the next questions would be, if that's so, was all the relevant cert testing done by the airframer," says another source.

As mentioned in my article about the AeroMobile leaky feeder, international carriers Emirates, Air New Zealand and V Australia are among the carriers affected.

On last count, some 86 Emirates aircraft carried eXPhone, though the carrier says it believes only a small number of aircraft will require replacement cables.

Last year AeroMobile said four V Australia 777s had full eXPhone provisions installed by Boeing from the factory (trays, wiring, circuit breakers and leaky feeder cable).

Air New Zealand's status has been a bit tougher to nail down, but it was supposed to receive its first eXPhone-fitted 777 late last year.

Then the Honeywell issue hit. And now the AeroMobile leaky feeder issue. It makes me wonder how Boeing stands on fitting GSM solutions to its aircraft right now...

And don't even get me started on Koito and it's rubber stamp!

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