No Southend pilot , it was 0931 GMT .
Thats when the data suddenly changed and the rapid descent started.

A private pilot has made an interesting testimony by phone on a French TV.
He was flying a single engine aircraft when he was asked by Marseille Control on 120.55 to look around. He was informed that the last plot of the missing aircraft was at FL60 on a 010 heading in the area he was flying. At that time he was VMC and the weather very good. He climbed to FL60 but could not see anything. He also contacted Barcelonnette airfield to ask if they saw of heard something but the answer was negative.
The accident area is in fact the " Massif des Trois Evêchés ", a high mountain rising up to 2900m. (44.285 6.507).
The weather is worsening now and rain/snow is forecast.

Most reliable info is from the statement by the French minister of transport who overflew the accident site. The statement put the accident near Prads-Haute-Bléone. There is the steeply rising massif of l'Estrop (2961m) to the NE with several ridges and peaks rising above 2700 metres. Judging from the flight path the aircraft would have hit the SW slopes.

Update:

The location is confirmed as le Vallon de Galebre, a steep cirque along the SW face of l'Estrop. http://www.panoramio.com/photo/113508243

Would the combination of this being an older aircraft plus the fact that it was being flown around Europe rather than long-haul suggest that there would be a higher than normal number of pressurization cycles on the airframe? If so, could that be a consideration?

The aircraft did not deviate. It flew on it's flight planned course. Not every flight is a straight line between two points.

"0935 UTC is 1135 CET. "


It will be next week

German wings operate under the same LCC model as Easyjet and Ryanair. Freight in not usually carried. If Barcelona may be an easy marque for those without good passports but I think the hand baggage and hold baggage screening is sound.
My view is that this accident has all the hallmarks of an accident not an act of terrorism. Most accidents are a result of a chain of events which have a catastrophic outcome. Time will tell.

so why is the planned course from Barcelona to Düsseldorf so far off the shortest direct line? it does seems somewhat obtuse but there must be a good reason.

It is not a command and control aircraft and only has standard CCWR. You are confusing it with the E3F.

Ok, lets just clear this up...

MM7168 (NOT the Airbus) squawks 7700 at 09:35 GMT, which is 10:35am Central European Time (Promise!) just to the East in Northern Italy.

The Airbus, started the rapid descent at 09:31 GMT, or 10:31 CET.

We're confident that there's zero connection?

"Ok, lets just clear this up...

MM7168 (NOT the Airbus) squawks 7700 at 09:35 GMT, which is 10:35am Central European Time (Promise!) just to the East in Northern Italy.

The Airbus, started the rapid descent at 09:31 GMT, or 10:31 CET.

We're confident that there's zero connection?"

we can't be confident there is but can't be confident there isn't too so it's just pure speculation, MM7168 would fly with its transponder on and it would be seen on ATC radar anyway

Prads-Haute-Bléone
 

If the crash site is near here rather than the higher mountains to the NE as originally reported the access will be somewhat better as the forest is littered with DFCI...hard gravel roads for the pompiers....(but now snow covered)

Know the region from gliders and by road fairly well...it's on the mountain soaring route from Gap to the Parcours. Not that it helps anyone.

An icing/failure of the pitot static would lead to a stable decent at ~350kts IAS how, exactly?

Is this kind of unsubstantiated/unqualified speculation really necessary?

Not sure if related to the search but the factory Airbus A350 (F-WXWB) is currently airbourne near the crash area having been doing racetracks over the mediterranean for a while.

@AreOut of course, every page of this thread is pure speculation!

"MM7168 would fly with its transponder on and it would be seen on ATC radar anyway" - I'm not sure what point you're making?

One jet descends and crashes, the other declares an emergency, within 5 minutes of each other in the same area both at FL350. Those are the facts.

Speculation is normal if reasonable
 

You have to consider what fits.Decompression fits but needs something else(like incapacitation-esp Capt,maybe dual)to explain the aftermath.
Airbus software anomaly fits but Lufthansa's reputation would tend to discount this.Terrorism could also fit but unlikely.It leads back to decompression with incapacitation.Thats with what we know now.

Because the underlying air corridors mostly aren't on a straight path either, but look more like this:



https://i.imgur.com/AuYChvG.jpg

Picture of crash site
 

We don't know much here but we do have a bit more info than on the two recent Asian incidents. The aircraft descended at a steady rate in a straight line for several minutes until it hit the ground. That says to me that it was under aerodynamic control but not under the pilots' control. So it didn't explode in flight, it probably wasn't hijacked, and relatively simple things like a single engine failure weren't the sole cause. And that the simple answer to the 'why didn't they/why did they' questions is probably that they couldn't, for reasons yet to be identified.

Of the recent events, the one it's most like is MH370 (which was of course a Boeing) - but this time we should have the recorders pretty quickly to find out what happened.

@PortVale According to Germanwings CEO, D-AIPX had a maintenance check yesterday by Lufthansa, and the last C check was the summer of 2013. So it was due a major Check, however the aircraft landed yesterday from Madrid at 21:28.

It flew 4U9524 STD 05:45 departing late at 06:01 arriving a few minutes late at 07:57 before departing 25 minutes late at 09:00 (STD 08:35).

Probably a routine overnight maintenance check. The aircraft had accumulated approximately 58,300 flight hours in some 46,700 flights.

Nope. My understanding is that French AF C-135FR-s have a C&C capability, at least I have witnessed them being used for that role in Chad with same tactics, the C-135 circling above target area at 320-350 while the smaller fry go in to do the job.