Reply to: Missing plane

[Troll]

snigger:-

A330 has composite components so needs a new way of dispersing strikes

Boeing

chortle

dude


and:


Real-world Faraday cages

Things that often act as Faraday cages

* Elevators.
* Some traditional architectural materials such as plaster with metal lath, and rebar reinforced concrete.
* Steel and aluminum buildings and sheds.[2]
* The cooking chamber of a microwave oven.
* RFID passport and credit card shielding sleeves.
* Cars and aircraft, when struck by lightning. The metal frame and outer skin of the vehicle cause the electrical charge to travel safely away from the occupants. This differs from a popular urban legend that claims that a car's tires cause the lightning strike to reach the ground. However, radio and cellular phone signals can still reach inside the vehicle since their wavelengths are significantly smaller than the windows and other openings in the vehicle's conductive frame, though internal signal strength may be diminished.
* The internal metal lining of most consumer electronics, as well as the metal case of most personal computers.
* A shopping bag lined with aluminum foil acts as a Faraday cage. It is often used by shoplifters to steal RFID tagged items

Seem to recall an oil rig helicopter crashing due to lightning strike on a composite rotor, also the A380 has a laminate of aluminium & CF in its structure to keep the weight down

Hmmm how safe are aircraft with carbon fibre bits?

[wxman]

LOL, stormchasers are good for a few things

Air France Flight 447:
Detailed meteorological analysis

http://www.weathergraphics.com/tim/af447/

It is possible that the plane suffered massive damage while flying through a storm system. Hail was not a factor.

[TheRefactornator]

The portable base station attenna type, naval, defence etc can be reasonably stable when used in enclosed areas with thin shell. The more widely available and afforable domestic type need line of sight to the satellite. Boats will have the antenna mounted on the mast so no problem there.

[Moscow Mule]

Yep - if it works inside the metal hull of a boat / ship, why not a 'plane?

Hopefully someone who knows more about this would be able to answer but I'd imagine(?) that the frequency being used for a sat phone is different to that of NDB, IFF, TACAN, weather radar, ATC (etc)?

Theory here

Wavelenths here

I can't be arsed to do the sums, but I'm pretty sure a sat phone signal will get through a plane window.

[TheRefactornator]

Inside a plane?

You changed the spec. They're not too good indoors / in-vehicle but can work reasonably well if the skin of the building or outer shell is thin, the success of which depends on the hardware architecture..

[Menelaus]

Inside a plane?

Yep - if it works inside the metal hull of a boat / ship, why not a 'plane?

Hopefully someone who knows more about this would be able to answer but I'd imagine(?) that the frequency being used for a sat phone is different to that of NDB, IFF, TACAN, weather radar, ATC (etc)?

[Moscow Mule]

Inside a plane?

If the plane is made of carbon fibre, or you sit by a window...

[TimberWolf]

Sure

Inside a plane?

[TheRefactornator]

Do mobile phones work over the Atlantic under their own steam, i.e. even if the plane has no electricity?

Sure

[Menelaus]

Do mobile phones work over the Atlantic under their own steam, i.e. even if the plane has no electricity?

Wouldn't have thought so - where would the base station be? A sat phone would work, but a normal mobile? Probably not.

Air France do have seat-back phones, but the aerial for them is in / on the fuselage and if it was hit by a big enough electrical current it'd screw them up, I fear.

[TimberWolf]

Do mobile phones work over the Atlantic under their own steam, i.e. even if the plane has no electricity?

[Beavis]

Don't be so stupid! Do you even know what a faraday cage is?

snigger:-

A330 has composite components so needs a new way of dispersing strikes

Boeing

chortle

dude


and:


Real-world Faraday cages

Things that often act as Faraday cages

* Elevators.
* Some traditional architectural materials such as plaster with metal lath, and rebar reinforced concrete.
* Steel and aluminum buildings and sheds.[2]
* The cooking chamber of a microwave oven.
* RFID passport and credit card shielding sleeves.
* Cars and aircraft, when struck by lightning. The metal frame and outer skin of the vehicle cause the electrical charge to travel safely away from the occupants. This differs from a popular urban legend that claims that a car's tires cause the lightning strike to reach the ground. However, radio and cellular phone signals can still reach inside the vehicle since their wavelengths are significantly smaller than the windows and other openings in the vehicle's conductive frame, though internal signal strength may be diminished.
* The internal metal lining of most consumer electronics, as well as the metal case of most personal computers.
* A shopping bag lined with aluminum foil acts as a Faraday cage. It is often used by shoplifters to steal RFID tagged items

[Menelaus]

According to the news, the black box could be at 12,000 feet depth.

Worryingly, bits are being reported on the BBC as having been found 60km apart which might support a prognosis of the aircraft having broken up at altitude.

It'll be interesting to find out what's happened, and no mistake.

[Cyberman]

Back on topic.

I'm not sure the distance between the coast of Brazil and the mid-Atlantic ridge but hopefully the CVR / FDR will be recoverable from depth to identify the cause of the incident - whether (as WxMan suggests above) a bomb or something more mundane but no less tragic.

According to the news, the black box could be at 12,000 feet depth.

[Peoplesoft bloke]

It pains me to say this – but I don’t believe that a terrest[sic] attack (bomb) can be ruled out. Why was it done so early.

Even if the plane lost a wing due to turbulence then a message could still be sent.

It is the reports of wreckage (although small) that would indicate to me that the plane suffered structural damage while flying – given that there was no May Day issued one can not rule out a cockpit bomb.

My thoughts are also with all affected..

True that a bomb can't be ruled out, but there's plenty of precedent for lack of a PAN call when serious structural problems occur - and I doubt your claim that "a message could still be sent" if a plane lost "a wing". We aren't talking about Biggles limping home with a broken Sopwith. Modern aircraft wings are (mostly) a single unit machined from billet alloy, if the forces are strong enough to snap the wing, they will also destroy the fuselage in no time - don't forget the wings are much stronger. The lack of a call could be explained in a number of ways, not all of which would indicate a bomb, although it can't be ruled out as you say.