And they do have a copter on board:

http://i.imgur.com/ukWtp5h.jpg

Wikipedia:

Some posts on this thread contradict the above.

So which part(s), if any, of the above quotes are incorrect to the extent that on-or-above sea surface searches with appropriate equipment won't locate the FDR when within the ranges stated?

Earl
 

Basically the hydraulic actuators for the primary flight control surfaces are signalled electronically from the flight deck controls, with the degree of computer input/ moderating that takes place dependant on the level at which the FBW is operating at ( normal >secondary>direct). However just in case of a total electrical failure Boeing did indeed provide a manual back up in the form of good old fashioned cables to the stab and selected spoilers...according to the FCOM:

"Mechanical Backup
In the unlikely event of a complete electrical system shut–down, cables from the flight deck to the stabilizer and selected spoilers allow the pilot to fly straight and level until the electrical system is restarted."

Debris
 

Hi , I have read every post on here and I am wondering if there could be a lot of debris still floating about from the hurricane that hit the Philipines not long ago?

Oh I think everyone appreciates their work. What is frustrating is that the details of their analysis has not been made public. I don't blame Inmarsat for this, it is down to the Malaysia transport authorities to produce a report with all the details which are known, but not released.

I fully understand the anger and frustrations of the family members. At this stage in the AF447 investigation the BEA issued an interim report with everything known, including full details of the ACARS messages, crew bios, cargo manifest, the works.

It is not enough to have the big man say "The plane is lost, some clever people in England have worked it out, trust us." Show us the work. Show us the ping details, show us the cargo manifest, show us the radar track, give us the ATC transcript, even!

Not sure exactly to what contradiction you refer. Is it range propagation? You mention 'above sea surface'.

Are you inferring that a 'microphone' or hydrophone not in the water can detect the ULB? Looking at the cross media transmission first, the speed of sound in a dense medium (water) is around 4800 feet per second and around 1100 feet per second in air. A wave or sound beam will refract at the media boundary. At certain angles it will be reflected rather than pass through. The physics example is a light beam striking a prism and 'total internal refraction.' IIRC, a beam of light passing from a dense medium to a less dense medium will be refracted away from the normal.

However the sea is not an homogenous mass of water. Temperature and salinity vary with depth. The water body has well defined layers; it is possible to even see and feel these layers when scuba diving. The speed of sound will vary with salinity (hence density) and temperature. Sound waves on striking these layers will either reflect or pass through depending upon the vertical angle between the emitter and the hydrophone.

It follows that a hydrophone directly above the emitter might hear the ULB but in most of the figures you have quoted the signal strength may decline too much for surface capture.

The first thing then is to determine the bathythermal layers and place the hydrophone in the same layer as the emitter. Next is to lower the hydrophone so that it would be as close as possible in the vertical to the emitter to maximise its horizontal range.

You would then have a sweep width of between 4 km and 44 km depending upon water conditions and the figures you quoted being applicable.

The Indonesian archipelago is a 3000 mile barrier from the Malaysian coast to the north of Australia. Such debris would have had to travel counter current through narrow straits, passed Australia, to the Indian Ocean.

The following link to an early AF447 thread post by auv-ee explains the basic facts of pinger location by someone who knows and has been actively involved in this work.

http://www.pprune.org/tech-log/39510...ml#post5683946

It wont take you long to work out that there is a relatively narrow range either side of the towed path which is dependent on th TPL being positioned around 1600 meters above the seabed profile.

Do you know that it actually departed with that on board, there has been many delays getting those operational..

@Pontius Navigator
I postulated in earlier post that because the Maldives have 2 767's and a 757 that maybe they're not too careful with garbage disposal and that this was an old part chucked away.

A Thai satellite has picked up 300 items of what appears to be debris about 200 km from the French debris patch. Just so frustrating the weather is bad for the next 24 hours.

In discussion about that supposed mine or fire bottle in the Maldives, does anyone seriously believe that the authorities would not have looked into the alleged finding by now? If they have and it was significant then does anyone seriously believe that so many governments would still be wasting so much money and resources searching 5000 miles away? :ugh:

Yes, it departed Fremantle with that MRH90 on board. :ok:

As mentioned earlier, a 37kHz radio signal is in the LF range and needs a very large antennae and considerable power to radiate any significant range.

37kHz audio, is in the VHF audio range capable of being detected with a transducer and then displayed on the appropriate equipment.

Some larger pix here:

Thai satellite spots possible wreckage | Bangkok Post: breakingnews

its been close to a week now that the australian authorities had said that a few possible aircraft debris been seen on satellite images. since then so many aircrafts and ships been doing rounds of the suspected area and still its so surprising that not even a single piece of debris is visually identified and checked hands on just so to make 100% sure that the aircraft has crashed there.

Satellites seem to spot whatever you want them to spot. If you want them to find evidence of chemical and nuclear facilities they'll oblige. If you want them to spot dinner plate sizes of aircraft wreckage they'll oblige. Anyone who has a satellite wants to be able to say they have spotted something. At this stage its all one-upmanship. All this manpower searching, nothing found, too many false positives.

Without trying to be too negative these images and the French images of yesterday look like ice. I took the picture below over seas to the South of Greenland a couple of years ago; height around 30000ft.

http://i59.tinypic.com/qysiaa.jpg

6 months drift to Australian west coast ?
 

This is a drift pattern of a buoy. It starts

2013-Aug-01 S 41°04' E 085°01

and ends

2014-Mar-27 S 34°57' E 110°12'


http://s4.postimg.org/y4d9wf54t/5333f421_6255_0.png

RichardC10
 

Wouldn't you though assume that these experts viewing the satellite images would be able to tell the difference between ice and a non ice object?