Two main types of location hardware, one acoustic, the other electromagnetic. Another words one puts out a sound and the other a electromagnetic wave.

Electromagnetic waves for practical purposes do not travel under water. Sound goes really well under water. The pinger is attached to a "black box" (read the one that makes the noise).

Surface flow
 

Interesting analysis of current surface flow in the SAR area. Seems to be mainly gyre-type.

earth :: an animated map of global wind and weather

Isn't it time to think about starting anew with current technology rather than upgrading old equipment? I read lots of talk about improving ELTs, extending CVR time and other shortcommings.
With todays technology, all the flight information, airframe performance, position, speed, CVR, etc, could simply be uploaded in (almost) real-time via satellite then to ground stations/ATC. Such an change could easily be piggy-backed onto the existing recorders & flight systems and not really require much more than (another) computer and a satellite 'phone. In deed, as many aircraft now have WiFi internet access, all the data could be carried over that link.
There would never arise where the condition & position of any aircraft was not known or traceable to a few miles anywhere in the planet.

Could a 777 pilot tell me what flight path behaviours could be expected if the aircraft was left in the cruise with controls free, no autopilot modes engaged:
1. In normal control law, and
2. In the next level down degraded control law (alternate??).

A 777 pilot (of which I am NOT one) would probably tell you that the flight control modes you have mentioned are specific to Airbus aircraft........

McLauchlin is the official Inmarsat spokesman.
I'll just leave these here without comment:

McLauchlin (to Bloomberg):
Hunt for Jet Switches to Visual Search as Radar Empty - Bloomberg

McLauchlin(to IBTimes):
Malaysia Airlines Flight MH370 Would Have Been Found If Communications Box Had $10 Upgrade

It doesn't! :ugh:

No - not in heading mode.

As has been pointed out the aircraft would have deviated quite a long way in heading mode due to the extreme magnetic variation in the South Indian Ocean. For the track flown it is more likely it was to an intended input of a waypoint or a change to fly South in Track mode - both of which would have required deliberate action from someone who understood the FMS/FMC. There were a limited number of people on board MH370 with that knowledge.

Or perhaps the "person or persons unknown" descended to 5000ft on a westbound heading until they knew that they were clear of military primary radar and then turned south and climbed to cruise altitude. From what I understand, the military radar didn't notice them at the time but the replay showed the flight heading west when they lost contact.

Dai lad - I believe that is nominative determinism

Looks like the engineers are already on the task of bolting the stable door now that MH370 cannot be found...

From the New York Times: http://www.nytimes.com/2014/03/22/bu...tter.html?_r=0

"Outside the U.S., Steps to Track Planes Better"

"PARIS — Some foreign regulators and airlines have moved much faster than their American counterparts to adopt more advanced airplane tracking technology."

I've been out of the Navy for a few years.

IF a ballistic missile submarine were deployed in the Indian Ocean, and
IF the US Navy were tasked by the DoD to move it to a position to do some underwater assistance,
the US Government would for sure not tell anyone.
Furthermore, as soon as anyone with acoustic sensing equipment arrived in the area, I'll suggest to you that any submarine of that sort in the area would be ordered to another location.

The whole point of that kind of submarines being on patrol is that Nobody Knows Where They Are outside of a very few folks. Their mission as a nuclear deterrent is serious business, and unlike the rest of naval forces, does not typically do PR and Show the Flag stuff.

Plenty of other assets can be assigned to such assistance missions.

Marine search will take months
 

Just looking at the marine AIS track of the search vessel 'XUE LONG' shows that she is doing 3 hour E-W tracks then side-stepping 3nm and doing W-E passes. All this at 12kts in seas chopped up by 26kt winds.


So to fully search an area of 600x600nm would take 10,000 hours or 417 days.


The underwater search will also be a slow process, as any underwater towed device will travel even slower.


A faster method would surely be a U2 type spy plane with high definition digital cameras... Do the Orions carry these cameras?

U2 overflights
 

U2 has a synthetic aperature radar (SAR) payload which sees through the clouds. I have wondered why this has not been deployed. I don't know if NASA has this capability, but I know DOD has this capability. The government could collect and view this data in real time, either overflying the search vehicles, or going out the night before, to help and narrow the search area.

BTW, Tomnod is using satellite SAR data on some of their images.

The next phase -- underwater search -- is going to be really hard
 

Over the past week, four satellites have reported sighting a debris field:
1. Photos taken on March 16th by an Australian satellite and released by an American company showed two large objects about 2,500 km (1,550 mi) southwest of Perth, Australia.
2. Photos taken on March 18th by a Chinese satellite showed one large object (22.5m x 13m) about 120 km (75 mi) from the Australian debris.
3. Photos taken on March 23rd by a French satellite showed 122 objects up to 75 feet long at a place about 120 km from the Australian debris.
4. Photos taken on March 24th by a Thai satellite showed up to 300 objects up to 52 feet long at a site about 200 km (125 mi) south of the French debris.

During a search like this, there will be a tendency for each satellite control team to try to confirm the other teams' observations first, before looking at new patches of the ocean. One hopes that all these teams are not simply chasing down the debris field that was sighted first, but are looking elsewhere, too. Many commentators have said that debris tends to collect here in the south Indian Ocean. Perhaps we should be asking why there have not been more satellite reports of debris.

In due course, some of this debris will be picked up. Assuming it is from MH370, the underwater recovery phase will begin. Even if some pieces were picked up and positively identified today, time has run out for the ELTs (Emergency Location Transmitters). It has been more than 20 days since they were activated; 15 or fewer days remain before the batteries die. There is no prospect that an underwater listening device will pick up the signal. The current location(s) of the debris field(s) are now so far from their locations when the satellite images were made, and they in turn are so far from the original ditching site, that a lengthy search pattern will have to be used.

The reality is that the ocean floor is going to have to be searched visually or, at the very least, with underwater radar. The travel speed of these devices is miniscule compared to the size of the search area. By way of comparison, consider the length of time it took to find the remains of the "Titanic" and remember that she sank only ten miles from the ship "Carpathia", whose position was known with much greater precision than the point of impact of MH370.

The cost in time and money of finding MH370 on the ocean floor may be too much to pay. It may be that the authorities will have to make a tough decision: not to search for the wreckage.

Is it just me, or do people here seem to overestimate the capabilities of modern technology, satellites, submarines and vastly underestimate the size of the Indian Ocean?

Even if MH370 left 10000 pieces of floating debris in a 5kmsq area, it is not surprising in the least that nothing been found yet. The search area has only been narrowed to an area the size of Texas, in a region which gets the some of the worst weather on the planet. With no landmasses to check the waves the swell is huge. Satellites can only pick out large contrasting pieces, and radar has difficulty seeing anything that doesn't break the surface, especially in large ocean swell.

And suggestions that submarines should just listen at random for the pinger are hopeless. The pings will only travel 2km and with a 500,000sqkm search area (at best) it would take years to search it all. In any case submarines tend not to hang around in this region of the world, because there is nothing there. Any submarines on there way will take some time to arrive.

It's remarkable we know as much as we do, but it's still not enough. Perhaps if we get a break in the weather and something is found soon, then maybe there is a chance to work backwards to the impact site. As the RAAF guy said, maybe then we will know which haystack to search.

glenbrook,
 

Not quite true. The AF447 accident happened on 1 June 2009 and a preliminary report was issued on 2 July 2009.

ICAO Annex 13 prescribes that a preliminary report shall be issued within thirty days of the event. This is what BEA did, give or take one day. Despite the agony surely felt by all those affected by the MH370 disappearance, the Malaysian authorities still have 12 days to comply with the Annex 13 requirement.

Synthetic Aperture Radar
 

RichManJoe
Synthetic Aperture Radar is wonderful. I worked on it in early days.
The problem with radar is that a very narrow beam requires a very large antenna.
Too large for an aircraft.
So a large aperture is "synthesised" by processing. This combines the returns from successive positions along track, to build a mathematically equivalent antenna hugely extended in the along track direction. This gives effectively an intensely narrow beam pointing out sideways, painting the entire surface below with across-track scan lines in very fine detail.
Works equally well for satellites.

It just so happens I was in the Nasa's JPL control room in 1978, and watched the very first image arrive from Seasat.
https://en.wikipedia.org/wiki/Seasat
Everyone present was gobsmacked by the quality of the images, with every individual ship (and even its wake, if I remember correctly) outstandingly clear.
This was much better than had been expected. This non-military satellite clearly had crushing military significance.
Three months later its catastrophic failure was announced. Those of us in the business had our doubts.

Thank you GarageYears.
LoboTX, here is the image, and the map # is on it.

et al,

I made this from it to compare. Could it be a cockpit window?

[IMG] http://t.co/doYdB0ryCG [/IMG]

It doesn't seem to want to insert the image... here is the link to it: http://t.co/doYdB0ryCG

Submarines
 

I understand the point made by Lonewolf about the US not wanting the positions known of any of its tactical nuclear submarines but there are many types of submarines and I am surprised that considering all the assets deployed there has been no mention of any other types.

For example, Malaysia itself has 2 French built submarines, the Australians have 6 Collins Class subs based in Western Australia, Japan has 16 and heaven knows how many the Chinese have.

As people experienced in SAR have pointed out, it is extremely difficult to spot semi submerged debris even in calmish conditions so surely a submarine at a shallow depth should be able to scan the surface of the sea above it using radar/sonar. There has to be an explanation as to why they are not being used. Taking the 6 Australian ones as an example, it does not seem to make sense that the positions of all have to remain secret as presumably some have to come back to base for resupply and then they would be visible by satellite.

Surely there must be submarines there - anyone have an educated answer/guess ?

CowgirlInAlaska
Best I've seen, by miles
Tomnod
Two windows indeed. About 8m square?
It appears to be at lat -43.78731 lon 95.335332