I was invited to speculate. Here's where logic takes us (not very far, I'm afraid, but it's a start):

The idea that a debris field was created in the SIO - and yet the world's collective search efforts have yet to identify a single ounce of it - is well beyond the bounds of common sense.

I concede that the search area is vast and inaccessible, and that, over time, debris sinks, degrades, and comingles with other junk. But all of those things take time; and many items (lifejackets, eg.) retain their visibility, flotation, and evidenciary value for years, so all that would have been needed to positively identify something was a sufficiently vast and hi-def satellite search.

I distinctly remember watching a televised news item about new technology that allowed satellites to read the headline on a newspaper held by someone on the ground. They used "newspaper" instead of "iPad", because the item I watched was broadcast in the 1970's. So I'm going to go out on a limb and suggest that current satellite technology is sufficient to scan quickly for possibilities, and zoom in to identify.

So here are the 3 possible avenues taken by the investigation leadership over the past 5 months:

#1 they decided to withhold this search technology (i.e. chose not to find anything)
#2 they applied the technology, found debris, kept it secret, yet still haven't found MH370
#3 they fully applied the technology, but didn't find debris

#1 requires either irrational search leadership, or the known non-existence of debris.
#2 requires irrational search leadership.
#3 requires the non-existence of debris.

Result: if the search leadership is rational, then there is no debris.

The southern-track-until-fuel-exhaustion hypothesis requires debris (a powerless 777 cannot magically "self-Sully" onto a rolling, roiling ocean).

Result: if the search leadership is rational, then the southern-track-until-fuel-exhaustion hypothesis is invalid.

Wind Tunnel

I don't know why I bother writing anything in this thread as no matter how rational or polite it gets deleted! I must be on auto delete :E ( That includes the MH17 thread :{ but finding any floating fragments whether life jackets or otherwise from the wreckage will not after all this time give an indication of the crash location.
You are not dealing with just currents and tides but also varying winds over a considerable period of time.

if the Ocean was relatively shallow there might be some small chance of finding static wreckage on the Ocean bed but with the considerable depth and pressure that chance is negligible bar an absolute miracle

Invited to speculate - that's got to be 50% of this thread... :8

However, look at what happened to the Asiana 777 which hit a sea wall then pirouetted on its nose down the runway then belly flopped back onto the ground. What bits fell off that? The tail cone due to the impact on the sea wall, some undercarriage parts and the engines. The fuselage stayed intact.

So what would happen with a relatively slow and level impact with the water, perhaps following an invented RNAV STAR to an imaginary airport 50 feet above the ocean? I would say the same - the tail may have remained in place without a hard strike but engines may have been lost. But the fuselage could have stayed intact. Engines would have sunk immediately, followed by the fuselage after a few hours. Given 2 - 3 weeks delay what would be still floating? Even if the wings and tail had broken away they may well have sunk. But after floating for 2 weeks or so would be nowhere near the fuselage which itself would not be near the engines which would have sunk close on vertically.

Beach-combing for debris may not be very productive.

Pace,
You and I both...
Quote:
"...finding any floating fragments whether life jackets or otherwise from the wreckage will not after all this time give an indication of the crash location."

No, except that if authentic they would indicate the a/c came down in the ocean.

Nope, your post is well beyond the bounds of common sense. SAR professionals such as myself have tried to explain why it is entirely possible (nay, probable) for a debris field to remain undetected...but armchair experts simply know better.

Hey ho, there are none so blind as those that cannot see.

Its not easy to spot wreckage from the air. Hours of staring at white waves wondering if one of them is something more than a wave. Grey clouds, grey seas, and grey aluminium.

If you want to find wreckage at sea, paint the planes fluoro yellow. White and grey are almost camouflage in poor conditions.

And thats before you consider how large the search area is, and the delay before the search started in the Indian ocean.

Its not always easy to even spot ships from the air. There are numerous WW2 examples of planes missing ships (and even convoys) when they must have passed almost overhead. Pilots from the Ark Royal launched torpedoes at the Sheffield when they believed they were attacking the Bismarck.

Im not at all surprised at the lack of wreckage. Maybe if the fuselage had been breached and lots of bright things spilled out. But a few control surfaces or even a couple of wings would be hard to find, even if still afloat at the time people started looking.

Please correct me if its wrong, but my understanding is the FOV of a satellite camera will decrease in proportion to its resolution.

Another words you can see a big area but not small things. Or you can read a headline, but only on a small area (for those that can read headlines). Hence to see the small stuff you would have to know where to look.

The ocean and search area is :mad: huge, combined with the fact they didn't get to the "most likely spot until significant time had past means dispersal was even worse.

Swissair 111 had an undetected fire on board which was initially underestimated. When the fire was detected, by following the checklist, and the pilots did exactly follow the procedure, they were finally unable to control the aircraft and died.

I strongly suggest to listen to the ATC/Cockpit voice recordings. They pilots decided, due to the smell of smoke which was not found, to head to Halifax. But they had to dump fuel. By that time, they did not know how catastrophic the fire was under the hood.

Remember that the MD11 was not having all the sophisticated systems as a B777.

MH370 had a small little SATCOM antenna on the side of the aircraft. The ACARS system is connected to two redundant SafetyBuses systems which have a 28V battery powered, aircraft independant power source. Generators, Bat or RAT are not needed to have the system alive.

There is no CB in the cockpit, like in a Boeing 737. You cannot pull it out just like this.

So, for me ot logical what event would stop ACARS to send information, except a big booom, like with TWA800.

A new Bathymetric Progress Map of the search area just released:
Progress report

And also a revised version of the report about the search area, with new info:
MH370 - Definition of Underwater Search Areas :
Some of the "queries" are in the comments of this page: Blog - Cautious optimism in search for MH370

Differences viewed in the "revised version of the report" after a quick look (Old >>> New):
p.02: Jaworkski >>> Jaworski
p.20: Note 16: Complete table of handshake satellite data values provided at appendix X >>> Nothing (there was no appendix X... and it is not in this revised version!). So all subsequent notes are numbered minus 1.
p.32: reference to figure 31 >>> reference to figure 32. It was a typo.
p.56: Table 4 >>> Table 3. There was a mis-numbering.
p.57: Four paragraphes added. From "The reason for the partial compensation..." to "This
combined factor was used to determine the ‘Satellite and EAFC Effect’ in the BFO calculations." Have to be read!
p.58: Tables 5 and 6 modified with one line added which explains why the "Downlink Doppler" was changing with a/c latitude (Table 6):
"Uplink Doppler" and "Downlink Doppler" >>> "Aircraft Doppler (uplink)", "Satellite Doppler (uplink)" and "Satellite Doppler (downlink)"

It appears from this revised version that the "Downlink Doppler" was the sum of the "pure" downlink Doppler (which have to be the same for different position of the a/c) and the Doppler from the velocity of the sat to the a/c (the Doppler from the velocity of the a/c to the sat being computed separately). This answers the question of "many"!

Interesting turn of phrase in first paragraph. Obviously it is not the role of ATSB to speculate on possible earlier events. The role of ATSB is locating the plane if possible. The Malaysians are responsible for investigating the psssinlr cause.

Diplomatic protocol would also preclude ATSB from speculating along lines that could embarrass Malaysia.

So ATSB is appropriately not speculating on cause. Yet they had to make some assumptions in order to define the area. Hence the most "neutral" possible hypothesis.

Hopefully the model is not too constrained such that it does not encompass alternative explanations. In particular, the document makes some comments about possible gliding distance if there were control inputs. At 90 odd km, the search areaay not be "wide" enough to cover a controlled glide.

To paraphrase, a conscious but unresponsive and unconscious crew event scenario is indistinguishable, and it had to be one or the other

Yes. But likely quite different profiles after fuel exhaustion. Is 90 odd km sufficient to encompass a glide for max range? I don't think so.

There will have been careful consideration of diplomacy in this document. Also carefully worded disclaimers to minimise any criticism in case of an alternative ultimate explanation. "Hey that was not our responsibility and was not relevant to our role."

It is certain there was very careful consideration given to every comment that even hints at cause in a document of this nature.

I am wondering about one thing in the definion of the search area report: If the AP had been off for that long, how could the satellite system log on? Doesn't it require a directional antenna? Wouldn't a spiral dive already have developed after 3 minutes, making any directional antenna use impossible? Or is the tracking that quick?

The 777 does not have a steerable antenna for the satcom. There is a low gain and a high gain antenna located on top of the fuselage which look above the horizon.

ATSB - Update 18 August 2014

Since the public release of the report 'MH370 – Definition of Underwater Search Areas' on 26 June 2014, the ATSB has received a number of queries about some of the technical details contained in the report. The queries have been made directly to the ATSB or through the Chief Commissioner’s blog, InFocus, on the ATSB website.

As a result of the queries, the ATSB is today releasing an updated version of the report to clarify a number of technical aspects. The changes to the report are detailed in the Addendum on the inside cover.

MH370 - Definition of Underwater Search Areas -PDF: 7.33MB- (updated 18 August 2014)

Hmmm... I would have assumed it was a phased array conformal antenna

Civilian shipping
 

Something that does not seem to be in the ATSB report us an analysis of civilian shipping location and course at the time of the 7th partial handshake. The information we do have is the exact time of this transmission, and the location of this arc. The location of ships in the vicinity of this arc at that time is surely available.

The ocean is huge and shipping is fairly low in density relative to other waters. However there is a reasonable amount of shipping between Australia and South Africa - the sea lane of most relevance to MH370. Many of the tracking services are only accessible via paid subscription. However one historical graphic I was able to find shows 1920 vessels in the Indian ocean for 6th April 2012, with a small minority of these in the general area of interest.

Given we have an absence of positive information (i.e. something seen), have we made all possible use of negative information. Might it help define the most likely areas to search if we use reports of what was NOT seen.

Sure any ships in the area could easily have missed something. There are countless stories from shipwrecked people ultimately rescued of not being seen by a passing ship.

However everything about the proposed new search area is based on analysis of various probabilities and compromises - which is logical given we can't search everywhere.

So could we assign (admittedly somewhat arbitrary) values for the probability of a ship seeing something had it been in the right area e.g. 777 spiralling into ocean, or a fresh debris field. Looking at the solar terminator at the time of the final handshake, it was daylight in the proposed search area. That increases the probability something would have been seen by a ship in the right place.

Can we use this information to calculate adjusted probabilities (i.e. MH370 less likely in this area as a ship in that area didn't see anything, and correspondingly other areas become more likely).

"Hmmm... I would have assumed it was a phased array conformal antenna" - Astramike

You are correct Sir, and I am wrong. There is a non steerable low gain antenna on the roof of the T7 but there is also a phased array high gain antenna.

The phased array antenna is an Esterline CMC Electronics Inc (Canada) model CMA-2102SB (source airframer.com)

It is 60" long, 18" wide and 4.5" high, takes 69 watts, can switch the beam in 50 microseconds and offers a minimum of 9dBiC gain over 100% of the hemisphere above the horizon. Looking straight up it gives 17dBiC gain.

dBiC is decibels of gain of the antenna relative to an isotropic antenna (no gain) dealing with a circularly polarized EM field.

The gains offered by this antenna range from 2 to 7 relative to an omnidirectional antenna.

MH370: Malaysian Firm Says Chinese Hackers Took Classified Data From Investigators’ C
 

MH370: Malaysian Firm Says Chinese Hackers Took Classified Data From Investigators? Computers

Chinese hackers targeted the computers of high-ranking officials at agencies involved in the investigation of Malaysia Airlines Flight MH370, just a day after it went missing, and stole classified information, a Malaysian newspaper said Wednesday.