"Roger that" is not an uncommon acknowledgement in U.S. aviation talk. I believe it comes from the military and has crossed over, in small doses, to general U.S. conversational English, typically from former military personnel. It's used to acknowledge (ie WILCO) or as a general agreement(I wish we could get going. "Roger that")

Boeing 777 avionics compartment vr panoramic
 

Just adding to Ensco's post which said "I know something about mental health and suicide. Anyone who wonders why someone would go to such lengths to mask a suicide, doesn't have that much familiarity with suicide.

It is actually reasonably common that someone commits suicide, but tries to disappear rather than be remembered for the act of the suicide.

Also the willingness to murder innocents in the process is not quite so rare as people are making it out to be. Ask any policeman about what they think really happened in many head-on collisions that are classified as accidents."

I'm in a different industry, but one where unfortunately we have suicides take place. And it is not unusual for someone to take several hours on the top of a building before jumping. So the continuation of the flight (rather than an immediate dive) might not have been planned or deliberate but the person starts the process with a flight diversion and removing the comms, and then takes time before finally committing the act.

I'm a pilot.

I have said "roger that" and "goodnight" many times.

I have never said them due to duress.:rolleyes:

A few radio technical comments
 

I've been reading the thread, and have a few comments based on my radio/RF Engineering/software/comms background (my aviation is only P-3 aircrew, private pilot, and CAP SAR):

"Ping" - we don't know if this is being used as a technical term or simply a shorthand way to describe a transmission used just for link establishment/maintenance. It might actually refer to an ICMP "ping" message, but I doubt it. The safest assumption is the most general - it's just a received, short transmission.

Regarding the search arcs - they appear to be at constant range (and elevation) from one satellite. This implies that they were established either by signal strength measurements or timing. Triangulation, and measurements with two satellites don't match this.

Without knowing deep details, we cannot be sure of which. I would guess they are using just signal strength. The satellite probably logs each message with a bit of RF data - frequency/channel, strength, antenna used. In either case, unless remarkably tight timing information is being kept, the arc position will not be very accurate. If signal strength, they probably used one or more pings when the position of the plane was known to establish a baseline.

I hope someone with deep knowledge of INMARSAT appears and comments.

A non-technical note: the arcs appear to correspond to just one ping - probably the last. We have not heard where the other pings were located - unless they, by some chance, just happened to also be on the arc (i.e. had the same signal strength). A question to be answered.

Another non-technical: I doubt the aircraft had to be flying to generate the pings - it just had to not have been destroyed or completely powered off.

Regarding cell phones at altitude. Radio signals at those frequencies (low noise) can travel a surprising distance. A ~1/2 watt cell phone can easily reach 100 miles, unless TDMA timing protocols rule it out (depends on the specific modulation scheme). Likewise, doppler from a moving aircraft is from the component of motion along the line to the tower. Thus, if the phone is talking to something at 90 degrees to the line of flight, there is zero doppler, with it increasing as the angle approaches 0/180. I recently had an email appear while I was riding at >FL300 and had forgotten to set the phone to airplane mode.

The same observation on radio signals at high frequencies means that hand-held walkie talkies could be used at quite a distance for communications from an aircraft. Even an FRS radio (cheap HT's sold at many stores) could be used.

Complete conspiracy theory here…. But you hear of "sleeper" agents in the spy world. Maybe in the terrorist world, they could be doing the same with pilots. Guys training, getting flying jobs, seeming completely normal for years, arousing no suspicion, until the day they are "needed".

Comms
 

Why would the perpatrators need to be anonymous?

Let us throw another spanner in the works.

I posit that there was a large quantity of gold bullion, or other very high value cargo in the hold of MH370. One or both of the flight crew conspired with a criminal gang to hi-jack the aircraft and fly it to a location where the criminal gang could recover the cargo.

Pure speculation of course, but it would certainly explain the lack of a crash site, lack of attribution to terrorist groups and the desire to remain anonymous. The destination would not necessarily require a runway if the aircrew were prepared to ditch or crash land the aircraft, or even abandon the aircraft, for it to crash at a known location.

Will Malaysian reveal a cargo list? If not, it may just lend credence to my posit.

Any body any thoughts on this?

Sadly true in too many cases.
I was one of those pedants who used to bust peoples' chops about that. It's bad radio discipline. Roger, Over, Out, WILCO ... a lot of terms have precise meanings if one bothers to learn what one has been trained to do. :mad:

A lot of our ship based air controllers got in the habit of using "roger that" but I am ten years out of date. I would hope that someone would have tried to clean up the airwaves, though maybe enough pedants are not around to have enough impact.

on "roger that"
 

I suppose that pro pilots in service for many years or in familiar airspace might develop verbal shortcuts or personal touches. For me, as I get farther away from my normal flying areas and familiar-sounding controllers' voices, I get more standard in my speech.

I'm only a private pilot, but my instructor taught me to use concise, correct phraseology by commenting mercilessly about others' goofy phraseology overheard on the air. He tolerated a bit of personal modification to the official wordings, but was careful to instill in his students a respect for the benefits of consistent language.

Many of the students at the school where I learned to fly continue on to pro aviation careers (especially in ATC) and so there's a good emphasis on phraseology there. Usually there was a bit of good natured ribbing over strange phrases they had heard fellow students utter on the air.

Occam's Razor
 

This would certainly be the simplest - and arguably most logical - explanation (see Ramjet555's post at 4097):

On a related note, does anyone know what this "debris" turned out to be?

http://www.themalaysianinsider.com/a...60_223_100.jpg

Roger That
 

I have to concur with Tourist. I'm a humble heli pilot and I use " roger that" all the time. I am very surprised to see it even being discussed in the context of this thread.

I suspect Boeing, Airbus and the rest are already one step ahead. I don't think anyone wants to see this repeated. You'll probably find the US will mandate some sort of enhanced monitoring under the auspices of the TSA and National Security....other nations will no doubt eventually follow suit.

And quite honestly I feel sorry if anyone is trying to monitor the PPRuNe discussions for useful tidbits...unless its a Hollywood script writer looking for a few pointers to help with their writer's block ! :cool:

What about previous 'ping's
 

If Inmarsat can establish that the 777 was on a particular arc during the last ping (these are the arcs we have seen recently) they can surely determine the arcs of the previous pings as well. Given that the groundspeed of the plane is probably known to with 10% at worst, a reasonable track of the plane's position should be possible. If it was pinging every half-hour, and we are absolutely certain of its position when the transponder was disconnected, then the range of possible flight paths based on a series of arcs and a estimated speed would be quite small.

I can't imagine why nobody is bringing this up. It's completely obvious.

Aircraft HF Radio Comms
 

This is interesting because intelligence networks like GCHQ do something along these lines and as the aircraft was equipped with something like Rockwell Collins HF 400W transceivers which can work any frequency between 2 and 30Mhz then it is possible those on the cockpit had capability of communicating on preassigned frequencies with a range of 1000s of miles.

Alice Springs- Jindee comment FWIW
 

About 15 years ago, as a tourist I passed thru Alice Springs- flew in- bussed out south via the ' gun barrel " hiway.
Was traveling with a random group- e.g. non affiliated.

And being generally aware of the OTH radar facility there - and later discussing it with some more knowledgeable people on the subject…

Its pretty sure the detection range publicly listed is much less than actual

As in being able to track military aircraft flying around during desert storm . .

My point is even if the Aussies went back to records and found some indication by matching times, possible tracks, etc it would probably be a while before they released it.

And I'm still quite sure the U S Navy is working on more than a ' hunch '-

But it will take spotting of a debris field and backtracking wind and waves to find if possible a ping . . . .

Even so it is a very big and DEEP ocean on the south leg of the arc

Scroggins and Ramjet555's post at 4097

While I realize that you don't think that INMARSAT technicians can tell the time; one thing that they are reasonably good at is which satellite the signals are being received by. The position of handoff between Malaysia and Vietnam where you would have the explosion - is outside the footprint of the geostationary satellite that was receiving the pings for several HOURS. Mathematical lateration calculations put the last ping North West of Thailand received by a satellite whose footprint does not extend as far East as Thailand.

Ramjet555
 

citation for above quote

It seems you left this fact out of your theory!

Further to the point, it is based on this evidence that the US Navy has moved its assets west into the Indian Ocean.

wild_goose
 

Precisely! I'd like to see a map showing each ping and it's arcs. I suspect the USN has this information.

Ramjet555s responce is the only one out of 'undreds of replies of rubbish that I have read in the past week.
Unless RR has improved its powerplants exponentially the references to 45000,(FL450) is unavailable because at the weights that the 777 was at it would only get to FL390 near the end of its scheduled flight.
It used to be a very light 747 that got over FL370, untill there was only about 4hrs fuel left on board.
For my money the aircraft had a technical problem(breakup) or sever control problem at less than 5 hours out of KL.

I agree with you goose, not only that, but we must assume that the arc, is really a sector of a sphere, as the Ping only tells them the distance from the satellite at a certain time, and this diagram is only 2 dimensional. And this particular arc or section of sphere is all the possible locations as of the LAST ping.

They would have the data of all the other hourly pings (7?) and by starting out with the last known actual position, where it was lost off the actual radar, assuming a reasonable airspeed, they could intersect the plane's assumed trajectory with the Ping arc and have an idea of possible locations.

The assumptions they are making are airspeed and direction - they can't tell that by the pings. . Lots of assumptions. Many possibilities.

I've given this some thought, and there are some possibilities.

First - one thing we know. There were approximately 50 less seats sold for the flight than max capacity. That might signify a heavy cargo. I would think that someone would have to plan that out ahead of time, otherwise the seats would be sold. If someone knew that regular shipments of something heavy (gold?) were being made, tracking available seats would point to which flight.

Also - this was a high-hour pilot with seniority. Presumably the red eye would not be a particularly desirable flight. It could be that if there was an important cargo or person on board, the airline assigned a senior pilot. If that was SOP, it could have been another indication of cargo.

an update re WSJ
 

Search teams have been withdrawn from the South China Sea, the area from which the plane's transponder, which relays identification signals to ground radar, sent its last signal. "Clearly, the search for MH370 has entered a new phase," he said.

"As of Saturday, 43 ships and 58 aircraft from 14 countries are involved in the search, the prime minister said.

The latest revelations indicate that the search areas will be significantly expanded, while Vietnam announced it would cease search operations following the prime minister's statement.

On Saturday, the U.S. Navy's Seventh Fleet confirmed that it had spent the day searching the Bay of Bengal far to the northwest of Malaysia. However, it now appears unlikely that Flight 370 could have flown there, given the bay's distance from both corridors highlighted by the prime minister.

A spokesman for the Seventh Fleet said patrol schedules were planned only one day in advance and the U.S. Navy "will not fly to the south" of the Bay of Bengal on Sunday, despite Mr. Najib's statement. "

THIS FOLLOWING THE COMMENT

" Based on the new data, aviation authorities of Malaysia and counterparts in other countries have determined that the plane's last satellite communication came from one of two corridors, Mr. Najib said: a northern one stretching approximately from the Kazakhstan-Turkmenistan border to northern Thailand or a southern one stretching approximately from Indonesia to the southern Indian Ocean.

If Flight 370 traveled north, it might have been above Thailand, China, Myanmar, Kazakhstan, Uzbekistan or Turkmenistan at 8.11 a.m., according to the satellite data released by Kuala Lumpur. However, it would have needed to fly through the airspace of several countries to have reached that point, and it is unlikely that it could have done so undetected, especially if it passed close to China or India, both of which have air-defense systems.
"


AND THE PLANE WAS FUELED FOR ABOUT 8 HOURS FLIGHT
"The routine messages sent by the aircraft show that Flight 370 was still airborne nearly six hours after it disappeared from Malaysian military radar. The Boeing BA +1.00% 777-200 plane with 239 people on board was carrying enough fuel to fly for eight hours, Malaysia Airlines confirmed on Saturday"

NO. the 40 degree arc is the possible position of the aircraft at the time of the "ping" to the satelite. The Aircraft could have been anywhere on that arc(In the red marked areas).

Right. But the degree of the three other pings has not been shared(yet).

Roger That / Readbacks
 

I'm a pilot too and pretty sure I've used this phrase on occasions but what I haven't seen is what he was responding to. If it was a frequency change to the Vietnamese controller then strictly speaking it is one of those items, like a runway clearance, heading, speed or altitude change where a readback is required and he didn't.

While it doesn't prove anything, other than rather casual phraseology late at night, it might have prompted the Malaysian controller to quickly ask for a readback before MH370 changed frequency to be sure of a clean handover.

Over-Reliance on Inmarsat Ping Data? Other Radio Signals?
 

Reading the Malaysian PM's statement as a whole, the thing that stands out is that it is carefully crafted to address an obvious question about the Malaysian government's handling of the matter:
The implied answer asserted by the PM could be paraphrased as follow:

• Malaysian government did (ultimately) notice that an aircraft had flown across peninsular Malaysia,
• The primary radar track was not connected with MH370 at first due to the absence of transponder data.
• The primary radar track was only connected with MH370 when the relevance of Satcom ping information was appreciated some days later.

Current attempts to pinpoint the location of the aircraft based on extrapolation from Inmarsat ping communications should be seen against this background, and be taken with a large pinch of salt.

It is tempting to overestimate the degree to which Inmarsat data can be relied on, all the more tempting as we have nothing else in the public domain. However, as pointed out by earlier contributors, estimating location from radio signal strength cannot give more than a very rough indication of range. It may be worth the effort and cost to conduct a full-fledged trial to confirm assumptions about signal strength etc. given the actual type of aircraft, antenna, flight attitude, etc.

More sophisticated techniques based on signal transit times etc. are more promising in theory, but the Inmarsat protocols are not primarily designed for this purpose. Transponders on the satellite may not have measured/collected/downlinked timing data except as necessary for link establishment and maintenance. TDMA related data may be most promising to the extent it remains extant.

As another contributor has noted, it is possible that ACARS also sent out pings on VHF which might have been received while MH370 was (again) in the vicinity of land (Malaysia or Indonesia). Space-based SIGINT may also be of assistance, but we will not hear about such efforts.

Obviously, contemporaneous visual satellite imagery would be the the easiest way to spot an aircraft in the middle of the Indian Ocean.

@bbg

I believe that BA38, the 777 that crashed at LHR, had spent a lot of its flight at 40,000ft? That was thought to have contributed to the icing problem.

I have no idea what load-control system you used to work with, but from my days doing weight & balance (4 years ago), I used to work with several different systems, all of them creating a NOTOC and an indication in the loadsheet (in the LDM section) when valuables where onboard (VAL/xxx/hold). It's something pretty usual in Switzerland, to have valuables onboard, so I'm used to print NOTOCs and loadsheets with that code...

Post #4077, Techgeek said "Please disprove this line of reasoning..."

You based your conclusion on hourly data updates. Revisit using updates that are twice as frequent.

Andy Pasztor, WSJ, broke the story about the data transmissions on Thursday. His report indicated that the data was in 30 minute increments. Pasztor initially reported that the plane could have flown up to four hours after the last official reported contact of 01:41. In an interview with NPR, he also said that it was possible that it (the aircraft) had landed.

Behind his report is the implication that data points are missing from a regular 30 minute interval pattern.

Yes. But you'd give the NOTOC to the crew with the load sheet wouldn't you? They wouldn't be informed weeks ahead, in order to plan a heist.

I agree, I was just stating that valuables are considered special load, and for that, pilots get a NOTOC, since it wasn't clear from previous statement.

This post is so outlandishly incorrect, it should be addressed to eliminate confusion
 

Ramjet555 said:

The "alright, good night" AND contact with Japan Bound flight came AFTER it was switched off.

Vietnam found plenty of that "evidence" and none of it was from the plane:
http://www.hindustantimes.com/world-...1-1193007.aspx

There is no physical way he could have. Distance and circumference of Earth do not cease to exist just because you want him to have seen what he thought maybe he saw

So the plane just hovered there for 7+ hours? And during this 7+ hours, no one was able to spot it while the search was underway?

There are a bunch of the pings, not one

...so it did hover then? And since the search started roughly 6 hours after the plane went missing, about 1.5 hours of the Hovering took place in the middle of the SAR team?

Good thing there wasnt a midair collision between SAR and the hovering MH370 with all that trafic - we must have dodged a major bullet there!

Ghost plane? Something big was picked up, and followed that path. Not only that, but there are at minimum 11 eye witness reports at the Malaysia/Thailand border putting a plane flying from the Gulf of Thailand towards the Straits between 1:30-1:45 (must be coincidence though as this is the same time the plane is hovering, right?)

Except for the evidence you don't want to hear

So all real evidence that all the Governments seem to be agreeing on now is just wrong, and those Governments are wrong, and because of that what all the real evidence indicates is also wrong - therefore, the plane has to be where it absolutely cant be after having a catastrophic event it couldn't have had? Makes sense...

the area is 30-75 Meters deep! if you stood the plane on its nose in the area it went down, odds are its tail would be sticking out above the surface! If 14 countries cant find the black box in that depth...

Do you not know how A) Small the body of water is there B) how many planes, ships and satellites have been combing thh area?

They were there watching everything within 6 hours. The debris would have had to have been seen THEN, and it wouldn't matter where it could have gone much, much, much later

no - Malaysia owes them an apology for lying to everyone for a week before telling them looking in that area was absolutely pointless. What we know
Planes tracking Disabled - THEN pilots talk to ATC and Japan Bound Plane - THEN Eyewitnesses put it over Malaysia/Thailand - THEN radar picks it up ... and they knew all that within hours of the event! That is why one of the first statements Malaysia made included "last contact at 2:40", "indication it turned around" and "eyewitness reports"

Also, there is no "evidence" what so ever, no matter how hard people try to twist things. Nothing AT ALL is there

Again, physically impossible

Get a scuba tank and do it yourself - it is THAT SHALLOW of water!

meanwhile, no one else should be wasting their time in the Gulf Of Thailand, there has never been a shred of evidence it was there and only a thought of "well, it last contacted us from here so it must be here"

And I would just like to point out, in your entire post, you did not even provide one fact other than the nod to Vietnam doing a good job - which they did do a great job trying to look for the needle miles away from anything resembling a haystack. China did a horrific job here though - releasing nonsense like the satellite image (which they later said basically 'oops, we shouldn't have released that, its not the plane', something which should have been pretty obvious since the so-called debris was said to be 3x the size of the plane) and then made the asinine claim of "seismic activity where there never is any" (despite it being IN the Ring Of Fire, at the exact time a 2.7 Earth Quake was taking place not far away) ... China had to have known they were talking straight nonsense, yet still put it out there giving people false hope the plane could have ever been in the Gulf of Thailand when it was known by Malaysia (and I imagine suspected by everyone) that it wasn't there

Why no military radar at night? Too expensive was the reply.
 

Nothing much happens they said, so the radar is switched off :ouch:

Yahoo News UK & Ireland - Latest World News & UK News Headlines

I'd like to help y'all understand the arcs because I think there is a misunderstanding of what they represent. IMHO they are not possible flight paths.

The arcs line up exactly with the range information from one single satellite, not two. This indicates that they are primarily getting their information from only one satellite (the only one in range).

Funny thing about these satellites (assuming the pic a few pages back is correct) is that they are all in a line so even if three or more were in range no "triangulation" would be possible because the satellites are not arranged in a triangle. GPS satellites are not arranged in a straight line for this exact reason.

All the arcs indicate is that at a few specific times the plane was roughly at a few points (or possibly only one point) along the arc, not that the plane flew exactly along the arc.

One satellite is going to give you a circle (in 2 dimensions, really a sphere but we can safely assume the plane is not in space or anywhere out of flight range to the west). Two satellites would give you duplicate points of intersection north and south. It would take a 3rd satellite that was not in line with the first 2 to triangulate and determine which of the north or south points was the correct one.

Since we are being shown arcs of a circle the information is only coming from one satellite.

Id like to know answers to OBD's 2 questions on fuel quantity at push back and cargo manifest.

In addition if a pilot is wearing a flight deck oxygen mask would that make his RT voice sound mumbled or muffled? And what is the approx duration of the flight deck 02 supply? Are we talking a few minutes or longer?

Communicator said

That is not correct. The Malaysia Government instantly recognized it as the plane, hence "last contact was 2:40" and "evidence to suggest the plane turned around" being relayed to the media on day 1 (remember, the initial thought by absolutely everyone everywhere was the plane was lost after 2 hours, not 1)

Only later, for God only knows what reason, did they start saying there must have been a catastrophic event taking place between 1:20-1:30 at the last known location - that despite their knowing the plane made verbal communication twice in that time frame, their hard evidence said it took a turn and eye witness accounts said it took a turn

@Communicator,The Inmarsat aperture angles have been determined by reference to the node establishment 'pings' tx/rx timings, meaning that the accuracy of the arcs shown is reasonable, though could be subject to some small errors associated with the internal pass-through time of the aircraft SatCom equipment.

EDIT: I made the following comment in Post #3819 over 12 hours ago;

Well, I would imagine that there is no way that information on the fuel and the cargo is going to be released to the public.
So while many would like it - they ain't going to get it.

Cargo
 

Can we stop all these nonsense theories about cargo theft?

If anyone had enough advance knowledge of the cargo and the flight it was carried on to plan to hijack the plane, they would have saved themselves a hell of a lot of money, risk and trouble by hijacking the truck that took it to or from the airport.

The only part the cargo has to play in the solving of this mystery is if it was in some way responsible for causing an explosion, fire or other incident in flight.

Oh and on the subject of the 'roger that' reply, do we know that the pilot making that comment was speaking English? If he was talking to Malaysian ATC he may have been speaking Malay and the above may simply be a poor translation into English.

HF / VHF comms
 

The key things here are 'if it stands out' and 'if it was heard'. Short HF transmissions in the middle of an Amateur Radio or Maritime frequency block are, I suggest, highly unlikely to draw attention to themselves unless there is something spectacularly unusual about them, even assuming that the signal is received loud and clear at a monitoring station. And even if someone spotted them immediately and identified the transmissions as unusual, unless the messages contained clear intent and identifiable place names, there is going to be very little that can be done about it. Something like "Alfa this is Bravo, all according to plan, ETA position Charlie four hours" isn't going to give much away unless you can recognise the speaker's voice or instantly triangulate it (good luck with that) to a location of high interest.

The radio bands are cluttered with all manner of transmissions from any number of sources, most of which are going to be unidentifiable unless they choose to identify themselves. Ships, aircraft, expeditions, taxis, radio hams, smugglers, take your pick ...

Full face Oxy masks usually are clear but a bit hollow and nasal in tone, not muffled. In a hijack situation the interloper is listening in and that should involve a non standard speaker or mic set up that could muffle things somewhat.

I agree with D.S.'s critique of the Ramjet555 theory.

The pilots are reasonable suspects, no matter how harsh, just as when someone is murdered in a home the spouse is normally on the suspect list.