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"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")
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Boeing 777 avionics compartment vr panoramic
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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. |
Originally Posted by Trimup
(Post 8378881)
Where, when and how are prone to "anything is possible" see the hundreds of posts on those topics already. Why and Who tend to improve focus. The flight crew is being discussed as the Who in many posts here and elsewhere but I have yet to see a Why that makes sense for either of them.
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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? |
Originally Posted by misd-agin
(Post 8378863)
"Roger that" is not an uncommon acknowledgement in U.S. aviation talk.
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):
It appears that most of the worlds journalists and managers of the search have failed to do any "air of reality"checks with this story. The searchers have failed to think logically with the exception of the Chinese Government and the Vietnamese Government who have done an incredible job and who both deserve an honourable mention for their accurate reporting. The Transponder and Flight Data STOPPED indicating a catastrophic explosion. The WRECKAGE DEBRIS was repeatedly observed, photographed and provided to searchers. Boats arriving could not find it. Those Photographs did not LIE, they were not fabricated. They are REAL EVIDENCE. Oil Rig Worker Michael McKay was the First and Only Eye Witness to the explosion and his "Bearing confirms that it was along the flight path near where the Transponder Stopped. The Satelite "PINGING" by Imarasat shows it ENDED in the same area as where the Transponder Stopped. The problem is, Imarsat information has got the TIME wrong, it was NOT AFTER the accident time but AT the accident time the last reported "PING" was heard. There appears to be a miscalculation of time or , the FL MH370 flew in circles in the same area for 7.5 hours and then crashed in the same area. Imarsat is not showing an accurate map. The map shown is misleading and fails to allow for known errors that if allowed for place the last signal in the same area. The Primary radar is dubious, and does not show clear evidence to support any flight away from the last known position. There is NO evidence to support a highjacking. Any search manager should take a close look at that Imarsat informatio, demand to see video or stills of that primary radar BEFORE assuming the "Highjack" theory and or wasting many millions of dollars searching in any area OTHER THAN an Underwater search in the Immediate area after the transponder stopped. At around 500 Knots, the debris will have travelled about 5 miles forward of the last known position along the Planned Flight Path and it is there that the heavy wreckage will be found. The floating Debris has moved at about 50 miles a day and some maritime science needs to be used to determine from wind and currents since the crash time as to where that debris might be now. The world owes an apology to the Governments of China and Vietnam for their incredible work to date and for the arrogance of the west to ignore their vital evidence. Dito for Michael McKay who is the Sole Witness to this mid-air explosion. The US navy needs to take its own appraisal of the above information and start an underwater search centered on 5 nm ahead of the last known Transponder position on the Flight Path Track. 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.
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then, those involved would be sophisticated enough to know, or learn through monitoring the world, including PPRuNe discussions, and make the necessary modifications IF (again) that is technically possible on the a/c systems. 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
What has not been mentioned by the previous posters suggesting HF is that nowadays huge chunks of HF spectrum can be recorded using SDR and played back at leisure, with particular attention to transmissions sticking out as unusual. Likewise VHF, if anyone is recording it in that way. 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
The U.S. officials said the communication was four “pings” over a period of hours after the last ground contact with the plane, Malaysia Airlines Flight 370, which disappeared on its way from Kuala Lumpur to Beijing with 239 people on board. 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.
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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 may be totally off here and I will welcome any correction but: The 40 deg arc is being shown on maps as the supposed northerly option of the flight path. There is no way that the aircraft flew along the arc as if it was some huge DME arc. The flight path would have cut through various arcs, the 40 deg one being just one, with the hourly ping being on a different one each time. I must be missing something here...anyone? 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. |
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