I have a question about flight operations. Can someone who is knowledgeable answer this?
When a plane appears on air traffic control radar, there is a little identifying number next to the green blip. This number indicates the airline and flight number or type, doesn’t it? The air traffic controllers can tell from this number the type of plane they’re dealing with, can’t they?
Is it possible to in some way change this number, and thus change the identification of the plane to something innocuous?
If it’s possible to change this number, then the hijacked plane could have flown at very low altitude to hide from radar, and when it crossed over land and came in contact with some city’s air traffic control, it would show up as something normal in the ordinary air routes, transiting the region on its way to a fake destination. If the Malaysia plane shows up on the New Delhi radar as (let us say) Japan Air Lines flight 5527, then surely New Delhi air traffic control will just say, “JAL 5527 heavy, proceed on course 174 at 38000,” or whatever they say. So the Malaysian plane is in disguise and is crossing Indian airspace on its way to Jihadistan without having Indian F-18s go up to check it out. It looks legit.
Is any of this possible?
Is this possible?
Absolutely. (Although probably not course 174 — there be nothing but hungry sharks thataway.)
The Times of India ran an interesting analysis this past day:
Hiding in full view?
The northeast-bound jet now took a northwestern route from Kota Bahru in eastern Malaysia to Penang Island. It was last detected on military radar around 200 miles northwest of Penang.
Even that act of going off course may not have caused alarm at first if it was handled gradually, pilots said.
"Nobody pays attention to these things unless they are aware of the direction that the aircraft was heading in," said one first officer who has flown with Malaysia Airlines.
The airline said it had reconstructed the event in a simulator to try to figure out how the jet vanished and kept flying for what may have been more than seven hours.
Pilots say whoever was then in control may have kept the radio on in silent mode to hear what was going on around him, but would have avoided restarting the transponder at all costs.
"That would immediately make the aircraft visible ... like a bright light. Your registration, height, altitude and speed would all become visible," said an airline captain.
After casting off its identity, the aircraft set investigators a puzzle that has yet to be solved. It veered either northwards or southwards, within an hour's flying time of arcs stretching from the Caspian to the southern Indian Ocean.
The best way to avoid the attention of military radars would have been to fly at a fixed altitude, on a recognised flight path and at cruising speed without changing course, pilots say.
Malaysian officials dismissed as speculation reports that the jet may have flown at low altitude to avoid detection.
But pilots said the best chance of feeling its way through the well-defended northern route would have been to hide in full view of military radar inside commercial lanes — raising awkward questions over security in several parts of the Asia-Pacific.
"The military radar controllers would have seen him moving on a fixed line, figured that it was a commercial aircraft at a high altitude, and not really a danger especially if he was on a recognised flight path," said one pilot.
"Some countries would ask you to identify yourself, but you are flying through the night and that is the time when the least attention is being paid to unidentified aircraft. As long as the aircraft is not flying towards a military target or point, they may not bother with you."
It would be easier to simply turn it off and get right behind another scheduled airliner who was already flying across India. There was a Singapore Airlines plane doing that very thing at the very time and place where this Malaysian Airlines plane crossed its path and could have very easily gotten right behind it.
In that scenario, there’s no need for any other knowledge than simply switching it off.
IIRC, when Bush make his suprise visit to Iraq for thanksgiving they flew AF1, but claimed to be a Gulfstream private jet.
Is it possible to in some way change this number, and thus change the identification of the plane to something innocuous?
Short answer. NO
Modern transponders use what is called Mode S transponders. Since the mid nineties. Mode S transponders are more accurate and do alot other things not worth mentioning. Most importantly Mode S contain the unique aircraft identification.
Long answer. Yes, an aircraft id can be changed but not during flight and while transmitting.
The following from en.wikepedia.com
Upon interrogation, Mode S transponders transmit information about the aircraft to the SSR system, to TCAS receivers on board aircraft and to the ADS-B SSR system. This information includes the call sign of the aircraft and/or the transponder's permanent ICAO 24-bit address in the form of a hex code.
Mode S equipment on aircraft are assigned a unique ICAO 24-bit address or (informally) Mode-S "hex code" upon national registration and this address becomes a part of the aircraft's Certificate of Registration. Normally, the address is never changed, however, the transponders are reprogrammable and, occasionally, are moved from one aircraft to another (presumably for operational or cost purposes), either by maintenance or by changing the appropriate entry in the aircraft's Flight management system.