Could missing MH370 have stalked SIA flight to the north? Possible, say netizens

A theory

that lost flight MH370 could have stalked a Barcelona-bound Singapore Airlines flight undetected by radar has emerged from online research that mirrors the massive international search and rescue operations over the past 10 days.

The theory is consistent with a flight path along an arc that ends at the Caspian Sea in the north and southern Indian Ocean in the south now being searched by at least 26 nations.

Pilots contacted by The Malaysian Insider have come up with a similar theory, saying whoever in control of the missing Boeing 777-200ER would just have to switch off all the plane's lights and follow the night to avoid visual contact.

"Once the transponders are off and the lights are dimmed, Flight MH370 becomes a ghost flight in the night sky. It can follow other planes closely or fly below them without anyone knowing.

"It will know where the other planes are from the radio chatter," one pilot told The Malaysian Insider.

The online search and calculations

A Reddit social network contributor named "Sweeperguy" and hobbyist pilot Keith Ledgerwood suggested the theory that lost Malaysia Airlines Boeing 777-200ER had shadowed the Barcelona-bound SQ68 for most of the seven hours it remained in the air.

Incidentally, Flight SQ68 is a Boeing 777-300ER, a slightly longer version of the Malaysia Airlines passenger jet by 33 feet, and travelled near MH370 when it vanished from Malaysian military radar screens at 2.15am on March 8, 2014.

The theory has been gathering chatter on pprune.org or the Professional Pilots Rumour Network and on Ledgerwoord's Tumblr microblogging site since last weekend, when Prime Minister Datuk Seri Najib Razak disclosed new search areas for the passenger jet with 239 people on board.

"I'm thinking just close behind. It's the early hours of the morning and without some intel/warning, if a radar operator noticed two primary radar returns in the same area, but had a mode 3A/C response from the other plane, it probably wouldn't draw much attention," Sweeperguy wrote in Reddit on Saturday.

Mode 3/A is used to identify each aircraft in the radar's coverage area. Mode C is used to request/report an aircraft's altitude, according to a Wikipedia entry.

Piggybacking on SQ68

According to Singapore Airlines website, flight SQ68 was scheduled to leave the republic's Changi airport at 1.05am for Barcelona, some 25 minutes after MH370 flew from Kuala Lumpur to Beijing on the other direction.

"It looks like if MH370 turned after lost contact at 0130 (1.30am) and followed the track back over Malaysia and along the way points previously discussed, it would be in the position shown at 0215 (2.15am), which is 200 nautical miles north-west of Penang.

"This position is only about 30 nautical miles behind the 0215 position of SQ68 which is also a 777," Sweeperguy wrote in his Reddit post, using the local Malaysian time.

Sweeperguy said if MH370 had followed SQ68 along a north-west path over India, which he speculated, the missing passenger jet would be near the SIA jetliner over Pakistan five hours from its last known position at 2.15am.

"So, by closely following SQ68 at a similar altitude and speed, it's likely that any Indian radar operator would not notice or question two closely placed primary radar returns as long as he had the expected squawk from SQ68," he added.

In his Tumblr post, Ledgerwood came to the same conclusion that flight MH370 had flown to all the navigational waypoints disclosed by the Malaysian authorities until it was near the vicinity of SQ68 at about 2.15am.

He said it became apparent that when inspecting SQ68’s flight path history that flight MH370 had positioned itself directly behind the SIA plane "at approximately 18:00UTC and over the next 15 minutes had been following SQ68".

Flight MH370 undetected without transponders

"It is my belief that MH370 likely flew in the shadow of SQ68 through India and Afghanistan airspace.

"As MH370 was flying 'dark' without transponder / ADS-B output, SQ68 would have had no knowledge that MH370 was anywhere around and as it entered Indian airspace, it would have shown up as one single blip on the radar with only the transponder information of SQ68 lighting up ATC and military radar screens," Ledgerwood wrote in a post that has gone viral.

He pointed out that the SIA flight would not have detected the missing MH370 as "the Boeing 777 utilises a TCAS system for traffic avoidance; the system would ordinarily provide alerts and visualisation to pilots if another airplane was too close".

But that system only operates by receiving the transponder information from other planes and displaying it for the pilot, he said, adding "If MH370 was flying without the transponder, it would have been invisible to SQ68".

"In addition, the TCAS system onboard MH370 would have enabled the pilot(s) to easily locate and approach SIA68 over the Straits of Malacca as they appeared to have done.

"The system would have shown them the flight’s direction of travel and the altitude it was traveling which would have enabled them to perfectly time an intercept right behind the other Boeing 777," Ledgerwood said.

He said while MH370 did not follow SQ68 to Spain, it would have broken free from the shadow of the larger SIA jetliner and "could have then flown a path to it’s final landing site "such as China's Xinjiang province, Kyrgyzstan, or Turkmenistan.

"Each of these final locations would match up almost perfectly with the 7.5 hours of total flight time and trailing SIA68.

"In addition, these locations are all possibilities that are on the 'ARC' and fit with the data provided by Inmarsat from the SATCOM’s last known ping at 01:11UTC," Ledgerwood said.

No sign of flight MH370

Central Asian neighbours Kazakhstan and Kyrgyzstan said yesterday that no unidentified planes had crossed their airspace on March 8, making it unlikely that the lost Malaysia Airlines passenger jet could have diverted along a northern route via Thailand, said a Reuters report.

But the Malaysian national carrier's planes made nine regular flights to and from Europe over Kazakhstan's territory on March 8, officials said.

Aviation officials in Pakistan and India as well as Taliban militants in Afghanistan also told Reuters they knew nothing about the whereabouts of the missing plane after the search was extended into their territory from yesterday.

Malaysia has sent diplomatic notes to 14 nations requesting help for search and rescue operations, apart from radar and satellite intelligence, to piece together any trace of the missing wide-body plane.

The search for the missing jet, dubbed as an "unprecedented aviation mystery", continues today, some 240 hours after it vanished into thin air. - March 18, 2014.