AircraftNews.Com

Tenerife collision

MUMBAI: Two aircraft carrying nearly 250 passengers between them were speeding down separate runways of the Mumbai airport on Sunday morning before aborting their take-offs, seconds before reaching the intersection point of the runways.

The planes were seconds away from a collision which would have been catastrophic.

At 7.57am, Air India’s flight AI 348 to Delhi, with 119 passengers on board, was moving at 70 to 80 knots down the

main Runway 27, when it was asked to abort take-off by Air Traffic Control (ATC). Jet Airways’ flight 9W 651 to

Kolkata, with 120 passengers on board, was simultaneously moving at 90 to 100 knots down Runway 14 when it aborted a

take-off on its own after overhearing communication between the AI pilot and ATC.

The AI flight was using an Airbus 310, which cannot reject a take-off once it reaches a `decision speed’ of 122

knots. The Jet Airways Boeing 737 has a decision speed of 128 to 129 knots.

After the incident, charges began to fly, with ATC saying that it had not cleared the Air India plane for take-off,

but an Air-India spokesperson maintained that the clearance had been given.

M G Junghare, general manager, Mumbai airport, who heads the ATC unit, said the AI pilots were not given take-off

clearance. “Take-off clearance was given only to the Jet Airways flight. However, soon after, a controller saw the

AI flight rolling for take-off as well. Seeing this, he immediately advised the commander of the AI flight to abort

take-off,” said Jhungare.

An AI spokesperson said their aircraft was cleared for take-off. “The AI flight was cleared for take-off and after

that the pilots were asked to hold,” the airline spokesperson said.

According to an AI source, a very clear instruction was given by the controller: “AI 348 cleared for take-off,

Runway 27”. The source added that, as per the norm, the pilot read the instruction back verbatim to the controller.

“After the Tenerife crash, a word like `take-off’ is not used loosely. It is only used after an aircraft has lined

up on the runway and is waiting for the permission to start rolling,” said a senior commander.

In the 1977 Tenerife crash on a Spanish island
, miscommunication between pilots and controllers caused two Boeing 747s to collide on the runway, killing 583

passengers. “The word `departure’ is used when instructions to taxi or line up on the runway are given. Also, the

pilot reads back the exact same statement and in this case he read back the take-off clearance to the controller,”

said a senior commander.

A Jet Airways spokesperson said, “Though our pilots were not given instructions to reject a take-off by ATC,
they did it as a precautionary measure.”

The near-miss gains in significance when one considers that from today, the Mumbai airport has permission to operate

its cross-runways simultaneously 24 hours a day. Till now the secondary runway, 14-32, was operated for only eight

hours a day. The main runway, 09-27, runs east-west, while Runway 14-32 runs northwest-southeast.

An airport source said, “Both aircraft started rolling around the same time, which means they could have crashed

into each other at the runway intersection.” A few seconds after the AI aircraft began rolling towards take-off, an

air traffic controller gave an urgent instruction to reject the take-off.

“For an A310, it was a low speed at which to reject a take-off,” said a senior commander. However, the B737 had a

high-speed rejection, said a B737 commander. “It was pretty close,” he added, pointing out that Runway 14 is

shorter, so needs extra precautions.

The cockpit voice recorders and flight data recorders of the aircraft are now the focus of a probe. Director general

of civil aviation, Nasim Zaidi, said that an investigation into the incident has begun. The cockpit voice recorders

from both the aircraft have been downloaded. “Pilots of both the airlines have been called for interrogation on

Monday. We should be able to arrive at a conclusion in a couple of days,” Zaidi said.

The fortunate passengers left Mumbai later. The Jet Airways passengers finally left on a separate plane at 11.19am

and the AI passengers left on the same plane at 1.48pm.

From http://timesofindia.indiatimes.com/Cities/AI-Jet-planes-in-near-collision-at-Mumbai-airport/articleshow/4599936.cms