February 9, 2009, 10:00 IST (04:30 GMT)

TV channels are reporting that an Air India Airbus A321 performing flight IC866 was involved in a rejected take-off/near miss at Mumbai Chhatrapati Shivaji International Airport earlier this morning.

The flight had commenced its take-off run, when a helicopter which was given permission to land, strayed across the runway to land on the helipad. On sighting the helicopter the flight crew of IC866, rejected the take-off, applying emergency braking.

All passengers on board, estimated at 148 are safe. The tires of the aircraft require changing which is being done right now.

Initially it appears a fault of the air traffic control, which appears to have given permission to the helicopter to land, while at the same time, giving permission to the Air India flight to take-off.

Update 1 - 10:55 IST (05:25 GMT)

The shocker. The army helicopter was part a three helicopter convoy of Indian President Pratibha Patil.

The presidential convoy was conveying the President from the Governor's mansion, The Raj Bhavan, along with the top most leadership of the state of Maharashtra, to the airport. Due to security procedures, it is unknown whether the President was on board the chopper which strayed on to the runway.

Clearly a major mishap has been avoided, and there is bound to be a major investigation.

Information from aviation experts indicate the plane was at V-1 speed (around 100 knots). This is why the plane was able to perform a "rejected take-off", with the autobrake system kicking in. In another few seconds, the plane would have crossed the V-2 threshold, at which point the aircraft is travelling just to fast for it to stop on the runway. That would have surely resulted in a disaster of epic proportions.

The wheels of the Airbus A321 aircraft jammed after the rejected take-off, and the aircraft tyres burst due to the excess heat caused by the emergency braking. It has been taken back to the terminal. The passengers have been dis-embarked and are in the terminal. Arrangements for an alternate aircraft are being made.

Update 2 - 13:25 IST (07:55 GMT)

A Mumbai Airport official told news agencies.

"At around 09.00 hrs today, an Air Force chopper landed on the same runway from which Air India flight IC 866 (with 150 passengers on board) was taking off for Delhi, forcing the pilot of the plane to abort take off at the last minute,"

However there is some confusion. News reports claim

the Air India aircraft was taxiing to reach the main runway for the take off when the Air Traffic Control talked to the pilot regarding the helicopter. The pilot applied the brake to bring the aircraft to a halt

Whereas, all reports indicate a high speed take-off reject, resulting in the nose wheel tyre blowing out, indicating the pilot had commenced the take-off run and was not taxiing.

Credit is being given to the alertness of Captain SS Kohli, pilot of IC 866, who aborted the take off. Captain Kohli said,

"The the chopper and our aircraft got the clearence from the ATC at the same time. The ATC had lost contact with the chopper."

"The chopper just landed without taking a landing clearance. I cannot say much more,"

Meanwhile, an official spokesperson of the President told news agencies that "Everything is perfectly fine. The President was attending her normal functions."

As per Timesnow TV.

A fleet of three helicopters including the one carrying Patil, along with Maharashtra Governor SC Jamir and some other dignitaries, had taken off from Mumbai's Naval base 'INS Kunjali' and were on their way to the airport since the President was to fly to Gondia by her special Indian Air Force Plane (IAF) plane to attend a function.

A probe into the incident has been ordered by the Directorate General of Civil Aviation, the sources said. A senior DGCA official is coming from New Delhi to Mumbai to join the investigation, they said.

An IAF spokesman said, "the pilots of the chopper had followed the instructions from Bombay approach meliculously. The Presidential entourage was cleared to take off from INS Kunjali and land at Santa Cruz between two taxiways". An inquiry has been ordered by the IAF into the incident, he said.

While full information is not yet available, this appears to be the most likely situation based on past knowledge, historic traffic patterns, and information.



Update 3 - 17:00 IST (11:30 GMT)

The Indian Directorate General of Civil Aviation (DGCA) released a statement at 16:10IST ((10:40 GMT)

Mumbai Airport, the busiest airport in India was witnessing heavy air traffic and operations today morning. The ATC Mumbai was aware of the Presidential visit and were watching the approach movement of the Presidential convoy of helicopters. At that time an aircraft of Air India was on the active runway-27. The ATC, noticing movement of the aircraft on the runway, asked the aircraft to immediately apply brakes and exit through the taxiway. The aircraft exited immediately and the helicopters landed safely.

Director General Civil Aviation has ordered an investigation of the incident under rule 77 and appointed Jt. DGCA as the Inquiry Officer for the purpose of carrying out the investigation. Jt. DGCA has reached Mumabi and started investigation proceedings.

Considering this incident involved the President of India, the poor controller on duty is in for a very rough time.

Update 4 - 20:00 IST (14:30 GMT)

The Air India aircraft is registration VT-PPF. An Airbus A321-211 construction number 3340, it did it first test flight on December 5, 2007, and was delivered by Airbus on December 14, 2007. It is powered by the CFM56-5B3/3 engines.

Image copyright Flickr user Pallav105

Monday June 16 2008

Monica Jha

BANGALORE: Pilots from two airlines (one domestic and one international) have reportedly complained about problems in landing using instrument landing system (ILS) at the Bengaluru International Airport.

The runway (27 orientation, which is being used presently) at the new airport has a 3.4 degree glideslope for an ILS approach while the international standard for the same is 3 degree. The 3 degree glideslope (the angle of descend with respect to horizontal plane) is an acceptable descent profile world over and, therefore, auto pilots are designed for this profile. At BIA, which has a glideslope of more than 3 degrees, auto pilots do not work and pilots need to resort to manual landing, that can cause hard landing at times.

A three-degree glideslope gives a descent of approximately 318 feet per nautical mile (NM) while for a 3.4-degree glideslope, the descent would be about 370 feet per mile which means an aircraft would descend at a higher speed than recommended.

When an aircraft on ILS follows a 3 degree glideslope, passengers do not feel any discomfort but a 3.4 degree glideslope may result in a steep landing causing discomfort to passengers. The operator of BIA, Bangalore International Airport Limited (BIAL), apparently made a mistake in assessing the elevation of glide path location.

On a continuous descent, an aircraft must maintain a height of 50 feet at the threshold of a runway. Due to errors in calculating the elevation this height at BIA was found to be less than 50 feet. So, BIA had to increase the glideslope to maintain a height of 50 feet at the threshold of runway. However, the glideslope for runway when used in 09 orientation is 3 degrees.

To ratify the problem, BIA would need to relocate its glide path antenna further up, an expert from the aviation industry told this website's newspaper. "But, changing the position of glide path antenna at a live airport and a live runway is not possible as landing without ILS for a few days that would be necessitated for calibrations, would be extremely difficult. BIAL can do it when they change from 27 to 09 runway in November," he added.

Source : The New Indian Express