View Full Version : Mumbai airport RWY27 glidepath

India Charlie
28th Nov 2012, 16:22
News report in The Times of India, Mumbai:

Changing angle for that perfect landing
By Chinmayi Shalya, TNN | Nov 28, 2012, 02.38 AM IST

MUMBAI: In a bid to make landing at Mumbai airport more accurate, Mumbai International Airport Pvt Ltd (MIAL) and Airports Authority of India (AAI) are changing the glides path angle. The glide angle at the main runway (27) is 3.3 degrees now. It will be changed to 3 degrees.

On Tuesday, the main runway was unavailable for landing and the other end (09) was in use. Officials said that while work is under way, the glide scope on the main runway (27) will not be available for the coming two months. This means, that if visibility drops, all flights would land on the secondary runway or on the 09 end of the main runway. This may mean a delay of 10-15 minutes.

Airport officials say the glide angle on the main runway was steeper than globally recommended standards. This means aircraft descend at a steep angle and at a higher speed. This is now being changed so that aircraft can land more accurately and at the right speed. Glide path is an equipment that gives vertical guidance to a landing aircraft. The aircraft locks the signal and descent angle from the glide path and starts descending. Its function is to bring the aircraft to a proper spot or touchdown zone on the runway. Three degrees is considered optimum.

Though flights at Mumbai airport can land easily on runway 09, there are no rapid exit taxiways (RET). Hence, aircraft take 30-50 seconds extra to vacate the runway. Also, low visibility during winters can hamper flight operations. Officials said that without the glide path, main runway 27 will be used only when visibility is at least 2,800 meters. Else, runway 09 or the secondary runway will have to be used. These two face heavy tail wind conditions making it tough for big aircraft to land.

"With the glide path, the minimum required visibility on the main runway is 550m. Without it, it goes up to 2,800m. During winters, such high visibility is scarcely possible and landing will have to be moved to the other end of the runway where tail winds are heavy," said an airport official. "This means that certain airlines operating long haul flights on bigger aircraft will have to cut load and fly into Mumbai," he added. Officials also said that in case visibility drops below 1,800m (the required minimum for the 09 end and the secondary runway, the airport will have to be shut. "This, however, is an extreme case scenario," said an airport official.

An MIAL spokesperson said, "A higher glide angle has inherent operational disadvantages such as its unsuitability for Cat-II and Cat-III ILS approaches. MIAL is working jointly with AAI, Airlines and DGCA on this. Trials of the new flight procedures if successful will further enhance CSIA's operational efficiency and safety standards. Also taking all the historical weather pattern into consideration, the trial period is chosen at the best time of the year for getting desired results."

Always thought the 3.3 deg glide angle was kept so, owing to terrain in the approach path of RWY 27...

28th Nov 2012, 18:39
Excellent, making it ok for the "Beluga" to do the night turns then :E

29th Nov 2012, 01:58
You gotta have a sense of humor to fly into BOM. ;)

Here's an earlier thread about the ILS to RW 27 OTS:


29th Nov 2012, 06:28
Agree to that...

India Charlie
29th Nov 2012, 08:10
At Mumbai, as of now, as far as I know, aircraft are cleared to descent to 3,700 ft to intercept the LOC and G/S for RWY 27. Correct me if I'm wrong, but after reduction of the G/S angle, intercept altitude will have to reduced as well, am I right? What then? Is it safe?

29th Nov 2012, 08:47
Yes BOM is a pain in the ass for many reasons

However unless I'm missing something how does a 3.3 deg G/S cause the Aircraft to fly faster???? It still does the required VREF +additives or VLS + additives for its weight, flap setting and ambient conditions.This speed doesn't change with a steeper gradient!!!
Yes the required descent V/S is higher and the thrust required slightly less to maintain the G/S but the speed is the same as any other Airport!!


29th Nov 2012, 08:59
What put me off at BOM had nothing to do with the G/S but seeing all that squatting that was going on first thing in the morning taxying into the ramp;)

29th Nov 2012, 09:04
21 Bum salute :E

29th Nov 2012, 09:06
Ahhhhh yes, the delightful "crappers corner"

By George
29th Nov 2012, 09:15
In my old Company the problem was at 3.3 degrees you were unable to couple up and had to hand fly the approach (heaven forbid). This change will allow a coupled approach to a lower minimum. If I remember correctly, it was slightly downhill and always very slippery when wet. On take-off it was always a hoot watching the landing lights at night disturbing the toilet habits of the locals. One place I do not miss.

29th Nov 2012, 13:08
Any indication about what they are going to do about the hill, which is the reason for the 3.3 in the first place???
Tootle pip!!

Shaka Zulu
29th Nov 2012, 13:30
Rad Alt <2000'AGL over that hill I presume....

29th Nov 2012, 17:23
Have they stopped using RWY 14/32?
It would be nice if they could move the GS so the whole RWY 27 could be used. The displaced threshold combined with a non grooved, uneven RWY and monsoon rain... I never was really comfortable landing there when the weather was bad.

29th Nov 2012, 23:48
Not to forget the Dogs all over the movement areas!!
Not to forget the vis on the ATIS 5000m but you could see the runway clearly from 30 nm!!
Not to forget being told to maintain 320kts then getting vectored all over the sky!!

Ahhh, such a nice place to miss, makes Delhi look ok.

30th Nov 2012, 10:29
I always found Bombay a much better place, At least when you told them to do something, they usually complied.

30th Nov 2012, 11:16
Oh yes and once BOM ground called us whilst taxiing out and said "increase your ground speed to 30 kts...." In a heavy accent.......
I replied "say again". They repeated it.

We were taxiing at night in the wet around tight corners in a 773 so I told them in no uncertain terms to get stuffed!!

He didn't ask again.......:ok: