Overrun at VABB
 

Looks like its on the shorter of the 2 runways

https://timesofindia.indiatimes.com/...w/76172607.cms


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Above all, glad the crew was not harmed.

I wonder what the contamination level was on the runway surface. I see spray getting kicked up by reverses suggesting the surface was not dry.
Looking at the 10-9A for VABB, I don't see any reference to the runway being grooved.

You can see from the video that it’s actively raining but it doesn’t seem like more than light rain. At least where the person is recording from.

Glad everyone is physically ok.

Just wanted to throw this out there as a lot of us, umm older folks (and younger as well) never noticed the definition of wet runway changed back in 2015. Of note, grooves no longer matter in the slightest...

https://www.faa.gov/documentlibrary/...r/ac_25-31.pdf

I lived and worked in India for three years for a local airline. The Mumbai airport can be very challenging in heavy rain. At least when I was there in 2008-2011 there was not a single grooved runway in the entire country. Removal of accumulated rubber usually only happens after an incident prods the local authorities into action. The airport in normal times is stretched way beyond capacity causing the controllers to cram arrivals close together and push pilots to exit runways quickly. Combine that with runways with displaced thresholds and one with a higher than 3.0 glide path and that airport can be quite sporty during the Monsoon. I personally watched two go off the end while I was over there. One was an ATR running full reverse right up until it splatted stop in the mud. Takeoffs sometimes can be interesting when you hit deep pools of standing water. Glad that it sounds like everyone and the aircraft are OK.

Airfields (anywhere) are notorious for not reporting runway conditions correctly. India sucks. Glad crew is ok.

Looks like there was a compressor stall on the #1 engine while in reverse, according to that video.

A good reason to identify the lack of runway grooves as an increased threat when preparing to land on a wet/contaminated runway.

And they freak out when storms are in the vicinity, plus you just can’t hold forever so ya tell’m bye bye my plane now.

Whilst using heavy breaking on non grooved wet runways, water under the wheels can turn to steam, which then reverts the rubber to its natural form melting the rubber which obviously greatly reduces breaking effectiveness. That’s what you’re seeing.

They do matter in real life, just not for perf calculations.

Maybe we get used to the grooves here and take it for granted.

On the FPR there is a note when flying into VABB that says to select moderate rain on APS due to none grooved and poor water drainage on runways. It is much more conservative than selecting wet function.

I once landed on 4R at DTW. I was the first one to land after the runway was plowed and MUs reported at 50.
Braking action was nil. I didn't get the airplane slowed enough to pull off until Y7. I was lucky it was 4R and didn't run off the runway.

Maybe so, although since the MD has some pretty capable anti-skid, I'm skeptical. In order to get reverted rubber hydroplaning going, you probably need to have a locked wheel. I doubt all of them locked and if that is steam, it's coming from way more than just one tire. Take a look at the engines and you'll see they're in full reverse (note at least 1 compressor stall on #1 as a result). So, like the guy you responded to stated, the reversers are kicking up a bunch of the standing water on the runway in front of the engines.

More than one
 

Looks like multiple compressor stalls!

They landed on RW14. The wind will come out somewhere from 020-030 gusting over 20kts. Looks like a failure from the airports stand point and of course the Captain. I cannot tell from the video if they used F35 or F50? Maybe some of the contributors can post for us. Thanks.

I suppose the investigation is complete, just like that ?

what "failure" did the Captain commit ? Is this a single pilot airplane ? is the airport information published ? by who ? weather reporting is done by who ? etc. Have prior safety reports been made about that runway by FedEx crews and submitted to the safety team ? what was done with them ?

aircraft accidents/incidents today (2020) are looked at thru the lens of the Swiss cheese model, not "Joe is at fault for f**cking up" etc.

that may be old school but the thinking has changed on "blame"

Grooved or PFC runways are used in determining performance. FAR Part 25 Amendment 25-92 in 1998 mandated that airplanes must be certified using both dry and wet takeoff data. The amendment also provides guidance for calculating performance on grooved or PFC runways, either using 70 percent of the dry Mu coefficient or the formulas provided in FAR 25.109. Grooved or PFC runway performance is only available when the runway is wet, not contaminated.

If the airplane was certified after 1998, the performance data for grooved/PFC runways is probably in the AFM/DPI or PET, and Boeing models 747-8, 787, 737 Max have this data.

For landing, Mumbai is an airport where operators should strongly consider applying SAFO 19003 guidance. If landing on grooved runways with heavy rain, or smooth runways with moderate or heavy rain, use RwyCC 2. Grooved/PFC runways are effective when the runway condition is wet. If the runway is contaminated, the efficacy of grooves is nil, which is effectively what the SAFO is stating.

SAFO 19003 was published due to 5 runway excursions in an approximately 30 day period last May/June, all due in part to rainy conditions.

Who is ultimately in charge of that aircraft? Who makes the final decision. I don't care if there were 2, 3, or 4 crew members on this particular flight, the final authority lies with the person who signed for it.

As far as the weather goes? Look it up. It is fairly easy to find. If the airport wants you to land on a wet, non-grooved, displaced threshold with a tailwind then you better make sure you will be able to stop. It doesn't matter what your landing assessment said you were legal to do it. Is it a good idea? In this case it wasn't. Thankfully no one was hurt and maybe just some minor engine trouble.

Go ahead and investigate and hope the brakes were not working but guess what, this will be pilot error as one of the contributing factors. Hopefully we all learn from it, including myself.

Cheers

Thank you, wise one. How about we maybe wait until some facts come out before we assign blame?

There was no damage to the airplane. Not a huge deal.

Call me old school but I agree with Beetlehog. Ultimately there’s no such thing as “the FO took me to the crash site”. If an error in judgement or decision making has led to an incident or regrettably; an accident, it comes down to who makes the big bucks.

If you look back at AF447, the captain left for inflight rest while the aircraft approached significant weather. Hindsight is a great thing, but it’s also a hole created in the Swiss cheese. We have increasingly evolved into a “threat base” style of operating, which has lead to a massive reduction in safety related incidents industry wide.

While we wait for the final report of the Atlas 767 crash, do you think human factors wont play a huge role in the investigation? Am I out of line to suggest that (with many previous crashes caused by somatogravic illusion) the Captain should have voiced polite concern to his FO that avoiding weather while manually flying may not have been the best decision?

Again, how about waiting just a little while before assigning blame. There are just tons of variables. What were the reported winds and runway conditions? Rubber deposits? Aircraft malfunction?

It very well could be a case of pilot error, but most of us wait until we get more information. In the end, there is no damage to the aircraft, so it’s really not that big of a deal. Maybe if we’re patient, we can all learn something that can make us safer pilots.

I completely agree. I’m not laying the blame on any individual, I was only agreeing with the general notion of a previous post that states; the Captain is ultimately responsible.

Without a doubt...

That airplane looks like it doesn't have any brakes. They are in full reverse and only going around 60 knots for the last 2,000 ft of runway. He eats up the last 2,000 ft and hardly slows down. The water getting sucked into the engine and out the reversers is just that not compressor stalls. I've never seen a MD11 or DC-10 compressor stall in reverse? The guy looks like he turns off going around 30 knots still in full reverse. He looks like he just got it as slow as he could with the reversers then went off the side to stop the airplane in the grass.

Anyone know what really happened?

If you look at the left engine you will see bright flashes the cover the inlet indicating a compressor stall DID happen.

How often do you see an MD-11 using full reverse thrust at a low ground speed? Full reverse thrust at a low ground speed will disturb the air in front of the engine which could easily cause a compressor stall.

They didn't go into the grass. There's a relatively small overrun at the end of rwy 14 that they entered by about 10 meters. Probably stopped with the nose gear far enough past the entry to taxiways E1 or W1 that they decided to get towed. Definitely compressor stalled - easy to see in the video. As 2stg said, a common event when reverse is used to a very slow ground speed.

Ok that’s true but what if.all available information at the time indicated that a safe landing could be made and it’s found out the information was not complete or erroneous?

Gentlemen,

Let's not lose sight of how serious this could have been. Just because there was no damage to the aircraft doesn't diminish the potential severity of this incident. As many of you know, this particular airport is surrounded on all sides by little "shanty" houses.

I would like to write a little about landing performance if I may. For the crowd that says "if the computer says it is legal than it is safe"; look at the totality of the situation and start CRM'ing these events a little better. The gentleman or lady sitting next to you might have some very valuable information you might not have thought of or have experienced before. Computers are very nice to have to compute T.O.L. performance but it is still up to us to think critically about other variables. A wise Captain once told me "son, if you don't make that touchdown zone, all those numbers you just pulled out of your backside don't mean a darn thing!" He used more colorful language but the point still is lodged in my brain and hopefully I will never forget it.

I haven't been to this particular airport in some years but from my recollection the build up of rubber at the ends was pretty significant. From the video some of you have written that their braking looked "nill-ish" and it might have been due to their location and I am guessing they were probably landing around 491,500 lbs. This is an awful lot of inertia to stop. Be careful out there guys and gals. Cheers

I forgot to mention one other thing that might be useful for everyone. I have never had to do this kind of technique thankfully but another wise Captain told me that if you think you might be going off the end of the runway get off the centerline and put your brake wheels on some "clean" pavement if you can. What are your thoughts on this technique? I always thought that for us average airmen this is probably asking too much but it definitely has its merit and should be mentioned. Off my soapbox. Sorry.

Are you suggesting there is a decrease in performance when trying to brake on a surface that has a large buildup of deposited rubber?

yes that is exactly what I am saying.

Makes sense. Wonder if the FAA endorses this technique. I’m guessing they don’t.

I doubt they do but every little bit helps in a pinch I like to say. I am not sure how effective this would be for the b747 but for tricycle gear configs it can help especially center gear tricycle's. Every time that center gear hits the centerline paint the braking effectiveness is terrible when wet or contaminated. Just my two cents.

Excellent insight. You’re saying if you land long that it might invalidate your landing performance data? Wow, I never would have imagined!

And yet this kind of stuff happens more than it should. Thanks for your contribution though. Very rich and compelling.

Any more wisdom? These are just great insights!

I've found that to shorten your landing distance substantially, leaving the gear up is highly effective.

That does work well on your first try. :)

And you will need full power to taxi into parking...

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