A QUESTION ABOUT MH1155 PEN - KUL ON NOV. 25, 2013

[Aaron Brown 0]

I flew on a MH1155 on a Monday 25 November 2013, a 737-800, from PEN - KUL taking off at 17.45, ten minutes later than schedule. Unfortunately, I didn't get the registration number of the aircraft. The flight was slightly delayed but the pilot managed to catch on with the time of arrival about 18.35 in KUL. When we were about to land, an A380 reg. no. 9M-MNC landed before us and I believed it was from LHR. The unexpected thing happened when it was our turn to land, the plane was slammed down onto the runaway and bounced back up again for another slam resulting in everybody shouting and screaming. It was a VERY, VERY, VERY hard landing (not that many MH flights land smoothly in good times anyway), a one that I have not experienced before. Fortunately, we managed to land safely (Thank God for that). When we got to the gate B2, the captain who flew us, a Capt. Rueben (not sure about the spelling) came on the PA apologising for the hard landing. He mentioned about a down draft that brought us down hard from quite a height (I believe it was about 20 feet or more) by the A380. My questions are 1. Shouldn't there be a separation between these two aircrafts to ensure safe landing in avoiding the vortices created by the four engines of the A380 or is there any detector on the aircraft able to monitor this? 2. In the worst circumstance, if the smaller plane was brought down from a much higher height, would the result be catastrophic (as in a break in the fuselage)? 3. Due to this incident, is it mandatory for the aircraft to go under an inspection to ensure that there is no damage to the structure of the fuselage? Maybe some experts in this forum can enlighten me on this as it was quite nerve wrecking after another abort landing I had in BKI during bad weather. Two events in a row are not that comforting.

[Walter Sim 1]

 

My 2 sens worth

 

1) ICAO has classified aircrafts to various wake vortex categories and has provided recommended seperation minima that is to be practiced to avoid effects of wake turbulence. This is however not a hard and fast rule that must be followed. Clearance to land (at least in KUL) is granted by the tower when the preceding aircraft has vacated the runway. Whether or not a safe landing can be made is to the judgement of the flight crew. Typically a 737 (medium category) following an A380 (super category) is recommended to have at least 7nm seperation on approach according to ICAO. Whether or not this is adhered to is depending on the flight crew. It can be that the A380 did not follow the speed control procedure in KUL causing him to slow down too early, and letting the aircraft behind catch up or it could be the pilots slowed down a bit late. I'm not here to judge the crew but just to let you know that there are many reason to this happening. There are also times when there is a need to abort the landing due to wake turbulence during the last 50 feet during the flare.Though the flight crew will always anticipate for wake turbulence when following a heavier aircraft, and will be prepared to counter the effects. As to my knowledge I don't think there's a wake turbulence detector.

 

2) I have not personally heard of any aircraft breaking into half due to wake turbulence, windshear yes.

 

3) The captain may write in if he suspects a hard landing has been made. When that happens, the aircraft is grounded until it is certified fit to fly by the engineers. Also on some aircrafts engineering may preset a landing G limit to the aircraft in which if the aircraft exceeds the said G or sink rate during landing it triggers a report and engineers will have a look at it when the aircraft is at the gate.

Edited November 30, 2013 by Walter Sim

[derik 0]

well explained walter

[Aaron Brown 0]

Thanks very much for the explanation Walter.

[Gavin Andrew David 6]

Rest assured it triggered an automated FOQA[ Flight Operations Quality Assurance ] report and relevant people will be informed as well as necessary checks done on the aircraft.

[Johan Z 0]

Off topic: I remember sitting on the ancient 734 at KUL waiting to take off and 777 landed in front of us. It was amazing and scary at the same time.

[Mushrif A 3]

Off topic: I remember sitting on the ancient 734 at KUL waiting to take off and 777 landed in front of us. It was amazing and scary at the same time.

You were on the rwy and the 772 flew right over you before touching down?

[Johan Z 0]

The key word is 'waiting'. Put your glasses on.

[Naim 6]

Ahhhh ... wake turbulence. I got it in 2007, pretty scary experience. See first part of this story: http://travel.nuraina.com/thailand-bangkok/

[Arthur Van Straten 0]

A very comprehensive explanation of Airbus A380 Wake Vortex Guidance is publisherd here:

It will answer Aaron's questions.

 

http://www.skybrary.aero/index.php/Airbus_A380_Wake_Vortex_Guidance

 

And yes, wake turbulence can bring succeeding arcraft down, it has happened in all possible variations. Google it.

One more thing, although ATC could tell you which category is in front of you during landing, the crew of the aircarft that follows

can pick this up also when listening to the callsigns in use. For example, when your hear "Lufthansa 2322 Super, you are number one cleared to land", you know that it is a Lufthansa A380.

If ATC vectors you too close for comfort behind a Super, which happens sometimes, the following aircraft can reject and asks for more separation. That would then result in some interesting "tin moving".

 

In the case of Aaron's flight experience, it could be so that all crew and ATC did things right. But there is one element which can screw up things at the last seconds, meteorological conditions. Their variations at low level can either help you out or bite you in the a*s.

In this particuler case the crew was caught out at the flare, and had to accept the bounce. All in a days work.

And as Gavin has said, FOQA will trigger appropriate action. (It should be).

 

You can experience some intersting wake turbulence yourself, i do not know if it is possible at KLIA but, if possible, walk to the approach end of the runway in use.

Position yourself about 500 to 800 meters from the threshold, most probaly between the approach lights, and wait.

When a jet flighs over you in landing configuration you hear the normal noise. But, after 30 or seconds, there comes the wake, touching the ground. For an A320, you hear wushing sounds, grass and small trees are moving wildly and yourself notice a windgush. When a Super comes overhead, you will notice the difference clearly after 30 to 50 seconds. If there is a crosswind, move downwind a bit.

 

Cheers

A.

[Aaron Brown 0]

Thank you everyone and Arthur for a very good reference on the wake turbulence. However, I still think that MAS should have a check on this particular aircraft (I wish I have the rego). Anyway, this is one particular moment that I don't want to experience again although maybe it was less severe than Dr. Naim's tilting aircraft. Nevertheless, the experience is not for the faint hearted. I need to gather my nerves of steel now before flying.

[Waiping 12]

Off topic: I remember sitting on the ancient 734 at KUL waiting to take off and 777 landed in front of us. It was amazing and scary at the same time.

I don't quite get the scary part. It should be awesome!

[Alan F. 0]

MH1155 aircraft possibly 9M-FFE seen from 'radar tracking data' (around the same time as 9M-MNC), but no information on it in FR24.com database.

[Mushrif A 3]

The key word is 'waiting'. Put your glasses on.

 

I dont need new glasses or any glasses...the key word wasnt "waiting" but "front". Front as in perpendicular in front or facing the same direction.

[Aaron Brown 0]

MH1155 aircraft possibly 9M-FFE seen from 'radar tracking data' (around the same time as 9M-MNC), but no information on it in FR24.com database.

 

 

Alan - Yes, I believe it was an ex- Firefly with the old livery.

[leon t 0]

I have experienced 3 hard landings by MH 734s in the past couple of years, and several more than firm landings. All these happened during fair to good weather condition - once was a heavy landing in SIN, another was in KK and the third was in KLIA and not only firm but the 734 landed on its right boogie first and the whole plane was like going to jack-knife to the other side and the pax were going "oh-s and ah-s" but fortunately it set back ok. I do not buy the reasoning that these were due to "last min heavy winds or wind change" as often offered by the pilots.

However in my flights with AK so far and i do travel with them at least a min of 2 to 4 sectors a month for short working trips and their landings have so far been alright and never too firm and on quite a number of occassions the landings were excellent that the pilots just "kiss" or grease the runway and all these in fair weather conditions.

Just earlier this morning i was on AK 1807 at 11am and a MH A380 took off just before we did and barely two mins later was our turn - and i expected some wake turbulence on take-off from my readings but the take off and climb was perfectly normal - and the CPT landed smoothly in SIN.

[Arthur Van Straten 0]

Hi leon t.

 

As for your departure on flight AK1807 behind a "super", the two minutes separation is normal under these circumstances.

Here is what the captain on your flight knew when he lined up for take off. "He knew that he would rotate well before the super's

point of rotation and that he would climb out above the super's wake vortexes". All in a days work.

 

As for your misfortune in experiencing some lesser qualified landings with MH, it is difficult, if not impossible, to judge from a cabin seat point of view

if there is a crosswind or thermal activity in the threshold area.

From a passenger perspective the weather can look fine, it is sunny and there are nice puffy clouds above you. So, a passenger would think, why this heavy landing?

The answer would be visible in the cockpit, combined with a basic understanding of meteorologic conditions, as i said, a crosswind gust, release of a thermal during flare, or, it was the copilots turn to land.

 

Hope this helps your understanding.

 

Cheers

A.

[BC Tam 2]

The answer would be visible in the cockpit, combined with a basic understanding of meteorologic conditions, as i said, a crosswind gust, release of a thermal during flare, or, it was the copilots turn to land.

Cunningly subtle

[Amirul Mazlan 0]

Excerpt from B737 FCTM

 

" Prolonged flare increases airplane pitch attitude 2° to 3°. When prolonged flare is coupled with a misjudged height above the runway, a tail strike is possible. Do not prolong the flare in an attempt to achieve a perfectly smooth touchdown. A smooth touchdown is not the criterion for a safe landing. "