SQ 322 Emergency Landing 19/4

[FSJZ]

If normal A380 landings are like that, I really can't imagine what SQ322's emergency landing would have felt like.

I think SQ322 landed normally just like any other A380 landing, but due to the heavy landing weight of the aircraft and, according to StefanVXR8, reverse thrust was not used, so the brakes would have generated tremendous heat to stop the plane. Once a certain temperature is reached, the tires will automatically deflate, as a safety feature, to prevent it from exploding under great heat. Just my 5 cents on this issue.

Although I still won't rule out the tires deflating upon touchdown due to the heavy landing weight

[SQ228]

From a pax point of view, it is a very different type of landing from, say a 777, with its huge landing gear, which is silky smooth and gentle 99% of the time.

Agree with you on that one. I once landed at Changi in one of the 773 refits and I swear I couldn't tell when we had actually made contact with the tarmac.

[StefanVXR8]

IMO Stefan is an experienced passenger severely lacking in technical expertise

On what basis your assumption? He has a little more technical expertise than you give him credit for......

What evidence have you got to support this? From a technical report it says its a air bleed issue. This supports what your pilot reported and also is linked to the air con.

Guys, Unfortunately I suffer from a medical condition which requires me to take a very strong opiate based drug for pain relief, this in turn makes me very sensitive to air temperature.

Now, for the duration of the time that we were sat waiting for engines 3 and 4 to be started there was no aircon working at all, the fact that I had sweat running down my neck was testimony to that!

Once the engines were started for the duration of taxi'ing, take off, short flight and several hours sat waiting whilst we were being disembarked I can definitely tell you the air con was working, the ambient temperature in the cabin was cool and I had stopped sweating and it normally requires cool air flowing for that to happen.

So I'd ask that you give me some credit for knowing whether or not it was working, it most certainly wasn't ambient air from outside being stirred up inside the cabin, this was Singapore remember.

If you are pilots yourselves then I totally understand your defensive stance on this.

But from my opinion, and yes I'm not an airline engineer but I do have a relative understanding of all things mechanical, the problem was not with failed air con.

The pilot specifically said he was unable to start those two engines and from my position in 79K on the upper deck I could hear the engines power up and almost immediately down again, this happened repeatedly for almost two hours.

Once the ground engineers (or whatever you guys call them) came on they had managed to start the engines within 15 minutes, at this point the air temp dropped pretty quickly, you could certainly feel the colder air circulating.

We were then up and in the air within another 15 minutes and as I've mentioned before the take off wasn't 'normal'. I've flown on the A380 enough times to know what a normal take off feels like but this one felt kind of off balance.

As everyone around me started to settle down for the flight, and indeed so did I, whilst looking at the window I noted that we didn't seem to be gaining any altitude, I could see all of the ships down in the bay and they weren't getting any smaller!

After about 15-20 minutes the pilot/captain/whatever announced that we were unable to get above 8,000ft and there was a pressurisation issue and we were to return to Changi.

I was fully aware how heavy we were and to be honest I was expecting a much harder landing than we had, it felt no harder than a normal landing in an A380 the main difference of course being the harshness of the braking, which was pretty extreme. As someone who owns and drives a car with 600BHP I know 'emergency' braking when I feel it/need it.

To me I definitely didn't sense any reverse thrust and yes I'm aware the A380 only has thrust on two of the four engines, and again I know how quiet these are, but on my side of the aircraft, apart from the noise of braking and runway vibration I didn't here a peep from the thrusters.

Once we landed he went through the usual about why the emergency crews were there, further announced we were waiting for the brakes/wheels/tyres to cool, further announcement to say they had cooled drastically and then a further announcement to say they (several) had deflated.

From the point he announced that we were to disembark via air steps and coaches it took exactly 3 hours to get everyone off, pretty quick no?

So please feel free to enlighten me further, if the aircon and airbleed wasn't working were was the cool air coming from?

I understand the airbleed issue limiting altitude etc but I still believe that two of those engines were not operating correctly way beyond not being able to operate those two functions if you see what I mean.

Stefan

[cscs1956]

Good observation.

[frontdeskflyer]

StefanVXR8 answer

Hello Stefan ,

I made extraction of some of your above message and added my technical answers. Your words are in italic letters:



Now, for the duration of the time that we were sat waiting for engines 3 and 4 to be started there was no aircon working at all, the fact that I had sweat running down my neck was testimony to that!

Once the engines were started for the duration of taxi'ing, take off, short flight and several hours sat waiting whilst we were being disembarked I can definitely tell you the air con was working, the ambient temperature in the cabin was cool and I had stopped sweating and it normally requires cool air flowing for that to happen.

Once the ground engineers (or whatever you guys call them) came on they had managed to start the engines within 15 minutes, at this point the air temp dropped pretty quickly, you could certainly feel the colder air circulating.


That’s quite normal :

On ground, air conditioning is coming from the APU and conditioned (heat or cold) by 2 air-conditioning units= packs, each of those 2 packs contains 2 cooling units.

During engines start up, air conditioning is momentarily off, as APU cannot provide both air for cooling and air for engine start up. And cabin temperature rises very quickly in a plane without aircond , because of human heat, IFE, lights.

When engines are fully started, air cond comes back with air from the engines (4 bleed air valves) and the 2 packs.




But from my opinion, and yes I'm not an airline engineer but I do have a relative understanding of all things mechanical, the problem was not with failed air con.

The pilot specifically said he was unable to start those two engines and from my position in 79K on the upper deck I could hear the engines power up and almost immediately down again, this happened repeatedly for almost two hours.

We were then up and in the air within another 15 minutes and as I've mentioned before the take off wasn't 'normal'. I've flown on the A380 enough times to know what a normal take off feels like but this one felt kind of off balance.

As everyone around me started to settle down for the flight, and indeed so did I, whilst looking at the window I noted that we didn't seem to be gaining any altitude, I could see all of the ships down in the bay and they weren't getting any smaller!


Aircraft climbed to 10.000 ft, A380 is not a big climber when heavy and hot outside..and probably the technical problem developped after takeoff and they were doing check list and assessment of the problem. No need to climb further if you have some air problem.

After about 15-20 minutes the pilot/captain/whatever announced that we were unable to get above 8,000ft and there was a pressurisation issue and we were to return to Changi.

So please feel free to enlighten me further, if the aircon and airbleed wasn't working were was the cool air coming from?[/I]



Air is coming from the 4 engines, it’s called bleed air. There are 4 bleed air valves (in fact 8 as when engines are on idle, bleed air is low and 4 more bleed air valves open, in flight, only 4 bleed air valves open)

Bleed air 1 and 2 is then conditioned in air cond unit left.
Bleed air 3 and 4 is then conditioned in air cond unit right.

Cross bleed from opposite side is possible in some cases of failure.

Same air coming out the 2 air cond units is used to air cond and to pressurize aircraft.

One bleed air valve failure is not a big problem as bleed air can come from the other side of the aircraft (cross bleed air alimentation)

Failure of 2 bleed air valve is more a problem. On ground you cannot be dispatched with 2 bleed air inoperative. In flight, it’s quite the same issue, aircond/pressurization with only 2 bleed air is an issue.

Same issue when one or 2 packs fails, whatever the element of the circuit ( valve, controller, regulation.



I was fully aware how heavy we were and to be honest I was expecting a much harder landing than we had, it felt no harder than a normal landing in an A380 the main difference of course being the harshness of the braking, which was pretty extreme. As someone who owns and drives a car with 600BHP I know 'emergency' braking when I feel it/need it.

To me I definitely didn't sense any reverse thrust and yes I'm aware the A380 only has thrust on two of the four engines, and again I know how quiet these are, but on my side of the aircraft, apart from the noise of braking and runway vibration I didn't here a peep from the thrusters.



Nobody is speaking of any fuel dump ? May be not necessary due to weight, but it needs some clarification?

I do not doubt your perception, but air turn back in an probably heavy aircraft is not usual in terms of landing performance. On usual landing, reversers are not mandatory on dry runways, but on overweight landing, use of reversers seems more comfortable to me in operational words.



Once we landed he went through the usual about why the emergency crews were there, further announced we were waiting for the brakes/wheels/tyres to cool, further announcement to say they had cooled drastically and then a further announcement to say they (several) had deflated.


Quite normal, on high weight, landing speed is higher and kinetic energy rises quickly (square speed) and braking energy has to dissipate in heat and to avoid tyre explosion due to heat, special valve opens and deflate tires when brakes are too hot. Temperature rises about 10 minutes after braking.



I understand the airbleed issue limiting altitude etc but I still believe that two of those engines were not operating correctly way beyond not being able to operate those two functions if you see what I mean.I


I do not know what technical clues are giving you this perception apart start up issues . Start up issues can be from air start valve, air starter, igniters ot low air pressure to the stater. It’s not an engine it self problem . Engine can run and fly with start valve or some igniter deactivated.

Hope it helps your understanding of what happened to your flight .

[StefanVXR8]

Thanks for the lengthy reply, certainly does clarify some points.

I'm pretty sure we didn't perform any kind of fuel dump, certainly no mention of it and looking at the flight route we never really left the built up area of Singapore at all.

Stefan