AirCon Drippings on a 74A
 

Exactly, you must be asking, WHAT???

Yes. I was on 506/04 and the AC was dripping. all crew knew about it (at least in J) as everyone was stuffing towels while i gave up and moved to the G seat from K. I've also mentioned that in the questionaire (along with other problems) but I dont see anything will be done till i pursue further.

I have also complained to the FAs and they were quite apologetic about the incident, but I wonder if CX is going to actively do anything about it. TBH I was on an award trip and tried out JL and BA as well. only if JL had better schedule i'd jump ship anytime. Or in that case, burn miles on JL...

sidenote: my gf told me it was also dripping in row 30... what's wrong with these planes!!!

Nothing. I have been rained upon on 777 as well as 747 on a variety of airlines and is not a CX specific issue.

It has also hailed inside the cabin with small particles of ice falling from above.

It has to do with condensation build up in the air-conditioning systems and is usually most prevalent when there is high humidity outside.

Ditto on some of the KA A330s. The ice particles are pretty common

There's some basic physics involved here, but it does seem to me that there is something different on the CX/KA planes from others. For example, I fly regularly on Cebu Pacific and there when they fire up the air con there are great clouds of condensation pumping out of the vents for several minutes, but that is far preferable to the dripping and ice storms that we get on CX.

I have had condensation problems on SQ 747 and AA 777 in the past.
However nothing has been as bad as my recent CX 74A in the nose where there was a great puddle on the floor between 1A and 1K.

Yes, I've seen water dripping down the walls of an AA 777, but nothing like your puddle, Moomba. I'll be sure to watch for this on my JFK/HKG CX flights, out next week and back in September, 777s of course. Puddle??? Yuck.

The crew were quite concerned about it from a First passenger perspective and made sure that the fellow in 1A and myself in 2A watched ourselves when moving about. It was only a problem on the ground and dried up as soon as we were airborne.

There were torrential tropical rainstorms outside at HKG at the time and had been all day which I think had something to do with the severity of the problem.

so it deosnt seem like i can make a case anywhere? oh wells. it's just annoying for what it causes...

Who said chivalry was dead eh?

Not surprising. Relative humidity (how saturated air is at a given temperature) in east Asia this time of the year is usually close to 100%. Any drop in temperature e.g., by cooling devices, drops the capacity of air to hold water and hence you get condensation and accumulation of water (ever noticed window and automobile air conditioners have drips at their evaporators - these work by transferring energy (heat) from the hot air inside and transfers the energy to the coolant which expands). Most aircraft sit with doors open between flights and get warm quickly. A/C is turned on just before boarding and when you try to cool the hot and humid cabin quickly with no forced ventilation to the outside (a/c are not really equipped to do this), all that water is going to have to go somewhere.

It's just that in flight, the air is so dry (I've seen references of 5-10% relative humidity - the deserts of the S.W. U.S. are around 10-20% RH by comparison) that it pretty much dries out the whole a/c (and not to mention humans onboard).

Thanks teach! :)

Just to clarify....airplane AC systems are not coolant type systems i.e. freon etc, they are air-cycle machines. They compress the air to squeeze out the moisture but that actually heats the air...so afterwards the air expands which cools it down (and usually some of the water is injected back into the air to humidify it).

http://en.wikipedia.org/wiki/Environ...Unit_.28CAU.29

huh?....

I think christep was referencing the fact that Row 30 is the first row of Economy on the 74A. If that is where your girlfriend was sitting, and you were in J, it would mean you did not offer your seat up to her.

Brownie points or relative comfort? Is J worth the doghouse? Decisions, decisions!

This has nothing to do with it... It doesn't matter what the Air-Cycle machine does... The only thing that the AC might do is cool the air so much that Ice-pellet starting to fly out from the ducts... but this is not the case of the water dripping from the ceiling...


However, YVR Cockroach is correct... it has all got to do with relative humidity... with Hong Kong (and most of South East Asia and most of tropics) being so humid, once the Air-Cond is fire up after Engine start (ground cooling doesn't count as they are not very powerful), the Air-Cycle machine will often cool down the air too quickly... a lot of time with a very warm cabin, it will pump out cold air from the pipe that is only a few degree Celsius, as the system is trying its best to cool the cabin to the preset temperature set at the cockpit / flight attendent panel (hence the ice pellet or the white moist air coming out from the vent)... however air this cold will also cause condensation at the inside of the aircraft fuselage inside the overhead crown space (just above the overhead bins)... once enough condensation occurs, water starts to fall into the cabin between the overhead panels...

This is especially worse on Boeing 747 and 777 because the overhead crown space (space between the overhead ceiling and overhead bin and the actual fuselage) is so much bigger than any of the Airbus aircraft... hence there are more moisture trapped...

So this is not a problem with CX... it is a fundamental design of the Boeing 747 & 777... It also sometimes happens on Airbus on a very moist and humid day as well...

Just my two cents...