kl911
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CX B773 At Hong Kong, Fuel Emergency

Wed Sep 19, 2012 4:46 pm

I didnt read this before although it happened Sept. 13.

A Cathay Pacific plane declaring fuel emergency, and while turning for landing a suspected loss of seperation with an A330 occured.

I am surprised that this happened, HKG wasnt a diversion but planned destination, and it was the 1st go-around. So HOW can a 773 have less then minimum fuel onboard for this relatively short hop?


Quote:

"A Cathay Boeing 777-300, registration B-HNM performing flight CX-736 from Singapore (Singapore) to Hong Kong (China), was on approach to Hong Kong's runway 25R when the crew initiated a go-around from less than 240 feet MSL due to strong tail wind at 13:51L (05:51Z), declared minimum fuel and requested a visual return to runway 07L. The aircraft landed safely on runway 07L about 16 minutes after aborting their first approach.

Rumours appearing on the Internet "knew" that the crew just turned around for a return to runway 07L leaving the expat controller with a near impossible situation and a serious loss of separation with another A330 in the area, the controller doing an extraordinary job in resolving the situation."


Source: http://avherald.com/h?article=456184e3&opt=0
 
wilco737
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RE: CX B773 At Hong Kong, Fuel Emergency

Wed Sep 19, 2012 4:52 pm

Well, if you depart with the required fuel on board and you don't expect bad weather at the destination you only have a bit of reserve fuel. And when you don't get an approach right away, you burn a lot of fuel and a go around cost a lot of fuel! So this can happen as you cannot be prepared for everything...
And you don't have full tanks every time you depart....

wilco737
  
 
kl911
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RE: CX B773 At Hong Kong, Fuel Emergency

Wed Sep 19, 2012 4:58 pm

Quoting wilco737 (Reply 1):
Well, if you depart with the required fuel on board and you don't expect bad weather at the destination you only have a bit of reserve fuel

Thanks Wilco, so planes dont automatically depart with extra fuel in case something suddenly require a diversion further away, even when at departure everything looks good?
 
wilco737
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RE: CX B773 At Hong Kong, Fuel Emergency

Wed Sep 19, 2012 5:06 pm

You have reserves on Board which are enough for Minor contingencies, a Diversion to the alternativ aerodrome and a final Reserve. But this final reserve shouldn't be touched at all. Once you are below this you have to declare emergency and land ASAP. I doubt the CX crew was close to that, but I guess they expected good weather in HKG and only had a bit of extra fuel on board. Another 15-20 minutes delay during arrival and that extra fuel is used. Then you have the alternate fuel still available, but the go around eats up a lot of fuel as well, so I guess at this time they were below the required fuel to fly to the alternate aerodrome and decided to stay near HKG. It is allowed to use the alternate fuel at your destination if a landing is likely. So at an airport like HKG you should be able to land.
And after this go around they simply wanted to land ASAP. A change of runways usually takes quite some time as well...

wilco737
  

[Edited 2012-09-19 10:07:08]
 
roseflyer
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RE: CX B773 At Hong Kong, Fuel Emergency

Wed Sep 19, 2012 5:32 pm

The weather looked bad in the article, so it is possible that they had a hold on arrival. Multiple aircraft were going around so there likely were quite some delays into HKG. The article doesn’t say how long they held, but it sounds like it is possible they could have been holding for a while before getting cleared for the approach only to have to go around. Switching runways takes time and a go around takes a lot of fuel.

Most airlines are relatively tight with fuel reserves. It is acceptable to have a diversion 1 in 1,000 flights instead of loading up extra fuel on every plane and wasting fuel carrying fuel. Each airline has their own calculations for how much fuel is necessary over the minimum. Some have razor thin margins such as 15 minutes of holding fuel, fuel for an alternate and then reserve. Some are very cautious. When weather gets worse en route, diversions happen, and another mishap such as a go around can cause a minimum fuel emergency.
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CZ346
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RE: CX B773 At Hong Kong, Fuel Emergency

Wed Sep 19, 2012 5:58 pm

There was no emergency declared here - just a request for priority due to being at fuel minimums.

We typically put in enough fuel to get to destination, fly the missed, get to our alternate + 30 minutes, then the manufacturer reserves, but like Wilco said that varies per airline and country. Flights can't carry too much more fuel than required because of the light loads needed to safely land the aircraft while maintaining wheels, struts, airframe integrity, etc.

Weather dependent, alternates into HKG frequently end up being Macau, which is 18 minutes on the missed from 25R and 22 for 25R assume (I don't know 07L/R off the top of my head). These guys were definitely down there, but there was was very little danger and it's a good thing they had good conts.
 
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CCA
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RE: CX B773 At Hong Kong, Fuel Emergency

Thu Sep 20, 2012 8:58 am

Quote:
declared minimum fuel



.....

Minimum Fuel

Indicates that an aircraft's fuel supply has reached a state where, upon reaching the destination, it can accept little or no delay. This is not an emergency situation but merely indicates an emergency situation is possible should any undue delay occur.
P1 in A330, A340, A346, B742, B744, B748.
 
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zeke
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RE: CX B773 At Hong Kong, Fuel Emergency

Thu Sep 20, 2012 10:34 am

Quoting kl911 (Thread starter):
A Cathay Pacific plane declaring fuel emergency, and while turning for landing a suspected loss of seperation with an A330 occured.

"Minimum fuel" is a new ICAO phraseology which is being trialled in HKG, CCA has provided the exact definition in reply 6, it is not a fuel emergency, a fuel emergency is a Maday. As far as I am aware, they landed with fuel in excess of the legal minimum.

The loss of separation was a different 777, read the article you linked again.

Quoting kl911 (Thread starter):

I am surprised that this happened, HKG wasnt a diversion but planned destination, and it was the 1st go-around

Wx forecasts are valid for 5nm around the aerodrome, it says nothing about the area further out. The wind on approach changed from a 10 kt headwind to 30 kts of tailwind.

Quoting kl911 (Thread starter):
So HOW can a 773 have less then minimum fuel onboard for this relatively short hop?

They departed with excess of the legal minimum, and below maximum fuel.

Quoting kl911 (Reply 2):
so planes dont automatically depart with extra fuel in case something suddenly require a diversion further away, even when at departure everything looks good?

No, not unless there is a compelling reason to. Sometimes we even depart without an alternate, just 2 hours of additional holding fuel.

Quoting Roseflyer (Reply 4):
The article doesn%u2019t say how long they held, but it sounds like it is possible they could have been holding for a while before getting cleared for the approach only to have to go around. Switching runways takes time and a go around takes a lot of fuel.

We have had a process over the last few years where the very experienced expat controllers have been shown the door leaving HKG with a lot of very young, less experienced local controllers. There have been a number of instances in the past 24 months where controllers have basically lost strategic and tactical control over the airspace. The number of movements in HKG is increasing, airspace is constrained by China in the north, Macau to the west, and hills to the south and east. With the addition of significant Wx changes.......

Quoting Roseflyer (Reply 4):
Some have razor thin margins such as 15 minutes of holding fuel, fuel for an alternate and then reserve. Some are very cautious.

CX is very conservative, we carry a lot more fuel than a lot of other operators, generally all flights into HKG carry a few extra tonnes of fuel.
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roseflyer
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RE: CX B773 At Hong Kong, Fuel Emergency

Thu Sep 20, 2012 7:27 pm

Quoting zeke (Reply 7):
CX is very conservative, we carry a lot more fuel than a lot of other operators, generally all flights into HKG carry a few extra tonnes of fuel.

That doesn't surprise me at all. Usually the airlines that have tight margins aren't the ones flying widebodies. Widebodies have a lot of flexibility since on regional flights like this, you aren't going to be tight against MTOW or MLW.

The airlines that have super tight margins are the ones operating smaller airplanes. Some very discount 737/A320 operators have it down to very small margins because they are extremely tight with costs. Others like ERJ and CRJ operators have to have small margins because they are always coming up against MTOW and MLW. Too much holding fuel will often push an ERJ145 above its max landing weight, so there are reasons to keep extra fuel to a minimum.
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