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-   -   Fuel Critical (https://www.pprune.org/fragrant-harbour/316798-fuel-critical.html)

SuzieWong 8th Mar 2008 12:48

Thanks FR.
And yes our system is partly for blame. Nobody really figures out what delay each a/c to expect -well we have Flow Controller now but not many do it by the book. Somebody complain only the other day about getting Siera A star then vector all over the sea for 20 minutes. Not good. I heard we have some new system coming that will help.

I just watch the Avianca on youtube that somebody posted. Our system is very the same- each controller just does there bit, not really a big picture going on. I know that was extreme wx but we are the same just after typhoons. That is the worst time for us when some a/c going around, some don't want to leave the hold and try there luck, some diverting, some want to try again straght away. Nobody can tell you the delay in such situation.

throw a dyce 9th Mar 2008 08:40

Suzie,
As HK gets busier then HKATC are going to have to react accordingly.20 mins wandering around the South China Sea is no delay even at a medium UK airport.Most operators carry the fuel,although even some have trouble with this.Our own version of long hauls on min reserves are North Sea helicopters.They don't carry the fuel to even hold for a short time,so they must fly the ILS with min delay.However we can have anywhere up to 10 wanting the same thing at the same time.The fixed wings are very often held for 20mins+ and that's life.I can see our radar controller with 10 pieces of HK priority requests in front of him/her.They would all go in the bin.
We in the UK operate 3 mile radar separation,and you need it.A few months back we had to use 5 miles due radar outage,and it reduced our capacity by 30%.Your CAD is delaying aircraft because it cannot adopt thinking that is over 30 years old.Amazing.Aircraft on the ILS should be minimum vortex or 3 mile spacing.Could be even 2.5 miles in certain conditions and types.:ok:
If your system had the capacity to get them on the ground quicker,then perhaps this fuel problem would be reduced.You can't have an airport like CLK operating with no holding.However the CAD must be seen to reduce it own delays to minimum.Then aircraft in fuel state may only get 2-3 mins holding,which would be acceptable.

Five Green 10th Mar 2008 00:42

Say again ?
 
Throw a die :

Ok so maybe my attempt at humour (yes with an O) went over your head.

The fact that you mention Avianca means that you are aware of the problems associated with the english language and the (at the time) lack of a standardized (with a Z) phrase from the ATC and Pilot sides.

Bearing that in mind, any airline where the predominate first language is not English and most airline crew who are native (ICAO 6) speakers but not regulars to LHR, both have the potential to misunderstand a phrase that is contradictory. NO DELAY means no delay, (great skippa looks like it is straight in to Heathrow eh what!), minimum delay means expect some delay (golly gov better look that up to see how much delayand add some fuel!)

So unless UK ATC comes up with a better phrase , as foreign carriers increase service, you can expect more problems with low fuel.

Also I am not sure you completely understand the range of potential problems that can put pilots into the low fuel state. You seem to think that everything should run like a train schedule (well a Japanese Train anyway). Well amazingly it does 999 out of 1000. As pilots though we are faced with more potential for unexpected higher burn than even a few years ago. While weather and en-route forecasting is accurate most of the time, it is still off once in awhile. It happens more over the pacific and North Pole routes than over Europe for example. Those pesky jetstreams can move fast. Also crowded skies mean optimum flight levels are often taken. Fuel temp issues often mean going very fast or descending both of which eat into contingency fuel. Even today you can be asked to do 360 s over India or Pakistan. You do one 360 and you loose a lot of fuel. Unexpected enroute comm failures (ex. loosing CPDLC) often mean re-routing and loss of contingency, and these are just a few reasons.

Oh and here is another pet peeve. Not all busy airports use holding when traffic backs up. I know that airspace is at a premium over LHR. However a long slow circuit at higher altitude burns far less fuel. The act of banking a heavy jet increases the thrust and therefore the fuel burn as compared to straight and level long downwind vectors over the same time period. I would much rather a long descending vector back a 250kts then a 6 turn hold at 220kts.

In conclusion, I sympathise with ATCers as your job is not getting any easier. However all I ask in return Mr. Dice is that you get down off your high horse and consider those of us who have been strapped in the aluminum tube battling our way across the world all night !!

On other thing VHHH has gone to minimum spacing on approaches now.

FLEX: Nicely put.

Five Green out ! (I am definitely laying off the Red Wine from now on!!)

HeavyWrenchFlyer 10th Mar 2008 05:22

The only thing that really matters like anything else in aviation is what the official definition of the phrase is. If something isn't in writing then it means nothing.

Here's the definition of the equivalent phrase from where this situation was first addressed, the US FAA (Ref. AIM 5-5-15):


5-85
MINIMUM FUEL ADVISORY

a. Pilot -

1. Advise ATC of your minimum fuel status when your
fuel supply has reached a state where, upon reaching destination,
you cannot accept any undue delay.
2. Be aware this is not an emergency situation, but
merely an advisory that indicates an emergency situation is
possible should any undue delay occur.
3. Be aware a minimum fuel advisory does not imply a
need for traffic priority.
4. If the remaining usable fuel supply suggests the
need for traffic priority to ensure a safe landing, you should
declare an emergency account low fuel and report fuel remaining
in minutes. [References omitted.]
b. Controller -
1. When an aircraft declares a state of minimum fuel,
relay this information to the facility to whom control
jurisdiction is transferred.
2. Be alert for any occurrence which might delay the
aircraft.




Now the question is what the HKCAD's official definition of the phrase 'Fuel Critical' is, if they don't have one IN WRITING then I guess it means nothing until there's an accident or incident from leaving pilots, dispatchers and controllers to pull something out of their butt to answer the question for themselsves.

If certain flights are regularly using this then it's obvious they're taking advantage of the system. The following aviation case law is a good example of what the FAA thinks of mis-using the min fuel decleration although I admit it's not an exact example of long haul flight issues.

http://www.ntsb.gov/alj/o_n_o/docs/AVIATION/3932.PDF

Liam Gallagher 10th Mar 2008 08:30

I think some folk are over-complicating this
 
Notwithstanding the use of the words Emergency or Mayday, the only time I have seen or heard of any CX aircraft asking for priority on fuel is by way of a request to IOC (Cathay Ops), which I assume is then passed to HKATC if IOC deems appropriate. This priority is, I assume, to be at the gift of the controller and will only give us priority over OTHER CX AIRCRAFT. It is a parallel scenario to asking for departure priority if you have no APU on a hot HK day/evening:ok:

The practical effect for us (on the 3 or so occasions I have used it) is, firstly, it enables us, given certain other conditions, to drop holding alternate fuel (ish) and secondly, when loading the FMC (Computer) we can have an educated guess as to track miles from FIR arrival to landing. We can then decide if this arrival fuel is suffice to continue past a suitable enroute airfield.

This is done many hours out from HK and is a refinement of our pre-departure fuel planning. As someone else stated, this is not black and white. However, what becomes very black and white is your actions once in the HK FIR. You have made your fuel plan and you must accept what you are given, weather, traffic etc...no blubbing. Your only option now is to declare an emergency once you believe you may land at less than Reserves... which is I verily believe to be an International Standard procedure.....

BalusKaptan 10th Mar 2008 09:54

Good answer Subwoofer.
While very few (someone quoted 0.1%) of flights burn more than CFP those that do can for very legit reasons. An example, left Departure point with CFP with a Tad for Mum yet have been sent down 10,000' enroute due traffic, another occassion rerouted a few hours into the flight taking an additional 20 minutes enroute.
The "Note" you are handed is for you to act on at you're discretion but only as in rearranging Company (CX) aircraft for arrival sequence and not to the detriment of any other company.
This system is in place in other Airports around the world not least for a well known Airline from a well known Sand Pit.

Liam Gallagher 10th Mar 2008 11:21

The person who quoted the 0.1% has never operated the 744 out of NAM ULH. All those pax weigh 78Kgs.....:rolleyes: Haven't even touched on the issue of the Totaliser vs Calculated split or the jetstream over Japan... because that really would be complicating it.

As for taking a "tad for Mum"; difficult when you are full tanks, max ramp or Max take-off and even if you had space for another tonne, you would burn 600 of it; leaving only an additional 400 for the approach into HK....250kts/Fl130 at Melon takes care of that....

This is all shades of grey....

throw a dyce 10th Mar 2008 11:28

5 Green,
Well last I heard the minimum radar separation was 4 miles in HK.You can put heavies 3 miles behind mediums,or between mediums.If HK have now got 3 mile radar sep then :D but it's about 10 years too late.

As heavywrench states that minimum fuel advisiory does not mean traffic priority.It CPA want priority over other CPA aircraft,then they still could be number 10 behind other airlines.I think all ATCO's are aware that long hauls have been airborne a long time,and will deal with them as quickly as possible.
That is regardless of carriers.I have been on the flight decks before fam flights were kicked into touch,so I'm well aware of the problems you face.But you seem to have a real problem with UK ATC thinking on this.Perhaps it might be a solution to HKATC problem perhaps not.At least it's predictable that at UK airports up to 20 mins holding is the norm.If you can't make that we can try and give a more accurate estimate,and if it's over you will get an EAT.
As for holding,then we are required to keep you in controlled airspace.You may like to wander all over the place at 250 kts,but we can't keep you in CAS.Also the LTMA has many airfields in close proximity so holding is the only option.In addition a huge conga line all over the South China sea is very labour intensive for the ATCO.Much easier to hold vertically and peel them off.
If UK thinking is that rubbish,then why is CPA represented on UK safety boards?

Lowkoon 10th Mar 2008 11:36

A different perspective. Put it back on the operator. Ask them if they are declaring a fuel emergency, if not, treat them like everyone else. It will stop the idiots in our company who are having a pissing contest to see who can arrive back in HKG with the "LEAST" amount of fuel. Take it further, look in to it. Find out who the PIC is, and you will see the same old faces. Put it back on these idiots who arrive with bare legal minimums or less at one of the busiest most restrictive airports in Asia.If it is a genuine fuel emergency, they will have no problem declaring it.

bekolblockage 10th Mar 2008 14:55


Well last I heard the minimum radar separation was 4 miles in HK.You can put heavies 3 miles behind mediums,or between mediums.If HK have now got 3 mile radar sep then but it's about 10 years too late.
Just to be completely anal retentive about it TAD, our minimum radar separation is 3NM. Our agreed minimum inter-arrival spacing is 4NM. That takes care of 70% of the pairs based on the traffic mix here.

Not a moment too soon.:ok: (Gotta give us something to work on for the next 10 years :E )

throw a dyce 11th Mar 2008 08:08

Hi Bekol,
Yes I had a little read of it in the HK AIP on line.(Yes I know :8)
The Multi Radar Tracking is 4 miles,but you can use 3nm on Sha Chau within 30 nm.So why can't you put heavies 3nm behind mediums on finals.There is no vortex issues,and with the right radar it is legal.
I know 4nm is ok for 70% of the traffic mix,but what about the other 30%.That is delaying aircraft for no reason,apart from the CAD won't look to use separation,arrival spacing that we have used for 30+ years.
Also HK with 4 radars,primary and SSR basically doing the same job within 40 NM,can the Multi Radar Tracking be reduced to 3NM.We only have one primary radar with SSR and have used 3NM for 30+ years.
Is there any technical reason it can't be done.Yes I know it's the CAD and I have asked enough why questions.


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