Max Range A320 Ferry

[Natstrackalpha]

Given zero wind for this Still Air exercise.


Given an optimum fuel burn of the A320


Say if you had to ferry an empty one from A to B


Dist: 5250 miles.


I worked out the optimum speed based on the optimum gross ff and specific ff.


down to x kg/ground nautical mile.


So we`ll fly that with an alternate before TOD and and alternate around Dest.


My question therefore is - does anyone have any operational information on the difference between being full of pax and bags and being empty?


We are lighter by up to 18 tons.


Taking off with an empty weight f 41 T and a fuel weight of 19.3T then can we assume a straight climb up to cruise flight level and virtually no time to accell at cruise level to cruise speed compared to being fat`n`full`n`heavy.


With this in mind (LRC empty ferry) would you fill it up and project your 1st fuel top, or, would you take off with less fuel on the first leg (because you need two tonnes for the climb any way - so if you are less fuel you will use less for the climb, carry less and all the rest of it . . . less?


So there are 2 ways of doing it.


Either you do perf climbs and cruise with little weight and stop for fuel.


Or you tank up to the gunnels and sit there until first fuel stop.


(Those of you wishing to define "sitting there" - don`t bother answering)

[BOAC]

A slightly odd post? What are your parameters? Standard/ferry tanks? Fuel Cost? Time? Crew? Tech stop costings? Airframe/engine useage? Landing/handling fees?

I assume your Flight Planning system (you have one?) predicts one tech stop, in which case...................?

[chimbu warrior]

I recall reading that Tigerair ferried an A320 from Clark (RPLC) to Melbourne (YMML), which is a great circle distance of 3444 nautical miles (I have no idea of what the winds were). My guess is that Avalon was their alternate.

I thought A320 only held 18.9 tonnes of fuel; at least that is what the copy of the manual I have seen suggests.

5250 miles (even statute miles, or 4562 nautical miles) seems very optimistic with anything less than about 250 knots tailwind.

[compressor stall]

My calcs show over 3000nm you'd burn an extra 2T of fuel carrying 10T payload (departing with same full fuel loads). There'd be even more of a difference if you didn't take the 2T of fuel.

[BOAC]

:confused::confused: - where does this "10T' payload come from? Nat said 'empty'?

By the way, you do NOT burn 'extra fuel' on a sector. Yes, you burn fuel to carry fuel, but it is all calculated into the planning system - based on weight. How can you NOT take 'the extra 2T'? Possibly getting confused with tankering?

[compressor stall]

BOAC,

The one question to which I was answering was

does anyone have any operational information on the difference between being full of pax and bags and being empty?

From that the OP can choose to extrapolate as required.

It seemed easiest and logical to me at the time to create a - very crude - rule of thumb that showed the variability in fuel burn with a round figure payload of 10T difference. You could also run it on min fuel and show the difference. Horses for courses.

I just ran two plans both departing with full fuel between two ports of around 3000nm and compared the result.

And, yes, thank-you I am familiar with tankering. That's why I said in my post, "Departing with the same fuel loads".

There are so many variables here (engine types, MTOWs, wx, alternates, ACT config etc) that it's all a bit pie in the sky stuff.:suspect: And I'm still not sure I understand the other questions...

[BOAC]

Sorry - I see that now. As you say And I'm still not sure I understand the other questions... indeed does anyone have any operational information on the difference between being full of pax and bags and being empty? - makes me wonder whoever is asking the question is anything to do with flying!

Maybe he/she will be back to explain?

[Natstrackalpha]

Okay.


A320 standard tanks - 19.3 max fuel load. CFMs - tanks empty.

Given 5250 NM

Plan upload fuel to first fuel stop 1750 NM - at that APS weight plus crew/crew bags and fuel required + res/alternate + final extra.

Land, fuel to 2nd fuel stop equally about 1750 NM, land re-fuel then to destination.

Time/Dist. in the climb 20/31 mins 83 NM
Time Dist. in the descent 111 NM ---

1750 NM - minus climb and descent = 1556 @ 2180/hr. = 7374 kg
Climb 2,000 kg
Descent 600 kg

total first leg 9974 kg + res 3391 = 13,365 kg (+2,900 contingency in the tanks)
second leg kg 9974
third leg to destination 9974 kg

total fuel 13,365+9,974+9,974= 29,922

Landing with 3391 (+2900 contingency) in the tanks. . . . is one way of doing it or,

uplift to full tanks 19.3 T and go a tad further for the first and subsequent fuel stops, or en-route diversion. this being heavy on fuel for the first half of the trip and light for the next giving better kg/gnm.

Example - there was a 747 going from an airport in Southern England all the way to K.L. empty - except for 12T in the hold of 1 pallet.
the rest was basic weight plus the tanks filled to screaming. As it, the aeroplane, being a 74 could carry that much juice then the maths were simple.

[FlightDetent]

Referring to FCOM PER-FPL-QFP-40-A

Why not try with just one stop? Assuming 2,5t to land with.

With 18t of payload:
. 41t DOW
. 59t ZFW
. 61,5t LW
. 77t TOW limiting
we get 15,5 t of fuel to use > that is 2700 NM (6h15m)

With 0 payload
. 41t DOW
. 41t ZFW
. 43,5 LW
. 2700 NM mission segment
we need 11700 kgs to make it, and 150 for taxi.


PS: what was the core of question again?

[Natstrackalpha]

Sorry Chimbu - I was not intending to fly the entire leg on one tank?!! My fault. I am assuming a gross figure of 2,000 NM as an absolute maximum - in actual fact Airbus claims the A320 will fly to 2400NM which looks nice on the brochure but can hardly be taken into consideration for operational flying!

I was looking initially at asking if we should fuel to first stop using full tanks and landing with reserves plus my own contingency of 2,900 in the tanks. I see that a common land figure is FOB 8T which is fine by me and is usually with pax.

Assuming there is no change (in `reserves` policy) flying empty or with pax then 8T on landing is very ok.

The other parameters , as BOAC mentioned are Landing fee for the fuel and route costs - these are ground negotiations, which don`t have much to do with the flight itself. The point being - we`ll buy a load of fuel off them if they let us land for free - any takers? That's 19.3 tonnes of fuel the revenue from which will buy lunch on a very quiet day in the middle of nowhere when this A320 comes whispering in.


I had not factored in a tech stop as opposed to the fuel stops.

Being light uses less fuel and the fuel burn minimum, although obviously depending on Tem Dev at altitude has been fairly coined by detent who has found a gff less than mine and mine were good at 2180/hr but they were not empty GFF figures but ZFW up to 10 to 18 tons more.


The inherent question which I thought was clear and apparent to you hot shot jockeys of the stratosphere were -


Do we fill light and go faster and further because of this or do we fill max fuel and try to project max range attainable which is of course based on the wind to get us our Specific Fuel Flow.


In this flight planning stage of the flight to get us across the globe at light weights without incurring massive bills all over the place.


Which brings me onto question 2 (this is going to read like a b----y newspaper!) why do BA sometimes go the GCT route over the top of Siberia to get to the East and yet sometimes for an equally long journey take the more southern via India and Bangkok route? I mean on some of their routes the GCT will be further North than they actually fly - is this because of potential tech stops and better facilities available at some places more than others?



The cheapest way of in flight fuel whilst landing with reserves and my own personal little 2.9 in the tanks as well.


Is is an interpolation thang. It does depend on wind and `the day`


It also depends on weight and FL and temp deviation therefore `the day` again.


It would be nice in competition if we got there, beat the other team by costing loads less in fuel and overall cost altogether - and yet, always banging in with res and 2.9T to enjoy one`s pension.


RES

In today`s modern technology accurate fuel prediction in the flight planning stage is made even more possible by modern technology and internet information giving real time situations with regard to dep/en-route/dest weather coupled with a knowledge of climatology for the season and with a global view of the weather systems at any one time - then reserves are more manageable then in yesteryear. Even so, the legal reserves are the figures to go by and if the pilot, sorry, if the Captain decides that an extra 2,900kg is prudent then that is what will be loaded - this is flight planning after all, not Economics.


Whereby one is moral and life saving, diminishing risk - flight planning - and the other is an amoral study of pure cost - economics.

[BOAC]

I am finding your questions and thought processes extremely confusing - what exactly are your 'qualifications' to be planning this trip?

Explain how you are going to 'buy lunch' by uplifting 19.3T when you have told us you will be landing with 8T? If you are going to be 'uplifting 19.3T' then 'whispering in' is exactly what you will be doing.:ugh:

What is different about this trip from flying 2700nm from a to b on a revenue flight? Why 'fill to full'? What is wrong with FD's figures? Why land with 8T?

PS A fuel stop IS a tech stop..................

One 'tech stop' should be more than adequate.

The answers to your 'new' question will be:
a)Destination?
b)Winds
c)Political issues
d)Flow control
and possibly some others too..

[Natstrackalpha]

Indeed - Lifting 19.3 would indeed have been a dry tanks arrival - not what anyone had in mind at all. LOL:rolleyes: the rolly eyes are for me not for you.


There is nothing wrong with FD`s figures and I thanked him accordingly - its just that, well, if I had factored in a mandatory reserve I would have come up with more than he did in the tanks on landing. Also - I was assuming that 8 tonnes was a cool figure based on - - if I applied reserves as per what is writ plus my own 2.9T, actually, my 2.9T is my absolute come hell or high water figure that I will never be false to. If I flew and used reserves for whatever reason go around/diversion then landed I would still have my 2.9T in the tanks on a really bad day.


If I calculate the legal requirement for reserves AND add on my 2.9T then the whole lot comes to a shade short of 8T.
You were right, of course, about the 19.3 being due to whispering in.


My argument is offset by my claim that today`s modern tech enables a more accurate prediction / forecast of local conditions - and that any prudent choice of diversion/alternate (due to weather or dead elephants on the runway say) would, could and should be made way before TOD that way the diversion (fuel-wise) is less as opposed to going all the way down and climbing back up to altitude again only to swan around at lower levels burning ever greater amounts of fuel.


In answer to your question " What is different about this trip from flying 2700nm from a to b on a revenue flight?" My answer is:


On a revenue flight we could weigh around MTOW.

[TyroPicard]

KISS....
1. Choose the cheapest tech stop, about half-way, in terms of fuel cost and handling charges.
2. Take minimum fuel for both sectors.

[BOAC]

Too simple, I fear, TP. Nattrack - sometimes revenue flights operate empty, but I guess you know that.

[Meikleour]

BOAC: I, and I suspect you, may be a little bemused by Natstrackalpha's above postings!

Am I correct in thinking that he considers that a landing fuel remaining on his A320 of 8 tonnes(!) is normal? ie. fixed reserve + diversion fuel for more than 3 hours distant alternate?! I wish I flew for his airline!

[Natstrackalpha]

Look less of the innuendo - say it!!


@ Meikleour (http://www.pprune.org/members/183752-meikleour)


Take my piddly 2.9T out ok - what have you got? Hmmm? Work it out. Now apply the reserves - what have you got ok? now take the trip fuel out and the climb and descent what have you got apply all this with a go around at 1500 ft and a low level diversion. Hey zero fuel right?


This will never happen - what have you got zero - where did I get the figures from - the mandatory reserve requirements - duh not rocket s-t science.


If I apply Detent`s and moreover Tyro Picard`s simple formula / advice and shove in the reserves that I want then we have a policy for departure - in fact the reserves are factored in there somewhere


So Meilakur, what are you saying - are you saying I`ve not enough or too much fuel. FFS!


I don`t mind being corrected - but you can perhaps do it without taking the p--s! And, and, before you come back with `I`m` taking the piss - then you actually do the planning and factor in a legal reserve and perhaps I will listen to you rather than read your c---p about whatever airline this is - Detent and Tyro - Thank you - and BOAC too (for making me think)
Melikeler - come back with figures - like the others did. MF!


And, if you took out my 2.9 in the tanks on T/D then you would have 2.33 hours of flying - so why is that a bad thing, because we are carrying too much fuel? (JFC)

[Meikleour]

Natstrackalpha: have I struck a raw nerve?

No innuendo, my point was that you seem to consider landing a A320 with 8.0 tonnes of fuel remaining on a non tankering sector as quite normal! Thats even in excess of Island Holding! Very generous and must make for a very relaxed operation.
My point is - you seem to fly for an operator with a very generous fuel policy or one that gets very cheap fuel.

PS if you find my "nom de plume" too difficult to spell - try cut & paste!

[Natstrackalpha]

Meikleour,


Sorry.


I thought Island Holding was 4 hours. Rather - I was taught that island holding was 4 hours by the same approved establishment that went bust and shoved us all out onto the street. Asking for our money back is not an option.


I take on board what you are saying. Thank you.


You have all been very helpful. I must admit I`ve seen more than one airliner approach with 3.5 hrs. of fuel or more.


On a last one - which was a final and last ever stop as the aircraft was due to get pulled apart in the aircraft graveyard - the Chief Engineer when he came into the aircraft on the ground complained about the excessive fuel left in the tanks, as was often the case with that particular Chief Pilot who was then and will always be one of my heroes. They employed that pilot right up until retirement where old age determined his last days of flying.

[FlightDetent]

Gordian knot? :)

[Natstrackalpha]

Its not Gordian but a retractable.


I`ve run it through again and again.


Off Block full 19.3 landing with 4955kg on landing.


5h. 59` 2729 NM -


2nd leg to dest =

[TyroPicard]

Gross error check using QRH confirms your numbers ... good luck!

[calypso]

I am sorry to say but you do not seem qualified/experienced enough to plan this venture. Get someone experienced to give you a hand and use them to learn how to do it the professional way. They will consider not just fuel burn but fuel prices at different stations, the need to tanker or not, Flight time limitations, tech stop costs including handling and landing charges, overflight permits, enroute alternates, etc, etc, etc. They will save your operation tens of thousands....

if I applied reserves as per what is writ plus my own 2.9T, actually, my 2.9T is my absolute come hell or high water figure that I will never be false to

That is an utterly meaningless statement, specially as you do not even seem to know how many miles or minutes that will give you for an empty A320. What you need is to actually work out is how much fuel you will need under realistic scenarios based on congestion, holding, usable alternates, approach aids and weather. 2.9 tons might be too much or not enough depending on the circumstances of the day. For example if you are planning a route significantly away from suitable alternates the minimum fuel will be determined by the depressurization case where you will need to fly for an extended period of time at 10,000 feet to reach a suitable enroute alternate

[Natstrackalpha]

Thanks calypso and TP and everyone.

[CargoOne]

3000 nm ferry on A320, with some tech stuff onboard (=1000 kgs payload), 19.3t fuel on departure, flight time 7:25, actual fuel burn 15200 kgs. 4+t remaining on landing. so in theory you can do up to 8:30 flight time if enroute alternates allow.. this was pretty mature V2527 non-sharklet aircraft.
also depends which engine and how old the airframe is.