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Tony747-400

Legal remaining fuel after landing?

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Hi everyone.

 

Could someone tell me if there's a rule that an aircraft must land with a minimum amount of fuel left in the tanks? When I'm flight planning I allow for go arounds, diversions etc but would I also need to consider that in the event of those I must still land with a certain amount of fuel?

 

If this is the case would the amount left be in flying time or in weight? And does it vary in different countries or continents?

 

Thanks

 

Tony

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There is no real requirement to land with a specific amount of fuel (for nitpickers, note the emphasis on landing, and you're welcome to go digging through the regs). The regs only specify that you must plan a certain amount, and what you're going to be looking at is the requirements in 91.167 and 121.639 (and below). What you'll see tacked on to most plans, however, is some extra for the worst possible case scenario:

You burned your route fuel, alternate fuel, and the 45 min extra fuel. If you managed to land after all of that, it would still be nice to have some to taxi, or simply as a buffer because a plan, after all, is just a plan.

 

Note that all of the 121 regs state "dispatch" and "take off" an airplane. You really only have the requirement to leave the ground with fuel to cover the plan. If you somehow ended up with less than that when you hit the ground, it's not necessarily breaking the reg. The 91 version of the regs for VFR states similar, but the awkward catch is the IFR reg under 91, which is ambiguous about it, stating "no person may operate an aircraft [...]."

 

Additionally, an airline's own FAA-approved operations documents are backed by the FAA as regulatory, so if their ops documents specify you need to land with a certain amount, then you need to follow that.

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I've heard, and I honestly don't know if it's just a company policy or not, that there is a certain percentage of untouchable fuel in the tank. In other words, the tanks will always hold 15% or so of fuel, never to be used in planning. The way it was explained to me is if you start sucking the bottom of the tank, the sloshing about of the fuel could put you at higher risk of engine outs.

 

So in theory, you would take enough fuel for your flight, your reserve, your alternate if required, and then keep a certain percentage capcity that is not part fo your fuel budget. Any truth to that?

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Different Airlines Standard Operating Procedures, so that depends on what Airline SOP you select to proceed by, but in general you should land at your destination airport with Alternate Fuel (+ Holding Fuel if you didn't fly a holding). The PMDG tutorial will help you with that.

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The PMDG tutorial will help you with that.

Not using PMDG, or any other addon...just wondering forthe sake of interest in this topic. But you are probably correct with the untouchable reserve being a company SOP. Thanks.

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Rule of thumb aim for 12-15tonnes :) But Kyle is absolutely right

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Thanks for the replies.

 

I've always appreciated the help us flight simmers give each other on these forums, thank you.

 

As there seems no real legal requirements in the word, I will probably use a fictious SOP default of 250kg for the NGX approx 15-20mins flying time and about the same flying time for the 747-400, 2500kg.

 

Tony

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As there seems no real legal requirements in the word, I will probably use a fictious SOP default of 250kg for the NGX approx 15-20mins flying time and about the same flying time for the 747-400, 2500kg.

 

 

It could depend on the length of the flight, but that does not seem like near enough for most flights. Conditions can change, you could be assigned a different altitude than you planned, find conditions that cause you to request a different altitude such as stronger than forecast headwinds or lighter than forecast tailwinds. Your destination might experience a wind shift that causes a change in the active runway, causing you to hold with other inbounds until the airport gets "turned around", etc.

 

Please let me know when you are flying so I don't board......

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The only thing I would add to Kyles post is that some airports (here, anyway...) will specify on their airport documentation that you should plan for an additional 30 minutes (for example) of holding fuel at peak times in case you get stuck in a hold and aren't the top priority for inbound traffic.

 

Pegger, there is unusable fuel in aircraft. In GA types that I flew, the fuel pick up was raised slightly from the bottom of the tank. That meant that if any rubbish (bits of rust) found it's way into the tank it would not get sucked into the line, shortening your flight. It's not a huge quantity though - single digit percentage.

 

Mike

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Hi Guys,

 

In real world airlines would never dream of landing with these tiny amounts of fuel. I work on long haul 767's and 747's and thay arrive after a flight with approx 5 tonnes of fuel left on the 767's and 10 tonnes on the 747's.

 

I know that if Airlines get below a set amount then they have to declare a fuel emergency, they then get ATC priority to land. However this gets reported to the airworthiness athority and they will investigate.

 

Cheers

 

Neil

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Hi Tony,

 

In the land of the EU, bless us.....here are the fuel requirements for planning and inflight. A little lenghy, but it's the law.

 

EU-OPS 1.255. Pre Flight Planning

 

An operator must establish a fuel policy for the purpose of flight planning and in-flight re-planning to ensure that every

flight carries sufficient fuel for the planned operation and reserves to cover deviations from the planned operation.

 

An operator shall ensure that the planning of flights is at least based upon 1. and 2. below:

1. Procedures contained in the Operations Manual and data derived from:

(i) data provided by the aeroplane manufacturer; or

(ii) current aeroplane specific data derived from a fuel consumption monitoring system.

 

2. The operating conditions under which the flight is to be conducted including:

(i) realistic aeroplane fuel consumption data;

(ii) anticipated masses;

(iii) expected meteorological conditions; and

(iv) air navigation services provider(s) procedures and restrictions.

 

© An operator shall ensure that the pre-flight calculation of usable fuel required for a flight includes:

1. Taxi fuel; and

2. Trip fuel; and

3. Reserve fuel consisting of:

(i) contingency fuel (see OPS 1.192); and

(ii) alternate fuel, if a destination alternate aerodrome is required. (This does not preclude selection of the departure

aerodrome as the destination alternate aerodrome); and

(iii) final reserve fuel; and

(iv) additional fuel, if required by the type of operation (e.g. ETOPS); and

4. extra fuel if required by the commander.

 

(d) An operator shall ensure that in-flight re-planning procedures for calculating usable fuel required when a flight has to

proceed along a route or to a destination aerodrome other than originally planned includes:

1. trip fuel for the remainder of the flight; and

2. reserve fuel consisting of:

(i) contingency fuel; and

(ii) alternate fuel, if a destination alternate aerodrome is required (this does not preclude selection of the departure

aerodrome as the destination alternate aerodrome); and

(iii) final reserve fuel; and

(iv) additional fuel, if required by the type of operation (e.g. ETOPS); and

3. extra fuel if required by the commander.

 

EU-OPS 1.375. In Flight Fuel Planning

 

An operator shall establish a procedure to ensure that in-flight fuel checks and fuel management are carried out according

to the following criteria:

 

(a) in-flight fuel checks.

1. a commander must ensure that fuel checks are carried out in-flight at regular intervals. The usable remaining fuel

must be recorded and evaluated to:

(i) compare actual consumption with planned consumption;

(ii) check that the usable remaining fuel is sufficient to complete the flight, in accordance with paragraph (B) “Inflight

fuel management” below; and

(iii) determine the expected usable fuel remaining on arrival at the destination aerodrome;

2. the relevant fuel data must be recorded.

 

(B) in-flight fuel management.

1. the flight must be conducted so that the expected usable fuel remaining on arrival at the destination aerodrome is

not less than:

(i) the required alternate fuel plus final reserve fuel, or

(ii) the final reserve fuel if no alternate aerodrome is required;

2. however, if, as a result of an in-flight fuel check, the expected usable fuel remaining on arrival at the destination

aerodrome is less than:

(i) the required alternate fuel plus final reserve fuel, the commander must take into account the traffic and the

operational conditions prevailing at the destination aerodrome, at the destination alternate aerodrome and

at any other adequate aerodrome, in deciding whether to proceed to the destination aerodrome or to divert

so as to perform a safe landing with not less than final reserve fuel, or

(ii) the final reserve fuel if no alternate aerodrome is required, the commander must take appropriate action and

proceed to an adequate aerodrome so as to perform a safe landing with not less than final reserve fuel;

3. the commander shall declare an emergency when calculated usable fuel on landing, at the nearest adequate aerodrome

where a safe landing can be performed, is less than final reserve fuel.

 

So as you can see it's pretty clear that you must not land at your destination airport with less than final reserve + alternate fuel :)

 

My friend took this picture going into Guangzhou on night.

 

Kind Regards,

 

Martin Dahlerup

A320 First Officer

 

188248_10151488849072328_1234013356_n.jpg

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I usually try to plan fuel so that I land with no less than 5,000 pounds of fuel in the 737.

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FAA rules require IFR flights to have:

 

"No person may operate a civil aircraft in IFR conditions unless it carries enough fuel (considering weather reports and forecasts and weather conditions) to-"

• Complete the flight to the first airport of intended landing;

• (2) Fly from that airport to the alternate airport [if one is required]; and

• (3) Fly after that for 45 minutes at normal cruising speed or, for helicopters, fly after that for 30 minutes at normal cruising speed.

 

When planning your flight, include Nautical Air Miles and taxi/takeoff fuel. Nautical Air Miles is the distance travelled including wind factor. If you are fighting a headwind, there are more Nautical Air Miles. If you are getting a tailwind, there are fewer Nautical Air Miles.

 

There is no requirement for VFR flight but experience has taught me that applying IFR rules will save you more often than not.

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It could depend on the length of the flight, but that does not seem like near enough for most flights. Conditions can change, you could be assigned a different altitude than you planned, find conditions that cause you to request a different altitude such as stronger than forecast headwinds or lighter than forecast tailwinds. Your destination might experience a wind shift that causes a change in the active runway, causing you to hold with other inbounds until the airport gets "turned around", etc.

 

Please let me know when you are flying so I don't board......

 

Hi.

 

I do allow for all those possibilities, please see my original post.

My question was, what if you had to use your extra fuel etc have you still got to land with a legal amount left in the tanks?

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Hi.

 

I do allow for all those possibilities, please see my original post.

My question was, what if you had to use your extra fuel etc have you still got to land with a legal amount left in the tanks?

 

Simple answer is NO. there is no minimum legal amount of fuel to be left in the thanks after landing.

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Hi.

 

I do allow for all those possibilities, please see my original post.

My question was, what if you had to use your extra fuel etc have you still got to land with a legal amount left in the tanks?

 

Hi,

 

You may use your EXTRA FUEL as that's he commanders decision to carry. You must however NOT use you Altenate fuel or Final Reserve.

 

You are required to land at your destination with your Altenate fuel and Final Reserve. If your predictions look like you will not. you either have to replan or divert. Simple as that.

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Rule of thumb aim for 12-15tonnes :)

 

Please tell me you're referring to the 747.................

 

xD

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Please tell me you're referring to the 747.................

 

xD

 

Of course..

 

Sorry I thought OP said 747...

 

My mistake..

 

For NGX = 2-3 tonnes is common

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Of course..

 

Sorry I thought OP said 747...

 

My mistake..

 

For NGX = 2-3 tonnes is common

 

I thought so.

 

Thought it was a bit suss having 12t reserve in the NGX, with its 20t total cap.

 

The NGX also likes to spit out low fuel warnings with under 1t in each wing (something like that)

 

I prefer to land with about 3t reserve most times

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Speaking of Alternates ... are logging of Alternates in a flight plan required by FAA? I thought I recall a FedEx cargo pilot suggesting they never plan an Alternate?

 

BTW, it appears that most Aircraft in FSX will continue running all the way until 0 ... which is probably not accurate, but there again on larger commercial AC just how accurate is the "actual" fuel quantity on board? (not what was added but actual)

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Speaking of Alternates ... are logging of Alternates in a flight plan required by FAA? I thought I recall a FedEx cargo pilot suggesting they never plan an Alternate?

 

I'm not a professional pilot but I believe the following to be the case:

 

It isn't mandatory to file an alternate in your flight plan (this even means your minimum reserve can be less). But, if your plan doesn't have an alternate (sometimes the case for remote destinations), you won't be permitted to dispatch the flight unless weather at your destination is above certain minimums.

 

BTW, it appears that most Aircraft in FSX will continue running all the way until 0 ... which is probably not accurate, but there again on larger commercial AC just how accurate is the "actual" fuel quantity on board? (not what was added but actual)

 

Depends on the aircraft. A Cessna 172 just has float type sensors as you'd have in your car for example. In fact, they can be worse than those in a car as they're not damped, so even light turbulence causes the gauges to thrash around making them fairly useless. Any light aircraft pilot with any sense won't rely on them!

 

Airliners on the other hand use several (capacitive type I think) sensors, placed in multiple locations in each tank to get an accurate reading of fuel level. In addition, they have temperature sensors to provide density correction, giving the crew fuel levels in mass rather than volume. Mass provides more useful information, as 1,000kg of fuel contains the same amount of energy regardless of whether it ocupies 1m3 or 0.5m3.

 

Either way though, you're right; an aircraft engine won't keep running untill fuel is 0. The tanks will always have a certain amount of unusable fuel.

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Airliners on the other hand use several (capacitive type I think) sensors, placed in multiple locations in each tank to get an accurate reading of fuel level. In addition, they have temperature sensors to provide density correction, giving the crew fuel levels in mass rather than volume. Mass provides more useful information, as 1,000kg of fuel contains the same amount of energy regardless of whether it ocupies 1m3 or 0.5m3.

Airliner fuel quantity systems are very accurate these days (though that wasn't always case in the days of analogue electronics, despite multiple sensors). However, they are designed to show usable fuel. Unusable fuel is not indicated. So zero probably means no feed to the engines.

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Like some of the posters have already said, the best answer is there is no CFR requirement for a minimum fuel quantity for landing.

 

For domestic operations fuel planning, CFR 121.639 says you have to have enough fuel to accomplished the planned flight whether to the destination or furthest alternate, and after arriving have at least 45 minutes of fuel remaining (planning). However, during the actual flight, that 45 minutes of extra fuel can be used to get the airplane safely on the ground, even if the airplane lands with 10 minutes or even 1 minute of fuel remaining in the tanks, it's still legal.

 

CFR 121.639 Fuel supply: All domestic operations.

No person may dispatch or take off an airplane unless it has enough fuel—

(a) To fly to the airport to which it is dispatched;

(b)Thereafter, to fly to and land at the most distant alternate airport (where required) for the airport to which dispatched; and

©Thereafter, to fly for 45 minutes at normal cruising fuel consumption or, for certificate holders who are authorized to conduct day VFR operations in their operations specifications and who are operating non-transport category airplanes type certificated after December 31, 1964, to fly for 30 minutes at normal cruising fuel consumption for day VFR operations.

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Speaking of Alternates ... are logging of Alternates in a flight plan required by FAA? I thought I recall a FedEx cargo pilot suggesting they never plan an Alternate?

 

BTW, it appears that most Aircraft in FSX will continue running all the way until 0 ... which is probably not accurate, but there again on larger commercial AC just how accurate is the "actual" fuel quantity on board? (not what was added but actual)

 

Hi,

 

Here are a page from the A320 FCOM bulletin regarding FQI accuracy. The supplier could be the same for Boeing and Airbus, Smith and BFE Goodrich(A321)

 

FAR/JAR 251337 requires that "each fuel quantity indicator is calibrated to read "zero" doing level flight when the quantity of fuel remaining in the fank is equal to the unusable fuel supply..."

 

According to Airbus the max discrepency you should see between fuel uplifted and fuel reading is plus/minus 750kgs. There are accuracy margins on the bowser, density. Also take into account the APU fuel burn.

 

Hope this helps.

 

 

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