Sign in to follow this  
Guest etanin

Fuel required?

Recommended Posts

OK real pilots, how's it done.I know you take into account the following;-weight-trip distance-holding pattern-taxi time-alternate distance-weather-speedSo do you just use that or do you add something like a turnaround. Do some airlines require that if possible you be able to fly back to your departure? What else is taken into account for fuel load. I find that when I do my trip and figure out my fuel it seems that you are taking a chance if you don't add some extra for the "just in cases."

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

The following needs to be taken into account.(IFR)1. Weight2. Distance3. Winds at Altitude4. Taxi5. Approach (15 minutes approx)6. Missed Approach (15 minutes approx)7. To your alternate8. plus 45 minutes(VFR)1. Weight2. Distance3. Winds at Altitude4. Taxi/Takeoff5. plus 30 minutesNo account is taken for travelling back to your departure point... only to your alternate (for IFR). You also have to consider maximum taxi weight and maximum takeoff weight for some aircraft. Some airlines do carry a "just in case load". but by law only the above are required. Every extra pound you take, is money out of their pocket.

Share this post


Link to post
Share on other sites

>be able to fly back to your departure? Would it make any sense just using the common sense ? I don't think so. With so many airports to land at why would you want to be able to fly back :-hmmmMichael J.

Share this post


Link to post
Share on other sites

well..correct me if i'm wrong,but i believe strongly there are certain trips on which the aircraft has to take enough fuel to be able to fly back to the departure airport...i believe it holds true for certain etops operations...i'll try to find out more about it,or maybe some of the seasoned jet jockeys can come in?regards

Share this post


Link to post
Share on other sites

I can see this for aircraft whose initial arrival airport has no fuel available. This would happen quite often in northern Canada. In a case like this, legal fuel for the return trip would be required. Going back to my initial post, the more fuel you carry to your destination, the more expensive.But maybe there are some special cases out there that i'm not aware of.:-)

Share this post


Link to post
Share on other sites

>well..>>correct me if i'm wrong,but i believe strongly there are>certain trips on which the aircraft has to take enough fuel to>be able to fly back to the departure airport...i believe it>holds true for certain etops operations...For ETOPS you have to be always within 207 minutes of *some qualified* airport.The only special and extreme case I know of is flying between Chile and Easter Island. But even there you only carry enough fuel to return you back to mainland but before you passed a point *of no return*. Once you passed this point you are committed to press forward. So, no, you don't carry fuel for the whole round trip even there.Michael J.

Share this post


Link to post
Share on other sites

Hey there,There have been several posts above which accurately describe "block fuel" requirements. I'd just like to expound a bit on a couple of points:There is no rule stating you must carry enough fuel to return to your origin after "missing" at your destination. There are many, many rules in the FAR's governing fuel reserve requirements for every kind of operation you can think of. i.e - Turbine vs. Non-Turbine. Flag, Supplemental or Domestic operations. etc. It all depends on what you're trying to simulate.Assume for the sake of argument that you're flying a domestic flight in a turbine powered airplane. To be legal, you must carry enough fuel to fly to the point of intended landing, miss the approach, proceed to the most distant alternate, then fly for 45 minutes at normal cruise fuel consumption in calm wind. Then, as mentioned above, you would add Taxi fuel, Holding fuel if you anticipate any enroute holds, and any Extra fuel. Extra fuel is usually something the captain adds to make himself feel better. I call it: "Fuel for the wife and kids." It rarely serves any real purpose, since the Dispatcher has already accurately (and meticulously) planned the trip burn. All extra fuel does is cost the company money. But thats another story... So your typical release would include something that looks like this:BURN: 14656ALTN: 4000HOLD: 0XTRA: 1000TAXI: 500BLOCK: 20156T/O : 19656As far as the ETOPS thing goes, just know that 207 minutes is not a blanket thing. It takes an operator quite a while to work up to that limit. The first step is 75 minutes, then 120 and 180 minutes. Before moving to the next higher limit, an operator must maintain a set level of reliability for it's airfram/engine/APU combination. This evaluation period lasts between 6 months and a year.Also about ETOPS, those "points of no return" are called Equal Time Points, and represent a point is space along your intended route of flight, where the flight time between two suitable alternate airparts is equal. There are usually several ETP's along an ETOPS route.With regard to FS, it's very hard to accurately plan block fuel. In the real world it's done either automatically by a really smart computer, or done entirely by hand with a lot of paper. The paper method involves some of the things metioned above regarding Top-of-Climb and Descent, Cruise performance, etc. Most of the numbers are gleaned from charts that are derived for a given a/c configuration. They take into account many things like: Gross Weight, Flight Level, HW/TW components, climb and descent profile (M.80/280/250, etc.), and a host of other factors. Since this data is specific to each aircraft type, and is not readily available to ost FS users, it's very difficult to do right in FS. Anyway, hope you've found an answer or two in here somwhere...Best Regards,Nick

Share this post


Link to post
Share on other sites

Some airlines will "tanker fuel" (carry enough for return trip) if takeoff/landing weight allows on short legs. The reason is that sometimes it's cheaper to carry the fuel due to a higher fuel price at the turnaround airport. We used to do this in the DC-9 quite often and I do it in my Baron now when flying into large airports where the price of fuel is inflated.Ed Weber a,k,a tallpilot

Share this post


Link to post
Share on other sites

Good point, economics sometimes beats regulations.Some charter airlines often do it when flying to say some small Greek islands where fuel service is either spotty or prices are inflated.I recall for example that when Polish LOT was deciding between Airbus 310 and B 767 in 1988 they ultimately selected the latter since it could carry more fuel on their Warsaw-Chicago trips and they could still get below-market fuel prices from Russians at that time. So they wanted to buy as little fuel in Chicago as possible.Michael J.http://www.reality-xp.com/community/nr/rsc/rxp-higher.jpg

Share this post


Link to post
Share on other sites

Hey,I guess I should clarify my post above...Saying that Extra fuel served little purpose beyond making the pilot feel better (and costing the company money), obviously leaves out the possibility of a calculated decision from Management to tanker fuel due to cost or other operational considerations. I mistakenly ommitted that part... :)I'll stick to my guns regarding the rest of my statement, though! :-lol When a captain shoots from the hip, and decides he "wants" another 1, 2, or 4000lb of additional fuel, 9 times out of ten, that aircraft will arive downline with that extra fuel still on board. Now, that's not to say there's never a reason for a flightcrew to want more fuel. There are plenty of times when this is totally justified. However, I saw a good example not too long ago. I don't recall the specific numbers, but let it suffice to say this: If every flight of a major carrier took off with as little as 1,000lb of unneeded fuel, at the end of 1 year, the cost to that airlines is several million dollars. You would have accomplished the same thing by adding 1,000lb of concrete as ballast. Just food for thought... ;)Best Regards,Nick

Share this post


Link to post
Share on other sites

Do you fill the Aux tanks first and then the mains? or is it the other way around?I have always wondered that and since were talking about fuel amounts I though I would ask.Neat stuff :)Thanks

Share this post


Link to post
Share on other sites

Ihor,That would depend entirely on what airplane you're talking about. Tank configurations and fueling methods vary widely from one manufacturer to another, and from one type to another.For instance, in most aircraft, wing tanks are fueled until full, followed by the center tank. However, some aircraft like the 727 will fuel all tanks simultaneously. Once the wings are full, the remaining fuel load is put into the center tank (which has a higher capacity than the wings). Even the A321 has an ACT or "Additional Center Tank", which is filled last.And not to be outdone, larger aircraft like the 747, L1011, DC-10, MD-11, and wide-bodied Airbuses have additional combinations of Auxilliary, Reserve and Stabilizer tanks. The fueling methods and capacities vary widely among them. But in general, Main (wing) tanks are filled first, followed by the Center tank.Again, the process is really aircraft specific. So if you have one in mind, I'm sure we can find the real answer for you.Regards,Nick

Share this post


Link to post
Share on other sites

Nick, Thanks thats just what I was looking for. I should have said Wing and center not Aux and main but your answer covers it and more!ThanksTime to go and fill up!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this