Jump to content
Sign in to follow this  
tamsini

What would happen if you add fuel to FMS mid-flight

Recommended Posts

Hi all, just wondering, in the real-world, what would happen on a real-world flight if you try to add fuel in the FMS of a Boeing or Airbus? Obviously, there wouldn't be any fuel added to the aircraft (😁 ) so I assume it would wreak havoc on fuel calculations.

I just find it a bit silly that you can do so in our sim-world. Why can't the developers (especially the big guys) disable this feature once a flight begins?


Mario Di Lauro

Share this post


Link to post

Hardly anything.  Just do it - its a simulator.

 

Cheers
bs

  • Like 1

AMD RYZEN 9 5900X 12 CORE CPU - ZOTAC RTX 3060Ti GPU - NZXT H510i ELITE CASE - EVO M.2 970 500GB DRIVE - 32GB XTREEM 4000 MEM - XPG GOLD 80+ 650 WATT PS - NZXT 280 HYBRID COOLER

Share this post


Link to post

Why does it need to be disabled?  if you think it shouldn't be used inflight, then don't.

Sometimes folks either get the fuel planning wrong, or maybe the winds used by a fickle flight planner are way off.  No need in a simulator to force them to crash once they see there's a problem.  Of course if you want to be held accountable...leave the fuel load alone and take your lumps.

Also, the ability to set a fuel load mid-flight makes it possible to warp ahead on long legs, and then reduce the fuel load at the other end accordingly...in this case changing the fuel load means reducing it rather than adding fuel.

Regards


Bob Scott | President and CEO, AVSIM Inc
ATP Gulfstream II-III-IV-V

System1 (P3Dv5/v4): i9-13900KS @ 6.0GHz, water 2x360mm, ASUS Z790 Hero, 32GB GSkill 7800MHz CAS36, ASUS RTX4090
Samsung 55" JS8500 4K TV@30Hz,
3x 2TB WD SN850X 1x 4TB Crucial P3 M.2 NVME SSD, EVGA 1600T2 PSU, 1.2Gbps internet
Fiber link to Yamaha RX-V467 Home Theater Receiver, Polk/Klipsch 6" bookshelf speakers, Polk 12" subwoofer, 12.9" iPad Pro
PFC yoke/throttle quad/pedals with custom Hall sensor retrofit, Thermaltake View 71 case, Stream Deck XL button box

Sys2 (MSFS/XPlane): i9-10900K @ 5.1GHz, 32GB 3600/15, nVidia RTX4090FE, Alienware AW3821DW 38" 21:9 GSync, EVGA 1000P2
Thrustmaster TCA Boeing Yoke, TCA Airbus Sidestick, 2x TCA Airbus Throttle quads, PFC Cirrus Pedals, Coolermaster HAF932 case

Portable Sys3 (P3Dv4/FSX/DCS): i9-9900K @ 5.0 Ghz, Noctua NH-D15, 32GB 3200/16, EVGA RTX3090, Dell S2417DG 24" GSync
Corsair RM850x PSU, TM TCA Officer Pack, Saitek combat pedals, TM Warthog HOTAS, Coolermaster HAF XB case

Share this post


Link to post
13 minutes ago, bean_sprout said:

Hardly anything.  Just do it - its a simulator.

 

Cheers
bs

Hey Bean, what I'm saying is, I know we can do it in the sim but shouldn't it be made so we CANNOT do it?


Mario Di Lauro

Share this post


Link to post
1 hour ago, tamsini said:

Hey Bean, what I'm saying is, I know we can do it in the sim but shouldn't it be made so we CANNOT do it?

I think Bob’s answer below is the best choice. Just because you can do it doesn’t mean you have to or should. Just pretend the option isn’t there to do it. After all, we’re pretending to be flying.

 

1 hour ago, w6kd said:

Why does it need to be disabled?  if you think it shouldn't be used inflight, then don't.

 

 


Avsim Board of Directors | Avsim Forums Moderator

Share this post


Link to post

Agreed.  Freedom.  If you run out of gas, and just because you CAN refuel along the way, there is no pressure in doing so.  Let your poor calculations play out and crash and restart the flight from scratch with better planning.   It's simply a self-control issue.  I've suffered this myself, hey it happens...most of us didn't go to flight school.  I choose to die and restart each time.

Mark

 

  • Upvote 1

Share this post


Link to post

.....or Divert... it happens in the real world... unforecast fog etc


FAA ATP, CASA ATPL(A), MEIR, NVFR, Type Rated: A320, B747,B737, E120, B1900D/C KA350,

Multi Ratings: PA31-350, BE58, C310, PN68, PA44, BE76.

Checked out on: C210, R114, C206, PA28, C172, C152.

Processor: Intel(R) Core(TM) i9-7900X CPU @ 3.30GHz (20 CPUs), ~3.3GHzMemory: 64MB RAM, NVIDIA GeForce RTX 3080 Ti, Multi Monitor.
 

Share this post


Link to post
4 hours ago, toucanair said:

.....or Divert... it happens in the real world..

Exactly, its a fun challenge as well


Eric Anderson

Share this post


Link to post

I did it once when I really didn't pay attention to my planning.  

Nothing really happens - the aircraft balks a little form the added weight, but settles down pretty quickly.  The weights are readjusted.   Clearly you wouldn't go from near empty to near full.  I assume the only situation where you would want to add additional fuel is if you just want to add an extra margin which is no big deal.

Or,  the best option as @toucanairmentioned, it to play the part for real -  and divert.  Much more interesting

Share this post


Link to post

I mean that you somehow compare apples to oranges here. Real world planes don't have the same FMC Omption like a PMDG (or any other) plane. This part is only for the simulator to fill your payload and fuel.

If you enter something in the "real" part of the FMC, I expect the same results as in the real world, which is a wrong calculation.

I can't recall a payware aircraft where fuel and weight are controlled over the "normal" FMC.


Georgian Virtual Airports (UGMS Mestia / UGGT Telavi / UGAM Ambrolauri)
 
 

Share this post


Link to post

Or you can consider the option to add fuel as a way to replicate in-flight refuel. B737 has that ability (the navy variant called Poseidon) and A330s can do it too (the tanker version). 

No harm in enlarging the scope of the simulation. As others have said it's all about the user freedom. Use it or leave it. But even if an option seems unrealistic today (10 years ago no 737 or A330 could refuel in-flight) it doesn't mean that we have to forbid the user to do it. Sometimes reality catches up!

Share this post


Link to post

Interesting array of responses. I would have thought, for a full immersion experience, having the freedom to add fuel at FL360 would be a no-no.


Mario Di Lauro

Share this post


Link to post
3 minutes ago, tamsini said:

Interesting array of responses. I would have thought, for a full immersion experience, having the freedom to add fuel at FL360 would be a no-no.

Your plane, your sim, your rules.    

Pausing the sim is also possible mid-flight.  Completely immersion shattering, but doesn't mean it is a used option.  Where would one draw the line?

  • Like 1

Share this post


Link to post
11 minutes ago, ErichB said:

Your plane, your sim, your rules.    

Pausing the sim is also possible mid-flight.  Completely immersion shattering, but doesn't mean it is a used option.  Where would one draw the line?

Good point. 


Mario Di Lauro

Share this post


Link to post

In the aircraft I fly, throughout the flight I am updating the FMS with the current fuel on board. The fuel flow sensors within the FMS and the analog gauges we have in the engine stack can be off sometimes and I will update the fuel with the actual fuel on board to get a better idea of how much I will have at my destination. 

 


Nick Hatchel

"Sometimes, flying feels too godlike to be attained by man. Sometimes, the world from above seems too beautiful, too wonderful, too distant for human eyes to see …"
Charles A. Lindbergh, 1953

System: Custom Watercooled--Intel i7-8700k OC: 5.0 Ghz--Gigabyte Z370 Gaming 7--EVGA GTX 1080ti Founders Edition--16GB TridentZ RGB DDR4--240GB SSD--460GB SSD--1TB WD Blue HDD--Windows 10--55" Sony XBR55900E TV--GoFlight VantEdge Yoke--MFG Crosswind Pedals--FSXThrottle Quattro Throttle Quadrant--Thrustmaster Warthog HOTAS--TrackIR 5--VRInsight MCPii Boeing

Share this post


Link to post

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  
  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
×
×
  • Create New...