Fueling procedure

[NorthwestOrient]

I really haven't been able to find a concise answer for this in the AFM so far, so I figured I'd ask here.  What exactly is the proper way to load the fuel?  I found one document stating that the main tank must always be filled first, then the outers, then the tips.  However, most videos I've watched even for short flights show the real aircraft with quite a lot of fuel in the tips.  Is it absolutely mandatory for them to at least have some fuel in them?

Say for example I used the Simbrief profile linked in another thread here and it calculates 1300 lbs of fuel for the flight that I'm planning.  By the procedure I mentioned, I would fill the main tank to the brim and then split whatever is left into the outers, and ending up leaving the tips empty.  Is this correct?  The default X-Plane slider instead goes in reverse, filling the tips first, then the outers, and finally the center, and I have a feeling that isn't exactly right, but I can always be wrong.

Just looking for some clarity.

[CaptCrash]

There is a fuel limitation in the MU-2 based on the ZFW cg of the aircraft, if it is nose heavy then you can only put fuel in the mains or mains and outers. You can find this information in section 7 of the manual i posted in this forum. If there is no fueling limitation applied then you should fill the mains first, then the outers, then the tips. There can be several reasons for this here are a couple major one.
1) if a fuel transfer system failure occurs the resulting imbalance roll moment is greatly increased if all the fuel is out on the tips.
2) In the event of a bleed system failure or leak in the tip tanks you may not be able to transfer fuel from the tip tank(s) Proceed to 1.
If you use the manual and go through the flight planning for section, you can get proper fuel numbers. I put a request into simbrief(Navigraph) to add the MU-2.
Below is an image of my weight and balance form for the MU2. For Flight planning I plan an average climb TAS of about 185knots and 670pph for climb (this is based on the book values, the TOGA MU-2 fuel burn is about 14% too low). for cruise the flight planning tables lay it out quite nicely, and if you are using my mod, your speeds will be spot on but the fuel flows are still 14% too low.

[mjrhealth]

YEs I found the xplane fuel system can do some random stuff with this plane, sometimes end out of balance, so I do hope the fueling panel system gets a quick look into, and i dont believe the question about xplane fueling was answered.

Edited August 18, 2022 by mjrhealth

[tkyler]

On 7/28/2022 at 10:49 AM, NorthwestOrient said:

Is it absolutely mandatory for them to at least have some fuel in them?

It is not.  Technically, you don't need any fuel in the outers or tips if you don't need that much fuel.  When we flew cargo, we would regularly put fuel in the mains and outers but not the tips, to make it a bit easier on ground crews (see below).  Ideally, you don't want any fuel in the tips at landing.   Since the fuel system transfers fuel to the main automatically, then its logical to fill up that tank first.  From there, the outers and finally the tips if you need that much fuel.

As far as loading the tips before the mains, the tips are slightly easier to access by ground crew than the mains, but a bigger PITA also as there is a limit to the imbalance between tips during fueling, so ground crew have to go back and forth between the tips multiple times, which is quite annoying......so we'd just request fuel in the outers to speed the refueling process and be 'kind' to the refueling crew.  Again, the end goal was to have no fuel in the tips at landing.  Since fueling is "virtual" in sim and you can't annoy real people, it makes no difference if you put fuel in the tips and not the mains...at least with regards fuel burn..the auto transfer system takes care of the details.  But certainly the roll handling will be a bit slower with fuel in the tips, but its not like the Moo is aerobatic.

TK