Boeing 727-100C Fuel randomly resets to 100%

[biggiraffe]

Good Morning,

Now and then, I've noticed that the fuel quantity somehow gets reset to 100% at the end of a flight.  I only experience the problem in the 727-100C, and not every flight.  Today, I thought it was because the "Parking Brake" was set, because the quantity remained set once I left the gate.  However, today it reset after landing, though I was careful not to use the Parking Brake.  Has anyone else experienced this?  Am I inadvertently hitting a command that "refuels" the aircraft?

Thank you,

Kurt

[aerofoto - HJG Admin]

There's nothing within the simulation (that we provide at least) that'll result in any "auto-fuel reset".

In FS though .... if one parks at/near any fuel facility (at most virtual airports) upon the conclusion of one's flight, then, the fuel will typically "auto-reset" using any simulation and not just ours .... this's a known FS function

Whether or not this requires the brakes to be applied and engines shutdown first (it probably does) .... I know not

As I mentioned at the start .... there's nothing provided, by us, with the simulation (FDE or panel/gauges) that would account for what you're saying, so, it's quite likely that what I've suggested "may" well be the instigator of what you're describing.

Our simulations (all of them .... and not just the B727-100C) load into FS with 100% fuel and payload. The "full certified capacity" of each aircraft type (in accordance with the best official technical data we obtain, but, which can vary from sources) is worked into each of our W&B and FUEL configurations. This results in a nominal overload for each simulation .... and which is "perfectly normal" under such circumstances (otherwise we'd be providing just a typical loading only as most other groups/producers do .... whereas what we do enables more realistic flight planning to be undertaken especially in regard to distances). The end user is then expected to adjust either fuel, or payload, or both, in accordance with the requirements of their flights (reduce payload to promote fuel loading for range .... or .... reduce fuel loading to promote payload for less range .... or if one wishes .... one can reduce fuel load "only" whilst making no adjustment/s "at all" to payload (and which is my typical "test configuration" as outlined within my basic flying guides on this forum) .... and either option in order to ensure each simulation is set at/near its certified MGW.

We provide the choices aimed at promoting flexibility of flights, but once again, "nothing we provide or recommend" will result in an "auto-fuel reset.

Typically .... and unless parked at, or near, any FS fuel facility .... the fuel indication/s "after" engine shutdown will/should always indicate only what remains "after each flight" .... but .... these won't/can't reset.

Mark C
AKL/NZ

[biggiraffe]

Good Evening - Thank you, Mark!

Parking next to the fuel facility was, indeed, the problem. The reason I only saw it on the 727-100C is because of the type of flying... For most aircraft, I was doing the typical airline flight: Leave from a terminal gate and arrive at another gate. There were no fueling stations in the area. But on these flights that scrambled my load (727-100C), I was flying out of, and to, remote airports in northern Canada or in Australia. Parking would be right at the fuel station, thus resetting my load. I never paid attention to the fueling stations before and did not even know they would do that!

Now I will go find a way to turn that function off; either that, or check my end-of-flight fuel before coming to a complete stop.

Best regards,

Kurt

(By the way, I've been using the fuel load to get my desired gross weight since changing the fuel percentage is faster than adjusting all the payload blocks.  Most of the time the flights are short enough that there is still plenty of fuel left.  For the longer flights, I do vary the payload.)

[aerofoto - HJG Admin]

I will go find a way to turn that function off

I don't believe that's possible .... because, so far as I'm aware, it's a default function of FS itself.

I've been using the fuel load to get my desired gross weight

That's pretty much what I do too mostly (adjusting fuel loading only .... as per my forum based basic flying guides), but, seldom ever adjusting payload.

When I'm in the right mood .... I like to flight plan .... by taking the fuel I nee to get where I want to go, plus reserves, or occasionally planning my fuel loads to destination "and all they way back too" with the appropriate reserves.

All of this is "very practiceable" using any of the HJG simulations .... due to our desire to compile 100% fuel and payloads into each of our simulations .... for the end user to then adjust, as they need to, in order to suit the requirements of their intended flights.

Mark C
AKL/NZ

[biggiraffe]

Turns out (that is -- ME still learning) it's a bit more of a challenge to avoid fueling stations because not all are visible. So when I fly into those small airports, I guess I'll avoid parking next to buildings if I need the "after" fuel load. Anyway, this morning I successfully made the flight without losing my fuel load numbers - Thanks!

I used to watch Air California 737's and PSA 727's fly in and out of San Jose. They didn't often refuel there, so I knew they loaded the airplanes with enough fuel for several flights, thus saving lots of turnaround time. Air California, for example, usually turned their planes in 10 or 15 minutes.

Later in life, I learned that transport aircraft are designed so the Center of Gravity can vary by quite a bit without harming the flight characteristics.

All that to say: I agree it doesn't harm the realism by adjusting the fuel and not the payload. I "estimate" a gross weight range for each flight based on whether I think it would be a full passenger load or something less, adjust the fuel, and go fly.

Best regards,
Kurt

[aerofoto - HJG Admin]

We find a W&B influenced COG position located anywhere between the center wing position and wing LE (as displayed per the FS based W&B schematic) is fine .... it doesn't upset flight profiles too much if at all.

With some simulations though (as is true in the case of our B707/720/C135's) as the COG drifts forward .... usually on the basis of fuel spent .... it can then influence ground profiles slightly (compressing the NG strut and/or wheels into the scenery). Some things we can correct easily (per the like of payload and fuel recommendations) .... other things are more difficult to address completely .... whilst yet other things we have to have live with (to some extent).

What "WILL" (without question) disrupt both ground and flight profiles/stability though is an unevenly distributed fuel loading.

that is -- ME still learning

If it's any consolation .... as good as some of are even we're still learning some things in FS .... hence the like of our recently previewed B707/C-135 and MD-80/90 FDE updates which are still progressing

Mark C
AKL/NZ

[biggiraffe]

I have also done quite a few flights in the HJG 707-320B and 720B. When I adjust the fuel load for my takeoff weight, I use the same percentage on all fuel tanks (same technique I use with the other aircraft). This isn't technically correct since the center fuel tank is supposed to be burned off first, but it works fine.

As I understand it, the Boeing 707 has always been kind of "on the margin" on yaw stability. As the CG goes aft, the fin and rudder become less effective, so aft CG has to be watched. The addition of the "canoe" under the front of the E-8 JSTARS, which are all former 707-300C aircraft, further reduced the stabilty, though flight testing proved that the aircraft is safe when flown with CG limits (But then, that is true of all aircraft, isn't it?). When one E-8 was designated as a "trainer" and all the electronics removed, the decision was made to put ballast in the front cargo compartment to achieve the empty CG of the E-8C models rather than spend money flight testing to get a new CG range for a single aircraft.

Have a good evening,
Kurt

[aerofoto - HJG Admin]

As the CG goes aft, the fin and rudder become less effective

I suspect you might be making reference to the problem/s that occurred with the original short tail series B707's .... and prior to 1961 .... after which point they were modified with tail extensions and ventral fins following the 1959 pre-delivery "prang" of a BN B707-220 during an acceptance flight.

With our B707/720/C-135 simulations .... the COG, subject to fuel depletion, tends to want to drift forward .... and even in the case of COG that's "set up" more aft, than forward, it doesn't seem noticeably upset flight characteristics too much .... although such an aft focused W&B configuration isn't recommended for any MGW TO since it will tend to result in pitch/climb/acceleration related difficulties that can't easily be resolved .... even even when applying max power (if the AI pitch attitude exceeds 10* with these simulations and whilst at/near MGW .... then .... one's going to end up in "real trouble" ).

The "NEW" B707/720/C-135 FDE which we're currently drafting up for these simulations (those for the latter are already finished and pending release .... subject to the completion of another associated "SURPRISE") are "VASTLY SUPERIOR" to what's currently/publicly downloadable here at the moment, but, even as good/"BETTER" as these are .... we can't replicate all flight characteristics with absolute precision simply because the M$FS host program doesn't provide sufficient/all of the necessary parameters for us to be able to manipulate or otherwise exploit.

You can read a wee bit about these FDE upgrade projects per our following forum links ....

C-135 SERIES
tonymadgehjg.proboards.com/thread/9817/135-modifications

B707/720 SERIES
tonymadgehjg.proboards.com/thread/9822/b707-720-modifications

The currently downloadable FDE for these simulations (only) is, IMHO, "embarrassingly poor". This shouldn't be the least bit surprising though .... considering "NONE" of these B707/720/C135 simulations have ever undergone any FDE redevelopment since 2006/7 .... and what was done way back then was only sufficient to ensure the panels we offer all worked well with each of these simulations.

As I mentioned/hinted with this thread yesterday .... "even we're still learning new tricks" .... and the absolute truth is that way back then (around 2006/7) we simply didn't know how to do what we now know how to do with relative competence

Mark C
AKL/NZ

[biggiraffe]

I'm looking forward to the new FDE's, and I appreciate all the work you are putting into them. Flying the 707 with more accurate characteristics will be fun!

Best regards,
Kurt

[aerofoto - HJG Admin]

Flying the 707 with more accurate characteristics will be fun!

I prefer to call it "superior/better" flight dynamics .... given the word "accurate", in FS, can be something of a "misnomer" due to the lack of fidelity designed into certain aspects of the host program.

Even so .... a greater degree of "accuracy" is being realized (given how one B707 version performs in comparison to another) through what's slowly being achieved.

These FDE are/will be "MUCH BETTER".

Mark C
AKL/NZ

[biggiraffe]

Sounds good to me -- Flying with improved/superior/better flight dynamics will be enjoyable!

The flight simulator I really enjoyed was "Flight Assignment: ATP" by Sublogic. Though I'm not a pilot (aside from getting my glider pilot license long ago), I have read books about flying (including "Handling the Big Jets") and was quite please how "ATP" really cut down the 737's climbing at high altitude, or would not let you take a fully-loaded 747 to 41,000' until you burned off lots of fuel. That's one aspect of FS2004 that I haven't liked... The aircraft climb so happily at high altitude, or fly much too slowly without losing altitude.
Kurt

[aerofoto - HJG Admin]

Flying with improved/superior/better flight dynamics will be enjoyable!

It certainly will be .... make no mistake about that

I'm not a pilot (aside from getting my glider pilot license long ago), I have read books about flying (including "Handling the Big Jets")

That's where , and how, it all starts and there's "nothing wrong with that .... and one doesn't need to be a pilot to appreciate or understand aviation and flying

I'm not a pilot either .... and only one of us within this group is "professional air crew" .... BUT .... whether we're pilots/professional air crew, or not, the common denominator among us all here, both group and community-wise, is our interest in aviation and enthusiasm for both FS and other aviation hobby/ies that unites us.

Having come from THALION SOFTWARE's "A320 AIRBUS" during the very early 1990's, I had SUB-LOGIC's "ATP" too, but, almost just as quickly migrated to MSFS .... and where I've remained through each of it's successive evolution's, as of up to FSX at least, but, I "WILL NOT" be migrating to FS2020 .... a decision I made almost as soon as the latest FS version was announced since I've got "ABSOLUTELY NO INTEREST" in it, at all, after some 30 years of this hobby and 20 years of HJG representation.

What we like to do here, at HJG, is represent some of the best of past aviation classics .... and in doing so we've always "tried", since the early 2000's (think I'm the only member left now of the former/original HJG group .... which I discovered during 2000), is to not just represent "an aircraft type", but rather, to "try" represent it in respect of each of its often multiple sub variants too (where possible .... though sometimes such isn't always possible for us) .... both physically and performance-wise .... to simply "try'n" give those interested good representation, a decent understanding of the aircraft we represent, as well as "a taste" of what some of these great aviation classics were probably like to fly .... only in so far as all this's practical within the finite limits of FS itself.

This sort of development integrity is what attracted me to HJG during 2000 (where I started by becoming a research assistant for Michael VERLIN .... one of the founder members who's association with HJG predates my own) .... and it's also "the only reason" why I've remained with this group (through fair and foul weather) all these years since

I'm not saying, and have never implied, that what we do here is the best (HJG "will" eventually be superseded .... and that's a simple fact of both FS life and IT development), but, I will say that "up until now" we've probably done it "a little better/more thoroughly" (meaning with greater emphasis of accuracy .... in so much as such can be achieved) than most .... and which has been half of both the "frustration and fun" of it all along the way .... in so far as my own involvement with it at least and over these past 20 years

Mark C
AKL/NZ

[biggiraffe]

I do appreciate you folks who work the aircraft and flight models to give us good classic aircraft. I have never tried doing anything with the FDE, but I have delved into AI flightplans and repaints. When I fly, now, many of the 1970's-era airlines are around me. I bought many old airline timetables (mostly off ebay) and learned to program them into FS. And I have done many repaints, in a simplistic way (since I use Microsoft Paint, without all the special features of the paid programs). Maybe someday I'll learn to revise airports... One thing I'd like is to backdate SFO to the mid-70's.

Have a great weekend,
Kurt

[aerofoto - HJG Admin]

If you like back dated, or retro, sceneries .... Tom GIBSON (I'm sure you'll be aware because I've seen you over there) offers the best selection of these for FS .... only his offerings are representative of the 1950's and 60's era. For those that aren't already aware there's "a hell of a selection" (what I consider being "the best available") available here covering the USA and the world as follows ....

TOM GIBSON's CLASSIC AIRPORT SCENERIES
www.calclassic.com/scenery.htm

.... and some of which are "PERFECT" for the earliest of our B707/720, B727, CV-880, CV-990, and DC-8 liveries.

If fact I use a number of Tom's sceneries myself (and can therefore recommend them) .... as per my following African trip report of a couple of years ago ....
tonymadgehjg.proboards.com/thread/8576/boac-london-johannesburg-route-enactment

MArk C
AKL/NZ

[biggiraffe]

Yes, I sure do enjoy the California Classics site that Tom operates! I downloaded Denver Stapleton, and the Southwest US scenery backdates, and enjoy flying the F-27 and Electra from his site (might try the CV580, one of these days). I grew up mostly in San Jose, and in junior high and high school I used to think it was great when a family member was headed up to SFO and I could talk them into dropping me off at the airport for a couple of hours. So that is probably my main reason for wanting SFO in the early to mid 70's (and LAX, which I visited a few times back then)... memories.

Kurt