Quick question on the fuel system coding

[Dudley Henriques]

Understanding that the 230 centerline tips should always be selected on after engine start due to the pressurization issue..............
Assuming a full fuselage tank when starting, did you code to reflect the fuel burn rate even at idle to overcome the fuel transfer rate from the tips so that no overflow will occur out from the Sabre drain?
Many thanks

DH
 

[ericnelson7]

This might be a good time to mention the current (1.01) engine start procedure doesn't follow reality.  The USAF manual requires all fuel switches off for start, and only the "starting fuel" switch provides feed. In the current sim version, the engine won't start without the fuselage tank switch on, and the starting fuel switch seems to have no function. It would be enjoyable to start the jet as specified. The "starting fuel" switch guard should open farther and expose the switch for better control, especially for VR users.

Also note fuel switch lights in reality cannot be tested unless the switch is on, and as usual with press-test lights, a light currently on should go off with press.

 

[Dudley Henriques]

28 minutes ago, ericnelson7 said:

This might be a good time to mention the current (1.01) engine start procedure doesn't follow reality.  The USAF manual requires all fuel switches off for start, and only the "starting fuel" switch provides feed. In the current sim version, the engine won't start without the fuselage tank switch on, and the starting fuel switch seems to have no function. It would be enjoyable to start the jet as specified. The "starting fuel" switch guard should open farther and expose the switch for better control, especially for VR users.

Also note fuel switch lights in reality cannot be tested unless the switch is on, and as usual with press-test lights, a light currently on should go off with press.

 

I figured since the starting fuel switch has no function there had to be some "licence" taken with the way the fuel system was coded. What I am asking with my question to the devs is whether or not when they coded the system they accounted for a full fuselage tank when asking for the tip transfer switch to be ON after engine start. (Which is normal for the T33)
Reason for the question is to deal with any confusion when reading in the manual that any fuel transfer has to be watched so as not to have overflow in the fuselage tank.
In other words the reader might ask after reading the supplied manual and the way it has been written........"will I cause overflow if I open the tip tank transfer pump after engine start if the fuselage tank is already full"?
Just a potential point of confusion that might require some clarification.
The reality for this situation (actual T33) I believe is that the fuel burn rate (even at idle) for the J33 engine is more than high enough to handle the transfer rate of the fuel pumps even with ALL the pumps operation. So there should never actually be a situation where fuel is being emptied out through the Sabre drain.
In fact I think that if there actually IS fuel being drained out through the Sabre drain that might very well be of enough concern to cause an engine inspection.
I wasn't sure of this so in fact ran it by several friends who are operating T33's currently.
No big thing here really. Just a bit of possible confusion after reading the manual for the sim T-Bird.
DH 

Edited September 9 by Dudley Henriques

[richboy2307]

Hi DH,

14 hours ago, Dudley Henriques said:

Assuming a full fuselage tank when starting, did you code to reflect the fuel burn rate even at idle to overcome the fuel transfer rate from the tips so that no overflow will occur out from the Sabre drain?

Thanks for your question. The answer to this is Yes. The fuel won't vent simply when the FUSE tank is full. There is an additional condition that ALL the tanks are also turned ON at the same time for fuel venting to occur.

7 hours ago, Dudley Henriques said:

Reason for the question is to deal with any confusion when reading in the manual that any fuel transfer has to be watched so as not to have overflow in the fuselage tank.
In other words the reader might ask after reading the supplied manual and the way it has been written........"will I cause overflow if I open the tip tank transfer pump after engine start if the fuselage tank is already full"?
Just a potential point of confusion that might require some clarification.

Allow me to clarify below, and also illustrate via a video that I made for a similar support query submitted on our discord:

Quote

The plane only burns 0.1 gallons per second at idle. This "rate of burn" remains the same no matter which tank is being used.

The Weight & Balance window will show an "accelerated" rate when any of the AUX tanks are turned on, which is simply the "rate of transfer" and NOT an accelerated "rate of burn". This accelerated "rate of transfer" will be seen only when either...

• Fuel is being transferred from the selected AUX tank to the FUSE tank, until the point when FUSE tank is full. When the FUSE tank is full, the rate slows down to the "rate of burn" (0.1 gallons per second) from the selected AUX tank, whilst the FUSE tank remains full.
  
  Fuel will not vent in this scenario where only FUSE tank + one of the other AUX tanks are ON. So you can keep the "TIP / WING / L.E." tanks ON together with the FUSE tank without fuel venting happening as soon as the tank fills up.
   
• Fuel is being transferred overboard aka "fuel venting" is happening. This ONLY happens when ALL the tank pumps are on at the same time & the fuselage tank is already full. This is when you'll see all the tanks draining at accelerated values, as basically you're dumping fuel. The fuel vent light will also be on in this case.
  
  

Thanks!

[richboy2307]

8 hours ago, ericnelson7 said:

The "starting fuel" switch guard should open farther and expose the switch for better control, especially for VR users.

Also note fuel switch lights in reality cannot be tested unless the switch is on, and as usual with press-test lights, a light currently on should go off with press.

Thanks for the feedback, will share with our Team.

Thanks!

[einherz]

in manual for this model i found tip tanks have to be on for be sure we got enough... however i check that in the simulator, open fus and tips before engine start open load window and found nothing go down, so two pumps not overpush anything. however if i was care enough fuel press show same number with one or two or even with only normal position for fuse and everything else off. anyways. i just take 100% fuel, after start engine set fus and tips and i can fly as long as i want high of course. about pressure when we use pump and got more fuel flow from tanks then burn,  system can handle that if not all of them turned on. it's looks like our water system for wash machine, better take water switcher close for the machine's system wasn't under pressure, but we can live with it opened. if in the our water pipe lines pressure would be too high in that situation we just must open main switcher only when the machine works... so ideal in the star is use only fus, and when it go to empty add some from tip tanks, and then when it go to close to full switch tip tanks off, till it will empty and then use other tanks.. but we can use any 3 all the way... if we talking about speed of fuel flow from the pump it must be some faster than fuel burn, for fus tank will full all time, ideal way if fuel pump will use dynamic speed that will just a bitt more than current burning speed. any way i guess, if we got constant speed of fuel flow from tanks, it's must be very close to max burn speed on sea level and 98% for pilot be sure engine will got fuel in all situation so long as count for only fus tank, fus+tip, fus+other one or two or both types of tanks. with or without fuel counter when numbers of gallons run in. as it works in real, i have no idea:)

[Dudley Henriques]

10 hours ago, richboy2307 said:

Hi DH,

Thanks for your question. The answer to this is Yes. The fuel won't vent simply when the FUSE tank is full. There is an additional condition that ALL the tanks are also turned ON at the same time for fuel venting to occur.

Allow me to clarify below, and also illustrate via a video that I made for a similar support query submitted on our discord:

Thanks!

 

Excellent video. I believe this makes everything much clearer for everybody.
May I suggest you put this up on your website so all can view it?
Many thanks for your time.
DH

[richboy2307]

11 hours ago, Dudley Henriques said:

May I suggest you put this up on your website so all can view it?

Thanks. I'll add it to the FAQ: 

https://forum.inibuilds.com/forum/455-faqs/

[CF104]

Just adding some technical information as the fuel feed system is NOT working as it does in real life. 

With no mechanical failures, you can have the tip tanks , LE tanks, Wing tanks and fuse tank pumps all on without venting fuel overboard. There are 3 fuel supply float valves in the fuse tank for each wing group. These float valves are placed at different levels in the fuse tank to provide feed priority to the fuse tank as follows; #1 tip tanks, #2 LE tanks, #3 wing tanks. This means that with all pumps on (gang loaded), the tips feed until empty, then the LE tanks will feed until empty followed by the wing tanks until empty. This all happens automatically due to the float valves and there will not be any venting overboard even with all the pumps on. Gang loading the pumps is not a usual procedure but will NOT result in venting. With the 3 float valves working properly there is no way to overfill the fuselage tank and cause venting. The only way to get fuel venting through the sabre drain is if one or more of the 3 float valves in the fuselage tank has failed, a LE tank or wing tank check valve and boost pump is failed or through unusual attitudes. 

The information on the way it is currently modelled had to come from somewhere but my experience and training on the CT-133 say otherwise..

Cheers,

John

 

 

[Dudley Henriques]

6 minutes ago, CF104 said:

Just adding some technical information as the fuel feed system is NOT working as it does in real life. 

With no mechanical failures, you can have the tip tanks , LE tanks, Wing tanks and fuse tank pumps all on without venting fuel overboard. There are 3 fuel supply float valves in the fuse tank for each wing group. These float valves are placed at different levels in the fuse tank to provide feed priority to the fuse tank as follows; #1 tip tanks, #2 LE tanks, #3 wing tanks. This means that with all pumps on (gang loaded), the tips feed until empty, then the LE tanks will feed until empty followed by the wing tanks until empty. This all happens automatically due to the float valves and there will not be any venting overboard even with all the pumps on. Gang loading the pumps is not a usual procedure but will NOT result in venting. With the 3 float valves working properly there is no way to overfill the fuselage tank and cause venting. The only way to get fuel venting through the sabre drain is if one or more of the 3 float valves in the fuselage tank has failed, a LE tank or wing tank check valve and boost pump is failed or through unusual attitudes. 

The information on the way it is currently modelled had to come from somewhere but my experience and training on the CT-133 say otherwise..

Cheers,

John

 

 

This jives completely with my information coming from current operators of a T33.
My source tells me that ANY venting through the Sabre Drain is considered a major engine issue possibly requiring serious maintenance.
Dudley Henriques

[CF104]

1 minute ago, Dudley Henriques said:

This jives completely with my information coming from current operators of a T33.
My source tells me that ANY venting through the Sabre Drain is considered a major engine issue possibly requiring serious maintenance.
Dudley Henriques

Sabre drain venting is more of an airframe issue and not the engine. As a fuel user, the engine doesn't have influence over the fuel vent system. Regardless, fuel venting will require taking a lot of things apart to fix.

Cheers,

John

[Dudley Henriques]

5 minutes ago, CF104 said:

Sabre drain venting is more of an airframe issue and not the engine. As a fuel user, the engine doesn't have influence over the fuel vent system. Regardless, fuel venting will require taking a lot of things apart to fix.

Cheers,

John

Let's just omit the word "engine" and simply call it a Maintenance issue.
DH

[CF104]

2 hours ago, Dudley Henriques said:

Let's just omit the word "engine" and simply call it a Maintenance issue.
DH

No Worries. I just love waking up the old grey matter to remember the CT-133. It's a very simple jet compared to what I have worked on.

Cheers,

John

[CF104]

On 9/10/2024 at 12:45 AM, richboy2307 said:

Thanks for your question. The answer to this is Yes. The fuel won't vent simply when the FUSE tank is full. There is an additional condition that ALL the tanks are also turned ON at the same time for fuel venting to occur.

I'm curious as to the information you have regarding this. IRL, if this were to happen, the jet would be grounded to fix the problem. 

If this is from a civilian operator of a T-33, then their jet needs some work.

Cheers,

John

[CF104]

On 9/10/2024 at 10:51 PM, richboy2307 said:

Thanks. I'll add it to the FAQ: 

https://forum.inibuilds.com/forum/455-faqs/

Hello,

Just wondering if anybody from INI Builds is monitoring this thread? I added some relevant information regarding the T-33 fuel system but it appears this thread is in radio silence.

Cheers,

John

[Dudley Henriques]

13 hours ago, CF104 said:

Hello,

Just wondering if anybody from INI Builds is monitoring this thread? I added some relevant information regarding the T-33 fuel system but it appears this thread is in radio silence.

Cheers,

John

I'm not certain but I believe they are "moving on" .  

 

[Dudley Henriques]

Why there is an edit restriction for people posting on this forum is beyond me. The result for me anyway has been totally negative. 
I bought the plane. I like the plane. But I'll be "moving on" from the T33 due to a seeming lack of interest from Inibuilds and disgust at the editing policy here.
I just don't have the time to devote to non-productive activity.
Sorry. Looks like we both lost on this one.
DH

[Eddie]

Hello,

We read the feedback and any suggestions made and take it on-board, but may not always acknowledge that we've done so, but rest assured that you are heard. The team has their hands full with many projects but this does not mean we have "moved on" from the T-33. We see it in a stable position at the moment however that does not mean we've abandoned the product. I obviously cannot speak on any future updates until they are published. 

As for the "editing policy", I'm not sure I understand what you mean exactly. We have limited users from editing to deter any follow-up troll editing and such. We can however revisit this policy and look into changing it in the future, but no promises as that is a decision that involves how we moderate the forums. 

Thank you

[Dudley Henriques]

22 minutes ago, Eddie said:

Hello,

We read the feedback and any suggestions made and take it on-board, but may not always acknowledge that we've done so, but rest assured that you are heard. The team has their hands full with many projects but this does not mean we have "moved on" from the T-33. We see it in a stable position at the moment however that does not mean we've abandoned the product. I obviously cannot speak on any future updates until they are published. 

As for the "editing policy", I'm not sure I understand what you mean exactly. We have limited users from editing to deter any follow-up troll editing and such. We can however revisit this policy and look into changing it in the future, but no promises as that is a decision that involves how we moderate the forums. 

Thank you

No problem at all. It's just that this "intermediary stuff" just doesn't work for me. "I'll inform the team" I'm sure works well at your end but it's just not my thing.
Perhaps the problem is that I don't seem to fit very well in the "user" category.   LOL.    :-)))))))))))
Anyway, no harm done. I'll be passing on the T33 while at the same time wishing you and "the team" the very best.

Dudley Henriques
 

[CF104]

6 hours ago, Eddie said:

Hello,

We read the feedback and any suggestions made and take it on-board, but may not always acknowledge that we've done so, but rest assured that you are heard. The team has their hands full with many projects but this does not mean we have "moved on" from the T-33. We see it in a stable position at the moment however that does not mean we've abandoned the product. I obviously cannot speak on any future updates until they are published. 

As for the "editing policy", I'm not sure I understand what you mean exactly. We have limited users from editing to deter any follow-up troll editing and such. We can however revisit this policy and look into changing it in the future, but no promises as that is a decision that involves how we moderate the forums. 

Thank you

Thank you for responding.

As someone who takes the time to report bugs, and yes the fuel system is bugged, as well as provide some in depth knowledge and reasoning behind such a report I do find is a bit disingenuous that there is no acknowledgement of the content. A simple thank you for the information and that it's been forwarded to the devs would suffice.

I read into the statement "We see it in a stable position at the moment however that does not mean we've abandoned the product.", that INI Builds is stating that the product meets its promises. I highly disagree by quoting the following from your product page. "The in-depth, realistic systems simulations allow you to dive deep into its intricacies, from avionics to engine management.". Both the fuel system and RR engine don't meet the "in-depth and realistic" part of the statement. 

I've been working on aircraft for 42 years, including the CT-133, and can honestly state that the T-33 is a stupid simple aircraft. It shouldn't be too hard to get it right. I don't mind buying a product in initial release but it feels like this one was rushed.

Regards,

John