A-10C and A-10C II Kneeboard Suite - Updated 20 October 2023

[ASAP]

1 hour ago, jaylw314 said:

Would they even care about a wing tank imbalance?  AFAIK you could fly with one wing tank full and the other empty, the only prohibition is keeping the main tanks balanced to stay within CG limits, so it makes sense to keep the the fuel display on MAIN, with the TKS UNEQUAL warning light as a backup.

If you need to check the wing tanks when lead calls for an ops check, just flip it to WING and call 'wings dry' if they're empty.  It doesn't sound like the sort of thing to monitor continuously, unlike the main tank situation

 

1) it’s directed by an AFI.

2) Because a wing boost pump failure could result in a trapped fuel condition where you have thousands of pounds less available than what your totalizer is telling you. You want to diagnose that sooner rather than later so you don’t flame out an engine, or have to divert with a fuel emergency  

3) relying on a master caution as a first indication of a problem is not how the Air Force generally wants to fly their planes. Also the fuel unbalanced light only comes on once there is already a significant fuel imbalance. 

4)Also a wing tank not feeding is what’s going to cause the mains to become unbalanced.  And you’ll notice it faster by looking at the wing tanks.

5) Also you can see it earlier and fix it earlier if you look at the wing tanks.

6) if fuel isn’t feeding in your jet properly you have additional concerns than other than just the CG limits

7) two needles pointing at 3.5 for the first half the flight provides no useful information about what the fuel system is doing. Getting a real time indication of how much fuel is in the tanks feeding the engine is far more useful  

8)ops checks are mandated right before attacks and air to air engagements (at a minimum obviously, they are done every couple of minutes) those are all times pilots don’t want to have to make extra switch actuations for no real reason.  
 

9) if you have to flip a switch back and forth to get useable info every time you look at a gauge why wouldn’t you just leave it in the position that’s telling you what you want to know

10) again. It’s in an AFI. Pilots don’t have the option to ignore it. And if a wingman reaches wings dry prior to the flight lead calling for an ops check they are required to inform the flight lead. They can’t keep SA on how much fuel is in their wing tanks if their fuel gauge is pointlessly showing full main tanks all the time 

Edited April 18, 2023 by ASAP

[TAIPAN_]

It's funny in DCS though because many certainly do prefer the MAIN position, due to many MP servers setting the default fuel loadout with wing tanks empty because of the long endurance of the A10. Also due to the typically short flight distances we fly online, compared to real life.

Great kneeboards though thanks, and I often do use the WING position because I prefer to take my time and have plenty left for contingencies.

[Minsky]

Guess we could simply replace "MAIN" with "As needed", or rephrase the item like this:

Fuel display selector: WING or MAIN (if wings dry)

[jaylw314]

5 hours ago, ASAP said:

10) again. It’s in an AFI. Pilots don’t have the option to ignore it. And if a wingman reaches wings dry prior to the flight lead calling for an ops check they are required to inform the flight lead. They can’t keep SA on how much fuel is in their wing tanks if their fuel gauge is pointlessly showing full main tanks all the time 

That's funny, I read that AFI and I interpreted it differently.  However, I have no secondhand knowledge of how those instructions are actually implemented, so unless you do, arguing that point is needlessly pedantic.

As to the remainder of the points, I disagree with the logic.  If a wing pump fails (and you miss the warning), the bad tank will stop dropping until it starts gravity feeding, then it will continue at the same rate as the other.  The difference will only be obvious once one wing is empty and the other still has fuel.  By that point, the problem may have been going on for more than an hour.  OTOH, the main tank starts feeding immediately when the wing pump fails, so after only a few minutes, it's easier to spot a problem knowing the mains should be full, equal and unchanging (with fuel still in the wing tanks).  Staring at the wing tanks makes a problem obvious apparent later, while staring at the main tanks makes it obvious early.

It does seem to me that whatever setting you prefer, you'd still want to regularly check the other, be it during ops checks or otherwise.

5 hours ago, ASAP said:

6) if fuel isn’t feeding in your jet properly you have additional concerns than other than just the CG limits

CG out of limits is an immediate emergency that detracts from the higher goal of 'keeping the shiny side up'.  Improper fuel feeding is urgent but not an emergency.  I don't get that logic either.  It's worth noting there's an emergency procedure for main tank imbalance, but not wing tank imbalance.

Again, I don't have any info on how this is implemented IRL.  The fact that only the main tanks are self-sealing and tear resistant may be a reason to do it this way, for example.

Edited April 18, 2023 by jaylw314

[ASAP]

6 hours ago, Minsky said:

Guess we could simply replace "MAIN" with "As needed", or rephrase the item like this:

Fuel display selector: WING or MAIN (if wings dry)

Yeah this is why later versions of the checklist don’t tell you to set it to main. The line in the before start checklist just says to test the gauge.

[ASAP]

5 hours ago, jaylw314 said:

CG out of limits is an immediate emergency that detracts from the higher goal of 'keeping the shiny side up'.  Improper fuel feeding is urgent but not an emergency.  I don't get that logic either.  It's worth noting there's an emergency procedure for main tank imbalance, but not wing tank imbalance.

Again, I don't have any info on how this is implemented IRL.  The fact that only the main tanks are self-sealing and tear resistant may be a reason to do it this way, for example.

 

fuel leaks for instance are a much bigger emergency with a far higher likelihood of explosion. Trapped fuel is also a bigger problem because you have less gas available to get home. cg out of limits just gives you a speed restriction at altitudes that it’s pretty hard to exceed anyway. Set crossfeed and use the split throttles/tank gate as necessary to fix it. 
 

The wing tanks are not self sealing. If you get shot by small arms and have a slow leak in your wing you’d want to know about it before the wing tank is completely empty.  If your first indication is a main feeding when it shouldn’t be dropping it means that the wing tank is completely dry. If you monitor your wing tanks you’d see it dropping faster and you could use the extra couple of minutes to get headed home. 

[ASAP]

5 hours ago, jaylw314 said:

 

As to the remainder of the points, I disagree with the logic.  If a wing pump fails (and you miss the warning), the bad tank will stop dropping until it starts gravity feeding, then it will continue at the same rate as the other.  The difference will only be obvious once one wing is empty and the other still has fuel.  By that point, the problem may have been going on for more than an hour.  OTOH, the main tank starts feeding immediately when the wing pump fails, so after only a few minutes, it's easier to spot a problem knowing the mains should be full, equal and unchanging (with fuel still in the wing tanks).  Staring at the wing tanks makes a problem obvious apparent later, while staring at the main tanks makes it obvious early.

 

Well the whole reason I brought up the fuel indicator in the first place was because before my first post I was talking to a current pilot who told me they monitor the tanks that are currently feeding (xternal tanks, then wing, then main). But I realize this is like saying I have a girlfriend who goes to a different school,  you wouldn’t know her.  Believe it if you want or not  

If a wing tank is not feeding and proper action is not taken the wing won’t gravity feed until the main tank is nearly empty. At which point the TO says that it MIGHT gravity feed. At this point though your fuel system has already proven unreliable so trust it at your own risk. This is called trapped fuel and it’s possible that it will stay trapped.

looking at your mains to determine what is happening in your wings is relying on a secondary indication. 

[jaylw314]

2 hours ago, ASAP said:

fuel leaks for instance are a much bigger emergency with a far higher likelihood of explosion. Trapped fuel is also a bigger problem because you have less gas available to get home. cg out of limits just gives you a speed restriction at altitudes that it’s pretty hard to exceed anyway. Set crossfeed and use the split throttles/tank gate as necessary to fix it. 
 

The wing tanks are not self sealing. If you get shot by small arms and have a slow leak in your wing you’d want to know about it before the wing tank is completely empty.  If your first indication is a main feeding when it shouldn’t be dropping it means that the wing tank is completely dry. If you monitor your wing tanks you’d see it dropping faster and you could use the extra couple of minutes to get headed home. 

No, just no.  TKS UNEQUAL means you're approaching CG limits, but still okay with those speed restrictions.  CG out of limits occurs a few hundred pounds past that, and given that the only solution would be opening the tank gate, if you're pitching up and CG is aft of limit, the laws of physics may not allow for a graceful return to earth no matter how skilled the pilot (unless you happen to be in an F-16). 

Well, I'm definitely getting needlessly pedantic myself, and I think that putting 'as needed' in a checklist would be great.

[Minsky]

@ASAP So you are saying that the newer manual (mine is dated 2012) doesn't explain how exactly the fuel quantity check must be conducted?

The name kinda implies that we need to check if the pointers match the totalizer, and if the gauge shows the amount of fuel actually loaded.

Can't really do that without touching the switch.

[Minsky]

26 minutes ago, jaylw314 said:

I think that putting 'as needed' in a checklist would be great.

I don't mind.

Just need to make sure this passes the validation Maple Flags do in their campaigns.

Edited April 18, 2023 by Minsky

[ASAP]

50 minutes ago, Minsky said:

@ASAP So you are saying that the newer manual (mine is dated 2012) doesn't explain how exactly the fuel quantity check must be conducted?

The name kinda implies that we need to check if the pointers match the totalizer, and if the gauge shows the amount of fuel actually loaded.

Can't really do that without touching the switch.

It still has the note saying what should happen when you hold the test button. It just doesn’t have the second note saying to return it to main at the completion of the test. 

[ASAP]

1 hour ago, jaylw314 said:

No, just no.  TKS UNEQUAL means you're approaching CG limits, but still okay with those speed restrictions.  CG out of limits occurs a few hundred pounds past that, and given that the only solution would be opening the tank gate, if you're pitching up and CG is aft of limit, the laws of physics may not allow for a graceful return to earth no matter how skilled the pilot (unless you happen to be in an F-16). 

Well, I'm definitely getting needlessly pedantic myself, and I think that putting 'as needed' in a checklist would be great.

Lol. I love how often people say “just no” like they are making a solid point while referencing nothing. What is the actual aft CG limit and how high does the difference have to be pray tell? To get more pedantic and say what the -1 actually says… the light means there’s a difference of 750 +- 250 pounds. The -1 just says that if the right tank has a greater than 1000 pounds difference you have speed restrictions to abide by based on your altitude due to pitch sensitivity when flying faster. A fuel imbalance with the left tank heavy will not cause CG problems.

the tank gate is obviously not the only Solution (I provided three of them in my previous post). Shutting off the low side boost pumps and  splitting the throttles would also work. Those are slower methods, best initiated sooner rather than later… like when you notice the needles for your wing tanks developing an imbalance prior to the wings running dry.

 It also explicitly states that you should use “differential throttles, boost pump switches, or the tank gate switch as necessary to correct the fuel imbalance.” So your “just no” doesn’t jive with the checklist 

obviously a trained pilot understands their fuel system well enough to not open the tank gate in an aggressive climb and slosh all the fuel into the right main. But just in case the checklist also cautions against climbing and diving with the tank gate open or leaving it open longer than required to correct the imbalance.  Correcting an imbalance is the purpose of the tank gate so it’s odd you’re so vehemently against using it for that purpose. In straight and level flight opening the gate would rapidly equalize the tanks, not exacerbate the problem

 

Anyway I feel this poor horse has been beaten to death already. I only brought it up because while playing with a friend with some real world experience I asked how he does it and he said they are trained to do it the way I outlined above. I thought the community might appreciate the insight into real world ops.
 

To my original suggestion for the checklist, yeah “as required” works great, or just have that step say “fuel indicator -test” 

[jaylw314]

1 hour ago, ASAP said:

Lol. I love how often people say “just no” like they are making a solid point while referencing nothing. What is the actual aft CG limit and how high does the difference have to be pray tell? To get more pedantic and say what the -1 actually says… the light means there’s a difference of 750 +- 250 pounds. The -1 just says that if the right tank has a greater than 1000 pounds difference you have speed restrictions to abide by based on your altitude due to pitch sensitivity when flying faster. A fuel imbalance with the left tank heavy will not cause CG problems.

AFAIK there's no publicly available W&B data, so that's a straw man.  Out-of-CG accident reports are plenty, though (and plenty bad).

There is a specific reference in the -1 that <1000 lbs main tank imbalance will stay within CG limits.  Since the light can come on at 1000 lbs imbalance, and the speed caution is for a partial ammo load and 1000 lbs difference, that suggests there is some margin for error, but I can't know how much without the W&B info.  If the margin was massive for example, that would be nice to know and reassuring.  But first reference dictates that >1000 lbs there is a non-zero chance of an imminently catastrophic failure, which gets my attention.  In DCS, it's not rare to come home with no ammo, for example.