PSA: F-14 Performance/FM Development Status + Guided Discussion

[Callsign JoNay]

On 10/27/2021 at 2:49 PM, Callsign JoNay said:

So the consensus is the FM is almost right on the money for the A? Are there any diagrams to test against performance with Phoenix pylons?

I'm trying to figure out how their weight is modeled and I can't recall seeing an official hearblur answer. The rumor I've heard is that the weight and drag are modeled correctly, and rhe absence of gross weight change when they are removed in the ME is just a false indication (glitch) in the mission editor. However, I have never felt any additional sluggishness with the pylons attached, so I did a test last night on the most current open beta.

 

I tested 3 aircraft:

#1- An F-14B with empty Phoenix pylons and 8100 lbs fuel.

#2- An F-14B with no pylons and 8100 lbs fuel.

#3- An F-14B with no pylons and 10,300 lbs fuel. I chose this fuel quantity because as I understand it Phoenix pylons weight ~500 lbs each plus ~100 for each fairing.

 

Unlimuted fuel set in options so rhe gross weight stayed consistent through the test. I started at 500 feet sea level, 350 kts. Then I accelerated to 400 kts at full military power and began a smooth pitch up until wings symbol was 30 deg on the pitch ladder. I engaged attitude hold to minimize inputs that might cause inconsistent lift/drag. Then I held mil power until the aircraft dropped below zero on the VSI.

Both of the 8100 jets seemed to perform exactly the same, stalling out at 26,500 feet. The no pylon 10,300 jet stalled out 1500 feet below them at around 25,000 feet.

It seems to me that the weight of the pylons is not modeled. And the mission editor says a clean bird is 44,040 lbs which would seem to include the weight of the Phoenix rails according to publicly available info on the Tomcat's IRL gross weight. So it's confusing. Are the Phoenix rails weightless even though the ME says they weigh something? Is the gross weight as indicated in the ME inaccurate? It seems like it must be if the current FM matches the performance of the 4x AIM-7 4x AIM-9 loadout in the performance diagrams shared in this topic.

Video of my test below. Feel free to tell me if I screwed something up, or if any of your own tests indicate something different than mine. Just trying to get to the bottom of this.

 

Bumping this now that the recent firestorm has died down. Can anyone from HB comment on what's going on with the Phoenix pylons, or tell us how much our Tomcat actually weighs? 

 

[Victory205]

You can determine weight by flying on speed in the landing configuration with various fuel levels, weapons load outs and weight set using the mission editor.  Compare with the speed vs AOA chart in NATOPS, ensure that you are using the correct DLC state.

The results might be interesting.

[Baz000]

The idea being that your indicated airspeed at on speed AOA will show as faster when your aircraft is heavier compared to when your aircraft is lighter in gross weight, not taking additional drag from weapons or pylons into account.

Like you guys on here trying to measure SL top dash performance with a jet that has fuel pylon mounts under each engine nacelle vs void of them. Don't you think having those little additions protruding from the bottom of the plane may make the plane not reach top speed as quickly or as high of a speed?

Correct DLC state can only really be one of two things, right? Either the pilot has it activated by the stick button or not.

I was actually wondering about how "bring-back" capabilities do actually work on the F-14 for trapping on the boat. I think I understand for AIM-54 pretty well... Dooms day-6 (plan to shoot things) otherwise most you normally see would be 4, or 2, or 1. The problem with 6 was either you had to dump fuel or jett expensive missiles to get down to max trap weight, and if you chose dump fuel then you have very little margin for trapping at the boat before you need to hit the tanker. Also, the plane prefers the 54's in the "tunnel" vs the glove pylons.

So, I wonder if it gets somewhat more sporty to land with a 54 mounted on each glove pylon.

I was wondering about "bring-back" capabilities of various bomb loads loaded inside the tunnel, which arguably could weigh more than six 54s. In that case, I'd figure you would jettison bombs in the case of an mission abort? For example.

I do a lot of wondering...

 

 

Edited November 9, 2021 by Baz000

[Callsign JoNay]

6 hours ago, Victory205 said:

You can determine weight by flying on speed in the landing configuration with various fuel levels, weapons load outs and weight set using the mission editor.  Compare with the speed vs AOA chart in NATOPS, ensure that you are using the correct DLC state.

The results might be interesting.

Thanks for the idea. Tested with results below.

 

Aircraft #1 - Phoenix Pylons + 8,100 lbs Fuel

Aircraft #2 - No Phoenix Pylons + 8,100 lbs Fuel

Aircraft #3 - No Phoenix Pylons + 10,300 lbs Fuel (10,300 lbs fuel weight chosen to approximate the weight of IRL phoenix pylons and fairings, 8,100 + 2,200).

 

-No wind.

-Gun ammo removed.

-Unlimited fuel option checked.

-All drag indexes + Neutral DLC.

-Speed indication pulled from external view screen.

 

Aircraft #1: 135 kts = 51,000 lbs - 8,100 fuel = 42,900 lbs empty w/ phoenix pylons

Aircraft #2: 135 kts = 51,000 lbs - 8,100 fuel = 42,900 lbs empty weight w/o phoenix pylons

Aircraft #3: 139 kts = 53,750 lbs - 10,300 fuel = 43,450 lbs empty weight w/o phoenix pylons  

 

You're right, the results are interesting. It appears the empty weight is between 42,900-43,450. Not sure where the extra 550 lbs is coming from on aircraft #3. I ran the test twice and got the same results both times. I wonder why the Mission Editor lists an empty weight of 44,040?

 

Both my tests seem to indicate that the phoenix pylons and fairings add no weight to the empty weight of the aircraft, which is unfortunate. I've also attached my miz file in case anyone wants to inspect it for mistakes, or try the test for themselves.

 

Here's a video of me testing:

 

AOA Weight Test.miz

[Victory205]

One item that I’d highlight is that the AOA vs Speed chart is from 1976, the new DLC that is modeled in the sim hadn’t been “invented” yet and wasn’t in use. The F14B NATOPS number would be accurate in absolute terms, but the relative difference is still useful.

It gets even more interesting when you add missiles…

[Baz000]

Is that per chance why they seldom if ever would carry six aim-54? Normally I've seen 2 or 4 aim-54 in the tunnel.

Six is similar to that shot of a C model Hornet with 10 aim-120.

 

Edited November 10, 2021 by Baz000

[Quid]

1 hour ago, Baz000 said:

Is that per chance why they seldom if ever would carry six aim-54? Normally I've seen 2 or 4 aim-54 in the tunnel.

Six is similar to that shot of a C model Hornet with 10 aim-54.

Oh who climbs faster and gets to the highest altitude? A Tomcat with 6 Phoenix or a Tomcat with 2 heaters and 2 sparrows?

 

The reason I have read/heard for years for the rarity of 6 Phoenix is the recovery weight and not having enough gas for go-arounds (apart from a lot of drag).  Using the weights from the 1975 NATOPS, for example, having only 6x AIM-54As and their supporting rails/launchers on the early F-14A (no tanks, tank rails, Sidewinders or Sidewinder rails/launchers), the jet weighs 48,802lbs, against an (at the time) 51,800lbs max trap, leaving only 2998lbs of fuel max at touch-down. 

Later, the max trap was expanded to 54,000lbs; the F-14 itself got heavier (as did the AIM-54), but the margin got larger for the A.  Using the numbers from 1995, the F-14A, AIM-54 rails/launchers and 6x AIM-54Cs weigh 50,828lbs against a 54,000lbs max trap, leaving 3172lbs of fuel max at touch-down.  The margin for the F-14B and D would be smaller; the F-14B would have 1572lbs at max trap, the F-14D would have 1437lbs. 

Considering the F-14 commonly flew with tanks while deployed from the 1980s onward (though not an absolute truism, and you have a nice picture there of an F-14B without either tanks or rails), as well as Sidewinder rails, the available fuel at max trap would be even less and the drag even greater.  Add to this that the plane can't use every last drop and you have a margin for error to build in as well.  If we add, for example, the empty tanks, tank rails (856lbs), and sidewinder pylons, (226lbs), your F-14A has 2090lbs of fuel to play with while the F-14B has a scant 490lbs to hit the 54,000lbs max trap weight.

[Baz000]

That is pretty much what I heard but you do a far better and more precise job of throwing the specific numbers out there as well as covering the different versions of F-14 models.

One point I do want to add though is that I forgot if it is the CAG or the individual squadrons themselves that specify it but there is a minimum fuel level target be no less than to arrive trapped on deck (meaning a minimum reserve you are not intended to use unless in an emergency) as well as a set fuel state for example holding in the Marshall stack or after a few bolters where now you need to head to the tanker or have one hawk you over the carrier.

I saw a interview on sea wings (man I miss that show, and wings, and wings of the red star) where an A-6 BN was talking about his pilot missing the wires on like 7 attempts trying to land at night. I forget if he said if it was during a storm too or not may have been.

I only heard of the F-14 flying without external tanks on ashore, that said... There is a big difference between a F-14 flying without tanks and a F-18 without tanks, one has a far larger handicap than the other... Can you guess which?

found the clip of him talking about missing the wires 7 times after a very long mission.

"we just wanna get the thing down on the deck and go home."

 

Edited November 10, 2021 by Baz000

[Callsign JoNay]

3 hours ago, Victory205 said:

One item that I’d highlight is that the AOA vs Speed chart is from 1976, the new DLC that is modeled in the sim hadn’t been “invented” yet and wasn’t in use. The F14B NATOPS number would be accurate in absolute terms, but the relative difference is still useful.

It gets even more interesting when you add missiles…

I thought the chart I posted was from the F-14B Natops. Maybe I referenced the wrong page.  

 

Would be nice if someone from HB just told us specifically how much our tomcats weigh instead of leaving it up to user tests like these that include margin for error. And also if/when the weight/drag of the Phoenix rails will be implemented soon, or at least touch on whatever challenge they're having that is preventing them from doing it.

[Baz000]

Do you mean the Phoenix pallets that mount under the "tunnel"

[Snappy]

2 hours ago, Callsign JoNay said:

I thought the chart I posted was from the F-14B Natops. Maybe I referenced the wrong page.  

 

Would be nice if someone from HB just told us specifically how much our tomcats weigh instead of leaving it up to user tests like these that include margin for error. And also if/when the weight/drag of the Phoenix rails will be implemented soon, or at least touch on whatever challenge they're having that is preventing them from doing it.

There was already a previous discussion about this, somewhat inconclusive too I think, sounded like the rails weight is already included all the the time in the basic empty weight in DCS. But no official answer from Heatblur.

edit: Just saw you participated yourself in that thread, sorry guess you know about it then.

Regards,

 

 Snappy 

 

Edited November 10, 2021 by Snappy

[Victory205]

7 hours ago, Callsign JoNay said:

I thought the chart I posted was from the F-14B Natops. Maybe I referenced the wrong page.  

 

Would be nice if someone from HB just told us specifically how much our tomcats weigh instead of leaving it up to user tests like these that include margin for error. And also if/when the weight/drag of the Phoenix rails will be implemented soon, or at least touch on whatever challenge they're having that is preventing them from doing it.

My understanding is that DCS controls the weapons weights.

Try a couple of runs with missiles, see if the mission editor ordnance weights correlate.

Pretty close -

Edited November 10, 2021 by Victory205

[Callsign JoNay]

9 minutes ago, Victory205 said:

My understanding is that DCS controls the weapons weights.

Try a couple of runs with missiles, see if the mission editor ordnance weights correlate.

Pretty close -

 

Thanks.

Ok so some updates numbers based on your chart:

Aircraft #1 and #2, (135 kts), from my test both weigh 51,250, minus 8100 lbs fuel, for empty weight of 43,150 lbs.

 

Aircraft #3, (139 kts), from my test weighs 54,000, minus 10,300 lbs fuel, for an empty weight of 43,700 lbs.

 

So, it's still carrying that 550 lbs of mystery weight if I go by the natops AOA chart. Any idea where that's coming from? Am I performing my test at the wrong pressure, temp, altitude, wind speed, etc? Is there something I'm not considering? Or is it just a case of a WIP flight model?

 

And you're suggesting Phoenix pylons fall into the ordnance category controlled by ED? So I should be bugging them instead?

[Victory205]

You shouldn't be bugging anyone over ~500 notional pounds in a flight simulator.

Load some missiles, do the same evaluation, see if the fake weight of the rails still bothers you.

Are your empty weights close to what is displayed in the ME?

[Callsign JoNay]

57 minutes ago, Victory205 said:

You shouldn't be bugging anyone over ~500 notional pounds in a flight simulator.

Load some missiles, do the same evaluation, see if the fake weight of the rails still bothers you.

Are your empty weights close to what is displayed in the ME?

Empty weight displayed in the ME is 44,040. So it's 340-890 lbs heavier than the empty weights I'm calculating in the AOA tests.

 

The irritating part about it to me is I don't know if we're flying a 43,150 lb fighter that flies like a 43,150 lb fighter even though it's listed as a 44,040 lb fighter in the ME, or if we're flying a 44,040 lb fighter that has lift/thrust/drag values that make it perform like a 43,150 lb fighter. Know what I mean? I guess at that point it might not matter in a performance sense, but for those who are trying to calculate proper max recovery weights in the sim there is a 340-890 lb question mark on how to go about it. Yes, it's a video game, but we are nerds and like to get it right.

 

It would be nice if HB could just tell us what's going on so we know for sure, but I've made enough noise about this so I'll stop asking.

 

The lack of weight of the phoenix pylons and fairings is the biggest mystery, and seems like a relatively easy correction to make. The drag may be marginal since they are between the nacelles and have streamlined fairings to smooth the air friction, but they add up to ~2200 lbs,  which is not nothing. We're talking about the equivalent weight of a GBU-10.

 

Edited: Fixed some math errors.

Edited November 10, 2021 by Callsign JoNay

[sLYFa]

Missiles or not, the rails are not being accounted for.

If I cross check on-speed IAS and ME displayed aircraft weight, it matches pretty well with the approach speed chart (E.g with 54klbs I'm at about 138kts). If I use the "actual" weight by adding 2000lbs worth of PH rails to the ME weight, I'm always 2-3 knots slower than I should be.

The empty weight for the B of 44000lbs does match RW data, considering we cant remove the tank and ST 1A/8A rails, which adds roughly 400lbs to the NATOPS empty weight of 43600. Empty tanks are a little light with 110lbs compared the 200lbs they should be per docs but this is irrelevant. In general, stores and empty weights are pretty close to available data, EXCEPT the PH rails, which have zero weight in both ME and flight model.

[Victory205]

It doesn't matter. Sometimes it's useful to step back and convey a sense of perspective on much of this. The turn rate pedanatry (all over the DCS forums, not just here) emanates from the unfamiliarity with what is important, and what isn't. Aircraft within a flight get airborne off of a ship with fuel loads that differ by more than what you are concerned about, depending upon when the started, how long they were in burner on the cat, etc. Really nothing to worry about.

A pilot's ability to maneuver efficiently far, far offsets the weights that you are referencing.

Again, if you really want to learn, then select the same aircraft with the same configuration and go fight. It's never "fair", you end up fighting with what you have when a threat arrives. The nature of a sim will never replicate the real world. 

[sLYFa]

I'm merely stating my findings here, whatever players/devs do with with it is up to them. I'm personally not in the "1DPS is a big deal" camp and these 2000 rail pounds are on the edge of measurability in terms of flying.

[Victory205]

Missiles?

[Baz000]

This is the problem with DCS, they just throw you right into the cockpit of a high performance F-14 or name any other front line fighter... Without doing the pre-requisite work on first learning how to fly and understanding things and gaining basic foundational skills.

In our case we need like a crash course 

Is there a good module currently available we could fly in DCS to "prep" us for what amazing wonders wait for us in the F-14?

I got my FAA handbooks sitting on the shelf, i'm tempted to dust them off and try mastering each thing in there 1 step at a time.

I will say this tho, I finally got the hang of trimming the F-14 in level flight finally... You have to treat the wings moving like a configuration change... Now, I need to work on it in the landing configuration and trying to hold onspeed AOA.

Edited November 10, 2021 by Baz000

[Callsign JoNay]

51 minutes ago, Victory205 said:

The nature of a sim will never replicate the real world. 

Well not with that attitude, it won't. (Kidding)

 

I disagree that ~2000 lbs of phoenix rails don't matter. As of now we are able to recover with two AIM-54s worth of extra fuel than we should be able to if attempting to respect the 54,000 lb max trap weight, and we also get the benefits of the performance/handling of -2000 lbs around the boat too. 

[Sideburns]

54 minutes ago, Baz000 said:

This is the problem with DCS, they just throw you right into the cockpit of a high performance F-14 or name any other front line fighter... Without doing the pre-requisite work on first learning how to fly and understanding things and gaining basic foundational skills.

In our case we need like a crash course 

Is there a good module currently available we could fly in DCS to "prep" us for what amazing wonders wait for us in the F-14?

I got my FAA handbooks sitting on the shelf, i'm tempted to dust them off and try mastering each thing in there 1 step at a time.

I will say this tho, I finally got the hang of trimming the F-14 in level flight finally... You have to treat the wings moving like a configuration change... Now, I need to work on it in the landing configuration and trying to hold onspeed AOA.

 

Free T-45 mod? Free A4c mod? There are a lot of virtual squadrons out there that offer free training and syllabus if you're looking for a guiding hand.

Edited November 10, 2021 by Sideburns

[Victory205]

Wait, are you telling me that players that ignore G and speed limits observe max trap weights? Color, I mean, colour me gobsmacked! 

Do you realize that HM and EM diagrams generally ignore other limits? The NATOPS G limit occurs at 49,548 (IIRC) pounds. Rolling G starts at 5.2G's, yet look at the conditional weights on the charts. Are you all observing those when complaining about how .2 G's or 2000lbs are ruining your ability to fight? 

How about "Peacetime" and "Wartime" limits? Those are oft referenced, sometimes by pilots. Where are the references for those? Some pilot's offhanded comment on Youtube? 

All of the "this airplane is better than that airplane because I know a real pilot (yeah, right, more likely you read a comment online)" who said he beat this or that is nonsense and a waste of time. I get questions like this all the time from someone who wants ammunition to settle an argument.

So while you are keenly focused on rails, still no feedback on the missile weights?

[Baz000]

I'm not really a fan of mods, for one thing if you have any you don't get any troubleshooting support with DCS until you eliminate them as a potential cause... And my DCS already gives me plenty of problems at times without introducing any new ones to it.

[Victory205]

1 hour ago, Baz000 said:

This is the problem with DCS, they just throw you right into the cockpit of a high performance F-14 or name any other front line fighter... Without doing the pre-requisite work on first learning how to fly and understanding things and gaining basic foundational skills.

In our case we need like a crash course 

Is there a good module currently available we could fly in DCS to "prep" us for what amazing wonders wait for us in the F-14?

I got my FAA handbooks sitting on the shelf, i'm tempted to dust them off and try mastering each thing in there 1 step at a time.

I will say this tho, I finally got the hang of trimming the F-14 in level flight finally... You have to treat the wings moving like a configuration change... Now, I need to work on it in the landing configuration and trying to hold onspeed AOA.

 

That's because moving the wings is a configuration change.

How did you overcome the horrifying task of trimming an aircraft. Understand that the F14 constantly requires constant corrections, it's nothing different than any other aircraft, including FBW. 

I haven't spent much time in the T45 and don't have the A4, so can't comment on whether they provide positive training, but I get a sense that a lot of folks jump into the complex modules without spending time flying basics, holding altitude, turns, simple configuration changes, etc, without attempting to understand what is transpiring or how to anticipate. Simply turning off the HUD in the F14 and learning to perform the aforementioned tasks will help you understand what's going on, pitch attitudes and power required. I noticed that the gent doing the AOA vs Speed turned on the autothrottles (I think) to obtain his data, which speaks volumes. Almost all pilots I knew ensured that they would first be proficient without aids, because those aids wouldn't be available when it mattered most. 

That you can do it at all is astonishing. The Heatblur gang has a group that impressed me with their ability to get around the ship. My hat's off to the folks who spend the time and energy to get it right.