[RESOLVED] FM: Sinks to much during bank & groove.

[Nealius]

Well that's...interesting. Could be related; but if it is, it would be affecting more than the tomcat FM.

 

I tested a few modules and posted the results in a different thread, but I found the Tomcat's altimeter to be off by 80ft when parked at Shiraz, with altimeter dialed to mission QNH. To get airfield elevation I have to set altimeter to 30.13 when QNH should be 30.05. Prior to 2.5.5 the altimeter on the Tomcat (and other modules) was dead-on.

Edited July 18, 2019 by Nealius

[WindyTX]

In today's update 14 Aug 19 is the weight reporting fixed in a quick test I get on speed at roughly 165 fully loaded 70K ish Dump stores and tanks it drops to about 155. Dump fuel down to 6K and I am still seeing 155 on speed.

 

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[Victory205]

Max trap 54,000lbs on speed AOA with DLC engaged and neutral should be ~ 137 KIAS on the cockpit airspeed indicator. 131 KIAS DLC stowed.

 

That’s what I’m seeing.

[WindyTX]

I get the correct speed when I launch at that weight but not when I reduce the Aircraft from fully loaded down to that weight.

 

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[IronMike]

I get the correct speed when I launch at that weight but not when I reduce the Aircraft from fully loaded down to that weight.

 

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I think what you experience is that some stores pylons produce more drag after the ordnance has been expended. This is why sometimes it feels as if it takes less power to land with less fuel but two phoenixes on the rails, than having shot them off and more fuel, etc... The biggest discrepancy is produced by the smallest missile, the aim9, and even more so its empty pylon. In short: imo this falls under the drag issue we have to deal with atm.

 

https://forums.eagle.ru/showpost.php?p=4006898&postcount=1

[MBot]

Launching clean and returning with 5000 lb of fuel, I just had 150 knots on speed with DLC engaged.

 

It seems this patch was a step backwards. Just yesterday I was playing my regular training mission (clean launch, burning off fuel to max trap and then doing patterns until low on fuel) and was rejoicing on how much power I had once again in the pattern. In fact I had to readjust my throttle muscle-memory from the last weeks from giving too much power. Flying exactly the same training today after patching, I am again having troubles with maintaining altitude in level turns in the pattern (inadvertently retracting speed brakes and DLC multiple times).

Edited August 14, 2019 by MBot

[sLYFa]

Max trap 54,000lbs on speed AOA with DLC engaged and neutral should be ~ 137 KIAS on the cockpit airspeed indicator. 131 KIAS DLC stowed.

 

That’s what I’m seeing.

That's what I'm seeing too, but ONLY if I either:

-take off from land fully loaded, then burn fuel and/or fire missiles until 54,000lbs

-take off from the boat with 54,000lbs

-airstart with 54,000lbs

If I take off from the boat fully loaded and the burn down to 54,000lbs, I need about 150kts to stay on AoA

 

FWIW sea level top speeds did not differ between the scenarios. I therefore believe that some "ghost weight" is added to the airplane if you start on the carrier.

[fat creason]

There have been no changes to the aircraft's performance, lift, or drag in this update. It could be a change in stores drag but we have no real way of knowing.

[sLYFa]

There have been no changes to the aircraft's performance, lift, or drag in this update. It could be a change in stores drag but we have no real way of knowing.

 

Its been like that at least since this thread started. Don't know if it was present before that since I didn't notice it until after doing these test https://forums.eagle.ru/showpost.php?p=3981013&postcount=23

[MBot]

It seems this patch was a step backwards. Just yesterday I was playing my regular training mission (clean launch, burning off fuel to max trap and then doing patterns until low on fuel) and was rejoicing on how much power I had once again in the pattern. In fact I had to readjust my throttle muscle-memory from the last weeks from giving too much power. Flying exactly the same training today after patching, I am again having troubles with maintaining altitude in level turns in the pattern (inadvertently retracting speed brakes and DLC multiple times).

 

Thinking about this again, perhaps there was a difference between the two sessions. When I required so much power in the pattern, I was flying a clean yet but have removed the Phoenix pallets while still on the carrier. In the pre-patch session when I had sufficient power in the pattern, I flew a clean yet with possibly the Phoenix racks still attached (I don't quite remember). Perhaps the "ghost wheight" is applied only when using the rearming menu on the carrier?

[Biggus]

I've done some testing too.

 

 

My very rudimentary test is a mission I've attached. It is a modified version of the PG case 1 mission with some F-14Bs in different states. Two are ready on the catapult with no weapons (aside from the gun), one of which is at 53,596lb (9396lb of fuel) and the other is at 48,610lb (4050lb fuel). A third is about 8-10nm behind the boat, again clean but with loaded gun and weighs 47,152lb, of which 2593lb is fuel.

 

 

The issue is most obvious when you launch the max-weight bird, dump fuel down to 2500lb and compare it's fuel flow and on-speed speed to the plane that air-starts behind the boat. I believe there was a difference of 11kn and a significant increase in FF. The air-started bird was on-speed with flows around the 4.8-5.2k mark, and by 1800lb of fuel was on-speed at about 124kias. The max weight one was pushing 6.5k FF and was on-speed at roughly 135kn.

 

 

Experimenting with the low fuel weight carrier start demonstrates figures roughly halfway between.

 

 

This can't be correct behavior.

F-14B_IA_PG_case_1_modified.miz

[sLYFa]

Perhaps the "ghost wheight" is applied only when using the rearming menu on the carrier?

 

I did all my tests with hotstarts and no refueling/rearming. Interestingly, if you take off from the beach and land on the boat, then rearm/refuel and launch, everything is fine. It's spawning on the carrier that seems to produce the issue.

[lunaticfringe]

One begins to wonder if its connected to ED's current inertia fixing for aircraft sliding on the deck. Take a jet off the boat to shore, and it goes nuts. Take a jet off the boat on a circuit and go back, and it's still inordinately heavy. Take a jet off the shore out to the boat and it performs properly in the groove.

 

Strange.

[fat creason]

Its been like that at least since this thread started. Don't know if it was present before that since I didn't notice it until after doing these test https://forums.eagle.ru/showpost.php?p=3981013&postcount=23

 

Yeah, we think this has been an issue for about 6-8 weeks. It took a while to notice, we first noticed when I increased engine thrust and we somehow lost performance on the next patch that was not reflected in the FM testing. It could be that something with DCS API has changed and we need to fix something, but it's hard to tell and we have questions out to ED.

[Biggus]

One begins to wonder if its connected to ED's current inertia fixing for aircraft sliding on the deck. Take a jet off the boat to shore, and it goes nuts. Take a jet off the boat on a circuit and go back, and it's still inordinately heavy. Take a jet off the shore out to the boat and it performs properly in the groove.

 

Strange.

 

 

Tonight I'll try a land-based spawn with a flight to the carrier, a rearm and then launch and recover. Maybe that will narrow it down to a carrier bug vs a bug that gets applied when someone spawns.

 

 

Yeah, we think this has been an issue for about 6-8 weeks. It took a while to notice, we first noticed when I increased engine thrust and we somehow lost performance on the next patch that was not reflected in the FM testing. It could be that something with DCS API has changed and we need to fix something, but it's hard to tell and we have questions out to ED.

 

 

Judging by the normal patch note omissions I wouldn't be surprised at all if this is the case. I really hope you get answers soon.

[Biggus]

Just to follow up on this, I added an F-14 lined up for takeoff at Al Minhad with enough fuel to put myself into a 10 mile straight-in approach to the boat with 3,000lb. No weapons besides gun, totally clean aircraft. On-speed AOA around 126kn. Trapped, opened rearm/refuel dialogue and had the plane fueled up to 4,000lb. Launched and trapped again from 10nm behind the boat, maybe a knot or two slower on-speed than the first time but I was a touch lighter on fuel also. I then respawned as the lighter Tomcat on the catapult and noted higher fuel flows and higher on-speed AOA by about 5-6kn.

 

This would appear to indicate that the issue is at least partly with carrier spawned aircraft, not with any rearm/refuel interaction. If there is interest I can upload the revised mission file.

 

 

I am currently testing to see whether setting up aircraft with stored heading alignments is a contributing factor but I don't have many other things left to test after that.

[Biggus]

It appears that this is still an issue in the 2.5.5.35461 OB patch.

 

 

Still seeing differences between air start and boat spawned aircraft in exactly the same state. No weapons, 1500lb fuel. Air start Tomcat is on-speed at 124kn, carrier spawned is on-speed at 131kn. Fuel flow figures are improved though.

[BuzZoo]

Anyone know if this has been resolved?

I like to be able to go 6 shooter for carrier ops but found it so hard to get back on deck with this bug so I haven't tried in a while.

[fat creason]

Still nothing from ED on this bug.

[BuzZoo]

Thanks for the trademark fast reply fat creason!

Never mind, still been having a blast in the tomcat.

[CoBlue]

Still nothing from ED on this bug.

Any news on this?

[viper2097]

Is there still something bugged?

Unfortunately, I had never the time to do some real research with testing, but very often something "feels" very wrong when I'm banking in the groove. Even I#m quite low on fuel and have fired all weapons, I need to go to 100% thrust to not sink anymore. Of course, the speedbreak and DLC then also gets stowed then automaticaly...

[Frion1]

Same problem!

[CoBlue]

Is there still something bugged?

Unfortunately, I had never the time to do some real research with testing, but very often something "feels" very wrong when I'm banking in the groove. Even I#m quite low on fuel and have fired all weapons, I need to go to 100% thrust to not sink anymore. Of course, the speedbreak and DLC then also gets stowed then automaticaly...

Bugged for 3 months & counting..........we're flying with wrong weights, drag & God knows what else? After a mission the plane "thinks" it's heavier then it actually is.

 

It's all ED's fault, so don't blame HB. The same bug for F-18 & maybe other planes in DCS?. This should also effect the FM, fuel consumption etc etc.

 

But ED doesn't seem to take this seriously: https://forums.eagle.ru/showthread.php?t=247311

https://forums.eagle.ru/showthread.php?t=253738

[sLYFa]

If you take off from land, the flight performance is correct, even after landing and rearming on a carrier. Its starting on the boat that somehow adds additional unrealistic weight (and probably some drag too).