Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: 1K3 on December 22, 2006, 11:09:25 AM
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The climb rate of out current Seafire is much lower than the charts suggests. From 0 to 2,000 feet the seafire can achieve only 2,500 fpm vs ~3,000 showed on the charts. The max speed for seafire must be lower too:noid
(http://hitechcreations.com/ahhelp/models/charts/seafireclmb.gif)
(http://hitechcreations.com/ahhelp/models/charts/seafirespd.gif)
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Well, I tested the Seafire today... I agree that its climb rate is different from the posted chart. I recorded climb rate at every 1,000 foot interval until it ran out of WEP at 14,000 feet (using auto-climb). I charted the results in purple.
(http://home.att.net/~c.c.jordan/SeafireClimbActual.gif)
Speed at sea level was 304 mph TAS. This looks correct to the chart.
Speed at 16,500 feet was 370 mph TAS, which is very close to the chart.
Fuel load for all tests was 25%, zero burn.
My regards,
Widewing
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First: Shouldn't all tests be done with 100%? If they go by official flight tests and charts, chances are they had full fuel there, so I'd think these charts would be full fuel as well. (this was always my assumption with them).
Second: Maybe the chart hasn't been updated since the de-boosting of the SpitV? Didn't the Seafire share the same de-boosting? I don't fly it often so I can't say for sure. Thought I'd put it out there.
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The climb rates of a lot of planes are less than indicated in the charts.
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Originally posted by Krusty
First: Shouldn't all tests be done with 100%? If they go by official flight tests and charts, chances are they had full fuel there, so I'd think these charts would be full fuel as well. (this was always my assumption with them).
Second: Maybe the chart hasn't been updated since the de-boosting of the SpitV? Didn't the Seafire share the same de-boosting? I don't fly it often so I can't say for sure. Thought I'd put it out there.
IK3 stated that the Seafire doesn't climb at the rate indicated on the chart. I confirmed this. Using 25% gas illustrates that when flying with low fuel, the climb rate is significantly below the charted rate. Adding 100% fuel would only reduce climb further.
I do not know why the aircraft doesn't conform to the chart, I only verified the observation.
My regards,
Widewing
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But, in general, isn't using 25% gas in a climb test cheating? It's like choosing the ligthest gun load, the least amount of fuel and all that. If compared to actual charts of the real plane, the charts might be the same, but the real plane climbed a LOT better because it did it at a full load.
I don't get why HTC does the charts like that. (*shrug*)
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Originally posted by Krusty
But, in general, isn't using 25% gas in a climb test cheating? It's like choosing the ligthest gun load, the least amount of fuel and all that. If compared to actual charts of the real plane, the charts might be the same, but the real plane climbed a LOT better because it did it at a full load.
I don't get why HTC does the charts like that. (*shrug*)
Krusty, I was establishing the best possible rate of the climb for the Seafire. If that falls below the full load climb rate, it shows the full extent of the discrepancy.
My regards,
Widewing
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OOooooOOooohh... I see what you mean. Sorry, I'm rather dense today!
So, if even at 25% it does that poorly, it's WAY below spec, right?
I'm thinking maybe the Seafire was deboosted and it has the old chart or something.
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Originally posted by Krusty
Second: Maybe the chart hasn't been updated since the de-boosting of the SpitV? Didn't the Seafire share the same de-boosting? I don't fly it often so I can't say for sure. Thought I'd put it out there.
Nope Seafire wasn't 'de-boosted', still has the same Merlin 45/46 it always has had.
Only difference now is the Spit V has the same motor.
Bring the Merlin 32 Seafire L IIc to AH :) .
Or the Merlin 55M Seafire L III, hell lets have both.
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Bring on Seafire L III! Give it a lower ENY though cause it's a killer:)
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BTW, how does AH's Spit XIV rack up to RL? Or the Mk VIII?
Both of them would hit 20K in 5 mins. The XIV there in question is the early one.
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Originally posted by Krusty
First: Shouldn't all tests be done with 100%? If they go by official flight tests and charts, chances are they had full fuel there, so I'd think these charts would be full fuel as well. (this was always my assumption with them).
To be precise we'd need to know the specific aircraft configuration for the AH charts. What is the weight and external stores?
In RL, military specs would determine required performance under very specific conditions for contract purposes, however, whatever conditions produced the best numbers would be the one quoted in general literature. For precise numbers there would also be a whole list of performance charts provided which gave specific performance at specific weights/ loadouts/ altitudes. Hard to say how much of this material HTC has.
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According to HTC this is not possible.
http://www.hitechcreations.com/forums/showthread.php?s=&threadid=189254&highlight=Charts (http://www.hitechcreations.com/forums/showthread.php?s=&threadid=189254&highlight=Charts)
"Sloehand: The charts in the hangar can not be out of date, they are generated on the fly from the current AH model.
HiTech"
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Maybe in-game, but what about the ones on the webpage? When we got the new variants, there's been occasions where a chart is simply missing for a while (this was the case with the new P38s for many months). Then again maybe that's a process they have to run to produce the image, and they could be tardy in running the process. So it's possible the chart could be old. However, with this new info (btw: thanks for the info!) it doesn't seem likely.
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Originally posted by MOSQ
According to HTC this is not possible.
http://www.hitechcreations.com/forums/showthread.php?s=&threadid=189254&highlight=Charts (http://www.hitechcreations.com/forums/showthread.php?s=&threadid=189254&highlight=Charts)
"Sloehand: The charts in the hangar can not be out of date, they are generated on the fly from the current AH model.
HiTech"
In this case it is more than possible. I tested the Seafire three times and it averages 3:48 to climb to 12,000 feet using auto-climb. Climb varies between 2,975 to 3,075 feet per minute over that height. This is well below what is shown on the chart (in game or from the website). Perhaps they have the Seafire's weight incorrect. Nonetheless, it does not climb anywhere near the chart's rate, even when flying with just 25% fuel.
I also tested climb in MIL power. Again, with 25% fuel. All tests were done with the plane flying at 50 feet @ 160 mph. Auoto-climb was engaged and power brought up to WEP or MIL. Once again, the Seafire fell well short of the charted climb rate. See chart below.
(http://home.att.net/~c.c.jordan/SeafireClimbActual2.gif)
My regards,
Widewing
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Charts In hangar can not be out of date, on the web page they can be.
I am assuming the charts match right now, I havn't looked, so that meens somthing is amiss in either testing or the setup of the seafire.
we will take look at it.
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Originally posted by MOSQ
According to HTC this is not possible.
http://www.hitechcreations.com/forums/showthread.php?s=&threadid=189254&highlight=Charts (http://www.hitechcreations.com/forums/showthread.php?s=&threadid=189254&highlight=Charts)
"Sloehand: The charts in the hangar can not be out of date, they are generated on the fly from the current AH model.
HiTech"
He said it was impossible for the in-game charts to be out of date, not that it was impossible to see differing performance from the charts. The charts are based on a specific test weight. If the plane is not at that specific weight, you will see different results. It used to be that the charts had to be manually generated and propagated and that process could get overlooked leaving the charts out of date. That is no longer the case wrt the in-game charts.
The test weights used to generate charts are usually at a full fuel load and normal armament. However, that is not always the case. E.G., the performance in the P-51s is with the aux tank empty. This is dependent upon the data I'm using and the conditions they tested at.
The Seafire is in a special category of variant because it essentially shares the same airframe and powerplant as the Spit V. The performance difference between the two primarily comes from the additional weight. The beefed up structure, tailhook, and C wing with extra ammo load make up the weight difference between the two. If you compare the performance charts between the Seafire and Spit V, you will notice that they are in fact identical. The difference between the two is that the Spit V is at the test weight for that chart at 100% fuel while the Seafire is at the correct test weight at about 25% fuel. The F4U-1C is in a similar situation where it weighs slightly more than the 1D but uses the same performance chart.
That's the majority of the discrepancy. As I pointed out, the Seafire should be hitting the numbers at around a 25% fuel load but it clearly is not. In checking into this, the remaining discrepancy is in that the gauge is a bit off. Maybe we can get rate of climb into the E6B so those types of errors can be quickly spotted. Generally a discrepancy will be in the gauge but it can also more seriously be that I screwed up the weight schedule and the plane is either underweight or overweight. That's a lot easier to do than it sounds because of how the test software is setup but I've gotten pretty obsessive compulsive about rechecking that multiple times.
It would be nice to have something in the hangar that would tally up your weight as you changed your fuel and ordnance load and let you compare that against the test weight of the performance charts. Maybe output a wing loading number on the fly.
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75% of the seafire's internal fuel is ... what?... about 1,000lbs extra weight?
I'd think that with THAT much of a discrepency, this variant needs its own charts. At 25% it can't even touch the spitV with 100% gas. That really doesn't seem right, considering they're almost the same plane.
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Originally posted by Pyro
It would be nice to have something in the hangar that would tally up your weight as you changed your fuel and ordnance load and let you compare that against the test weight of the performance charts. Maybe output a wing loading number on the fly.
Couple basic output values on fly (while testing off-line) would make analysis much easier: Weight, TAS and g load (possibly divided for axis components of the plane). In addition some shooting related outputs would also be nice; exact range to the target, number of hits, hit %.
I have not played AH for a while but some time ago I tried to make some statistics by shooting the drones at long range. I recorded how many shots were needed to down a drone, but my shooting improved while testing so in practice the numbers I got were not particularly representative.
gripen
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Originally posted by Pyro
It would be nice to have something in the hangar that would tally up your weight as you changed your fuel and ordnance load and let you compare that against the test weight of the performance charts. Maybe output a wing loading number on the fly.
Excellent Idea!
Also the E6B output would be sweet.
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The chart still shows the +16lbs version of the Seafire IIc. The "new" one is +12lbs. Thus the lower climb rate.
When the Spits were redone, we asked why the Seafire IIc was de rated.
Operationally, it used +16lbs by November 1942, when it saw service, along with Spit Vs.
The Spit Vb we have in AH is a version from a year earlier (Feb 41) compared to the Seafire IIc (Nov 42).
Would be nice if they reconsidered and gave it its proper boost.
My previous post:
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Seafire IIc max boost
The Seafire IIC was first issued to the Fleet Air Arm in July of 1942.
The first action they fought in was "Torch" in November 1942 (Supermarine Seafire P.6 John Freeman) with 807, 880, 884 and 885 Sqns.
By that time, the Spitfire V series and the Seafire series had been modified to a combat boost limit of +16 lbs for 5 minutes (summer 1942).
Spit V here: http://www.spitfireperformance.com/spitv.html
"Aeroplane and Armament Experimental Establishment
Boscombe Down
25 November 1942
Spitfire Mk. VC AA.878
(Merlin 45)
Climb, speed, and cooling tests at combat rating
SUMMARY
The operational limitations of the Merlin 45 have been increased, the use of 3000 R.P.M. and +16 lb/sq.in. boost being now permitted for periods not exceeding 3 minutes during combat. Tests have been made to determine the performance of the aeroplane at this new rating, and also whether the oil and radiator cooling are adequate."
Seafire IIC here, http://www.spitfireperformance.com/seafireIIc.pdf and I will quote the entry:
"The increase in performance obtainable by using combat rating (+16 lb/sq.in ; boost 3000rpm) on a Spitfire Vc is given in the Part of Report No. A& A.E.E/692i and this increase will approximately be equal in the Seafire"
Final source is "Spitfire In Action" page 53 "An engine modification was introduced to give +16 lbs sq.in. manifold pressure at low level." -Refs to both the Seafire IB and Seafire IIC.
And finally...the original Seafire IIC in AH was correct, and had +16 lbs boost, it is not a 1941 Spit Vb.
*If there is a concern of over use, simply limit the Seafire to CVs only in the MA*, but imho it should have +16 lbs.
Thank you.
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Squire - If its a 1941 Seafire it would have to be one of the few converted RAF Spits.
Doesn't make sense.
All purpose built IIc's had 16lbs boost.
The 1941 Seafires were all converted from RAF Va's. Vb's and IIb's.
So we actually have a Seafire that never existed, as all the converted RAF ones were Seafire Ib's with 'A' frame arrestor hooks.
Guessing it was easier to give it the same FM as the Vb rather than do a new one.
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Well, my point is that the VAST majority of any Seafire IIc's would have been +16 lbs boost, even if there were some early ones with +12 lbs.
It should be as it was before, +16lbs.
In any case thats the discrepancy of the climb chart.
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Is 160mph its best climbing speed? Did you test it with any other speed?
-C+
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IF thats the case it makes it the RAREST Seafire ever built, hardly a representative version of the mark.
Considering only 110 Seafire IIcs were built with Merlin 46's (already the rarest version, the rest were built with Merlin 32's) they would have to be among the very first few off the production line.
Perfect time to fix them and give them the common Merlin 32 engine.
All of the original 110 built as Merlin 46 Seafires were retro-fitted with the Merlin 32.
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Originally posted by Charge
Is 160mph its best climbing speed? Did you test it with any other speed?
-C+
160 mph IAS is the Seafire's best climb speed. Therefore, any other speed would not have produced a better sustained rate of climb.
My regards,
Widewing
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Thank god I discovered that there's HUGE discrepansies betweem the AH seafire II chart and the actual performance of seafire II in the game.
Imo Seafire IIc should be boosted again to +16. Add clipped wing Seafire L III. Seafire IIIs were made up the majority of seafire linenup in RN.