Author Topic: Credibility (Read 1422 times)

Guppy35 · « **Reply #15 on:** December 11, 2007, 01:27:09 AM »

Quote

Originally posted by DweebFire
Guppy,

Thanks for clearing that up. The VIII used in the tests were the old rudder, the normal filter (like the ones on Mk.V spits) and Mk.VII wing tips.

The IX was Merlin 61 engine, regular rudder, likely a Mk.V filter as well since the test was during 1942.

That however is almost exactly the same as our Mk.IX in game and our weights are still off by some 140 + lbs.

So you are talking an early Spit IX which is in essence a Spitfire Vc with the Merlin 61, rounded rudder, normal span wings and no tropicalization.

The Spit VIII would have the beefed up fuselage, tropical filter, extended wing tips, retractable tail wheel and wing tanks. VIII's were meant for overseas service and were tropicalized from the start.

That in itself would probably amount to the weight difference.

DweebFire · « **Reply #16 on:** December 11, 2007, 04:29:06 PM »

True, yet the Spitfire IX in the tests are practically identical to the in-game Spitfire IX, the only difference being our IX has an Aero-Vee air filter and the one in the test likely did not.. it was a 1942 test, and that plane had an all-up weight of 7445 lbs, no DT's, no ord, just full ammo, B-type armament in a C-type wing; just like our IX.

The VIII with long span wings and (likely an Aboukir filter that I've seen on really early Mk.VIII's) and a normal chord rudder is the test plane. Our in-game one is the typical Spit VIII of late '43 - both planes are consistent in weights.. in the tests, the latter Spit VIII is 7800 lbs and the in-game VIII is 7807. Nothing seemingly wrong there. If anything the removal of long span should make the plane lighter. The wide chord rudder, I think, wouldn't add much weight.

And our weights still come up strange when using those calculations and plugging in these factors: weights and loadings

I'm not doubting that the Mk.VIII is heavier than the IX. The problem lies in the fact that the Mk.IX is too light and should reflect more upon the VIII's weight.

But when the calculations ARE completed from the test information, the weights seem weird since the Mk.VIII SHOULD weigh at LEAST 182 lbs. vs. the IX at all configurations, but using official all-up weights and subtracting fuel/ammo, we find the VIII is only 88 lbs. heavier.

So the game SEEMS to have correct weight differences between the VIII and IX but incorrect weights for the IX according to tests.

Wolfala · « **Reply #17 on:** December 11, 2007, 07:00:14 PM »

Quote

Originally posted by Guppy35
So you are talking an early Spit IX which is in essence a Spitfire Vc with the Merlin 61, rounded rudder, normal span wings and no tropicalization.

The Spit VIII would have the beefed up fuselage, tropical filter, extended wing tips, retractable tail wheel and wing tanks. VIII's were meant for overseas service and were tropicalized from the start.

That in itself would probably amount to the weight difference.

By this, do you mean they were bathed in Alodine from birth to account for the increase in gross weight?

Stoney74 · « **Reply #18 on:** December 11, 2007, 07:07:53 PM »

Quote

Originally posted by Wolfala
By this, do you mean they were bathed in Alodine from birth to account for the increase in gross weight?

I don't think Alodine is dense enough. It must be a healthy coat of Zinc Chromate on everything...

Squire · « **Reply #19 on:** December 11, 2007, 11:55:32 PM »

Merlin 61 Spitfire F.IX from the docs provided:

".2.4. Loading. The tests were made at a take-off weight 7805 lbs. with the bomb on"

Quoting the 1942 F. IX Merlin 61 takeoff weight, fuelled, and armed.

...Less the 500 lb bomb, you get 7303 lbs. Exactly the loaded weight of the F. IX Merlin 61 in Aces High, to the pound (with no bomb).

DweebFire · « **Reply #20 on:** December 12, 2007, 10:14:51 PM »

You're right but this is weird... why are the weights different from those in the weights and loading test...? Maybe the prop... on most tests, they say Hamilton Standard Hydrodynamic propellor or something like that... on this test, they just say 'four bladed propeller, Type R3/4F5/3'. Anyone know what that is?
Additionally it says that the 303 guns and accessories are removed and 'No W/T aerial I.F.F. aerials' Is this the test youre referring to?

I don't believe these weights make sense because the all-up weight ended as 7445 lbs. not 7805 or 7303 lbs. in the documents i provided in my previous post.

In this test, the long-span, Merlin 63 Mk.VIII has a weight of 7,760 lbs. even less than the game. I think an increase in wing span with a normal rudder would be heavier than a normal span with a 'Griffon' rudder.

Squire · « **Reply #21 on:** December 12, 2007, 11:02:57 PM »

There is a difference of more than a hundred pounds with some of the props (wood vs metal), as well the Spitfire IXs in many of those tests were carrying 95 Imp gallons, as opposed to the 85 gallons (102 US) the Aces High Spit IX has, thats another 78 pounds right there.

Some had two 48 gal Imp tanks (95) some had a 37 gal and a 48 gal (85).

Also, some Spit IXs had rear fuselage tanks, and again, thats going to mess with weights.

With a diff prop and a 37+48 tank, the weight diff could be as much as 188 pounds.

Seems there are many quoted weights for the F. IX, but I think 7303 loaded with no bomb carrier is close to the mark, with just fwrd fuel carried. There are other tests where they are fully equipped with loaded weights @7300-7400. You need an exhaustive list of the exact components to make a comparison, and thats hard to come by.

68Ripper · « **Reply #22 on:** December 13, 2007, 01:46:48 PM »

Maybe the test Pilot had a heavy meal?

DweebFire · « **Reply #23 on:** December 13, 2007, 02:58:30 PM »

The following link, I think, has enough of that info needed. Here

No Merlin 61 Spitfire IX carried the extra fuel in the rear tanks operationally in 1942. The test states the fuel load to be the standard 85 Imp. Gallons.

Also, the propeller type is stated in every test. If it isn't, the Spitfire is carrying the most common prop type. It's always somewhere there in the test description or on a list. The above test states that it was a Rotol Duraluminium (Dural) propeller.

If I'm not mistaken, the British definition of 'gross weight' is the weight with all accessories, full fuel, full ammo but no external tanks/ords. In addition, the planes are always armed with 2x 20mm cannon (120 rpg) and 4x.303" MGs (350 rpg) unless stated otherwise.

The weight still stands as 7445 lbs.

Squire · « **Reply #24 on:** December 13, 2007, 08:21:05 PM »

The prop type might be stated in every test, but the Spitfire IXs eventually went with the Rotol Hydulignum props (laminated wood) that are not from the test above.

Aces High does not have to model "AB917" from October 1942 (a converted MkV version, and one of the earliest in the production run) with a Rotol metal prop to have a Merlin 61 F.IXc

Weights in one specific model are not absolutes, unless the installed equipment never varied, and there is almost no combat a/c that thats true for.

I dont have HTCs data, and I cant say what model of the F.IXc they went with, unless they want to post it. They have never stated, to my knowledge what precise version they modelled.

Im not saying the couldn't model AB917, im just saying they didnt have to.

Personally, I would have liked to see a Merlin 63 F. IX, rather than the Merlin 61.

DweebFire · « **Reply #25 on:** December 14, 2007, 06:34:19 PM »

True, weights are never the same or rarely the same for 2 aircraft, even if of the same variant. All of the tests except the bomb test have the Spit's weight at or above 7400 lbs.

I too would rather have the Merlin 63 version... though we get more of the taste of time when they give us the Merlin 61 version.