Author Topic: Why this model of Spit IX? (Read 1918 times)

Buzzbait · « **on:** January 03, 2001, 11:40:00 PM »

Salute to all

I don't fly the Spit much, I prefer Boom and Zoom types, but I can't help but notice something about the Spit IX. This aircraft is obviously the Spit IXF. I tested it at S.L. for speed. The best I could get was 320mph at approx. 200ft. The Climb rate was more difficult to ascertain, but when using Alt. X, it worked out to 3750ft per min. starting at Sea Level and up to approx. 5,000ft.

Now there were several models of Spitfire IX made. The original was the IXF, which when tested a the Air Fighting Development Unit in late 1942, had a speed of approx. 313mph at S.L., 410mph at approx. 20,000ft. It was produced starting in late '42 and into '43. Later models had slightly improved performance from increased boost and higher octane fuel. Then there was the Spit IXHF, which was produced in small numbers and generally used as the basis for high altitude recon aircraft. But the most common was the Spitfire IXLF. Close to 70% of Spit IX's produced were the LF model. The LF sacrificed a little speed at altitude, (404mph at approx. 20,000ft) for more speed at Sea Level. (336mph) It also had a much better rate of climb, topping out at 4400 ft per min. compared to the approx. 3600 ft per min. of the original Spit IXF. It got this from running on significantly higher boost, and higher octane fuel.

It seems AH is using the Spit IXF, perhaps with the slightly higher boost. My question is: Why? It is far more representative to use the LF model.

I know some people on these boards have been licking their lips in anticipation of the arrival of the Spitfire XIV. But no less of an authority than JE "Johnnie" Johnson, British 38 kill Ace, who flew most of the Marks of Spitfires, including the Spit XIV, said the Spit IXLF was the best of the breed.

It is interesting to note that all the British Fighters date from late '42 and early '43 unlike the American or German aircraft.

We have models of American aircraft dating from late spring 1945, but the Hawker Tempest, which was introduced in May of 1944 is not present.

Anyway, wondering why?

Toad · « **Reply #1 on:** January 03, 2001, 11:42:00 PM »

Because they are not done adding aircraft?

hazed- · « **Reply #2 on:** January 04, 2001, 12:14:00 AM »

maybe its because HtC is american and they prefer to have the best US planes verses the mediocre axis stuff? hehe

just stirring the pot!

hazed

funked · « **Reply #3 on:** January 04, 2001, 12:22:00 AM »

LF would be nice. That's what the real 308 Sqn flew mostly and I'd love to have it.

------------------
Major Mike "FunkedUp" Waltz
Officer Commanding, 308 (Polish) Squadron "City of Cracow" RAF

Northolt Wing (1st Polish Fighter Wing)

[This message has been edited by funked (edited 01-04-2001).]

-duma- · « **Reply #4 on:** January 04, 2001, 03:12:00 AM »

Buzz, the Tempest will be added - but as a perk plane. I can sympathise with this, since the MA is almost always low level and even as is the Typhoon ('42 aircraft I think?) is one of the most competitive aircraft in the arena.

If Tempest was not a perk plane it'd pretty much rule the arena

F4UDOA · « **Reply #5 on:** January 04, 2001, 08:22:00 AM »

Buzzbait,

I think (but do not know) that one reason is the fuel factor. You mentioned higher octane fuel being used to increase performance. Is that fuel 100 octane, 115 octane or 125. I have heard as high as 150 for some model Spitty's. In any case HTC may be modeling the performance of these birds based on some standard for fuel. Consider the USN used 115 octane fuel when testing the F4U-4. That extra 15 octane gave it a climb of 4770FPM from 3850FPM with 100octane fuel. Which one should be modeled? See where I'm going. I think every A/C in AH is based on a standard for fuel that was used by there country.

funked · « **Reply #6 on:** January 04, 2001, 10:38:00 AM »

Nope fuel had nothing to do with the performance difference between F, LF, and HF. The performance figures Buzzbait quotes are for standard (100 octane) fuel.

Here are some figures for an LF with 150 octane:

Height Top Speed Time to climb mins Rate of Climb ft/min
2,000 360 0 m 25 s 4,725
4,000 364 0 m 50 s 4,730
6,000 364 1 m 15 s 4,735
10,000 370 2 m 6 s 4,745
13,800 389 . 4,350
20,000 388 4 m 30 s 3,450
30,000 380 8 m 17 s 1,950

http://www.fourthfightergroup.com/eagles/spit9.html

[This message has been edited by funked (edited 01-04-2001).]

SKurj · « **Reply #7 on:** January 04, 2001, 11:39:00 AM »

there used to be a horse around here somewhere....

AKskurj

Bradburger · « **Reply #8 on:** January 04, 2001, 11:54:00 AM »

I wondered when the AH crowd would ask this question. It seems another community is asking it as well!

http://agw.dogfighter.com/agw//Forum3/HTML/017289.html

Cheers

Paul

LJK Raubvogel · « **Reply #9 on:** January 04, 2001, 07:00:00 PM »

LF, F, they all explode the same.

------------------
LJK_Raubvogel
LuftJägerKorps

[This message has been edited by LJK Raubvogel (edited 01-04-2001).]

Spatula · « **Reply #10 on:** January 04, 2001, 10:12:00 PM »

roflol raub

Hans · « **Reply #11 on:** January 05, 2001, 03:12:00 AM »

LF, F, and HF are the different types of WINGS that can be mounted to the fuselage of the Spitfire.

LF is low altitude, and is a clipped-tip wing.

F is the normal wing.

HF is high altitude, and has a longer wingspan.

Also, the Spits have a suffix letter, and it refers to the guns in the wing.

-A is eight .303 machineguns.
-B is two cannons, and four .303 machinguns.
-C is four cannons.
-E is two cannons and two .50 caliber machinguns.

So, and Spitfire LF Mk IVC is a clipped wing, four cannon armed version of the Spitfire 4 airframe/engine.

A Spitfire F Mk XIVA is a normal shapped wing with eight little .303 machineguns armed version of the Spitfire 14 airframe/engine.

Hans.

Nath-BDP · « **Reply #12 on:** January 05, 2001, 12:23:00 PM »

LF, F or HF also indicates what type of environment the engine is designed for.

Example

The LF. Mk V's Merlin 45M, 50M and 55M (M was the suffix given to Merlins that had a cropped supercharger blower of 9.5-in diameter) had their supercharger blower decreased in size to allow it to obtain higher speeds at altitudes of below 6k which the regular Mk V with a Merlin 45 or 46 could not (at lower altitudes the high-altitude optimized Merlin 45(46)'s automatic boost control unit (ABCU) which prevented over-boosting could cause pre-detonation and possible damaged to the cylinders--the same went for the Spitfire IX with the -61 engine.) , along with the clipped wings. Also, most of the Mk Vs that were converted to LF were older machines that had been in use for quite awhile. Thus the LF Mk V was affectionately nicknamed the "clipped, cropped and clapped spitty", referring to its wings, supercharger and age respectively.

------------------
Nath_____
9./JG 54 "Grünherz"

"It felt as if an angel was pushing..."
-Reponse of Gen. Adolf Galland after flying the fourth prototype Me 262 in May 1943.

[This message has been edited by Nath-BDP (edited 01-05-2001).]

Nath-BDP · « **Reply #13 on:** January 05, 2001, 12:33:00 PM »

Hans typeth:

Quote

-A is eight .303 machineguns.
-B is two cannons, and four .303 machinguns.
-C is four cannons.
-E is two cannons and two .50 caliber machinguns.

Are those designations for later Spitfire variants?

The Mark I-to-V used the suffixes as continues:

A, 8 .303.

B, 2x 20mm Hisp. and 4x .303.

C referred to the redesigned and strengthened structure of Spitfire V airframes since most Spit Vs were upgraded from Spit I or IIs, the weight of the new engine and several other accommodations put burden on the structure of the aircraft. The C could hold the A or B armament. Or 4 20mm cannon only. The C wing was referred to as the 'Universal' wing.

P.S. not all LF fighters had clipped wings, some had the standard but with the -M engines.

------------------
Nath_____
9./JG 54 "Grünherz"

"It felt as if an angel was pushing..."
-Reponse of Gen. Adolf Galland after flying the fourth prototype Me 262 in May 1943.

[This message has been edited by Nath-BDP (edited 01-05-2001).]

[This message has been edited by Nath-BDP (edited 01-05-2001).]

Bradburger · « **Reply #14 on:** January 05, 2001, 02:29:00 PM »

Nath your correct.

To clarify things, these are the variants of the MkIX that were produced:

F.IX - Merlin 61,63 or 63A - B, C or E wing(Normal span or clipped)

LF.IX - Merlin 66 - B, C or E (Normal span or clipped

HFIX - Merlin 70 - C or E wing
(normal span or extended*)

*mostly had standard wingtips as the extended tips were not popular due to adverse effects on handling.

The wing designations applied for all marks up to the XVIII although the A wing was only used on the MK1, MKII & early V's. The 'C' wing could have four cannons if the 303's were deleted but was usually the same as the 'B'.

Btw there was also the FRIX which was a field modification of either an F or LFIX and fitted with a single camera for fighter-recon duties. These aircraft were painted a pale pink colour overall (See link in my previous post for an example).

Cheers

Paul

[This message has been edited by Bradburger (edited 01-05-2001).]