DCS: Spitfire Mk LF IXc Discussion

[Kurfürst]

Dive instructions for the Spitfire II, warning of airframe failures due to control characteristics (because of very light elevator controls, it is easy to overstrain the airframe, even accidentally)

 

 

[Kurfürst]

RAAF testing with serial production Mk VIII JF 934.

 

[Kurfürst]

Range of Spitfire IX (M 61)

 

[Kurfürst]

Conclusion from the report "Note on the Speed of Production Spitfires". It is concluded that there were some increase in drag from added external equipment, bumps, cannon barrels and the like, and furthermore the production quality was so low at a point that serial production Mk Vs (as opposed to shiny prototypes) could not even reach the top speed of the previous Mk I.

 

The Mark IX saw "some improvement" in the poor quality of surface finish.

 

[Kurfürst]

GGS Gyro gunsight was not regularly fitted to Spitfire aircraft even in March - April 1945:

 

See "Was Gyro gunsight used - No, Not Fitted."

 

 

There are a few exaples of the sight being fitted towards the end of April 1945, a few weeks before the war's end.

 

http://www.wwiiaircraftperformance.org/130_Samouelle_24april45.jpg

[MiloMorai]

GGS Gyro gunsight was not regularly fitted to Spitfire aircraft even in March - April 1945:

 

One squadron, No.130, with Spitfire XIVs. Spitfire XIVs are not Spitfire IXs.

 

As for the other posts, other Marks are irrelevant as this thread is about the Mk V and Mk IX, so please don't clutter the thread with unrelated info.

Edited July 17, 2014 by MiloMorai
fixed quote

[Friedrich-4B]

Emergency exit in dive is difficult (Mark II):

 

 

Pilot's Notes for Mk II? This doesn't have anything to do with the Mk IX - all Spitfires after the Mk II had hood jettisoning equipment fitted so the pilot didn't have to attempt to slide the hood open in an emergency.

 

Dive bombing prohibited on Spitfire Mark VIII:

 

 

In a Post-War RAAF document describing reported defects on Mk VIIIs - rest of report not shown and nothing to do with 2 TAF Spitfire IXs.

 

'All care' should be excercised when using the metal covered ailerons in high speed dives because of the 'great strain imposed' on the Spitfire:

 

 

Extract of a report from 1941 - guess this is an attempt to convince the audience that the Spitfire was a delicate, fragile beast. According to Morgan and Shacklady it would seem that the Spitfire IXs could handle things better than Kurfurst likes to think.

 

Dive instructions for the Spitfire II, warning of airframe failures due to control characteristics (because of very light elevator controls, it is easy to overstrain the airframe, even accidentally)

 

 

 

Not relevant to the Spitfire IX which, apart from early versions converted from Mk VCs, had larger elevator horn balances which helped solve the problem.

 

RAAF testing with serial production Mk VIII JF 934.

 

 

And this applies to European based Mk IXs how?

 

Range of Spitfire IX (M 61)

 

 

Yes and? No mention of drop tanks? Merlin 61 with carburettor rather than injection unit of Merlin 66?

 

Conclusion from the report "Note on the Speed of Production Spitfires". It is concluded that there were some increase in drag from added external equipment, bumps, cannon barrels and the like, and furthermore the production quality was so low at a point that serial production Mk Vs (as opposed to shiny prototypes) could not even reach the top speed of the previous Mk I.

 

The Mark IX saw "some improvement" in the poor quality of surface finish.

 

 

What Kurfurst conveniently left out:

 

 

Plus there was this follow up document:

 

Presumably Kurfurst is implying that the 1942 reports were not heeded and the surface finish of Spitfires remained poor for the rest of the war.

 

So a whole lot of material relevant to Spitfire IIs, Vs and VIIIs, with very little relevant to 2 TAF Mk IXs. No idea of the relevance of any of these partial documents, interesting as they are, to Ed's pending Mk IX.

Edited July 17, 2014 by Friedrich-4/B

[Kurfürst]

Further on the clipping of Spitfire wings.

 

Apparently the modification was beneficial to those production machines which had a "poor set of ailerons" and at the same time, little improvement was observed on machines with good set of ailerons. The application of sensitive Frise type ailerons used also on the Spitfire may have also contributed, as this type was sensitive for correct balancing and pairing.

 

The clipping of the wings was therefore not recommended, apart from fixing structural issues observed with the Spitfire during maneuvers involving diving.

 

 

 

 

 

Clipping was probably done to reduce wing twisting reducing roll rate...

 

[Friedrich-4B]

Further on the clipping of Spitfire wings.

 

Apparently the modification was beneficial to those production machines which had a "poor set of ailerons" and at the same time, little improvement was observed on machines with good set of ailerons. The application of sensitive Frise type ailerons used also on the Spitfire may have also contributed, as this type was sensitive for correct balancing and pairing.

 

The clipping of the wings was therefore not recommended, apart from fixing structural issues observed with the Spitfire during maneuvers involving diving.

 

 

A questionnaire which asks six pilots to compare their Spitfire Vbs against Fw 190s: general consensus was that the clipped wings improved lateral control and helped against Fw 190, although not sufficiently to beat it. Nothing new or sensational there, and how does it relate to 2 TAF Spitfire IXs?

 

 

How useful is this as a "definitive" analysis? "No report can be made...concerning combat with enemy aircraft with clipped wing aircraft." How many pilots were questioned and how representative is this of Fighter Command as a whole?

 

 

Report on the Spitfire XII which had a Griffon engine and a propeller that rotated in the opposite direction to that of the Merlin. Okay.

 

 

One negative report, and a positive report:

 

 

Clipping was probably done to reduce wing twisting reducing roll rate...

 

 

An extract from an RAE comment concerning a NACA report on a Spitfire VA: if the wings did indeed twist in flight, clipping the wings and enhancing torsional rigidity would enhance aileron efficiency, as noted in the AFDU report posted above.

 

Otherwise, no reports specific to Mk IX with clipped wings; as it is 2 TAF didn't seem to have many clipped L.F Mk IXs so, again, interesting as these are in their own right none of these documents seem to be relevant to ED's Spitfire IX.

Edited July 17, 2014 by Friedrich-4/B

[Kurfürst]

From :

 

"Measurements of the flying qualities of a Supermarine Sptitife VA airplane." NACA Advanced Confidental Report, by William H. Phillips and Joseph R. Vensel.

 

The tests were conducted at Langley field, Va., during the period from December 30, 1941 to January 29, 1942. Sixteen flights and apprx. 18 hours flying time were required to complete the tests.

 

[...]

 

Desription of the the Supermarine Spitfire airplane

 

Name and Type : Supermarine Spitfire VA (Air Mininstry No. W3119).

Engine : R-R Merlin XLV

Weight, empty : 4960 lbs

Normal gross weight : 6237 lbs

Weight as flown for tests : 6184 lbs

 

Ailerons (metal-covered)

Lenght (each) : 6 feet, 10 1/2 inches

Area (total area, each) : 9.45 sq. feet

Balance area (each) : 2.45 square feet

 

[...]

 

A stick force of 2 lbs to the right and 3 lbs to the left was required to overcome aileron friction.

 

[...]

 

Lateral Stability and Control

 

Aileron-control characteristics : The effectiveness of the ailerons of the Supermarine Spitfire airplane was determined by recording the rolling velocity produced by abrubtly deflecting the ailerons at various speeds. The aileron angles and stick forces were measured. It should be noted that the airplane tested was equipeed with metal covered ailerons.

 

[...]

 

The ailerons were sufficiently effective at low speeds, and were relatively light at small deflections in high speed flight. The forces required to obtain high rolling velocities in high-speed flight were considered excessive.

With a stick force of 30 lbs, full deflection of the ailerons could be obtained at speeds lower than 110 miles per hour. A value of pb/2V of 0.09 radian in left rolls and 0.08 radian in right rolls were obtained with full deflection.

 

Rolling velocity (at 6000 ft altitude) of about 59 degrees per second could be obtained with 30 lbs stick force at 230 miles per hour indicated speed.

 

The ailerons were relatively light for small deflections, but the slope of the curve of stick force against deflection increased progressively with deflection, so that about five times as much force was required to fully deflect the ailerons as was needed to reach one-half of the maximum travel. The effectiveness of the ailerons increased almost linearly with deflection all the way up to maximum position. The value of pb/2V obtained for a given ailerons deflection was nearly the same in speeds and conditions tested. It may be concluded, therefore, that there was very little reduction in aileron effectiveness either by separation of flow near minimum speeds or by wing twist at high speed.

 

Fig 27 shows the aileron deflection, stick force, and helix angle obtained in a series of roll at various speeds intended to represent the maximum rolling velocity that could be readily obtained.

 

The pilot was able to exert a maximum of about 40 lbs on the stick. With this force, full deflection could be attained only up to about 130 miles per hour. Beyond this speed, the rapid increase in stick force near maximum deflection prevented full motion of the control stick. Only one-half of the available deflection was reached with a 40 lbs stick force at 300 miles per hour, with the result that the pb/2V obtainable at this speed was reduced to 0.04 radian, or one-half that reached at low speeds.

 

Another method of presenting the results of the aileron-roll measurements is that given in figure 28, where the force for different rolling velocities is plotted as a function of speed. The relatively light forces required to reach small rolling velocities are readily seen from this figure. The excessive forces required to reach high rolling velocities and the impossibility of obtaining maximum aileron deflection much above 140 miles per hour are also illustrated.

 

 

From :

 

STABILITY AND CONTROL SUB-COMMITEE. AERONAUTICAL RESEARCH COMMITEE

Comparision of aileron control charactheristics as determined in Flight Tests of P-36, P-40, 'Spitfire' and 'Hurricane' Pursuit airplanes.

 

By William H. Philps. N.A.C.A. Confidental Bulletin. 16th November, 1942

 

[..]

 

The aileron effectiveness of the various airplanes is compared in the following table on the basis of the response obtained with stick forces of 30 and 5 pounds. A force of 30 lbs is somewhat less than the greatest stick force exerted by the pilot. Repeated flight measurements have shown, however, that this forcer is a reasonable upper limit for manouvering at high speeds. A comparision at a stick force of 5 lbs are also included to bring out a rather interesting fact regarding the order of merit of aileron effectiveness for the various airplanes when very light forces are used :

 

Rolling velocities obtained with 30 lbs stick force at 230 mph indicated airspeed at 10 000 ft. (deg/sec)

 

P-36 : 43

P-40 : 90

Hurricane : 64

Spitfire : 63

 

Rolling velocities obtained with 5 lbs stick force at 230 mph indicated airspeed at 10 000 ft (deg/sec)

 

P-36 : 9

P-40 : 8

Hurricane : 19

Spitfire : 15

 

A further comparision of the aileron performance of the four airplanes is given in figure 2, which shows how the control force characteristics influence the rolling velocities obtained through the speed range."

 

Full report at: http://jsbsim.sourceforge.net/spit_flying.pdf

Edited July 18, 2014 by Kurfürst
added link for full report

[Narushima]

Reading this, I wonder, does DCS simulate pilot fatigue? Meaning after 20 minutes of doing aileron rolls will the pilot get tired and subsequently the roll rate will drop?

[NineLine]

Reading this, I wonder, does DCS simulate pilot fatigue? Meaning after 20 minutes of doing aileron rolls will the pilot get tired and subsequently the roll rate will drop?

 

I dont think so.

[9.JG27 DavidRed]

Reading this, I wonder, does DCS simulate pilot fatigue? Meaning after 20 minutes of doing aileron rolls will the pilot get tired and subsequently the roll rate will drop?

 

i hope not!

[Sharpe]

i hope not!

 

depends on your level of concentration.

[Kurfürst]

On the related note, how does DCS model the maximum physical főre the pilot can Apple to the stick?

[cichlidfan]

Reading this, I wonder, does DCS simulate pilot fatigue? Meaning after 20 minutes of doing aileron rolls will the pilot get tired and subsequently the roll rate will drop?

 

If they did we would just have more of the same 'real pilot stamina' arguments that we already have regarding G effects.

[klem]

I got fed up reading at page 12, can YO-YO give a roundup of what he is designing (mark/wing/engine/armament)?

[Kurfürst]

Soviet trial results of Spitfire Mk IXLF. The Soviet Union received 1000+ Spitfire IXs during the war and were used for home defense duties in rear.

 

Top speed was found to be 528 km/h at SL, 628 km/h at 5500, top climb rate 22,8 m/sec - quite impressive.

 

 

[Friedrich-4B]

Soviet trial results of Spitfire Mk IXLF. The Soviet Union received 1000+ Spitfire IXs during the war and were used for home defense duties in rear.

 

Top speed was found to be 528 km/h at SL, 628 km/h at 5500, top climb rate 22,8 m/sec - quite impressive.

 

 

 

Interestingly the top speed figures are about 20 mph slower than MA648 ("slightly above average") tested between November 1943 - Feb 1944, and 14 to 17 mph slower than early-mid production Spitfire IXs BS310 & BS543, retro-fitted with Merlin 66s: JL165 was a Mk VC converted to an early IX in March '43

 

 

and had a below average performance for any Mk IX, including the L.F Mk IX: the Soviet figures are more in line with JL165.

 

http://www.spitfireperformance.com/ma648.html;

 

a Rolls-Royce Bendix-Stromberg injection carburettor was subsequently adopted as standard on the Merlin 66, as was the lengthened intake with Vokes filter:

 

Edited July 21, 2014 by Friedrich-4/B

[Kurfürst]

Full NACA report on roll rate of P-36, P-40, Hurricane, Spitfire V (metal ailerons).

rollrate Р-36.40Хурик Спит.pdf

[Friedrich-4B]

From Robert Bracken's:

 

Two different events on July 2 and 3 1944:

 

 

 

 

From Shores and Thomas 2 TAF volume 2; 403 Sqn's combat was on July 2:

 

Chevers' Spitfire should have been listed as NH189 of 132Sqn which wasn't written off for future operations:

 

NH189 LFIX CBAF M66 33MU 1-5-44 132S 15-6-44 CAC 3-7-44 453S 'FU-Z' 27-7-44 412S 17-8-44 Combat with Me109s and Fw190s on standing patrol Nijmegen 27-9-44 F/O P E Hurtubise killed

Edited August 3, 2014 by Friedrich-4/B

[Charly_Owl]

Can't wait for Spitfire cockpit screenies *crosses fingers*

 

It's pretty much the only DCS WWII module we have seen nothing of so far.

[flare2000x]

Can't wait for Spitfire cockpit screenies *crosses fingers*

 

It's pretty much the only DCS WWII module we have seen nothing of so far.

 

It's also the reason I backed for DCS: WWII. I can't wait for the Spitfire to come out, 190s and 109s will be falling like rocks!

[BigJimMcBob]

"in the end we have learned that this "high proportion of 2 TAF Spitfires" were actually about 10 (ten) Squadrons, give or take a couple, most whom had very little or no actual contact at all with enemy fighters, and whom would be rightfully described by some as insignificant, penny packet numbers."

 

Quick check of Shores & Thomas shows that in the first 10 days of the invasion, Spitfire IXs of 2 TAF made 94 air-to-air claims (destroyed, probable, damaged) against Luftwaffe aircraft. Of these, 47 were made by Spitfires of 126, 127 and 132 Wings (equipped with the gyro gunsight as above), with a further 26 being accounted for by aircraft of 135 Wing (equipping with the gyro sight as above).

 

In short, most of the damage being done to the Luftwaffe in mid-'44 by Spitfire IXs of 2 TAF was being done by gyro-gunsight equipped aircraft.

Edited August 28, 2014 by BigJimMcBob

[Stephen Higginbotham]

Wow I have been all this time thinking that something was wrong with my P-51 program. I give it a little rudder or stick and it just seems to go all over the place. And stalls at a drop of a hat! flustrating.