The Spitfire I has had its engine performance and Lift profile modified to better reflect the historical aircraft's performance.
ENGINE
Merlin II inline liquid cooled engine with Single Stage Supercharger, Full Throttle Height of 15,000 ft at +6 boost (unrammed)
Pilots should note this is an earlier generation Merlin engine, and is slightly less reliable than more current types. Care should be exercised in the use and careful attention to rpms and temperatures.
5 minute Power Setting
+6 boost in Level High Speed Flight with rpms at or close to 3000 rpm
+6 boost in Climb or Combat Manoeuvre with rpms at close to 2850 rpm
30 minute Climb Setting
Coarse Pitch at +6 boost, 170-175mph climb speed
Unlimited Cruise Power Setting
Coarse Pitch at +3 boost or lower
PROPELLOR
Aircraft has a De-Havilland Two Speed Propellor, maximum rpms are not restricted by the propellor governor. Pilots will need to watch their engine rpms to avoid over-revving their engine or Propellor governor. Pilots should use their throttle to keep rpms to a maximum of 3000 rpm. A “Do not Exceed” limit of 3200 rpm is in effect for dives. Exceeding this engine speed will very likely result in the destruction of the engine.
The two settings available are either 'Fine Pitch' or 'Coarse Pitch'.
Pilots will notice that in both Coarse and Fine Pitch rpms rise as altitude is gained, this is a natural result of how these aircraft's propeller settings were tuned. Maximum rpms in Coarse Pitch were designed to arrive at approximately Full Throttle Height, (+6 boost) to allow maximum speeds at those altitudes to be attained. For this reason, rpms and performance at lower levels are less than desirable. This is one of the compromises of a simple two pitch propeller system.
FINE PITCH
Fine pitch is only intended for use in takeoff and landing, and below 2,000ft, and only in climbs and slow speed manoeuvre at or below that altitude. Any attempt to use Fine Pitch at higher altitudes or in dives or in higher speed situations will result in excessive engine and governor rpms and the destruction of the Pilot's engine.
COARSE PITCH
Coarse pitch is intended to be used for most situations, including Climb, Dive, Level Flight and Combat Manoeuvre. Pilots will need to watch their rpms, although the potential for over-revving the engine or prop governor is not as high as the rpms are more controllable.
PITCH CHANGE RATE AND USING THE PITCH CONTROL LEVER TO SIMULATE A VARIABLE PITCH SYSTEM
Pitch change rates Coarse to Fine and vice versa have been revised to documented historical speeds
Pitch change from Coarse to Fine or vice versa takes 10 seconds.
Pilots may use this slower pitch change mechanism in the same way as the real RAF pilots did, as a means to mimic a variable pitch system and gain a bit of acceleration when Coarse Pitch rpms are very low. When the prop is in Coarse Pitch and the rpms are low, the pilot can engage the lever to change to Fine Pitch. The rpms will then rise as the blade angles change giving more bite to the prop and a brief burst of acceleration. Before the rpms reach 3000 and the engine over-revs, the Pilot should change the lever position back to Coarse Pitch, so that the Prop pitch reverses, and the engine goes back to lower RPM's. This technique is only recommended for use between 0- 10,000ft, or when at altitudes over 20,000ft. Extreme caution should be used to avoid over-revving the engine.
===Temporary description to cover TF ver 3.01 with use of VP system. Detailed Re write to be added later.=== The Spitfire MKI 2 pitch system could in fact be used with limitations as a Variable Pitch system. Though not exactly designed with this in mind it was found by pilots that careful use of the Prop pitch control allowed them to set any desired RPM rather than just Coarse or Fine pitch setting. This did not provide the complete flexibility of a dedicated VP system but did allow intermediate RPM control.This was good for certain flight phases like climb and Cruise. Due to limitations in the Pitch plunger design it does not really lend itself to combat flying. In this patch we have enabled the pilot to select a desired RPM. Blade angle change rates are still the same as was used in the original 2 Pitch system. We have not changed the 3d modelling of the Pitch lever, this will be done at a later stage. In the real aircraft the Pitch Change control was of a plunger or Push Pull type control.
ENGINE TEMPERATURE MANAGEMENT
The aircraft has a liquid cooled, (100% Glycol) engine. Shutters can be opened and closed by the pilot to regulate the Radiator coolant temperature. In addition the aircraft has an automatic Oil Cooler, which is not controlled by the pilot. Gauges for both Radiator and Oil Cooler temperatures are displayed on the right side of cockpit dashboard.
Glycol Recommended Temperatures:
Minimum: 60c
Normal: 105-115c
Maximum: 116-120c
Oil Recommended Temperatures:
Minimum: 40c
Normal: 90-95c
Maximum: 96-98c
Note: Engine damage due to coolant or oil overheat CAN occur at lower than MAX temperatures. BEWARE of going close to those limits. Pay especial care when using +12 boost in low speed/high angle of attack manoeuvring.
STARTING THE ENGINE
Magneto 1 + 2 switches 'On'
Fuel Control to Main Tank 'Open'
Radiator Closed
Throttle to 10% open
Propellor in Fine Pitch
Start
ENGINE WARMUP
Engine must be warmed prior to takeoff. Leave Radiator closed till following:
Radiator Temperature gauge should read 60c prior to takeoff
Oil Temperature must be 40c prior to takeoff.
TAXIING
The Aircraft's radiator should be opened full before taxiing. The Spitfire is taxied using a combination of low engine power with applications of rudder and brakes providing the steering input. Pilots need to be very careful when applying brakes, as the aircraft can tip onto its nose easily. Pilots should use a 'fishtail' pattern during taxiing so they can see any obstacles in front of them.
TAKEOFF
Open Radiator to 100%
Select Fine Pitch
Use +6 boost Throttle setting
The aircraft will accelerate slower than one with a Constant Speed Propellor and a long runway is required. No attempt to lift the aircraft off early should be made, it should fly off the ground naturally. Flaps may be deployed if pilots wish to shorten their takeoff distance, however they should beware the nose down attitude which will result after tail comes up, this must be controlled or the aircraft's propeller blades will contact the ground.
After takeoff, aircraft should be levelled out, undercarriage and flaps raised before any turns attempted.
After aircraft is airborne:
Raise undercarriage
Raise Flaps (if they were used)
Once the aircraft reaches 180 mph Coarse Pitch can be selected
TRIM
The aircraft has trim for elevator and rudder. Pilots use the Sideslip Indicator on the right side of the cockpit dashboard to trim their rudder accurately. Needle should be centred. Pilots may also use the rudder to centre the sideslip needle during combat for accurate shooting.
PERFORMANCE
Max. Speed at Sea Level: 272 mph
Aircraft has a single stage supercharger, with the rammed Full Throttle Height, (FTH) being approx. 16250 ft at +6 boost. Performance falls off rapidly above this height. The Spitfire I is a responsive and manoeuvrable aircraft at low, medium and high altitudes. It is slower than the Bf-109 at all altitudes. It is faster than the Bf-110 at all altitudes. It will outturn 109's and 110's at low and medium and high altitudes. It loses performance at higher altitudes, especially over 25,000ft.
CONTINUOUS CLIMB
Open radiator to 50% at sea level to approx 10,000 ft, open to full as necessary to control temperature and as altitudes rise
Select +6 boost
Select Coarse Pitch
Climb at 175-180 mph Indicated Airspeed to start, decreasing to 130 mph at ceiling.
CARBURETOR MIXTURE
The engine is equipped with a carburettor which allows the pilot to select either 'Rich' or 'Lean' mixtures. 'Rich' mixture is used in all normal situations, takeoff, landing, climb, combat. 'Lean' mixture is only used to conserve fuel in level flight Cruise settings, and only when boost is set to '+1' or lower, and rpms to 2600 or lower. Use of 'Lean' mixture setting at higher rpms or boost will result in the destruction of the engine.
DIVING
Maximum Dive Speed: 420 mph Indicated Airspeed.
Maximum Dive Rpm's: 3200
Pilots should exercise caution when pulling out of a high speed dive, they should be cautious about using full elevator, especially with nose up elevator trim, and should be especially cautious when they have taken damage to their wings.
LANDING
Descend below 1000 ft and reduce throttle to slow aircraft to 160 mph
Select Fine pitch
Select Down Flaps
Select Undercarriage down
Trim aircraft for level flight, reduce speed to 130 mph, very gentle turns
On Runway glide approach, reduce speed to 120 mph, then to 100mph over threshold, cutting throttle. Holding the nose level, allow the aircraft to sink gently at 100 mph, touching at 90mph.
Make sure the aircraft is settled on all three wheels before beginning to brake, pump brakes extremely gently and do not hold them. The Spitfire has a tendency to tip over onto its nose if anything other than very gentle braking is used.
Ответить с цитированием
Сообщение от Yak-1
