Building the Supermarine Spitfire

Flight Manual Data

Engine Data:

Supercharged V6 Isuzu 3.5

Fuel 98 to 100 Octane

Oil 15w 40

Engine Limitations:

Max 5200 rpm

Oil pressure 60-80 psi

Cruise 3200-3400 rpm

Fuel pressure 42-52 psi

Flying Limitations

Vmo 193 kts

Vle 110 kts

Vfe 90 kts.

Pre Start Checklist

Brakes ON

U/C Levers both forward

U/C Electrical Switches both down

Flaps Up

Fuel - Sufficient for Flight

Fuel Cock Lever ON

Throttle CLOSED

Propellor - FULL FINE

Radiator Cowl Flaps OPEN

Master Switch - ON

MoTeC Switch - ON

Ignition Switches - ON

After Start Checklist

Oil Pressure - CHECK

Allow engine to warm up at 1000-2000 rpm until water temperature reaches 80 deg C. and oil temperature 50 C.

Avionics Master Switch - ON

Com/Nav Radios & Transponder - ON

Pre Take-Off Checklist

Engine Instruments - CHECK

Flight Instruments - CHECK

Ignition Systems - CHECK



Trim - SET FOR T/O

Flaps - UP

Controls - FULL & FREE

After Take-Off Checklist

Gear - UP

Flaps - UP

Climb Power - SET

Weight and Balance Data


For weighing and weight and balance references:

Horizontal Datum: Topside fuselage longeron

Vertical Datum: Front face of the firewall

Centre of Gravity Range

Using the front face of the firewall as vertical datum and the top, side, fuselage longeron as horizontal datum, the centre of gravity range, in % of MAC is set at: Forward limit: 18% (520 mm aft of datum) Rear limit: 34%. (745 mm aft of datum) This centre of gravity range to be verified by flight test including spin / spin recovery trials and applies to all gross weights up to 810 kg.


For weight and balance purposes these arms from the vertical datum, front face of the firewall apply:

Pilot: + 1100 mm

Fuel: + 400 mm

Oil : - 600 mm

Baggage: + 1600 mm

Passenger: + 1600 mm

Propeller: - 1260 mm

Spinner/Plate:- 1375 mm

Rear fuselage ballast: +4900 mm

Weighing to be with unusable fuel only, full ail, full engine coolant ,no baggage.

Centre of Gravity Position ~:

Where X = Distance of Centre of Gravity Aft of Firewall

Where W1 = Weight measured at Mainwheels

Where W2 = Weight measured at Tailwheel

Where A = Distance from Firewall to Mainwheels

Where B = Distance from Mainwheels to Tailwheel

Where W = Empty Weight


Design Gross Weight 810 kg

Typical Empty Weight: 551kg

Weight of Non Flying Parts:

Pilot: 110kg

Engine, mount, controls cowls etc: 245 kg


Fuselage complete:114kg


Fuel ( Part of 115L):84kg

Baggage 2nd pilot:75


Wing Weight:

Outer panels (2):64kg

Centre section:56kg

Undercarriage assemblies (2):24kg



Design Gross Weight 720kg

Typical Empty Weight: 551kg

Weight of Non Flying Parts: Pilot 86kg

Engine, mount, controls 245kg

Propeller Spinner 20kg

Fuselage complete 114kg

Tailplane 18kg Fuel ( Part of 115L) 93kg

NFP TOTAL 576 kg

Wing Weight: Outer panels (2) 64kg

Centre section 56kg

Undercarriage assemblies (2) 24kg




Using set criteria the following loading combinations must be contained inside the nominated, in-flight, Centre of Gravity limits. For dual flight the rear passenger allowance is to be calculated and then placarded.

Foward CG Limit Case Maximum fuel 84 kg

Minimum weight pilot 55 kg

Forward CG Limit set at: 18% MAC

Rear CG Limit Case: Only unusable fuel

Maximum pilot 110 kg

Passenger calculated

Rear C.G limit set at: 34% MAC

To bring the tailwheel weight ,when weighed empty in the level attitude, to between 2kg and 4kg, up to 6 kg of ballast may need to be added to the fin ballast point.

Warnings, Cautions and Notes

The following definitions apply to warnings, cautions and notes used in the flight manual.

WARNING: means that the non-observation of the corresponding procedure leads to an immediate or important degradation of the flight safety

CAUTION: means that the non-observation of the corresponding procedure leads to a minor or to a more or less long term degradation of the flight safety

NOTE: draws the attention to any special item not directly related to safety but which is important or unusual.


Wing span: 27.5Ft

Wing Area : 122 SqFt

Mean Aerodynamic Chord: 1380mm

Wing Aspect Ratio: 6:1

Span fixed centre section: 7.8Ft

Span of each outer panel: 9.85Ft

Dihedral: 5 Deg

Design gross weight: 810kg

Engine : Isuzu V6 Supercharged

Horse power: 330hp

Propeller: Variable pitch propellers meeting engine makers requirements and the airframe weight and balance limits are allowed

Diameter pitch: 78 in

Aileron up travel: 14 deg

Aileron down travel: 12 deg

Elevator up travel : 18 deg

Elevator down travel: 15 deg

Rudder travel each way: 30 deg

Landing flap down travel: 70 deg

Main Fuel tank capacity: 115 litres

Wing Tank capacity: 85 litres each

Wing incidence to datum: +2.0 deg

Wing outer panel washout: -2.5 deg

Horizontal tailplane incidence: 0 deg

Flap system: Electric

Retracting U/C System: Electric

Steel tube U/C legs: Rubber/Spring in Compression

Hydraulic wheel brakes: Disc

12 volt electrical system: 30 amp

Elevator trim: Push/Pull

Main wheels: 15-600-6

Main tyre pressure: 35 psi


The Spitfire MK 26 is of all metal construction, pressed ribs and frames, with alloy tube section main spar caps. A mixture of aircraft grade and commercial grade materials are used: The wing main spar utilises 6061-T6 square alloy tubing for the top and bottom caps and 2024-T3 alclad sheet alloy for shear webs. The aircraft is skinned in 2024-T3 alclad sheet alloy All frames and ribs are formed from 2024-T3 alclad sheet alloy The undercarriage legs are 31 6 stainless steel tube and 41 30n steel parts The engine mount is 4130n round tube of varying dia and wall thickness The structure is rivetted using mainly blind rivets. Engine cowls are constructed in Fire Resistant epoxy resin/glass cloth. Normal aviation construction conventions are applied throughout the structure, flight and engine control systems.


For reference purposes, throughout this document, the relevant parts of FAR Part 23 references and guidelines will be shown " (23-*)"

" The relevant parts of JAR-VLA will be shown "(VIA***)"



The Mk26 when loaded to 810 kg will carry one pilot, one passenger and a significant fuel load. In this condition FAR 23 "Utility Category" limitations apply.


The basis of VLA Aerobatic Category justification. The Mk26 when kept to solo only (no passenger) will operate at a gross weight of 720 kg which would be the basis of Aerobatic Category justification.

This Type Report does not specifically address Aerobatic Category for the Mk26 but does provide some basic specifications for later use and shows where structural tests have gone to this level.


Design load factors are determined from VLA Appendix A table 3 observing the basic factors set out in VLA 337 and FAR A23 .


Limit positive load factor Va NI +4.4

Limit negative load factor Va N2 -2.2

Ultimate positive load factor +6.6

Ultimate negative load factor -3.3

Limit positive load factor VC N3 +4.4

Limit negative load fador VC N4 -2.2

General safety factor 1.5

Other safety factors are applied to specific parts of the structure and systems as recommended in FAR 23 I JAR guidelines.


JAR and FAR differ in their requirements for body weight. Since body weight is a significant part of a small aircraft and can seriously affect the balance. The more conservative line of JAR 22 which asks for a solo pilot with parachute to be a maximum of 110 kg and a minimum of 55 kg and 2 pilots combined to not exceed 200kg has been adopted. This directly influences such things a seat design, harness restraint, maximum weight of non flying parts, Centre of Gravity range etc. The reality is that in 2006, body weights are on the increase which is accounted for in the JAR 22 requirements.

Pilot weights include parachute if worn. This aircraft is to be weighed and these weights shown by cockpit placard for each category.


With a calibrated pitot/static head under the LH wing tip, Position Error is negligible in the working speed range. All speeds to be confirmed by flight test.


Stall Speed (flap U/C retracted) Vs1

Stall Speed (flap and U/C extended) Vso

* Max Speed Flap extended VFe

* Design Manoeuvre Speed Va

* Design Speed for Maximum gusts Vb

* Maximum Structural Cruise Speed Vno

*Maximum Operating Limit Speed Vmo

* Maximum U/C extend Speed Vlo

* Maximum Speed U/C extended Vle



* These speeds can be assumed to be I.A.S. and are to be placarded in the cockpit and used for A.S.I. colour coding.


(Knots CAS)

The following speeds are determined for various aspects of flight test work taken at Gross Weight 810kg, Utility Category. These speeds for design and test flight are considered to be CAS and subject to both Instrument Calibration Error and Position Error for conversion to IAS.

Stall speed Flaps & U/C extended:Vso = 43kts

1.2 Vso = 54kts

1.3 Vso = 59kts

1.4 Vso = 61kts

Stall speed clean:Vs = 52kts

1.2 Vs = 65kts

1.3 Vs = 71kts

1.4 Vs = 76kts

Demonstrated Cruise speed @ SL: Vh = 160kt

Design Cruise Speed:Vc = 136kts

Design Dive Speed: Vdmin 215kts

Placarded maximum Vmo:(.9*Vdmin) 190kts