The Battle of BritainThe Battle of Britain
Adrian Stewart
Copyrighted Presentation Mike Lavelle
2015 - The 75th Anniversary Remembrance David Lednicer - 8 April 2015
Events that Influenced the Battle of Britain
The Battle of BritainThe Battle of Britain
Copyrighted Presentation Mike Lavelle
The Real Story: British Fighters vs. German Fighters
The Battle of BritainThe Battle of Britain
• British fighters:– Hawker Hurricane I – Supermarine Spitfire I & II– Boulton Paul Defiant I
• German:– Messerschmitt Bf 109E– Messerschmitt BF 110C
The Opponents
The Battle of BritainThe Battle of Britain• Hawker
– Sidney Camm– Roy Chaplin
• Vickers Supermarine– R.J. Mitchell– Joseph Smith (after 1937)– Beverly Shenstone
• Boulton Paul– John Dudley North
• Messerschmitt (Bayerische Flugzeugwerke until 1938)– Willy Messerschmitt– Robert Lusser
Principal Designers
The Battle of BritainThe Battle of Britain
• Designed to Specification F.5/34– Interceptor monoplane with eight
machine guns and speeds in excess of 300 mph
– Specification F.36/34 written to match Hawker design submission
• Conservative design for 1935– Space-frame, fabric covered fuselage
and wings– Stressed-skin metal wing later
introduced– Unsophisticated aerodynamics
Hurricane Development
Fuel tanks
The Battle of BritainThe Battle of Britain
• Designed to Specification F.7/30
– Monoplane “zone” fighter with four machine guns and speeds in excess of 215 mph
– Specification F.10/35 written to match Supermarine design submission
• Advanced design for 1935
– Stressed-skin metal fuselage and wing
– Sophisticated aerodynamics
Spitfire Development
Fuel tanks
The Battle of BritainThe Battle of Britain
• Designed to Specification F.9/35
– Two-seat four-gun turret fighter
– “Bomber destroyer” concept
– No forward-firing armament
• Advanced design for 1937
– Stressed-skin metal fuselage and wing
– Modestly sophisticated aerodynamics
Defiant Development
Fuel tanks
The Battle of BritainThe Battle of Britain
• Designed to specification L.A. 1432/33– Short-range interceptor with top speed
of 250 mph at 19,690 feet– Climb to 19,690 feet in 17 minutes
and flight duration of 90 minutes• Advanced design for 1934
– Power increased by 50% with installation of fuel-injected DB 601A in the Bf 109E
– Stressed-skin metal fuselage and wing– Sophisticated aerodynamics
Bf 109 Development
Fuel tank
The Battle of BritainThe Battle of Britain
• Designed against a RLM request
– Long-range twin-engine, three-seat, all-metal monoplane
– Armed with cannon
• Advanced design for 1935
– Stressed-skin metal fuselage and wing
– Sophisticated aerodynamics
Bf 110 Development
Fuel tanks
The Battle of BritainThe Battle of Britain
• Hurricane fuel header tank was not isolated from the cockpit
• Spitfire fuel tank was ahead of the fireproof bulkhead
• Self-sealing capability and armor added to Hurricane and Spitfire fuel tanks during the Battle of Britain
• Bf 109E did not have a self-sealing fuel tank
• Bf 110C did have a self-sealing fuel tanks
Fire Danger
Flt Lt James Nicolson, only member of the
Fighter Command to be awarded a Victoria
Cross during the Battle of Britain
The Battle of BritainThe Battle of Britain
• Cockpits were not pressurized– Pilots breathing 100% oxygen above
15,000 feet• Cockpits reported to be well-heated • G-suits not invented yet• Flight suits were not fire-resistant
– Nomex fabric not invented yet• Over-water survival suits not invented yet• Crash helmets not invented yet• Rescue radios and beacons not invented yet
Flying Kit
The Battle of BritainThe Battle of BritainAerodynamics – Pressure Distributions
NACA 22XX airfoils
NACA 2R1 XX airfoils
Note forward loading on airfoils
Hurricane design used older Clark YH airfoil
The Battle of BritainThe Battle of BritainLater Designs, for Comparison
Airfoil loaded further aft
The Battle of BritainThe Battle of Britain
• Spitfire I & II
– Radiator on right, oil cooler on left
• Hurricane I & Defiant I
– Radiator on centerline
• Bf 109E & Bf 110C
– Radiators on both sides
Cooling System Ducts
The Battle of BritainThe Battle of Britain
• Rolls Royce Merlin II– 27 litre V-12– 1,030 hp at sea level– Single stage, single speed direct-
drive supercharger– 100 octane fuel
• Daimler Benz DB 601A– 34 litre inverted V-12– 1,085 hp at sea level– Single stage, single speed
hydraulic-drive supercharger– 87 octane fuel
Engines
The Battle of BritainThe Battle of BritainEngines
0
5000
10000
15000
20000
25000
30000
0 200 400 600 800 1000 1200 1400
Altit
ude
(fee
t)
Power Output (hp)
Merlin II 6.25 psi boost
Merlin III 12 psi boost
DB 601A 1.3 atm boost
DB 601A 1.4 atm boost
Supercharging maintains power to higher altitude
1.3 atm = 4.41 psi boost1.4 atm = 5.88 psi boost
Merlins could run at higher boost, partly due
to higher octane fuel
The Battle of BritainThe Battle of Britain
• Hurricane
– 600 miles
• Spitfire
– 395 miles
• Defiant
– 465 miles
• Bf 109E
– 410 miles
• Bf 110C
– 900 miles
Radius of Action
200 mile radius
100 mile radius
The Battle of BritainThe Battle of Britain
• Bf 110C
– 2 x 20 mm MG-FFM cannon in nose
– 4 x 7.92 mm MG 17 machine guns in nose
– 1 x 7.92 mm MG 17 machine gun aft-facing
• Hurricane and Spitfire
– 8 x 0.303 caliber machine guns
• Defiant
– 4 x 0.303 caliber machine guns in turret
• Bf 109E
– 2 x 7.92 mm MG 17 machine guns in cowling
– 2 x 20 mm MG-FF or FFM wing cannon
Armament
Cannon shells contain explosive,
bullets don’t
The Battle of BritainThe Battle of BritainVisibility• Hurricane I
– Framing obscures view
– Little rearward visibility
– Rear-view mirror
– Bullet resistant glass windshield• Spitfire I & II
– Good visibility in all directions
– Rear-view mirror
– Bullet resistant glass windshield
• Bf 109E
– Framing obscures view
– Very tight
– No rear-view mirror
– Some had bullet resistant glass windshields
The Battle of BritainThe Battle of Britain
• Early warning
– British had long-range aerial coverage with centralized command and control
– Germans only used radar to monitor shipping
• Combat formations
– Germans used “fluid four”
– British quickly adopted this
• Sun position
– Mornings favored Germans
– Afternoons favored British
Tactical Considerations
The Battle of BritainThe Battle of Britain
• Level speed
• Rate of climb
• Turning radius
• Roll rate
• Diving
• Ceiling
Maneuvering Factors
The Battle of BritainThe Battle of BritainCombat Pattern
Luftwaffe bombers at 16-20,000 feet
Luftwaffe escort fighters
Goal of RAF fighters
Altitude
The Battle of BritainThe Battle of BritainClimb Performance
0
5000
10000
15000
20000
25000
30000
35000
0 500 1000 1500 2000 2500 3000 3500 4000
Altit
ude
(fee
t)
Rate of Climb (feet/min)
Spitfire I 6.25 psi boost
Hurricane I 12 psi boost
Hurricane I 6.25 psi boost
Defiant I 6.25 psi boost
Bf 109E
Bf 110C
The Battle of BritainThe Battle of BritainLevel Speed
0
5000
10000
15000
20000
25000
30000
35000
0 50 100 150 200 250 300 350 400
Altit
ude
(fee
t)
Level Speed (mph true)
Spitfire I 6.25 psi boost
Spitfire I 12 psi boost
Hurricane I 6.25 psi boost
Hurricane I 12 psi boost
Defiant I 6.25 psi boost
BF 109E
Bf 109E 1.33 atm boost
Bf 110C-1
The Battle of BritainThe Battle of BritainTurn Radius
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
-800 -400 0 400 800 1200 1600 2000 2400
feet
feet
Hurricane I
Spitfire I
Bf 109E
Bf 110C
14 second turn
The Battle of BritainThe Battle of BritainRoll Rate
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 50 100 150 200 250 300 350 400
Tim
e to
45
deg
of b
ank
(sec
)
Airspeed (mph IAS)
Sptifire I RAE
Sptifire V NACA
Hurricane I NACA
Bf 109E RAE
Fabric covered ailerons
Metal covered ailerons
The Battle of BritainThe Battle of Britain
0
50
100
150
200
250
300
350
400
450
500
Hurricane I Spitfire I Defiant I Bf 109E Bf 110C
Indi
cate
d Ai
rspe
ed (m
ph)
DivingControl problems made this speed
hazardous
The Battle of BritainThe Battle of BritainDive Initiation Issue
• RR Merlin had a SU carburetor – If a dive was started with a push-over, the fuel
flow would be disrupted by the negative gs– Engine would cut out– Dives had to be initiated with a half-roll, then a
pull– Problem fixed (in 1941) with a restrictor
diaphragm, developed by Beatrice 'Tilly' Shilling of the RAE
• DB 601A was fuel injected– Bosch had precision machining necessary to build
metering pumps– Dives could be started with a push-over
The Battle of BritainThe Battle of BritainAltitude Performance
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
Hurricane I Spitfire I Defiant I Bf 109E Bf 110C
Altit
ude
(fee
t)
The Battle of BritainThe Battle of BritainConclusion
• Defiant I– Ill-conceived concept– Poor performance– Withdrawn from day combat in late August 1940
• Bf 110C– Good firepower and range– Lacked maneuverability
• Spitfire I and Bf 109E– Closely matched– Bf 109E had insufficient fuel
• Hurricane I– Outclassed, but still useful
The Battle of BritainThe Battle of BritainThe Outcome
• RAF lost:– 1,547 aircraft– 544 aircrew
• Luftwaffe lost:– 1,887 aircraft– 2,698 aircrew
• Defenders decisively defeated potential invaders
The Battle of BritainThe Battle of Britain
Copyrighted Presentation Mike Lavelle
Why All This is Important to Me
My Family’s Escape: May 10 to June 1940
Departed Lisbon for Brazil November 19, 1940
The Battle of BritainThe Battle of BritainWhere to See the Aircraft
• Spitfire
– Historic Flight Foundation (LF Mk.Ixe)
– Flying Heritage Collection (LF Mk.Vc)
• Hurricane
– Flying Heritage Collection (Sea Hurricane Mk XII)
• Defiant I
– RAF Museum in Hendon UK
• Bf 109E
– Flying Heritage Collection
• Bf 110C
– Several survivors in Europe