Heavy attacks on London, broken up by Fighter Command. Highest German losses since 18 August [185 claimed by the RAF] force a serious rethink by the German High Command.

Night: Heavy damage to London.

Weather: Fair with some cloud patches. Fine during the evening.

By mid-September 1940, the Luftwaffe’s campaign against Fighter Command had reached a critical juncture. Adolf Hitler had set a provisional date of 17 September for Operation Sea Lion, contingent on German air superiority being achieved. With time running out and the autumn weather becoming increasingly unpredictable, Reichsmarschall Hermann Göring issued orders on 14 September for a maximum-effort daylight assault on London the following day. It would be the fifth large-scale attack on the capital and was intended to crush British morale and destroy the last of Fighter Command’s strength. Specific flight paths and bombing altitudes were distributed to bomber Gruppen. While the Germans remained unaware of the limitations of British radar above 20,000 feet, they had begun flying at higher altitudes in the belief that such tactics had delayed RAF interceptions in recent raids.

Despite repeated promises that one final blow would bring victory, morale among German aircrews was low. Luftwaffe crews had been told in July and again in August that Fighter Command was nearly defeated, yet every raid met fierce resistance. As General Adolf Galland later recalled:

“Failure to achieve any notable success, constantly changing orders betraying lack of purpose and obvious misjudgment of the situation by the Command… had a most demoralizing effect on us, the fighter pilots, who were already overtaxed by physical and mental strain.”

In Britain, the picture was different. Fighter Command had recovered much of its operational strength. Airfields had been repaired, aircraft losses replenished, and radar stations were restored to full capacity. The Luftwaffe’s daily bombing of aerodromes had not succeeded in breaking down the system. By 15 September, the RAF was ready.

Enemy Action by Day

Weather over southern England had cleared after overnight rain, with fine conditions prevailing beneath a broken cloud base. At RAF Uxbridge, Air Vice-Marshal Keith Park received early radar reports indicating increased German aerial activity over northern France. That morning, Prime Minister Winston Churchill visited No. 11 Group headquarters. At the time of his arrival, the plotting tables showed little more than scattered reconnaissance tracks, and WAAF personnel continued their duties as normal.

The first daylight combat occurred shortly after 08:00 hours. A Heinkel He 111 from Aufklärungsgruppe 51, engaged in long-range reconnaissance, was intercepted over the Channel by Hurricanes of No. 87 Squadron and shot down. A Heinkel He 59 air-sea rescue aircraft was dispatched to search for survivors but found no trace of the bomber or its five-man crew. Further high-altitude reconnaissance flights by Ju 88s penetrated deep into Britain during the morning, photographing targets ranging from RAF Sealand and Chatham Dockyard to Manchester and Liverpool. These aircraft flew above the effective interception ceiling, and all returned safely.

Though these early movements caused no damage, their scale and pattern suggested that a major operation was imminent.

10:10–13:00 Hours: The Noon Attack

At 10:10 hours, the first major German formation became airborne. Major Alois Lindmayr, Gruppenkommandeur of I./Kampfgeschwader 76, led the attack. A veteran of the French campaign and holder of the Knight’s Cross, Lindmayr commanded a force of Dornier Do 17s drawn from both I. and III./KG 76. III./KG 76 contributed 19 aircraft from Cormeilles-en-Vexin, while I./KG 76—reduced by attrition—could muster only eight serviceable bombers. As a result, two Gruppen were committed to perform the task normally assigned to one.

The formation rendezvoused over Amiens before proceeding toward Cap Gris-Nez to meet its fighter escort. En route, cloud disrupted cohesion, delaying the force by approximately ten minutes while it reformed. Two bombers failed to rejoin and returned to base. Among the attacking aircraft was a Dornier piloted by Feldwebel Rudolf Heitsch, experimentally fitted with a rear-mounted infantry flamethrower intended to deter close pursuit.

At 10:30 hours, Chain Home radar stations—particularly Dover—reported a hostile concentration forming over the Pas-de-Calais. The filter room at Stanmore confirmed the tracks, and group and sector commands were alerted that more than forty aircraft were entering Kentish airspace. By 11:04 hours, Lindmayr’s force had reached Calais. Wing Commander Lord Willoughby de Broke, Park’s senior controller, observed the raid’s progress alongside Park and the Prime Minister, uncertain whether the plots represented bombers or fighter sweeps.

Park elected to gamble. At 11:15 hours, he committed nine squadrons from Biggin Hill, ordering Nos. 72 and 92 Squadrons to patrol at 25,000 feet over Canterbury. No. 603 Squadron was to follow and attack the close escort. Further squadrons were held in readiness at Northolt, Kenley, Debden, Hornchurch, and North Weald.

The bombers crossed the English coast at Folkestone at 11:36 hours. Escorting them were Bf 109s from JG 27 and I./JG 52 at medium altitude, JG 53 providing top cover, and approximately thirty aircraft from JG 3 flying close escort. Elements of Lehrgeschwader 2 operated ahead of the main force. A strong headwind slowed the Dorniers, increasing fuel consumption among the Bf 109s while simultaneously aiding RAF fighters climbing from the north.

At 11:50 hours, Spitfires of Nos. 72 and 92 Squadrons attacked from above, breaking up JG 53’s top cover. No. 603 Squadron soon joined the fight, engaging JG 3’s close escort. Hurricanes from Nos. 253 and 501 Squadrons delivered head-on attacks against the bombers, holding their formation steady under intense defensive fire. Additional squadrons—Nos. 229 and 303—became engaged as the battle spread across Kent.

Park’s tactic of attacking continuously along the bombers’ route succeeded in draining escort fuel reserves. By 12:07 hours, as the outskirts of London came into view, the Bf 109s began to disengage and return to France, leaving the bombers exposed.

Hurricanes from Nos. 504 and 257 Squadrons intercepted the trailing Dorniers over south London. One bomber, piloted by Feldwebel Robert Zehbe of 1./KG 76, fell behind with engine trouble and attracted repeated attacks. Sergeant Ray Holmes of No. 504 Squadron, out of ammunition, collided with the aircraft during the engagement. The Dornier disintegrated, crashing onto the forecourt of Victoria Station, while bombs detached during its descent struck areas near Buckingham Palace, causing damage but failing to explode. Holmes bailed out injured and survived; Zehbe also bailed out but later died of his wounds.

Contrary to later popular accounts, Holmes’s combat report did not describe a deliberate ramming. The incident nevertheless became embedded in public mythology as an emblem of desperate resistance.

At the same time, Bader’s Duxford Wing—Nos. 19, 242, 302, 310, and 611 Squadrons—arrived over London at 11:22 hours and attacked as the bombers released their loads. Dorniers dropped their bombs at approximately 12:07 hours, striking rail lines near Battersea Park. Though tracks and a viaduct were damaged, repairs were completed within days.

Within minutes, KG 76’s formation was shattered. Six Dorniers were destroyed and many others badly damaged. One of the losses was Heitsch’s flame-thrower-equipped aircraft, in which the experimental device malfunctioned at altitude, spraying oil and attracting fighter attacks. The surviving bombers withdrew under limited escort.

By 13:00 hours, the first phase had ended. Churchill, watching the plots clear from the table, expressed satisfaction as RAF fighters returned to refuel and rearm. Of the Duxford Wing’s 56 aircraft, only 49 remained serviceable for the afternoon.

13:45–15:45 Hours: The Afternoon Attack

Even as KG 76’s survivors landed in France, a far larger second wave was assembling. Bomber units from KG 2, KG 3, KG 26, and KG 53 took off to attack the London docks and industrial targets north and south of the Thames. In total, 114 bombers advanced in four columns, supported by a powerful fighter screen from JG 3, JG 26, JG 53, JG 77, and elements of LG 2 and ZG 26.

Chain Home detected the raid at 13:45 hours. Park ordered successive waves of interceptions, eventually committing nearly every available squadron. By 14:20 hours, the RAF had 276 fighters airborne, though the Germans still enjoyed a numerical advantage—particularly in Bf 109s.

Initial engagements erupted over Romney Marsh, where Spitfires of Nos. 41, 92, and 222 Squadrons clashed with JG 26. Hurricanes from Nos. 213 and 607 attacked KG 3 head-on, followed by further assaults from Nos. 605 and 501 Squadrons. Despite losses, the Dorniers pressed on, reaching the Thames at 14:31 under heavy anti-aircraft fire.

At approximately 14:35 hours, Churchill stood beside Park in the Uxbridge operations room, watching as every squadron marker was committed. Turning to Park, he asked quietly,

“What other reserves have we?”

Park replied,

“There are none.”

The decisive fighting unfolded near Gravesend. Do 17s of KG 3 and He 111s of KG 26 were struck by Hurricanes from Nos. 17, 46, 249, 257, 504, and 603 Squadrons. Three Dorniers were destroyed in the opening passes, including the aircraft of Hauptmann Ernst Püttmann. KG 53 and KG 2 were attacked in turn by Spitfires and Hurricanes from Nos. 1 (RCAF), 66, 72, 229, 73, 253, and 303 Squadrons.

Cloud hindered interception accuracy but also obscured targets. At 14:45 hours, approximately 100 bombers dropped 120 tons of ordnance, concentrating on West Ham after failing to locate the Surrey Commercial Docks. The Bromley-by-Bow gasworks was badly damaged, Upton Park station hit, and residential districts were devastated. Seventeen civilians were killed and more than a hundred injured.

As fuel ran low, the Bf 109s withdrew, leaving the bombers vulnerable. During the retreat, RAF fighters destroyed numerous stragglers. KG 2 lost eight Do 17s, KG 3 six, and KG 53 six He 111s, including that of Major Max Gruber. Fighter units also sustained heavy losses. RAF claims far exceeded actual results, but German casualties were severe.

By 15:45 hours, the surviving formations were streaming back across the Channel in disarray.

Other Daylight and Evening Raids

At approximately 15:00 hours, more than twenty unescorted He 111s from III./KG 55 attempted an attack on naval targets at Portland. They were intercepted by Spitfires of No. 152 Squadron, suffering losses while inflicting only minor damage.

At 17:40 hours, aircraft from Erprobungsgruppe 210 attacked Southampton, aiming at the Spitfire factory at Woolston. Despite intense anti-aircraft fire, the factory escaped destruction, though nearby residential areas and infrastructure were damaged, causing civilian casualties.

Further minor reconnaissance and nuisance raids occurred into the evening.

Enemy Action by Night

Night bombing began at 22:48 hours when KG 27 attacked Liverpool, causing widespread damage but relatively few casualties. Additional raids struck Eastbourne, Worthing, Bournemouth, Cardiff, Bristol, Manchester, and towns across the Midlands and North West. RAF night fighters flew 64 sorties and intercepted several aircraft but achieved no confirmed victories.

Summary

Sunday, 15 September 1940, was a decisive turning point in the Battle of Britain. Fighter Command, fully committed, had repelled two of the largest coordinated attacks of the campaign. The Luftwaffe suffered unsustainable losses. Hitler’s assumption that the RAF was on the verge of collapse was conclusively disproved. Operation Sea Lion was postponed indefinitely.

This day—later commemorated as Battle of Britain Day—marked the moment when the strategic initiative in the air war shifted firmly to Britain. As Churchill watched from the operations room at Uxbridge, he understood the significance. Britain had not only survived—it had fought back and won.

German Losses:
Airmen: 93 | Aircraft: 61

British Losses:
Airmen: 16 | Aircraft: 31

Hurricane N2537, No. 229 Squadron
P/O G.L.D. Doutrepont killed. Crashed onto Staplehurst Railway Station after being shot down by Bf 109s.
http://www.bbm.org.uk/airmen/Doutrepont.htm

Hurricane P3876, No. 1 RCAF Squadron
F/O R. Smither killed. Attacked and shot down by Bf 109. Pilot failed to bale out.
http://www.bbm.org.uk/airmen/Smither.htm

Hurricane P3865, No. 73 Squadron
P/O R.A. Marchand killed. Crashed into farm at Teynham after being shot down by Bf 109s.
http://www.bbm.org.uk/airmen/as-Marchand.htm

Spitfire R6690, No. 609 Squadron
P/O G.N. Gaunt killed. Crashed in flames near Kenley after being hit by gunfire from Bf 110.
http://www.bbm.org.uk/airmen/GauntGN.htm

Spitfire P9324, No. 41 Squadron
P/O G.A. Langley killed. Crashed into building after being shot down by Bf 109s.
http://www.bbm.org.uk/airmen/LangleyGA.htm

Hurricane P2760, No. 501 Squadron
P/O A.E.A von den Hove d’Ertsenrijck killed. Aircraft exploded in mid-air after hit by gunfire from Bf 109.
http://www.bbm.org.uk/airmen/Denhove.htm

Hurricane N2481, No. 504 Squadron
P/O J.V. Gurteen killed. Shot down by enemy aircraft and crashed at full throttle into residential house.
http://www.bbm.org.uk/airmen/Gurteen.htm

Hurricane P2954, No. 302 Squadron
F/Lt T.P. Chlopik killed. Shot down by enemy aircraft. Baled out but died on landing.
http://www.bbm.org.uk/airmen/Chlopik.htm

Hurricane N2705, No. 504 Squadron
F/O M. Jebb died of injuries 19/9/40. Crashed at Dartford after combat with enemy aircraft.
http://bbm.org.uk/airmen/Jebb.htm

Hurricane P2836, No. 238 Squadron
Sgt L. Pidd killed. Baled out after being shot down by enemy aircraft but was dead on landing.
http://www.bbm.org.uk/airmen/Pidd.htm

Hurricane P3577, No. 303 Squadron
Sgt M. Brzezowski. Listed as missing. Believed crashed in Thames Estuary after combat with Bf 109s.
http://www.bbm.org.uk/airmen/Brzezowski.htm

Spitfire X4324, No. 603 Squadron
F/O A.P. Pease killed. Shot down by Bf 109. Pilot did not bale out.
http://www.bbm.org.uk/airmen/Pease.htm

Spitfire X4070, No. 19 Squadron
Sgt J.A. Potter taken POW. Ditched damage aircraft off French coast and captured by German military.
http://www.bbm.org.uk/airmen/Potter.htm

Hurricane P3660, No. 56 Squadron
Sgt T.R. Tweed killed. Failed to come out of spin during dog fight practice over base.

Photo Descriptions

1. A Dornier Do 17Z bomber of KG 76 in flight, 1940. Bundesarchiv, Bild 101I-341-0489-10A / Spieth / CC-BY-SA 3.0.
2. Squadron Leader Rupert Leigh of No. 66 Squadron climbs into his Spitfire Mk I, R6800 LZ-N, at Gravesend, September 1940. © IWM (HU 104504)
3. The final moments of Dornier Do 17Z-2 ‘F1+FH’ (Wk-Nr 2361) of 1.Staffel/KG 76, brought down by Sergeant Ray Holmes of No. 504 Hurricane Squadron on 15 September, 1940.
4. Soldiers survey the carnage after a Dornier Do 17 bomber crashed onto the forecourt of Victoria Station following a mid-air collision with Sergeant Ray Holmes’ Hurricane on 15 September 1940 over central London. The shop of well-known clock supplier James Walker Ltd was badly damaged and a mass of mantel clocks are scattered across the pavement.
5. The wreckage of the Hurricane that collided with a Dornier Do 17 bomber on 15 September 1940, is placed near Buckingham Palace Road in central London. The crater that contained the Rolls-Royce Merlin engine and other wreckage was simply filled in and covered over. In 2004, the engine was recovered during a televised archaeological dig in the presence of its former pilot, Sergeant Ray Holmes of No. 504 Squadron, who had bailed out of the aircraft after colliding with the German bomber.
6. The Duxford ‘Big Wing’ led by Squadron Leader Douglas Bader. © IWM (CH 1429)
7. Dornier Do 17Z (F1+FS) of 8./KG 76, flown by Feldwebel Rudolf Heitsch, force-landed at Castle Farm near Shoreham on 15 September 1940 after a low-level chase by No. 609 Squadron Spitfires flown by Flight Lieutenant Dundas and Pilot Officer Tobin. The bomber, part of a formation intercepted over Kent, narrowly missed power cables before coming down. Its crew were captured by the Home Guard: Heitsch and his observer were unhurt, the gunner wounded, and the wireless operator fatally injured. The aircraft was fitted with a tail-mounted flamethrower intended to deter pursuers, though it malfunctioned, spraying only oil. A local hop picker was also wounded by stray fire.
8. RAF personnel dismantle Dornier Do 17Z (F1+FS) of 8./KG 76, flown by Feldwebel Rudolf Heitsch. Stripped panels have been heaped in the foreground as the salvage crew – which appears to include civilians – continue their work. A trailer stands ready to the left of the starboard wing.
9. Bomb damage along Bridge Road in Woolston following the Luftwaffe attack on 15 September 1940.