Blenheim squadrons were still in immediate and high demand after their withdrawal from France as part of the British action during the Norwegian Campaign.
Typically operating from bases in the northern areas of the British mainland, such as RAF Lossiemouth, flying for extended periods over the North Sea led to the weather posing almost as much of a risk as enemy combatants, particularly as most of the Blenheim IVs lacked any heating or de-icing systems; in response, some aircraft were later equipped with boilers fixed onto the starboard engine exhaust.
A sizeable number of losses occurred, caused by both enemy action and mid-air engine failures due to icing.

After the fall of France in June 1940, the Free French Air Force was formed at RAF Odiham, Hampshire, in the form of Groupe Mixte de Combat (GMC) 1, consisting of a mixed bag of Blenheims and Westland Lysander liaison/observation aircraft, which were later dispatched to North Africa and saw action against Italian and German forces.

Blenheim units operated throughout the Battle of Britain, often taking heavy casualties, although they were never accorded the publicity of the fighter squadrons.
From July to December 1940, Blenheims raided German-occupied airfields both in daylight and at night.
Although most of these raids were unproductive, there were some successes; on 1 August five out of twelve Blenheims sent to attack Haamstede and Evere (Brussels) were able to bomb, destroying or heavily damaging three Bf 109s of II./JG 27 and apparently killing a Staffelkapitän identified as Hauptmann Albrecht von Ankum-Frank.
Two other 109s were claimed by Blenheim gunners.
Another successful raid on Haamstede was made by a single Blenheim on 7 August which destroyed one 109 of 4./JG 54, heavily damaged another, and caused lighter damage to four more.

There were also some missions which produced an almost 100% casualty rate amongst the Blenheims.
One such operation was mounted on 13 August 1940 against a Luftwaffe airfield near Aalborg in north-western Denmark by twelve aircraft of 82 Squadron.
One Blenheim returned early (the pilot was later charged and due to appear before a court martial, but was killed on another operation); the other eleven, which reached Denmark, were shot down, five by flak and six by Bf 109s.
Blenheim units had also been formed to carry out long-range strategic reconnaissance missions over Germany and German-occupied territories.
In this role, the Blenheims once again proved to be too slow and vulnerable against Luftwaffe fighters and they took constant casualties.

On 12 August 1941, an action described by the Daily Telegraph in 2006 as being the "RAF's most audacious and dangerous low-level bombing raid, a large-scale attack against power stations near Cologne" took place.
The raid was a low-level daylight raid by 54 Blenheims under the command of Wing Commander Nichol of No.
114 Squadron RAF.
They hit their targets (Fortuna Power Station in Oberaußem-Fortuna and the Goldenberg Power Station in Hürth-Knapsack), but twelve of the Blenheims were lost during the raid, 22% of those that took part, which was far above the sustainable loss rate of less than 5%.
The England cricketer Sqn Ldr Bill Edrich was awarded the DFC for his part in the raid.

Starting on 5 September 1940, Blenheims of Bomber Command began a bombing campaign targeting German-occupied ports along the English Channel, alongside heavier bomber types.
Bomber Command Blenheims also performed anti-shipping patrols due to Coastal Command's own strike squadrons being heavily depleted throughout the latter half of 1940.
On 11 March 1940, a Blenheim IV, P4852, became the first RAF aircraft to sink a U-boat, having scored two direct hits on U-31 in the Schillig Roads.
In April 1941, a campaign aiming to completely close off the Channel to enemy shipping was launched using an initial flight of Blenheims stationed at RAF Manston.
Between April and June that year, a total of 297 Blenheims of No 2.
Group attacked German shipping at sea, losing 36 aircraft, while Coastal Command launched 143 attacks in t
Blenheim squadrons were still in immediate and high demand after their withdrawal from France as part of the British action during the Norwegian Campaign. Typically operating from bases in the northern areas of the British mainland, such as RAF Lossiemouth, flying for extended periods over the North Sea led to the weather posing almost as much of a risk as enemy combatants, particularly as most of the Blenheim IVs lacked any heating or de-icing systems; in response, some aircraft were later equipped with boilers fixed onto the starboard engine exhaust. A sizeable number of losses occurred, caused by both enemy action and mid-air engine failures due to icing.
After the fall of France in June 1940, the Free French Air Force was formed at RAF Odiham, Hampshire, in the form of Groupe Mixte de Combat (GMC) 1, consisting of a mixed bag of Blenheims and Westland Lysander liaison/observation aircraft, which were later dispatched to North Africa and saw action against Italian and German forces.
Blenheim units operated throughout the Battle of Britain, often taking heavy casualties, although they were never accorded the publicity of the fighter squadrons. From July to December 1940, Blenheims raided German-occupied airfields both in daylight and at night. Although most of these raids were unproductive, there were some successes; on 1 August five out of twelve Blenheims sent to attack Haamstede and Evere (Brussels) were able to bomb, destroying or heavily damaging three Bf 109s of II./JG 27 and apparently killing a Staffelkapitän identified as Hauptmann Albrecht von Ankum-Frank. Two other 109s were claimed by Blenheim gunners. Another successful raid on Haamstede was made by a single Blenheim on 7 August which destroyed one 109 of 4./JG 54, heavily damaged another, and caused lighter damage to four more.
There were also some missions which produced an almost 100% casualty rate amongst the Blenheims. One such operation was mounted on 13 August 1940 against a Luftwaffe airfield near Aalborg in north-western Denmark by twelve aircraft of 82 Squadron. One Blenheim returned early (the pilot was later charged and due to appear before a court martial, but was killed on another operation); the other eleven, which reached Denmark, were shot down, five by flak and six by Bf 109s. Blenheim units had also been formed to carry out long-range strategic reconnaissance missions over Germany and German-occupied territories. In this role, the Blenheims once again proved to be too slow and vulnerable against Luftwaffe fighters and they took constant casualties.
On 12 August 1941, an action described by the Daily Telegraph in 2006 as being the "RAF's most audacious and dangerous low-level bombing raid, a large-scale attack against power stations near Cologne" took place. The raid was a low-level daylight raid by 54 Blenheims under the command of Wing Commander Nichol of No. 114 Squadron RAF. They hit their targets (Fortuna Power Station in Oberaußem-Fortuna and the Goldenberg Power Station in Hürth-Knapsack), but twelve of the Blenheims were lost during the raid, 22% of those that took part, which was far above the sustainable loss rate of less than 5%. The England cricketer Sqn Ldr Bill Edrich was awarded the DFC for his part in the raid.
Starting on 5 September 1940, Blenheims of Bomber Command began a bombing campaign targeting German-occupied ports along the English Channel, alongside heavier bomber types. Bomber Command Blenheims also performed anti-shipping patrols due to Coastal Command's own strike squadrons being heavily depleted throughout the latter half of 1940. On 11 March 1940, a Blenheim IV, P4852, became the first RAF aircraft to sink a U-boat, having scored two direct hits on U-31 in the Schillig Roads. In April 1941, a campaign aiming to completely close off the Channel to enemy shipping was launched using an initial flight of Blenheims stationed at RAF Manston. Between April and June that year, a total of 297 Blenheims of No 2. Group attacked German shipping at sea, losing 36 aircraft, while Coastal Command launched 143 attacks in t
Bristol Blenheim