Twelve Spitfires took off shortly after noon to rendezvous at Biggin Hill with another squadron before heading for Dunkirk:
| Red Section | Blue Section |
| Flt Lt Persse-Joynt | Flt Lt Barran |
| Fg Off Ayre | Fg Off Beaumont |
| Fg Off Edge | Fg Off Gilbert |
| Yellow Section | Green Section |
| Fg Off Howell | Fg Off Russell |
| Fg Off Dawson | Plt Off Overton |
| Fg Off Dundas | Sqn Ldr Avent (OC) |
These pilots were all Auxiliaries but three: Howell, Russell and Overton were regulars or VRs. Only two had any real combat experience, those being Persse-Joynt and Ayre. It was like David about to meet Goliath! What made it worse was that the OC wasn’t leading! He had taken command of 609 in December 1939, unqualified on Spitfires, and was totally ineffective as a leader or commanding officer, so the senior Flt Lt was leading the formation.
The weather was terrible, and 609 spent 40 minutes using up 25% fuel waiting to meet other squadrons. Patrolling at 15,000ft over Dunkirk for an hour the visibility was zero and there was no contact with the enemy. There was also heavy mist at lower levels which hindered the return, and they were all already very short of fuel and this caused major problems. Fg Off Dundas force landed in a field at Frinton with just vapour in his tanks, whilst Fg Off Howell came down nearby but managed to refuel and get back undamaged to Northolt. Fg Off Dawson made it to Southend where he too refuelled and the rest got into Manston. But Fg Off Ayre ran out of fuel completely and was killed trying to force land near Oakley, becoming 609’s first casualty of the war. Not an auspicious end to 609’s first full combat operation.