Hi There,
According to Mike Westrop's superb
A History of No. 10 Squadron RNAS, this happened on 8 June 1917. Quote: "B Flight and C Flights carried out a northern and southern offensive patrol in the afternoon. B Flight encountered and engaged a formation of Albatros scouts which proved to be a trap. Collishaw was fortunate to survive a crash after N5490's controls were shot away when he sprung the trap."
According to
Royal Naval Aircraft Serials and Units 1911-1919,Sopwith Triplane N5490 was indeed crashed at Droglandt on 8 June by Collishaw, but the airplane was salvaged and sent to Air Depot Dunkerque (St. Pol), and returned to action with No. 9 Sqn RNAS on 20 July 1917; F/L Whealy claimed two Albatros scouts in it, then it went to No. 1 Sqn where it was flown by FSL RE MacMillan, who claimed an Albatros OOC on 19 September 1917 - but he was forced down and captured the same day, claimed by Vzfw Kosmahl of Jasta 26.
As far as a German claims for Collishaw on 8 June, I'm not sure there's a clear candidate:
Vzflgmstr Bottler (sometimes noted as 'Bossler') of Marine Feld Jasta 1 claimed a Sopwith Triplane (?) north of Warneton, possibly at 1125 hrs.
Offz.Stv.
Max Müller of Jasta 28 claimed a Triplane at Quesnoy at about 1910 hrs German time. He wrote in a letter on 9 June: "This is to inform you that I shot down a Triplane yesterday. Again it fell in a thousand pieces."
Oblt. K Mettlich of Jasta 8 claimed two "Sopwiths" at Moorslede at 1420 hrs, but these are generally considered to have been Pups of No. 66 Squadron, which lost two pilots KIA and another wounded (another claim was made by Voigt of Jasta 8). It will be noted that two of the 66 Sqn Pups collided.
On 8 June, FLt. T G Culling of No. 1 Squadron was killed in Triplane N5491 (note the close serial no. to Collishaw's N5490).
Also on 8 June, FSLt. T R Swinburne of No. 1 Naval was KIA in Triplane N6293.
And, FSLt H F Stackard of No. 9 Sqn RNAS was shot up and wounded in Triplane N5451.
Russ Gannon will probably join in on this thread with improved information.