RAF balloon/airship men to USA in 1918

[Errol Martyn]

A bit of a long shot but I wonder if anyone here has come across the reason why four RAF airmen/ncos ground crew with balloon and/or airship experience were sent to the USA in 1918?

 

They embarked on the Adriatic at Liverpool on 15 May 18 for 'S. P. duty' in America. I've not been able to identify the ship they returned on (may have been a military one?) but they were all posted to RAF Depot, Blandford on 26 Nov 18. Their names were James Richard Bleeze, Edwin Joseph Brett, Lawrence Cartlidge and  Henry Davenport. I've checked out the AIR79s for the three that are available on findmypast but none give any further information.

 

Cheers,

Errol