216 Squadron - 1919 - Lt. Sullivan and Lt. Westall

[Leendert]

On 29 March 1919 a British aircraft carrying mail to Cologne crashed at Vaals, Netherlands, which is on the three border point NL-BE-D/GE.
The RAF had a postal run between Folkestone and Cologne in those days.
Dutch newspapers report that one pilot later died in a hospital due to sustained injuries.

The Terlincthun Cemetery at Boulogne has two casuallties of 216 Squadron with a reference that they died in a postal flight. They are Lt Frank Sullivan (date of death 29-03-1919) and Lt. Arthur Arthur Westall (30-03-1919).

Were these lieutenants victims of the crash at Vaals and if not, then who was?

Thanks for any info.

Regards,

Leendert