On what date did Vickers Wellington production begin?

[Larry]

Strangely I have all the dates for first flights etc but on what date did production of the type begin?

If the prototype first flew on 15th June 1936 how much time elapsed before Vickers actually set up their factory and started?

Wellington Mk I, L4212, conducted its first flight on 23 December 1937 but even if it took 60 hours to assemble, there must have been months to get ready. From when?

[MW Giles]

K4049 first flew on 15.06.36
First order was issued 15.08.36 (contract 549268/36)
First flight of production a/c L4212 23.12.37
L4212 delivered to RAE at Martlesham Heath 25.01.38
L4213 assigned 05.07.38 AMRD at RAE and delivered to A&AEE 02.12.38
L4214 assigned 04.08.38 to 148 Sqn but this was cancelled and delivered 30.08.38 to RAE
L4215 assigned 148 Sqn 04.08.38 but this was cancelled and delivered 99 Sqn 10.10.38
L4216 assigned to 9 Sqn 28.09.38 but this was cancelled and delivered to 99 Sqn 11.10.38
L4217 assigned to 99 Sqn 14.10.38 and delivered 15.10.38
34 a/c delivered by end of 1938

16 months from order to first flight of production a/c. When did the first parts of L4212 go into a jig or when was the first piece of geodetic forged and machined - your guess is as good as mine

26 months from order to first delivery to an active squadron

Martin