[Graham Boak]

This is not something that is properly explained anywhere. It may well be linked to the further development of the DH Hydromatic propellor, giving a better range of pitch angles than previously available. The texts do state that this propellor was tried for carrier launches, with Malta deliveries specifically in mind. The trials were successful, and the propellor used on deliveries. As a general rule, the Mk.Vb had the DH propellor and the Mk.Vc the Rotol - I would be reluctant to be definitive about that!

However, it is perhaps less of a backward step than might be imagined. The Mk.Vc was heavier than the Mk.Vb, as a result of modifications giving a stronger wing and a wider range of capabilities. Given the same engine, the Mk.Vb could even be better than the Mk.Vc for the pure intercept roles on Malta, even without allowing for any benefit of the new prop. The standard armaments were identical, as were fuel tanks and most of the details.

Note that the Mk.Vb was generally retained for operations from the UK and the Mk.Vc sent overseas.

The majority of the early production of the Mk.Vc went to Malta: there were not a lot of spare Mk.Vc because Australia also had a high priority at this time.