The Royal Aircraft Factory B.E.12b was a higher powered version of the basic B.E.12 that was designed as a Home Defence aircraft but that entered service after the Zeppelin raids it was designed to counter had almost stopped.
The prototype B.E.12b was produced by fitting a 200hp Hispano-Siuze engine to a standard B.E.12. The production B.E.12b retained the equal span two bay wings of the B.E.12, partly because the B.E.12a had not been popular with its pilots. The new engine improved the aircraft's rate of climb so much that one hundred aircraft were ordered. The B.E.12b was designed as a night fighter. This explains why the forward firing Lewis gun was mounted above the upper wing, firing over the propeller – the upper wing prevented the muzzle flash from the gun from damaging the pilot's night vision. The B.E.12b also had navigation lights and Holt flare brackets under their lower wings to make it easier to land at night, and some had their exhausts modified act as flame dampers.
Of the hundred B.E.12bs that were ordered, at least 36 reached Home Defence squadrons during 1918, serving with Nos.37, 50, 75, 76 and 77 squadrons of the R.F.C. and infant R.A.F. By the time they entered service the Zeppelins had been replaced by large bombers, many with a service ceiling far above that of the normal B.E.12. The B.E.12b was almost obsolete as it entered service, and many of the 74 unallocated aircraft may have been completed as standard B.E.12s.
Engine: Hispano-Suiza V-8