Single-seater fighter with slots closed.
HANDLEY PAGE H.P.21. Built in the mid-nineteen-twenties, the Handley Page single-seat H.P.21 "Scout" experimental was an advanced monoplane with slotted wings. Powered by a 232-h.p . B.R.2 engine, it had a top speed of 146 m.p.h. and a service ceiling of 21,000 ft. Span was 29 ft. 3 in. and gross weight 2.030 lb. Twin machine guns were provided and float could be fitted if desired.

Single-seater fighter with slots open.
Early lift slots and flaps on a Handley Page monoplane built for the American navy. The engine was a Bentley rotary.

If any of your readers have got a copy of Air Pictorial for August 1955 they might care to compare this rare view of the Handley Page HPS-1, bought in the fall of 1923 by the Navy Department for comparative tests, with the H.P.21 in its original configuration with horn-balanced rudder. This two-gun fighter was intended for shipboard use but somehow never made the grade. Biplanes were still very much a la mode in the 1920s. What can be seen in this view is the starboard full-span, 'safety slat' invented by Dr. Lachmann.