Прототип Gladiator (K5200) отличался от серийных машин открытой кабиной. На снимке виден обтекатель 7,7-мм пулемета Lewis под правым крылом.
The Gloster S.S.37 being flown by Gerry Saver after receiving the serial K5200 for trials at Martlesham Heath.

The Gloster SS.37 at the time of its first test flight in late 1934.

The first Gladiator II for Portugal, G5, was fitted with a Mercury VIII engine. It was tested at Martlesham in July 1938.

The SS.37 fitted with a Fairey-Reed three-bladed fixed-pitch metal propeller and powered by a Mercury IX engine.

The Gloster SS.37 in its original form and bearing the RAF serial number K5200 for the Martlesham trials. The picture was taken on June 25, 1935, shortly before the aircraft's appearance at the RAF Display at Hendon, for which it bears the Experimental Aircraft Park No 1 just behind the engine cowling.

Для ВВС построили 231 Gladiator Mk I, а последние 28 машин были сразу сданы на хранение для восполнения возможных потерь. На снимке: третья серийная машина.
Among the finest aerobatic machines in the world to-day is the Gloster Gladiator single-seater four-gun fighter which, despite the fact that it is of comparatively old design, is still extremely popular. A similar machine known as the Sea Gladiator is in use as a fleet fighter.
The third production Gladiator I, K6131, taken on RAF charge in February 1937, above its native Gloucestershire. Note the transparent cover over the pilot's cockpit.