From being disbanded in September 1919, 151 Squadron had remained as a number only in Air Ministry Records.

During the 1930’s the situation in Europe had deteriorated rapidly with the German nation gaining political and military strength in spite of the Armistice Treaty which had been signed. There was unrest and mistrust amongst the main powers of Europe and this led to a rethink in terms of Service requirements and general armaments. 

World War I had shewn the importance of Air Power both as a strategic force and as a support force for army operations. Unfortunately, it had been assumed that the Armistice meant everlasting peace, but as with all “bits of paper” this was to prove a fallacy. 

With trade recessions biting hard into the country’s economy, and with opposition from pacifist and politically biased factions there was reluctance to spend money on armaments in general. However, there was clear thinking by some industrialists, and fortunately for the world at large, the Hawker and the Supermarine Companies were working hard on designs of revolutionary aircraft for defensive roles. Unfortunately, Germany was working along similar lines although the Jumo engine was not ready for fitting to their developed airframe, that of the BY (Me) 109 machine. To meet their programme, Germany purchased Rolls Royce Kestrel engines between 1931 and 1934. It is believed that these Kestrel engines were used in the BF (Me) 109 aircraft.

After a period of seventeen years as a “forgotten” disbanded unit, 151 Squadron was re-formed at North Weald in Kent on August 4th 1936 under the command of S/Ldr Hyde. It was equipped with Gloster Gauntlet aircraft, these being single engined bi-planes and typical of the day.

The Squadron was formed from a nucleus of No 56 Squadron, but its build up to full strength was slow due to the restraints of the time.

Equipped with Gloster Gauntlets, much of the training carried out took the form of aerobatics as used in World War I combats, and which were ideal for this type of aircraft.

The skills in flying were shown off to the public in the form of Air Displays which most large towns and cities seemed to expect on a regular basis. Films like “Hell’s Angels” and the names of Air Aces had strongly imprinted the name of the Royal Air Force on everyone’s mind and consequently the RAF had a strong following. 151 Squadron took an active part in these displays, and at the rehearsals, the continuous practice and training which went into them served as a good basis for polishing the skills necessary to handle fighter aircraft.

The Gloster Gauntlet had a top speed of 230 mph, this speed being an appreciable advance on that of the Sopwith Camel which had been the Squadron’s aircraft when it disbanded in 1919. The Gauntlet was highly manoeuvrable and ideal for the enhancement of flying skills.

The uncertainties of 1938, with the so called “Munich crisis”, spurred Defence Chiefs into action, and in that year, 151 Squadron was placed under the command of S/Ldr Donaldson. In 1938, the Squadron took delivery of its first Hawker Hurricane aircraft. These aircraft were basically fabric covered mono-planes with a metal covered front fuselage, thus following the well proven construction features of the Hawker Bi-planes of the day, i.e. the Fury, Hart etc. The engine powering the Hurricane was the Rolls Royce Merlin, this being a natural development of the Kestrel. Its power was 1030 H.P., giving the Hurricane a top speed of 312 mph, but an early model had achieved a record breaking run in flying from London to Edinburgh at an average ground speed of 415 mph.

Taking on board a completely new aircraft, i.e. a monoplane as opposed to a biplane, with four times the engine power, and what was then considered to be first class armament of eight forward firing machine guns of 0.303 calibre (four in each wing), led to a very intensive training programme being undertaken, it being felt that the days of World War II were imminent.

Between 1936 and 1939 many interception exercises were carried out in conjunction with Bomber Command, it being accepted by the then Prime Minister, the Rt. Hon Stanley Baldwin, that “Bombers would always get through”. With this philosophy, which had been proved correct in Ethiopia and in the Spanish Civil War, it was decided that the role of the Fighter for protection of the United Kingdom was to be the dominant factor of the Defence Policy.

 Germany had increased its own Bomber Force, and had proved its capability in Spain, at such a rate that it would be impossible to catch up. With a large Bomber force, Germany would go for a “knock out” blow, but Sir Thomas Inskip, the Minister for Co-ordination of Defence, declared that the role of the RAF was to prevent Germany from “knocking out” Britain. It was also established that more fighters could be built for a given expenditure than bombers, and they could also fly at much higher speeds. On December 22 1937, the Cabinet accepted the fighter policy.

 L. S. Heath, who joined the ground crew of 151 Squadron after call up of the RAF Volunteer Reserve in March 1939, recalls:

“The hangar occupied by 151 Squadron at North Weald was located close to the Epping-Ongar road, and convenient to the ”Kia-Ora”cafe which was run by an auburn haired New Zealand lady. Adjacent to the hangar was a hole in the hedge which was quite handy for getting refreshments as necessary - so much for security!

The aircraft at that time were Hurricane Mark I, fitted with Merlin 2 engines and a Watts fixed pitch propeller. The wings were mainly fabric covered with eight 0.303 machine guns fitted. These aircraft were early production models with serial numbers L1600-L1700 groups. The Squadron letters were GG, later changed to DZ. Twelve aircraft were on Squadron charge with two on immediate reserve and four more on Command reserve.

In the months up to the outbreak of world War II the Squadron was involved in intensive training with a number of exercises taking place. There was an air Show called the "Empire air Day”, during which S/Ldr Donaldson showed how an Avro Tudor could be flown, The Tudor was used because for some unknown reason the AOC had forbidden aerobatics in Hurricanes at these shows.

Also at North Weald was No 56 Squadron, also equipped with Hurricanes, and just prior to the outbreak of hostilities, No 17 Squadron also arrived for conversion from Gauntlets to Hurricanes. When No 17 Squadron left, 600 Squadron arrived with Blenheim fighters, these machines being equipped with four machine guns in the “belly” of the aircraft. At this, John Cunningham, later of Night Fighter fame, and later still of Test Pilot fame, was with 604 Squadron."

Such was the status of 151 Squadron and other Squadrons of Fighter Command when war finally broke out on September 3 1939.