By 1936, it became clear to ARR leaders that they needed more planes if they wanted to assure Romania's air defense. That year, the Supreme Army Council decided on the 17th of June 1936 to purchase some 406 new airplanes in order to create 36 new squadron by the end of 1938. First of all it was decided that the airforce would receive some 195 fighters during the next two years. For the new fighters, bombers and trainers , the ARR wanted to use its IAR K14, K9 and K7 engines. All of these were versions of Gnome-Rhone's K series of engines, built under license at IAR's engine factory.

One year later, the first Savoia-Marchetti SM-79B bombers started to arrive from Italy, boosting ARR's offensive capabilities. In 1938, a true "bomb" exploded : the K14 engines couldn't pass the tests because the French engineers who originally designed them had made more than a few mistakes regarding oil consumption. The result was a true "oil drinking" machine, who could deliver only 857 of the 1000 HP promised. Things got worse when it was discovered that the chief of IAR's engine factory, engineer Carp had falsified early test results. Carp had disagreed with the decision of buying the license from Gnome-Rhone, but afterwards he got overconfident, believing he'd be able to correct the flaws all by himself. He was wrong, and now hundreds of engines were waiting in depots for someone to fix the problems. IAR engineers assured the Undersecretary of Air that they could improve the K14 engines, but this would take some time. Meanwhile, on the 12th of June 1938, the new Ministry of Air came up with a three-stage program for boosting ARR's strength : in a first phase, until the end of 1938, besides the 406 new airplanes, the ARR would benefit from improved airfield infrastructure, and receive large amounts of AA artillery destined to defend the new airfields. In a second phase, between the 1st of January 1939 and the 1st of April 1942, a total of 169 planes needed to form 13 new squadrons would be bought : 40 reconnaissance planes for 4 observation squadrons, 105 fighters for 6 fighter squadrons and 24 bombers for 3 "heavy" bomber squadrons. Finally, the last stage of the plan called for the purchase of 48 bombers for 6 new bomber squadrons and 48 ground-attack planes for 4 new "assault" squadrons by the 1st of April, 1944. Had this program been realised, the ARR was supposed to have over 800 combat aircraft by mid-1944 ( although many of them would have been several years old by that time ). The plan was approved, and since time was in very short supply it was decided to send immediately a delegation to the major aviation centers of Western Europe. They were on the lookout for a new, powerful engine for the fighters and bombers, a new modern fighter and, if possible, a new type of medium bomber.

On the 15th of June 1938, the commission arrived in England. General Gheorghe Negrescu was once again a member of it since he was in charge of estimating the capabilities of any foreign plane proposed to the ARR. First, the commission arrived at the Hawker factory, where they were shown and offered the Hawker Hurricane I fighter, which was pretty much a tried and tested plane. Afterwards, the Vickers plant, near London was visited, but the long-range Wellington bomber about to enter mass-production was not needed by the ARR. Another Vickers factory, this time situated near Southampton was visited the next day. The first batch of 80 Spitfire I fighters was about to roll out of the factory, but this time the plane wasn't offered to the Romanians, although they were more than interested. Finally came the Rolls-Royce engine factory, where the Rolls-Royce Merlin engine was presented to the commission. They was impressed by its simple but reliable construction and 600 flying hours life span, so talks about buying the license began. Negrescu would later write that "The general impression after our tour of England was very good : very good material, excellent engines, particularly the Rolls-Royce Merlin, very good fighters and bombers, but mass-production was just getting started."

Next came Germany, where the Romanians arrived on the 25th of June. On the next day, they met with general Udet, who was chief of the Technical Service within the RLM ( The German Air Ministry ). Udet made the arrangements, and starting with the 28th of June, the commission visited the Henschel, Arado, Junkers, Heinkel, Dornier, Siemens-Bramo, Argus, BMW and Daimler-Benz factories. Everywhere they went, they saw large, modern airfields with hangars and runways full of new planes, as well as factories where dozens of state-of-the-art planes were in different stages of assembly. Several types of airplanes and engines were shown to the commission, but eventually they were impressed by : the Heinkel He-111 and Dornier Do-17 bombers, the Junkers Ju-87 dive bomber, the Messerschmitt Bf-109 fighter ( although it hadn't actually been shown, but they were interested nevertheless ) and the Heinkel He-112 fighter. As for engines, the DB 600 and the Junkers Jumo 211 were the most tempting ones as they could both deliver up to 1000 HP, but only the BMW 132 engine could be ordered and delivered in short time. Overall, it had been a impressive tour, as general Negrescu had to admit : "...in Germany one could see not only interesting prototypes, but, besides the large numbers of planes already existing on airfields, you could see an entire industrial infrastructure, ready for mass-production."

Finally, on the 12th of July, 1938, the commission arrived in France, where they were surprised to hear the French were displeased with the fact that they been to Germany before. But the bad news were just starting : " We went to see the plants of the Amiot and Lioré-Olivier companies, who had developed a couple of twin-engine monoplane bombers which were shown to us at Villacoublay airfield. Both planes were of some interest, but the impression left by what we saw inside the factories was a disillusion compared to what we had seen in England and Germany. At Amiot, the chief constructor, a capable engineer, which I had known for a long time, was barely tooling up for production together with a few workers, but everything was done slowly, as if nothing was happening in the world. At the Lioré-Olivier works, preparations for mass-production were somewhat more advanced, but yet you couldn't see movement and there was hardly any sign of life in the yard. We flew to the Potez works, near the town of Albert, to see how things were going with our order for 20 Potez 633 light bombers, but we felt the same disappointment. Our planes were far from being ready, although the delivery terms had long since been exceeded. Next we visited the Gnome-Rhone and Hispano-Suiza engine factories. Things were not going to get better. At Gnome-Rhone, the 1000 HP engines failed bench tests constantly, and the factory had not changed since the 20's when I had seen it the last time... At the Lorraine-Dietrich and Renault engine factories there was simply nothing to see. So, we had finished our tour through the French plants quite quickly. France had left me a bad impression : after having seen the French aeronautical industry in its heydays, when it was the first in the world, it was quite painful. "

In January 1939, IAR's engineers announced the Undersecretary of Air that they cold now supply an improved version of the IAR K14, designated as IAR K14 1000R. It was then decided that IAR's new fighter, the IAR-80, who was rapidly approaching prototype phase, should be equipped with this powerplant if the Jumo 211 fail to arrive on schedule. When the second world war broke out, Britain agreed to deliver 40 Bristol Blenheim light bombers and just a squadron of Hawker Hurricane I fighters ( just 12 planes instead of 50 as the ARR demanded ). In such conditions, the Romanian airforce was not looking very good, although there was a ray of hope : the IAR-80 fighter's performances had exceeded all expectations so it was ordered immediately into production. With war approaching fast, every effort was being made to increase ARR's strength.

In September 1939, the Romanian airforce was made up of some 300 planes of various types and performances. This number was, of course, below the minimal requirements of air defense, and, unfortunately, Romania would soon lose some of its traditional suppliers : Poland, France, Britain.

As the war continued and the string of German successes seemed endless, Romania was forced to seek German help in order to deal with the Soviet threat One major part of the German assistance consisted in training and supplying the Romanian army with adequate equipment. The very first branch of the armed forces which was to benefit from this program was the airforce.The cooperation with the Luftwaffe started with the visit of the German general Kurt von Tippelskirch, on the 5th of September 1940. Shortly after this visit ( read inspection ), Germany decided to assist the Romanian airforce, by delivering modern planes and training Romanian pilots and aviation mechanics.

The ARR fought heroically on the east and home fronts, from the 22nd of June 1941 until the 23rd of August 1944, when Romania left the Axis and signed an armistice with the Allies. At that moment, it had in its inventory around 369 fighters, 172 bombers, 211 reconnaissance planes and over 1100 trainers. Total rose to about 1692 planes divided into 61 squadrons, and some 415 aircraft took part in the last campaign of the war : the anti-Axis campaign.

On the 10th of May 1945 the ARR flew its last combat mission, bringing to an end the four years of bitter war. Altogether, the war had coasted the ARR well over 600 planes, as well as 4972 casualties : 972 killed , 1167 wounded and 838 missing in action against the Allies and the USSR, and 356 killed, 371 wounded and 468 missing in action against the Axis. The Romanian pilots claimed a total of around 1150 air victories on all campaigns, while the AA artillery shot down 1110 more enemy aircraft, bringing the total to almost 2300 enemy airplanes destroyed throughout the war.

The end of the war found the ARR squadrons together with Romanian ground forces less than 100 km from Prague. From 1941 to 1945, it had faced the strongest airforces in the world : the Soviet airforce, the USAF, the RAF and finally the Luftwaffe. Pitched into battle against enemies who constantly outnumbered it, equipped with planes that were often inferior, forced time after time to rely solely on its own resources, the ARR managed to dominate its opponents on a good number of occasions. Such results were possible only thanks to the qualities of its pilots and aircrews, who proved again and again that they were at least as good as the German, Allied or Soviet ones.