The second police action began on December 19 1948 under codename 'Kraai’[1]. In a surprise attack with airborne troops, Sukarno and other Republican government leaders were captured. Mustangs were also used. The Mustangs of 122 squadron were stationed at 11VB Polonia Medan and 13VB Tabing near Padang (Central Sumatra). On both North and Central Sumatra, the squadron provided support for the advance to Fort de Kock[2] [3], the landing of troops on Lake Singkarak was secured and important targets were taken out.

"The first police action, which began on July 21 1947 and ended August 5 1947, [1] was code-named "Operation Product ". It’s goal was to get hold of rubber, tobacco, sugar, tea, etc. to help pay for the costs of the war. Estimated at 3 million Dutch Guilders per day." In July 1947 122 Squadron only had 4 operational (fly-ready) P-51’s out of a total of 9 P-51 fighter aircraft and 10 pilots available.

Planes and crew 1947 January 1947, the squadron had 17 P-51s, of which 65% were ready to fly, a Lockheed L-12 for transport and 11 pilots. In April 1947 the staff had 11 officers, 32 petty officers and 76 corporals and men. About half of what was needed. In July 1947 the squadron had 9 P-51 aircraft of which 4 were ready to fly, the Lockheed L-12 and 10 pilots.

Initially the squadron was given the task of attacking the forest edge with rockets, bombs and machine guns. At the end of November 1946, the Commanding officer for North Sumatra gave the order to 'purify’[1] and permanently occupy the area around the airport. In December 1946 the 122th flew 86 operational sorties. "Medan airport under mortar fire. During the night of 20 to 21 December, malicious mortar shells were aimed at the airfield, which exploded 20 meters away from a B-25.

To have air support on Sumatra and to replace the RAF Spitfire unit stationed on Medan, 122 Squadron was established November 1 1946 on 1VB Tjililitan in Jakarta. After 1942 ML-KNIL continued to fly in Australia and New Guinea with the Curtiss P-40, but by 1945 this type was obsolete. Therefore the American authorities were asked for re-equipment with 41 aircraft of the type P-51 Mustang, beginning with 120 squadron[1].

After the Japanese capitulation on August 15 1945, airbase Polonia fell into British hands later that year by parts of 26th Indian Division. Not long after followed by the 4th Brigade Indian Division and the 155th RAF Spitfire squadron coming to Medan. Airbase Polonia, later designated 11VB, was located about 2.5 km south of Medan and had 1700-meter runway.