The Japanese attack on Sumatra began with air raids on P1: low-level Strafing attacks by Mitsubishi Zero fighters were an impossible HAA target, while without instruments the gunners could only put up barrage fire against high level bombers, and had no success.
Palembang was also raided.
On the same day that Singapore fell (14 February) the Japanese launched their invasion of Sumatra.
This began with a paratroop drop at P1 and Pladjoe – until the actual drop the approaching Kawasaki Ki-56 transports were thought to be friendly Lockheed Hudsons (both aircraft were developed from the Lockheed Model 14 Super Electra).
Once the paratroop drop began, the AA batteries opened fire, shooting down one aircraft, causing another to force-land and others to veer off course (including the fighters and bombers that accompanied the transports, 15 HAA Bty shot down three aircraft).
The transports gained height to avoid the gunfire, and the paratroops dropped from too high, making them vulnerable to airburst fire.
However the drop was successful, and the paratroops began working through the jungle to the installations.
One 3.7-inch Troop was rescued by a party of RAF pilots and ground crew with a Vickers machine gun and rifles, who cleared a drop zone.
A 3.7-inch shell fired with minimum fuze over open sights cleared a nest of snipers from a tree, while another destroyed a captured Bofors LAA gun.

As the airfield was overrun, the gunners attempted to pull back to Palembang, but there were only two serviceable AEC Matador gun tractors left.
The remaining guns were disabled and a convoy of gunners and RAF personnel attempted to retreat.
The road was under fire and the convoy ran into a road block, so the HAA and LAA gunners and RAF men made their way in small parties to Palembang, having taken heavy casualties along the way.
Only one 3.7-inch gun was recovered, which was sited at the ferry site at Palembang
At the refinery the commander of 12 HAA Bty had formed a party from his battery HQ to attack another drop zone, and engaged the Japanese in a five-hour fire-fight with small arms.
The battery's guns were in action all day, claiming 16 'kills' in conjunction with 78/35 LAA Bty.
As Japanese invasion barges approached next day, the Dutch commander destroyed the refinery and evacuated to P2, which was still operational.
Once again, the AA gunners at the refinery had to disable most of their guns; two 3.7s were ferried across the river to cover the railway and bridges, then on to P2, but the gun of 15 HAA Bty at the ferry had to be abandoned.

Once the last aircraft had flown out of P2,  the decision was made to evacuate southern Sumatra.
The force retreated to Oosthaven by road and rail, destroying the remaining AA guns which could not negotiate the bridges on the route.
From Oosthaven the surviving RAF personnel and AA gunners were shipped to Java.
The Japanese attack on Sumatra began with air raids on P1: low-level Strafing attacks by Mitsubishi Zero fighters were an impossible HAA target, while without instruments the gunners could only put up barrage fire against high level bombers, and had no success. Palembang was also raided. On the same day that Singapore fell (14 February) the Japanese launched their invasion of Sumatra. This began with a paratroop drop at P1 and Pladjoe – until the actual drop the approaching Kawasaki Ki-56 transports were thought to be friendly Lockheed Hudsons (both aircraft were developed from the Lockheed Model 14 Super Electra). Once the paratroop drop began, the AA batteries opened fire, shooting down one aircraft, causing another to force-land and others to veer off course (including the fighters and bombers that accompanied the transports, 15 HAA Bty shot down three aircraft). The transports gained height to avoid the gunfire, and the paratroops dropped from too high, making them vulnerable to airburst fire. However the drop was successful, and the paratroops began working through the jungle to the installations. One 3.7-inch Troop was rescued by a party of RAF pilots and ground crew with a Vickers machine gun and rifles, who cleared a drop zone. A 3.7-inch shell fired with minimum fuze over open sights cleared a nest of snipers from a tree, while another destroyed a captured Bofors LAA gun.
As the airfield was overrun, the gunners attempted to pull back to Palembang, but there were only two serviceable AEC Matador gun tractors left. The remaining guns were disabled and a convoy of gunners and RAF personnel attempted to retreat. The road was under fire and the convoy ran into a road block, so the HAA and LAA gunners and RAF men made their way in small parties to Palembang, having taken heavy casualties along the way. Only one 3.7-inch gun was recovered, which was sited at the ferry site at Palembang
At the refinery the commander of 12 HAA Bty had formed a party from his battery HQ to attack another drop zone, and engaged the Japanese in a five-hour fire-fight with small arms. The battery's guns were in action all day, claiming 16 'kills' in conjunction with 78/35 LAA Bty. As Japanese invasion barges approached next day, the Dutch commander destroyed the refinery and evacuated to P2, which was still operational. Once again, the AA gunners at the refinery had to disable most of their guns; two 3.7s were ferried across the river to cover the railway and bridges, then on to P2, but the gun of 15 HAA Bty at the ferry had to be abandoned.
Once the last aircraft had flown out of P2,  the decision was made to evacuate southern Sumatra. The force retreated to Oosthaven by road and rail, destroying the remaining AA guns which could not negotiate the bridges on the route. From Oosthaven the surviving RAF personnel and AA gunners were shipped to Java.
6th Heavy Anti-Aircraft Regiment, Royal Artillery