American missions against Dumpu
December 26, 1942–November 5, 1943

June 27, 1943
(5th AF) B-25's bomb and strafe occupied areas including Dumpu.

November 5, 1943
(5th AF) B-25's pound positions northwest of Dumpu.

Japanese missions against Dumpu Airfield and Dumpu
November 6, 1943–March 15, 1944

November 6, 1943
(JAAF) Japanese planes strike Dumpu.

March 15, 1944
(JAAF) Five Ki-48 Lilys from 208th Sentai took off on a bombing mission against Nadzab flying in three waves but experienced bad weather
The first wave reached Hansa Bay, skirted the coast and could not penetrate the rain clouds, ended up over Long Island and returned. Third wave got to a position between Manam Island and Karkar Island, then turned back due to bad weather. The second wave: Lt Saito and S/Mjr Tsukagoe diverted to Dumpu, dropping 8 Ka-4 bombs with unobserved results. One Ki-48 Lily shot down by anti-aircraft fire and crashed near Dumpu.

References
JAAF 208th Sentai mission report March 15, 1944 via Richard Dunn