All Solomon Islands

During an anti-submarine mission, one of the engine failed. The captain reduced his altitude in an attempt to ditch the aircraft when control was lost. Aircraft dove into the sea and crashed few miles off shore. All five crew members were killed.
Crew (1st Squadron):
P/O George Parker,
P/O Thomas Vautier,
F/Sgt Leo Comesky,
Sgt Barry Rosenberg,
Sgt Leslie Smith.

The crew was engaged in a bombing mission over Rabaul with two other similar aircraft and left Honiara at 0525LT. While approaching the target, NZ4614 disappeared and apparently crashed into the Solomon Sea. The crew of both other aircraft started a SAR mission to find the wreckage but without success. All operations were eventually suspended on September 17 as no trace of the aircraft was found. As the Japanese forces evacuated the region in February 1944, it was concluded the crash was not caused by enemy action.
Crew:
F/Lt Roye Stevens,
F/O John Carson,
W/O Geoffrey Innes,
P/O Stanley Dawson,
F/O John McGuire.

The aircraft left Canton Island (Kiribati) at 1100LT bound for Honiara Airport, on Guadalcanal Island, Solomon Islands, with an ETA at 2100LT. While on approach by night, the four engine aircraft hit a mountain slope (2,000 feet high) located on the Florida Island, north of Honiara. The wreckage was spotted two days later, on July 28. Debris were found some 200 feet from the summit and all 27 occupants were killed.
Crew:
Hugh W. Prince, pilot,
Frederick F. Gundrum Jr., copilot,
Willard L. Churchill, flight engineer,
Eddie B. Hult, navigator,
J. Arthur Strumph, radio operator,
William A. Staley, traffic clerk.
Passengers:
Air Commodore Isaac John Fitch,
Lt Col John C. Pearson,
Maj R. R. Barton-Tates,
Lt Col Paul H. Berkowitz,
Lt Col Euliss L. Duggan,
Col Charles P. Burnett Jr.,
1st Lt Stephen J. Maliszewski,
2nd Lt William P. Foil,
Cpt Herbert R. Gore,
Cpt John S. Ingraham,
Maj Morton L. Talley Jr. 10
Source, photo and more info on
http://www.archaehistoria.org/index.php?option=com_content&view=article&id=123:site-flor5-aircraft-top-secret-cargo-consairway-c-87-liberator-express-41-11706&catid=21&Itemid=102

While cruising over the Guadalcanal Island, the aircraft hit a mountain slope and crashed. All 15 occupants were killed.

The aircraft left Torikina Airfield on Bougainville Island at 1008LT bound for Honiara on Guadalcanal Island. The last radio contact was just after take off completed in marginal weather conditions (light rain and visibility limited to one mile). The aircraft never arrived in Honiara and all SAR operations did not find any trace of the aircraft nor the 23 crew members.

En route, while cruising over the Choiseul Island, the seaplane hit a mountain and was destroyed. All nine occupants were killed.
Crew:
Lieutenant C. Burkhardt, pilot, 8.

Shortly after takeoff from Talina Island (Telin Island), while climbing, the aircraft crashed in unknown circumstances into the sea, few yards off shore. All 22 occupants were killed.

While completing a turn in poor weather conditions and low visibility, the twin engine aircraft crashed into the sea and exploded. A crew member was able to swim to the beach while four other occupants were killed.
Crew (1st Squadron):
P/O Charles Harney, †
F/O Gifford Stansell, †
F/Sgt Leslie Smith, †
W/O James Burton, †
Sgt H. Ham.

Crashed into the sea off Malaita Island during a maritime patrol mission. Two crew members were rescued while five others were killed.

Crashed on take off from Honiara-Henderson Field. At least one crew member was killed.