Grumman S-2 Tracker

The airplane departed USS Yorktown on a maritime patrol flight off the North Vietnam coast. While cruising by night, the crew reported problems with the radar. Shortly later, the airplane crashed into the sea some 40 km off Hòn Mê Island, North Vietnam. Three days later, part of the starboard wing was found but no trace of the four crew members.
Crew:
Cdr Donald Richard Hubbs,
Lt(jg) Lee David Benson,
AX2 Randall John Nightingale,
ADR Thomas David Barber.

The crew departed USS Kearsarge on a training mission over the South China Sea. The accident occurred in unknown circumstances, causing the death of both crew members.

The Tracker was lost while on a logistics flight to the USS Hornet in the Gulf of Tonkin. The aircraft suffered a loss of oil pressure in the starboard engine and the propeller had to be feathered but the aircraft could not maintain altitude and had to be ditched. All four crew members were picked up safely.
Source: Chris Hobson

While flying along the South Vietnam coast, the crew informed ground that an engine caught fire. Control was lost and the airplane crashed into the sea. A crew member was rescued while two others died.
Those killed were:
Lt Cdr Robert Eugene Robinson,
Ens John Wesley Coghill.

The crew was completing a training mission out from Catania when the airplane crashed in unknown circumstances into the Ionian Sea some 32 km east of Catania. Both pilots were killed.

The twin engine aircraft departed USS Kearsarge for a night patrol flight overt the Gulf of Tonkin. After about three hours the carrier lost radar contact with the aircraft and at first light other aircraft were launched to search for the Tracker. The wreckage and personal flight gear was spotted in the water about 55 miles northeast of Huế but there was no sign of any of the crew.
Crew:
Lt Thomas Joseph McAteer,
Lt (jg) William Thomas Carter,
AX3 John Michael Riordan,
AX3 Eric John Schoderer.
Source: Chris Hobson.

Shortly after a morning takeoff from Oranjestad-Princess Beatrix Airport, while in initial climb, the twin engine aircraft encountered difficulties to gain height. It struck a kiwi tree then crashed near houses. Two crew members were injured while two others were killed. Few hours later, one of the survivor died from his injuries.
Crew:
Lt E. Ijpma, †
G. Folkerts, †
Lt J. J. Mantel, †
K. Kuik.

On the night of 21/22 January 1966, the Tracker was launched from USS Hornet to provide surveillance cover for the SAR destroyers that operated close to the North Vietnamese coastline and which were occasionally challenged by enemy patrol boats and small craft. Under the control of a guided missile destroyer, the USS Berkeley, the Tracker was investigating an unidentified radar screen. Within a few hours of the aircraft's disappearance Hanoi Radio reported that a US aircraft had been shot down in the Gulf of Tonkin to the south of Bach Long Vi Island. The time was good at the time of the loss and the sea was very calm, which might have made depth perception difficult for the crew. An extensive search was conducted in the Gulf for days, afterwards and on 1 February a four-man liferaft from the Tracker was picked up some 150 miles from the aircraft's last known position. On 14 March Lt Templin's flying helmet was found in the same area as the raft. However, no trace of the crew was ever found and they were all declared dead in 1975.
Crew:
Lt William Stannard Forman,
Lt Erwin Bernard Templin,
SN Edmund Henry Frenyea,
SA Robert Russell Sennett.
Source: Chris Hobson

The twin engine aircraft departed Naples-Capodichino Airport at 2330LT for a local training mission with a crew of four on board. While flying in the vicinity of Ischia Island, the airplane crashed in unknown circumstances into the Bay of Naples. Two crew members were rescued while two others were killed, Lt Col Guido Meglio, pilot, and Lt Pier Francesco De Angelis.

The crew was engaged in a fire fighting mission in the center of Sicily. As the mission was over, the crew was returning to his base at Sigonella NAS when, cruising by night at an insufficient altitude, the twin engine aircraft struck the slope of a mountain located near the village of Valguarnera. The wreckage was found few hours later and both pilots were killed.
Crew:
1st Lt Giancario Napolitano,
1st Lt Arnaldo Pala.