Two reserve air force pilots died Tuesday morning after their Cobra helicopter gunship crashed near Revadim, in the south of Israel.

Soldiers began to search for the chopper at 1 a.m., after radio contact with the pilots was lost.

Around the same time, an eyewitness called emergency services and reported that he had seen an aircraft giving off sparks before apparently going down in a wheat field.

Search and rescue crews scanned the area for the aircraft’s parts, which they first came upon at around 5 a.m.

The veteran pilots were on a routine flight exercise and did not radio in any news of technical difficulties.

Israeli Air Force chief Brig. Gen. Amir Eshel ordered an investigation into the crash, whose exact cause was unclear. Initial assessments pointed to a technical failure.

The army named the pilots as Lt. Col. Noam Ron, 49, from Oranit; and Major Erez Flexer, 31, from Haifa. The pilots’ families were informed of their loved ones’ deaths.

The Cobra attack helicopter – in Israel it bears the name Tzefa, or viper – has been in IAF service since the early ‘70s, making it one of the military’s longest-serving aircraft.

Despite its age, the Cobra is known as a reliable aircraft and hasn’t been involved in many accidents. In March 2008, however, a Cobra crashed in the Meditteranean due to technical malfunction, killing two.

The last fatal accident in the IAF was in July 2010, in Romania. During a military exercise with the local airforce, an Israeli Sikorsky helicopter crashed in the Carpathian Mountains.

The same model helicopter, the Sikorsky ch-53 – known in the IAF as the Yas’ur — was involved in the most fatal aviation disaster in the history of the air force. In February 1997, two helicopters collided in midair near the Lebanese border, killing all 73 soldiers on board.