Human error was likely the cause of the fatal training accident that killed Capt. Assaf Ramon on Sunday when the F-16 he was piloting crashed into the southern Hebron Hills, defense officials said Monday. On Sunday, Ramon - son of Israel's first astronaut, Ilan Ramon, who was killed in the fatal Columbia shuttle mission in 2003 - took off from the Nevatim air force base in the South in the early afternoon for dogfight training with another plane, flown by a veteran IAF pilot. The pair practiced three dogfights with their single-seater F-16As, but then the veteran pilot lost sight of Ramon's aircraft as they passed one another at 19,000 feet. "The fact that there was no call by Ramon for help or a report by him of a technical malfunction rules out the possibility of a mechanical breakdown," explained one defense official. Another indication was that the IAF did not ask Lockheed Martin, the manufacturer of the F-16, to send an engineering crew to Israel to assist in the investigation. On Monday, Brig.-Gen. Eden Atias, commander of the Nevatim base, told reporters that pilots would resume flight training on Tuesday. The IAF's F-16A models were grounded following the crash on Sunday. One of the scenarios the internal IAF investigation team is considering is that Ramon blacked out after taking a turn, during the fourth dogfight, at 9 Gs. Such blackouts usually last only a few seconds - enough time to plunge from that altitude to the ground. Meanwhile Monday, the Ramon crash reignited a debate within the IDF regarding the sensitive question of whether children from a bereaved family should be allowed to serve in combat units. According to current military procedures, the parent of the soldier needs to sign a waiver allowing the child to serve in a combat unit. In Ramon's case, his mother Rona signed the waiver three years ago, ahead of her son's enlistment in the air force. "This is something that needs to be reconsidered," explained one high-ranking officer. "We need to think about whether children who lost a father or mother in the IDF should be allowed to serve in positions where they, too, can be killed." Kadima MK Nahman Shai, a former IDF spokesman, called on the IDF to forbid bereaved children from serving in high-risk positions. Shai also asked MK Tzahi Hanegbi, chairman of the Foreign Affairs and Defense Committee, to convene a special session on the issue. "The current policy by which the IDF leaves the decision up to the mother needs to be reconsidered," Shai said.