Sen. John Cornyn (R-TX) has lifted a hold on Heidi Shyu's nomination to lead the Army's top acquisition office after Defense Department officials agreed to his request to investigate a controversial sole-source helicopter contract with a Russian arms dealer and try to hold a competition for a new helicopter contract, according to government officials and documents. Cornyn, a member of the Senate Armed Services Committee, had placed the hold on Shyu, the Army's acting acquisition executive, because of helicopter purchase...