The Obama administration has quietly forged ahead with its proposal to sell $60 billion worth of fighter jets and attack helicopters to Saudi Arabia unhampered by Congress, despite questions raised in legislative inquiries and in an internal congressional report about the wisdom of the deal. The massive arms deal would be the single largest sale of weapons to a foreign nation in the history of the U.S., outfitting Saudi Arabia with a fully modernized, potent new air force. Critics are questioning the deal, and the stealthy effort by the Obama administration to avoid a more probing congressional review by notifying Congress last month, just as members were headed home for the November elections. Congress had 30 days to raise objections -- a review period that concludes Saturday. The arrangement would ship 84 F-15 fighter jets and more than 175 attack helicopters to the Saudis over the next 15 years. Morris J. Amitay, a former head of the Pro-Israel lobbying group AIPAC, told ABC News a chief aim of the sale is insuring that Saudi Arabia can serve as another regional military counterweight to Iran. In part for that reason, he said, Israel has not been raising significant objections to the deal, even though he suspects Israel will push hard to insure the aircraft are not equipped with weapons systems as advanced as those held by Israel's own military.