The corporate jet that crashed into a warehouse in Teterboro, N.J., last month with 11 people on board was carrying too much of its weight in front, federal investigators said in a preliminary report released yesterday. The National Transportation Safety Board, which is still investigating the crash, said that the plane's center of gravity was "well forward of the allowable limit." Tests on a flight simulator showed that the plane would not have been able to lift off at its normal takeoff speed with the balance of fuel, passengers and baggage it was carrying, according to the report.