Sikorsky Aircraft on Monday signed an exclusive distribution agreement with Shirley, N.Y.-based Naasco Northeast to improve S-76 helicopter starter generators. The Naasco Mercury Mod upgrade extends the time between overhaul of the starter generators and cools the operating temperature while lowering operating costs and enhancing performance, the manufacturer said. Naasco (Booth No. 2358) said the patented modification is backed by a 1,000-hour warranty and is available to customers upon request.