Shop › Sikorsky UH-60 Blackhawk oil cooler aft bearing flange castellated nut socket Sikorsky UH-60 Blackhawk oil cooler aft bearing flange castellated nut socket CA$1,000.00 Only 1 available Castellated socket for UH-60 Oil cooler aft bearing flange nut removal.Essential for PMI 2 inspections. Castellated socket for UH-60 Oil cooler aft bearing flange nut removal.Essential for PMI 2 inspections. Get notified by email when this product is in stock. Add To Cart Added!