What was found
(CAN) SUBMITTER SUGGESTS THAT THEY CANNOT COMPLY WITH THE FLIGHT MANUAL REQUIREMENT TO SAMPLE FUEL AT THE ENGINE FUEL FILTER FOR CONTAMINANTS AS REQUIRED BY HUGHES PRE-FLIGHT. FIELD EXPERIENCE HAS INDICATED THAT THE ENGINE FUEL FILTER SAMPLE POINT IS VITAL. WHEN USING JET 'A' FUEL, THE ENGINE FUEL FILTER BOWL WILL COLLECT WATER THAT WAS NOT DETECTED AT THE FUEL CELL DRAIN. MANUFACTURER CONTACTED AND FLIGHT MANUAL WILL BE CORRECTED.