Lessons learned from NH90 NFH helicopter-ship interface: Testing across the complete Dutch fleet

Abstract

In general, the helicopter industry delivers a helicopter that has undergone elaborate in-flight test campaigns performed to demonstrate safe flight within the expected operational envelope. However, establishing the operational potential and limitations for safe shipboard operations is still considered a national responsibility. For some reason, there are still no internationally agreed regulations or standard procedures to establish the required helicopter-ship operational limitations. Consequently the kind of interpretation given to such limitations differs strongly between countries. As it is assumed that each country aims for maximum operational flexibility of a particular helicopter-ship combination, with minimum expenses and without any concessions to flight safety, this paper summarizes the lessons learned from the NH90 NFH helicopter-ship interface testing across the complete Dutch fleet. Aided by a predictive software tool, named “SHOL-X”, which eliminates subjective elements to the largest possible extend in order to determine operational envelopes for in-service conditions, the Netherlands Ministry of Defence was able to achieve tremendous savings in time and expenses of helicopter-ship qualification. This paper is specifically aimed at pilots and engineers who are involved in flight trials of helicopter-ship combinations as part of a complex flight test programme for which they are required to plan, conduct and report on helicopter-ship operational limitations.