Comparison of low speed helicopter flight trial techniques

Authors
Peter J.A. Booij, National Aerospace Laboratory, NLR, The Netherlands
Joost F. Hakkaart, National Aerospace Laboratory, NLR, The Netherlands
Egbert J. Smit, National Aerospace Laboratory, NLR, The Netherlands

Abstract

NLR has more than 45 years of experience in the field of helicopter-ship qualification testing. A cost effective and safe approach has been developed in the course of time, based on a thorough understanding of the helicopter's operational properties and the ship’s environment. Part of this approach are the 'shore based hover trials' in which the helicopter's low speed characteristics are investigated. Traditionally, these trials are performed by NLR by hovering in the naturally occurring wind. An alternative method is the use of a pace car. A project was started to compare these methods. Because a helmet mounted display or cockpit display can have additional benefits over the pace car method, this method was included in these trials. All three tested methods produced comparable test results and DIPES ratings with the Westland Lynx SH-14D helicopter. Each or any combination of the test methods can be applied to obtain optimum results in given weather conditions in a scheduled test period. The result is a cost efficient test campaign to obtain the low speed flight characteristics of a helicopter.