AEOLUS Flight Management System – Differential GPS landing system: An instant-on, tactical and precision approach capability

Abstract

Since the beginning of rotorcraft era, the HEMS/SAR (Helicopter Emergency/Search and Rescue) helicopters are called out to intervene in case of medical evacuation or emergency or C-SAR (Combat SAR) thanks to their capability to safely approach and land on hospital helideck or temporary and remote helipad very close to the critical area. Unfortunately, these operations are affected by weather, since they require Visual Metrological Condition (VMC) during the final segment of the descent. This proposal is aimed at extending the already certified Aeolus FMS’s User Approach capability beyond the VMC, integrating a brand new Differential GPS Landing System (D-GLS), within the avionics of AW189/AW169 helicopters. The D-GLS is based on a portable ground station comprising two GPS receivers and airborne GPS sensors capable to receive data from the ground station. It allows performing Precision approaches to a fixed or moving point, anywhere and in All Weather Condition with the same minima of ILS, LPV or GLS CAT-I approaches. D-GLS, differently from LPV or GLS, neither requires any fixed-earth point survey for the truth reference nor to be under SBAS signal for Accuracy and Integrity. Since the only requirement is to set-up the D-GLS ground station at the landing point, it can be classified as an “Instant-on”, Tactical and Precision Landing System.