Advanced VTOL Technologies (AVT) specialises in the assessment of Ship Helicopter Operational Limits (SHOLs) and other helicopter/ship interface related problems.
AVT also developes ship motion models for seakeeping assessment and helicopter/ship dynamic simulation purposes.
This is achieved by utilising a specifically developed advanced simulation tool Ondeck that can accurately model the dynamic interaction between a helicopter and ship to establish safe ship motion operating limits (SHOL's) and provide operational guidance. The Ondeck model has been in development by the Australian Defence Science and Technology Organisation (DSTO) since 1988.
For over 11 years AVT has been largely responsible for the development and enhancement of Ondeck, including the development tyre interaction algorithms, multi-degree of freedom undercarriage models, ship motion models and various methodoloigies for the rapid assessment of helicopter on-deck ship motion limits.
We have provided analysis services to the Australian Defence Force, as well as other defence forces including the Danish Navy, Swedish Navy and the New Zealand Navy and commercial organisations such as MacTaggart Scott and Prism Defence.
Accurate ship motion data is used where available to kinematically drive the ship for a range of sea states, relative wave headings and ship speeds. Where necessary ship simulation models are developed in house using the propriety ship motion analysis software ShipmoPC developed by Defence Research and Development Canada (DRDC).
The Ondeck software is a non-linear time domain code specifically optimised for the development of operational limits and the analysis of on-deck interface issues. It incorporates detailed non-linear representations of the helicopters including accurate representations of the undercarriage and tyres. The code can model wheel sliding and lift off, the interaction with multi-contact surfaces, undercarriage loads, lashing loads, rotor and wind loads as well as the effect of restraint systems like RAST and Decklock and the MacTaggart Scott TRIGON system.
As part of a Commonwealth supported Capability Technology Program (CTD) the software is now being modified to provide real time operational guidance and usage monitoring on ships. This Maritime Helicopter Aid (MHA) is expected to be involved in trials shortly and is expected to provide the optimal solution for maximising on-deck operational capability, improving safety as well providing a unique airframe usage monitoring capability.
The Ondeck software can be used to:
- predict safe ship motion limits including
- toppling / sliding limits
- lashed limits
- Restraint system limits
- estimate sea state capibility,
- assess landing loads,
- airframe clearance,
- optimise lashing scheme layouts,
- produce gear and airframe load data for structural and fatigue analysis.
- Assess restraint and ground handling systems
In all 11 helicopter types have been modeled including S70B-2 Seahawk, S70A Black Hawk, SK 50/50A Sea King, MRH-90, ARH Tiger, Squirrel, Lynx Mk90b, SH-2G Seasprite, CH-47 Chinook, S92, and a generic Bell 222.
Seahawk
MRH90
Seasprite
Bell222