This comprehensive digital collection contains authentic technical documentation for the legendary Westland Wessex helicopter series, compiled from official Air Publication archives of the Royal Navy, Royal Air Force, and Royal Australian Navy.
1. Wessex H.A.S. Mk.1 Operating Data Manual
AP 101C-0101-16 (Formerly AP.4723A-O.D.)
1 R.R. Gazelle Mk. 161 Engine
Promulgated by Command of the Defence Council, Ministry of Defence
For use in the Royal Navy
Amendment List 1, March 1970
Restricted
2. Wessex H.A.S. Mk.1 Pilot's Notes
AP.4723A-PN
November 1960
Prepared by Direction of the Minister of Aviation
Promulgated by Command of Their Lordships
Restricted
3. Wessex HAS Mk. 1 Aircraft Servicing Diagrams Manual - Electrical Installation and Location Diagrams
AP 101C-0101-10
Superseding AD 101C(101-012,-013)
Sponsored for use in the Royal Navy by HADIN
Publications authority: DATP/MOD(PE)
Issued July 1975
Restricted
4. Wessex HC Mk 2 & HC Mk 5C Pilot's Notes
AP101C-0102-15
2nd Edition, October 1972
By Command of the Defence Council
Prepared by RAF Handling Squadron
Amendment List 9
Restricted
5. Wessex HU Mk.5 and HC Mk.5C Aircraft Servicing Manual
AP101C-0105-1A
2nd Edition, November 1985
Superseding Section 1 and 2 of issue dated June 1967
Sponsored for use in the Royal Navy by DGA(N) and Royal Air Force by D. AIR ENG. (RAF)
Prepared by Westland plc
Publication Authority, Ministry of Defence ATP/MOD/PE
UK Restricted
6. Wessex H.U. Mk.5 Operating Data Manual
A.P.101C-0105-16
2 R.R. Gnome (Mk.112 Port and Mk.113 Stbd.)
Amendment List 4, September 1976
By Command of the Defence Council, Ministry of Defence
Sponsored for use in the Royal Navy by D.N.A.W. (RN)
Publication Authority H.B.P., Procurement Executive, Ministry of Defence
Restricted
7. Westland Wessex Mk. 31B Aircrew Notes
Royal Australian Navy
Restricted
8. Westland Wessex Mark 31 Sales Brochure
Westland Aircraft Limited promotional documentation
\"Focus on the Wessex Mark 31\"
The Westland Wessex stands as one of the most versatile and successful helicopters in British military aviation history. Developed by Westland Aircraft Limited as a licensed variant of the American Sikorsky S-58, the Wessex underwent significant British modifications, most notably the replacement of the original piston engine with turbine powerplants—initially the Napier Gazelle and later the coupled Rolls-Royce Gnome engines.
First entering service with the Royal Navy in 1961 as the H.A.S. Mk.1 (Helicopter Anti-Submarine), the Wessex quickly proved its worth in anti-submarine warfare operations during the Cold War. The aircraft's ability to operate from aircraft carriers and smaller vessels made it indispensable for protecting naval task forces from submarine threats. Throughout the 1960s and 1970s, additional variants emerged to meet evolving operational requirements: the HC Mk.2 for the Royal Air Force's tactical transport and search-and-rescue missions, the HU Mk.5 utility variant combining the best features of earlier models, and specialized versions for the Royal Australian Navy and other Commonwealth forces.
The Wessex distinguished itself across multiple theaters of operation and conflicts. During the Falklands War of 1982, Wessex helicopters performed critical roles in troop transport, casualty evacuation, and anti-submarine patrols, with several aircraft operating from both carriers and austere forward locations. The type also saw extensive service in Northern Ireland, Borneo, Aden, and numerous peacekeeping operations worldwide. Its reliability, lifting capacity, and ability to operate in harsh conditions—from Arctic waters to tropical jungles—earned it the respect and affection of crews and ground personnel alike.
Beyond military service, the Wessex found applications in civilian roles, particularly search-and-rescue operations where its all-weather capability and endurance proved life-saving. The Royal Air Force continued operating Wessex helicopters in the SAR role until 2003, with some aircraft accumulating over 40 years of service—a testament to the robust design and continuous upgrades that kept the type relevant across four decades.
Production of the Wessex spanned from 1958 to 1968, with approximately 380 aircraft built across all variants. Today, the Wessex holds a distinguished place in aviation history as a bridge between piston-engine and modern turbine helicopters, and as a workhorse that served with distinction in roles ranging from anti-submarine warfare to humanitarian relief.
These original technical manuals represent authentic documentation used throughout the Wessex's operational service life. Compiled from official Air Publication archives, they provide authoritative guidance on flight operations, maintenance procedures, systems descriptions, electrical installations, servicing diagrams, and airworthiness standards as promulgated by the Ministry of Defence and Ministry of Aviation. For restorers working to preserve surviving Wessex helicopters, historians researching Cold War-era rotorcraft development, aviation enthusiasts studying turbine helicopter evolution, or technical professionals requiring primary-source documentation, this collection offers comprehensive, authenticated reference material that captures the engineering excellence and operational versatility of this legendary British helicopter.
Copyright and Licensing: All documentation in this collection is owned by Online Aviation Library under collective copyright for manufacturers no longer in business, or through bilateral licensing agreements with active manufacturers for common information related to outdated aircraft models, engines, helicopters, and components. Copyrights owned by Online Aviation Library are registered in Canada under the company name "Sicuro Publishing" in the Canadian Copyright Database (https://www.ic.gc.ca/app/opic-cipo/cpyrghts/dsplySrch.do?lang=eng), with publicly searchable registration documentation available demonstrating legal ownership and legitimacy.
Intended Use: This digital documentation collection is provided for historical research, educational purposes, technical reference, restoration projects, and aviation heritage preservation. These materials represent historical technical standards and operational procedures as they existed during the aircraft's service period.
Not for Operational Use: This documentation is not intended for, and must not be used for, the operation, maintenance, or certification of any aircraft. Current operators must consult only the latest official publications, airworthiness directives, and regulatory guidance from appropriate aviation authorities.
Accuracy and Currency: While every effort has been made to preserve the authenticity and completeness of these historical documents, Online Aviation Library makes no warranties regarding the current applicability, technical accuracy for modern operations, or completeness of this information for any specific purpose.
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