Leigh Francis John Costain was Born 30 March 1950 and schooled in Tasmania. He joined RAN (Navy) on January 1967 as a 16 year-old, training as an Apprentice Aircraft Artificer at HMAS Nirimba (Sydney, NSW).
Having graduated from Nirimba in June 1970, Leigh married Annette on 4 July that year and almost immediately commenced pilot training on 81 Course, initially at RAAF Point Cook (1 Flying Training School), Melbourne, Victoria and then RAAF Pearce (2 Flying Training School), Perth, WA. Under training, he flew Winjeel and Macchi training aircraft, and graduated with his wings in June of 1972. His daughter, Lee-Ann, was born the following year.
Initially Leigh was posted to VC 724 Squadron, HMAS Albatross, Nowra, NSW for No 9 Skyhawk Operational Flying Conversion, but he did not complete the course due to a broken leg. Once healed, he was posted to RAAF 5 Squadron, Canberra for helicopter conversion, where he flew Iroquois UH-1B helicopters. His son, Damien, was born in February 1975.
Leigh then returned to HMAS Albatross (HC 723 Squadron) to consolidate and qualify for Naval flying operations – operating to/from ships at sea, search and rescue duties, range clearances and communications flights. Following that, he was to HS 817 Squadron for conversion and anti-submarine operations in the Sea King Mk 50/50A helicopters – ashore and embarked operations.
In December 1979 he was sent to RAF Shawbury, UK for qualified helicopter instructor’s course then to 705 Squadron RNAS Culdrose, Cornwall, UK as a staff instructor. Prince Andrew was undergoing helicopter conversion during Leigh’s tenure at 705 Squadron and Leigh and Annette shouted him to dinner at home – once he had graduated!!
In early 1983 the Costain family returned to Australia, where he rejoined HS 817 Squadron as QHI on Sea King and OIC Sea King Simulator. Later, he was posted to HC 723 Squadron for conversion onto AS 350 Squirrel helicopters then QHI on that type.
Leigh was then posted to HMAS Sydney for Bridge Watchkeeping training and certificates. Secondary duties included Aviation Officer and relief pilot for an AS 350 Flight embarked under Flight Commander, Derek Frew. He did a North Asian and Indian Ocean deployment and received his certificates in record time under CO Sydney CMDR Russ Lamb.
Following his sea time, Leigh served as Training Development Officer in Project SEA 1308 – Seahawk and Role Adaptable Weapons System acquisition followed in 1986 – initially Canberra-based but with extensive periods in USA (mainly NAS Jacksonville, Florida and Sikorsky, Hartford, Connecticut). This also meant Leigh was one of the first QHI’s qualified on S-70B-2. He was offered Fremantle Class Patrol Boat command but elected to stay on the Project due stability for children’s schooling.
He was on the team of the Seahawk Introduction and Trials Unit (SITU) on its raising in Feb 1988 under CMDR Tony Baker, AFC. During this time he continued training development and QHI duties.
On 2 August 1990, Iraq invaded Kuwait and the Australian Government committed a task group of 2 x FFG and 1 x AOR to the International coalition force for Iraqi containment operations in the Persian Gulf and Red Sea. A Seahawk was embarked in both HMA Ships Adelaide and Darwin. Leigh was the Seahawk P1 in the Adelaide detachment. The task group sailed from Sydney on 13 August and entered the Area of Operations (AO) on 3 September 1990. This was unique as the S-70B-2 had not yet been accepted into operational service and, while experience and exposure of the aircraft systems was a benefit of the deployment, there were impacts on progressing specific trials and training.
Op DAMASK 1 aircrew, including Leigh, out-chopped from the AO on 3 December 1990 returned to NAS Nowra on 21 December. Along with the ships’ companies, Leigh was awarded an Australian Service Medal for his contributions in the AO. The Op DAMASK 2 crews returned to NAS Nowra after DESERT STORM on 22 Apr 1991and were awarded the Australian Active Service Medal.
Returning to SITU, Leigh continued his training development duties on both the aircraft and simulator. He was also the senior QHI training incoming pilots and observers on the S-70B-2’s comprehensive systems.
On 23 July 1992, HS 816 Squadron commissioned as the parent squadron for the S-70B-2 Seahawk – Leigh was the Squadron’s inaugural Senior Pilot and, with a restructuring at the end of that year, he also became the Executive Officer and Deputy Commanding Officer. The Squadron won the Fleet Award’s McNichol Trophy for leading operations and safety in aviation for 1992.
Leigh completed his successful tenure as XO HS 816 in December 1993 and was awarded a Chief of Navy commendation for his dedication and professionalism associated with the introduction of the S-70B-2 to the Fleet. The Squadron at that time had 16 aircraft on inventory, generated four Flights and was building the fifth Flight as well as training replacement personnel for these Flights, the Simulator, Air Warfare Systems Centre, AMAFTU and the Squadron.
Leigh transferred to the Reserves and went on to complete a remarkable 44-year career almost entirely in the Fleet Air Arm. He retired as a Commander and remained within driving distance of NAS Nowra and his beloved aircraft. In late 2025 he was diagnosed with aggressive cancer and he passed away on 12 January 2026, remaining cheerful to the end. He was 75 years old.
A revered family-man, Leigh was also the proud father-in-law of Fiona and Jason; grandfather of Katja, Mitchell, Gavin and Joshua; grandfather-in-law of Holly; and great grandfather of Charlie, Frankie, Wynter and Poppy, who devastatingly passed away when only 12 days’ old on 23 August 2025.
Leigh’s funeral will be held at St Michael’s Catholic Church, North Street Nowra on Wednesday 21 January 2026 at 1300, after which he will be buried in Nowra General Cemetery, Naval Section. Relatives and friends are invited to attend the service.
His watch is done, and he did it with distinction.
Prepared from material supplied by Brett Dowsing. 13Jan26.
Image: Leigh’s last flight before full retirement.
