The RAF's last remaining C-130J Hercules transport aircraft are expected to be retired this year, with the A400M Atlas set to take their place.
Primarily used as a tactical transport aircraft, the C-130J variant has been in service since 1999 but the Hercules has been flown by the UK since 1966.
It has been used frequently in countries or regions where there is a threat to aircraft – its performance, tactics and defensive systems make it perfect for those operations.
So, how do the two aircraft compare?
Well, the C-130J Hercules is flown by two pilots and uses four 4,700shp Rolls-Royce AE2100D3 turboprop engines.
The aircraft has a wingspan of 132ft 7in (40.38m) and a cruising speed of 593km/h (368mph).
There are slight variations between the Mark 4 and Mark 5 aircraft.
The Mk4 has a length of 112ft 9in (34.34m) and a ferry range of 4,908km (3,049 miles), whilst the Mk5 has a length of 97ft 9in (29.77m) and a ferry range of 5,078km (3,155 miles).
Both variants have a maximum altitude of 40,000ft and a cruising altitude of 28,000ft.
The aircraft itself is highly flexible, with the ability to airdrop both stores and paratroopers and operate from natural surface landing zones – not just airbases and runways.
The crew of the Hercules are also highly skilled in low-level flying in order to perform in its role, whilst night-vision goggles allow the aircraft to perform the same duty at night.
Station-keeping equipment means it can remain in formation during bad weather, while Air Survival Apparatus can be carried for search and rescue missions.
The Hercules has been deployed in theatres across the globe since it entered service, including most recently in Sudan to help the UK Government's evacuation mission of the country.
The Hercules was also deployed to Turkey after the country was hit by a devastating earthquake in February 2023, as well as in the Middle East as part of the RAF's Operation Shader – combatting the threat of ISIS militants in Iraq and Syria.
The Atlas A400M entered service with the RAF in 2014, providing tactical airlift and strategic oversize list capabilities alongside the Hercules, and C-17 fleets.
The Atlas, like the Hercules, is also a four-engine turboprop aircraft.
It can carry a payload of 37 tonnes more than 2,000 nautical miles to both established and remote airfields, or short unprepared airstrips.
It can accommodate as many as 116 fully equipped troops, as well as vehicles and helicopters, including Chinooks.
It is also capable of carrying mixed loads, including nine aircraft pallets and 54 passengers, or other combinations of vehicles, pallets and personnel up to 37 tonnes.
It delivers each load via parachute or gravity extraction – dropping – from the aircraft's rear ramp.
It has a length of 147ft 11in (45.10m), a wingspan of 139ft 1in (42.40m), a maximum range of 7,593km (4,718 miles) and a maximum altitude of 40,000 ft.
Powered by four 11,000shp EuroProp International TP400 turboprops, the Altas has a maximum speed of 741 km/h (460mph).
The Atlas aircraft has been used in the UK's evacuation of Sudan, as well as during the evacuation of Kabul airport following Nato's withdrawal from Afghanistan.
On 15 May, Defence Secretary Ben Wallace defended the A400M after MPs in the Commons raised reports that said internal documents showed the aircraft is plagued by problems.
Mr Wallace pushed back against the concerns and said the A400M "outperforms" the Hercules in most areas.
"It's got a longer range, bigger capacity, can land in the same area, in fact, can land in shorter distance, and in Kabul, the massive evacuation of Kabul, one A400 had a fault for six hours and managed to continue on its course," he said.
"The simple reality is the A400 outperforms it (the Hercules), its availability was extremely successful, the Hercules only accounts for 10% of the fleet and the overall fleet for lift is now the biggest it has been for 50 years."
Defence Procurement Minister James Cartlidge also protected the aircraft's record, highlighting its key role in the Sudan evacuation mission.
"I know there is a great affection for the Hercules but just to go back to what the secretary of state was talking about in terms of the recent performance in Sudan, it's such an important operation," he told the House of Commons.
"The largest number of evacuees carried out of Sudan by the Hercules was 143. The largest number in an A400 I can confirm was around 100 more than that."
In March 2021, Mr Wallace announced the C-130J Hercules would be retired in 2023 after 24 years of service while 22 A400Ms would be part of efforts to "provide a more capable and flexible transport fleet".