Royal Marines have been preparing to deploy to the Caribbean during hurricane season.
Exercise Merlin Storm has been focusing on testing the Commando Helicopter Force's (CHF) ability to operate in a disaster assistance role.
The CHF is on standby to head to the Caribbean, bolstering a Royal Navy-led task group already on patrol in the region.
Merlin Storm has been held in both Wales and the south-west, and also involves troops from the British Army.
The exercise is designed to maintain skills between deployments, particularly focusing on ground and air coordination.
On the ground
The ground element of the exercise includes training personnel in identifying and defeating an enemy.
Captain Paul Fleet, Motor Transport Officer for the CHF, spoke about the challenges the training is preparing troops for.
"You can’t land and refuel helicopters in hostile and isolated, high-threat areas without being able to protect yourself," he said.
"So as the Marines, we are commandos first, and we deliver the protection to the battlefield helicopters and it’s a unique capability that we work very hard to uphold."
Lieutenant David Houghton-Barnes of the CHF said the training is vital for combatting any potential "skill fade", allowing personnel to practise underslung load lifting for aid, fuelling serials and reconnaissance.
"It’s getting everyone together and practising it in one place that's probably the key part where you get skill fade," he said.
"The actual evolutions for the air crew - lifting loads, moving troops, etc - is something they practise from day one and continue for every year they're in the job."
If there is a natural disaster local infrastructure could be destroyed, meaning moving troops into hard-to-reach places could be the difference between life and death.
The exercise allows personnel who have just returned from the Caribbean to offer valuable insight into how to best operate in areas where extreme conditions are possible, to those who may be deploying soon.
What is it like to fly on deployment?
One member of the team who has experience of flying a Wildcat on deployment is Captain Tom Arkell, a pilot with 847 Naval Air Squadron.
"The Caribbean, in particular, is quite a challenging environment to fly in," he said.
"It's clearly very hot, which makes the helicopter performance relatively poor, compared to colder climates.
"The hotter it is, the poorer the engine performance, and that's typical across any helicopter.
"When you're working, in particularly hot climates, or even high climates - you might be up at altitude at 4,000 or 5,000 feet, it degrades the engine performance, so that you're approaching your power limitations.
"The helicopter is well-configured to operate when it's hot and high, however, you just have to be a bit more careful, bit more gentle in the controls to ensure you don't exceed any tolerances."
The logistics of load lifting
In order to get the technique right, personnel need to have strong communication, precision timing and be able to operate as a team.
"In normal operations there's two aircrewmen in the back of the aircraft," Petty Officer Thomas Doyle from 845 Squadron explained, while showing Forces News around the inside of a Merlin helicopter.
"The number one aircrewman is predominantly up the front of the aircraft," he added.
"The number one aircrewman will be operating the TSU [Transport Support Unit], which operates stuff like your performance.
"When you have troops on board you put them in[to the TSU], so that updates the weight of the aircraft, so you can have an accurate performance for when you're moving."
Watch: How a Merlin crew works together to lift loads.
The aircrewman's job in this role would be to act as the "extra eyes" looking out the front, while positioned with a map in between the two seats of the cockpit so they can aid with navigation.
"If we're going to a landing area, which might be a bit tight, for example, the number one aircrewman will open the door and then will stand in the position [of the side door] looking out, checking the tips of the [rotor] blades and the tail's clear, and then giving the pilots an accurate voice marshal into going down, judging the height and the distance of where they need to go," he continues.
"The number two aircrewman [is] down the back of the aircraft, predominantly.
"He's going to be checking the tail, making sure that the tail's clear when you're landing.
"In a normal transit, the number two aircrewman will be monitoring fuel and low-level radios.
"The bubble windows at the back [of the Merlin] for the number two aircrewman is just so he can put his head right out of the window... and have a good view on the left and the right."
The other main job of the number two aircrewman is monitoring the helicopter's load hatch on the floor of the aircraft.
"To get in [the load bay], the number one aircrewman, traditionally, he'll get you the general vicinity of the load, and the number two aircrewman will... sight the load underneath the aircraft and do the fine tuning to get the aircraft over the top.
"Once the aircraft is in position over the top of load, we'll bring the aircraft down, we'll hook the load on, I'll check that the load is all true... and connected well.
"Then the number one aircrewman will raise the aircraft up whilst I'm in this position [looking through the loading hatch], just making sure everything is good with the load."
When the helicopter has taken off, the number two aircrewman will continue to monitor the load, making sure it is flying well.
"We train to be able to operate in all different weather conditions and that's why we do the training that we do," PO Doyle added.
As part of the exercise, air and on-the-ground elements have to work in unison, and it is essential during their upcoming deployment to the Caribbean to help and react fast during disaster relief, if required.
Refuelling is a key part of the exercise so, if needed, helicopters can carry out multiple missions.
"It’s basically used as a pitstop at different helicopter landing sites, so aircrafts can go and do a task and they can come back, have a quick refuel in a selected area, where we will be set up," said Naval Airman Sanchez Jansz.
"We can fuel them, up they go and off again and with that we’ve come with two big air portable fuel containers which hold up to 900 litres of aviation fuel."
They practise these manoeuvres numerous times, but it is also made possible through the efforts of the planning and logistics team.
"My role really is anything logistics support, so that can involve movement of personnel, ammunition, weapons," Lieutenant Katie Roberts, Logistics Officer said.
"Initially, there would be a recce by similar troops here.
"They can go out onto the ground [and] get a picture.
"They would be feeding that back to the ops room command wherever we might be - we might be on a ship, just off the coast or we could already be on land.
"Then, based on that information, we would look to call forward our equipment and supplies."