It’s early on Friday morning and the two-man crew of a F-15E Strike Eagle are making final checks before take-off.
First the navigation display, then weapons systems. The pilot pushes the throttles to full power and accelerates down the runway, leaving the huge Muwaffaq Salti airbase in north-west Jordan behind.
So begins their fateful journey over Iraq and down into south-western Iran, more than 800 miles away.
Having deployed to the Middle East from RAF Lakenheath in Suffolk last month as Donald Trump launched Operation Epic Fury, the American airmen had plenty of time to mull over their mission.
Who knows what came to mind as they contemplated the days ahead?
Perhaps they recalled the low-level flying exercises they conducted in South Wales – or maybe the gruelling ‘conduct after capture’ training in the Arizona desert.
Surely, they were buoyed by the fact that not a single US plane had been lost to enemy fire since the war began – and President Trump’s claim of complete dominance of the skies over Iran.
Once airborne, however, they had little time to think beyond the task in hand.
Engine performance, fuel status and avionics will have been constantly monitored by the pilot, who kept in regular contact with command.
Behind him in the cockpit’s rear seat, the weapons systems officer operated the complex radar, sensor and defence systems.
The F-15E Strike Eagle is designed for both air-to-air combat and long-range, ground attack missions.
Known as a ‘bomb truck’, it can carry up to 20,000lb of mixed air-to-ground and air-to-air weapons, including laser-guided bombs, missiles and even nuclear weapons.
Precise details are sketchy but cruising at more than 1,800mph the warplane probably likely took around 20 minutes to reach Iranian air space.
It is worth noting that, given what happened next, the Strike Eagle does not have the stealth capabilities of more recent generations of fighter jets.
Officials have indicated that it was heading towards the Strait of Hormuz when their worst fears were realised.
Some 100 miles inside Iran, the jet was hit by a surface-to-air missile. Tehran would later boast that a new air defence system was used to bring it down.
How much damage it sustained is unclear but the pilot and the weapon systems officer decided to bail out.
Pulling the ejection handles on their seats, they were propelled upwards by explosive charges, clearing the F-15 in a split second.
No amount of training would have mitigated the stress they endured when, after a brief freefall, their parachutes unfurled and they found themselves floating into enemy territory – the mountainous Kohgiluyeh and Boyer-Ahmad province, much of it covered by oak forest and home to wolves, bears and leopards.
Ejection seats are typically equipped with survival kits and communications devices.
Certainly, the airmen – each armed with a pistol and a knife – must have established contact with a command centre when they hit the ground, quite likely miles apart.
It is known the pilot activated a personal locator beacon.
Immediately after the first distress call, US military command launched a race-against-the-clock search-and-rescue operation, with President Trump being briefed at the White House.
The hazardous mission involved Special Forces on the ground and Black Hawk helicopters scrambled from Basra in Iraq accompanied by a C-130J Super Hercules, which operates as a mobile command-and-control centre.
It is understood indigenous groups in the area may have been previously contacted by US forces with the aim of creating contingency plans that could be activated to help with any rescues.
Iranians filmed the aircraft over neighbouring Khuzestan province and posted footage on social media – along with images of wreckage from the downed jet.
Wreckage pictures published by Iran’s state broadcaster purport to the show the F-15’s wingtip and the top section of a vertical stabiliser.
Justin Bronk, a senior research fellow who studies air power and technology at the Royal United Services Institute in London, said the markings were consistent with those of the 494th Fighter Squadron based at RAF Lakenheath, though they are believed to have shifted to Jordan for the war.
It was claimed on Saturday that two Black Hawks and the C130 Hercules fled the area during one rescue attempt, after Bakhtiari tribesmen opened fire with rifles, according to Fettah Mohammadi, deputy governor of Kohgiluyeh and Boyer-Ahmad province.
Video clips on Iranian social media show civilians in traditional dress firing at low-flying aircraft in mountain valleys.
In one clip, a young girl could be heard urging her father: ‘Hit it, Dad, hit it,’ as he aimed a rifle skywards.
Underscoring the mission’s risk, a Black Hawk was hit by ground fire but escaped to safety, while a second US military jet, an A-10 Thunderbolt II, known as the Warthog, was downed near the Strait of Hormuz, but the pilot was rescued.
US forces pinpointed the location of one of the F-15 crew, understood to be the pilot, in the Kohgiluyeh and Boyer-Ahmad province.
But they needed to act quickly. The Iranians were also closing in on him.
In a tense sequence of events lasting only minutes, US helicopters came under fire but ‘para-rescue jumpers’ – members of a daring US air force unit whose motto is ‘These Things We Do That Others May Live’ – managed to reach the pilot first and scoop him to safety.
‘Harrowing and massively dangerous is an understatement,’ a former commander of a para-rescue squadron said of the mission.
‘This is what they train to do, all over the world. They are known as the Swiss Army knives of the air force.’
The unit’s website says: ‘When an injured airman needs saving from a hostile or otherwise unreachable area, it’s our duty to bring them home…
‘[Our] highly trained experts take part in every aspect of the mission and are skilled parachutists, scuba divers and rock climbers, and they are even Arctic-trained to access any environment to save a life when they’re called to do so.’
Para-rescuers are trained as both combatants and paramedics and go through one of the hardest selection processes in the US military.
They also receive specialised courses in battlefield medicine, complex recovery operations and weapons.
On the ground, these teams are led by specialised combat rescue officers, who are responsible for planning, co-ordinating and executing the recovery missions.
Para-rescue teams deployed extensively throughout the wars in Iraq and Afghanistan, conducting thousands of missions to rescue US and allied troops who were wounded or required extraction.
In 2005, para-rescue teams were involved in the recovery of a Navy Seal who was wounded and seeking shelter in an Afghan village after his team was ambushed and its other three members killed. The incident was made into the film Lone Survivor.
It is thought the F-15 pilot was found in the Zagros mountains, which have one of the largest nomadic populations on Earth.
Determined not to let the other valuable propaganda prize – the weapons systems officer – slip from their grasp, the Iranians have offered a £50,000 reward (the average monthly income in the region is £200) to anyone who captures the airman alive.
They have sealed off an area in the province and are conducting a painstaking search.
It is unclear why it is taking US forces longer to rescue the second airman, and with every passing hour the prospect of reaching him before the Iranians grows slimmer.
