Plane Swap – The Science

On the eve of Luke Aikins’ unique Plane Swap project, we look behind the scenes

How the first-ever skydive between two planes was made possible – in theory, anyway!

On April 24, skydivers Luke Aikins and Andy Farrington will jump out of their airplanes leaving them unmanned, skydive into each other’s planes before regaining control and performing a safe landing with the aircraft – all in under a minute. A truly unique concept, ‘Plane Swap’ will require steely nerves and precise engineering for the duo.

Conceptualised by Luke Aikins, who was inspired by a 1990s photo in an aviation publication, the idea initially sounded preposterous – even to engineer, professor and pilot, Paulo Iscold.

Iscold had first met Aikins after his famous jump from 25,000ft without a parachute, landing into a giant net in 2016. The professor of aerospace engineering questioned Aikins’ sanity, but after plenty of discussions, he could appreciate the science behind the daredevil act.

I’m in, I want to do it. Whatever it takes, I will do it

Paulo Iscold

Paulo said: “He told me about the idea to swap planes in the air and it sounded crazy. Nobody had done it before and I liked the idea of getting involved in something no-one has ever done. I told him right away, ‘I’m in, I want to do it. Whatever it takes, I will do it’.”

Challenges

The biggest challenge for Iscold, who has designed numerous aeroplanes that have set multiple world records over the past two decades, was to develop a way for the planes to slow down rather than speed up when in a nose dive toward the ground. The planes also have to remain steady enough on that descent so that Luke and Andy can enter the planes, take control of the aircraft and fly.

Problem-solving

The aircraft needed to fly in formation straight toward the ground and remain steady enough for the skydivers to manoeuvre through the air and into the door. The planes’ descent rate also had to be slowed down; otherwise the aircraft would travel at too high a speed for the jumpers to catch and the planes would soon disintegrate because of the velocity.

This meant that Iscold and his team had to come up with two solutions that would be developed exclusively for the ‘Plane Swap’. The first was a speed brake, that would slow down the plane on the dive, and also keep it steady. The second was the development of an autopilot to control the planes as Luke and Andy exited and re-entered the aircraft.

Paulo explains: “Normally an autopilot is designed to fly the plane straight and level, not straight down. So we knew from day one we had to develop those parts. We also realised very early in development that the plane had to be able to move with the wind, as the skydivers would be subject to freefall drift. So they had to own the same mass of air.”

Speed Brake

Addressing the speed brake issue, team member Ryan Malherbe came up with a clever solution. The brake would be attached to the belly of the Cessna 182 planes and as they entered a dive, it would open up and go perpendicular to the belly of the planes. Following several trial runs which saw the plane lifted by a crane and the air brake deployed, numerous tests in the air allowed the team to make minute adjustments in order to achieve the 90-degree dive angle required for the stunt to be successful. This meant that the airflow around the wings and the tail of the plane had to be precisely calculated.

365 days of work for 40 seconds of outcome

Nose-Dive Autopilot

Next came customising the autopilot. For the stunt to be a success, the planes have to fly in a controlled formation toward the ground and work in tandem with the speed brake. Iscold worked closely with fellow Cal Poly San Luis Obispo professor, Leo Torres, to tackle the problem. Initially, the system was too precise and would continually self-correct the planes, making it difficult for Aikins and Farrington to re-enter them. This meant the autopilot was modified to become “lazy” and make it easier for the team.

The re-entry for each of the skydivers was a particularly difficult problem to solve, with the planes travelling at around 140mph during the nosedive. The G-force had to be considered as Luke and Andy need to enter the plane, hit the button to deactivate the nose-dive and automatically correct the plane back to an angle and fly away.

As an engineer, it’s super easy to create solutions for problems that don’t even exist

Paulo said: “The fact the plane would be vertical and you can’t sit on the seat was one of my main concerns. I came up with all sorts of solutions to allow them to move inside the plane while skydiving. During the first test, Andy managed to grab the strut and crawl towards the door frame. He had one leg and arm inside the plane, the other on the outside. That allowed him to start the dive recovery process and then sit back on the seat. This showed that as an engineer, it’s super easy to create solutions for problems that don’t even exist. That’s why we did all the test flights during the development of the project.”

Once the pilots retake control of the planes, the speed brake must be immediately retracted so that the plane can increase speed and velocity and come back to land. According to Paulo’s calculations, the entire stunt will take less than a minute once the planes go into the joint nose-dives. “All the work I’ve been doing for a year is for 40 seconds of flight. It’s 365 days of work for 40 seconds of outcome.”

Testing

Testing has been taking place for the past several months at San Luis Obispo Airport, with aerobatic pilot Aaron Fitzgerald taking part in numerous practice runs. These have provided Paulo Iscold and his team with plenty of data, so they are fully prepared for the warmer weather that is expected when ‘Plane Swap’ takes place over the Arizona desert on 24 April 2022.

Iscold said: “There is a little bit of difference with the hotter temperature. Freefall velocity will be higher because the air is less dense. But in San Luis Obispo, the offshore wind is also very turbulent. That shouldn’t be the case in Arizona. So the test flights have given us some very good averages and hopefully, Arizona won’t give us a crazy hot day.”

The difference between being crazy and a genius is teeny-tiny

Having completed numerous practice runs and collected reams of scientific data, Iscold now believes that Aikins isn’t quite as ‘crazy’ as he first seemed. He commented: “The difference between being crazy and a genius is teeny-tiny. Luke, for sure, is on the genius side. You talk with him and you might think that his ideas are crazy, but in the back of his mind, he has a plan and those plans are pretty well put together. So, no, he’s not crazy at all.”

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Watch Plane Swap Live on Sunday April 24

Hulu is the exclusive streaming partner of Plane Swap in the US, and Red Bull TV is the broadcast platform globally.

You can watch Plane Swap Live on Hulu and on the free sport tv app Red Bull TV HERE on April 24, 2022, beginning at 4:00PM PT / 7:00PM ET / 00:00AM BST / 01:00AM CEST / 09:00AM AEST.

Article and photos by Red Bull