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This gadget is helping French special forces nail their parachute landings

Even if you are parachuting alone and are reasonably lightweight, jumping out of a plane at 28,000 feet in the middle of the night while wearing an oxygen mask and descending into a hostile area is no easy undertaking.

It's far more difficult when you're doing the same mission while carrying not only pounds of gear but also another person who isn't a skilled paratrooper. That arrangement makes it nearly impossible to see down and measure your distance from the ground, preventing you from not only warning your passenger to lift their legs horizontally in a timely manner, but also precisely timing your landing move.

That is the situation addressed by the 13th Parachute Dragoon Unit, sometimes known as the 13th RDP, a French army regiment dedicated solely to acquiring human information from any theater in peacetime, conflict, or other emergencies.

The 13th RDP paratroopers had been utilizing a ground-detecting technology built over 30 years ago that they found inadequate until recently. So, inspired by the ultrasonic and electromagnetic reverse sensors found on some cars—the distance to whatever is behind your vehicle is calculated by the time it takes for the waves emitted by the sensors to bounce back to your vehicle—one of the soldiers with hundreds of tandem jumps under his belt devised a system that would beep at increasingly shorter intervals as he got closer to the ground.

He took the idea to France's Defense Innovation Agency (AID), a branch of the French Ministry of the Armed Forces dedicated to discovering and developing disruptive technologies, with the help of several colleagues. He received $51,000 from the AID to collaborate with Bordelaise Electronique, a tiny French electronics design firm, to develop a better system.

DAPCO (Dispositif d'Aide au Poser pour Chuteur Opérationnel) is the outcome, a gadget that resembles a little box (it's only 44 inches long) that aids operational paratroopers in landing. DAPCO employs lidar (acronym for Light Detection and Ranging), a pulsed laser-based technology. Given the known speed of light, the time it takes for the light to reach the earth and return to its source will reveal the exact distance between the source (in this case, the DAPCO on the paratrooper's chest) and the ground. A lighted altimeter on their wrists also provides this information, but the sound signal is more readily received.

According to Nicolas Tauzin, head of Bordelaise Electronique, they initially looked into two different technologies: radar and lidar. Radar, on the other hand, was swiftly ruled out as being too easy to detect: Radar beams are wider than laser beams, thus radar-detecting equipment are more common than laser-detecting instruments. "Lidar is much more discrete," says Tauzin, noting that the light beam is incredibly thin. "Lidar was the way to go overall, given the precision, weight, and size constraints we had to satisfy."

Before each leap, the operator calibrates DAPCO to account for the total weight under the parachute for that particular jump. Around 25 feet above the earth, the beeps become a continuous sound, as that is the altitude at which the paratrooper begins his landing procedure. Only the paratrooper can hear the beeps in his earbuds because the equipment is tied to his radio.

"We have a compass and a satellite positioning device to guide us along the prescribed route because we may travel roughly 45 miles with our operational parachutes following a HAHO jump," the paratroopers continue. HAHO stands for "High Altitude, High Opening," by the way.

Military paratroopers all around the world know what a HAHO leap is: they depart the plane at high altitude wearing an oxygen mask and open the parachute 10 to 15 seconds later. These jumps are commonly utilized in covert operations to avoid missions being jeopardized by the loud snapping sound emitted when a parachute unfurls. They are carried out by the Green Berets, the SEALs, the Delta Force, the Pararescuemen, the Combat Controller and Special Operations Weathermen of the United States Air Force, and the 75th Ranger Regiment, among others, in the United States.

"We land at 50 to 40 feet per second," explains the sergeant major who came up with the DAPCO concept. They also use a shock bag, which inflates beneath the backside of the passenger. The passenger will land on their bottom due to their lower position in front of the pilot paratrooper, so the shock bag will make the experience more comfortable as long as they have their legs horizontally out in front of them—otherwise, they may break a few bones, emphasizing the importance of knowing where the ground is. "Parachuting isn't a means to an end. It's just a means of getting us to the mission zone, so everyone needs to be in good health when we land," this person says.

The Special Forces have authorized DAPCO for operational use after it was deployed in roughly 70 testing jumps. Thirty are ready to be supplied to army special forces, while another 30 are ready to be given to air force special forces. The STAT, the French Army's testing unit, is now working on approving it for use by conventional paratroopers.