Swing arm attachment point (ACS system) broke during takeoff at approximately 10-15 feet AGL. Pilot felt a thud, tilted left, wing turned hard right. Pilot immediately reduced power and applied full brakes, landing safely with no injuries. The left swingarm was hanging from its backup strap. The internal swing arm 'puck' was found in the dirt.
Hardware failure
Maximum — exactly determined
Morning flight out of KGUC dirt strip (17/31), field elevation 7680'. Preflight found no faults. Motor tuned for elevation/temp. Forward power-on launch heading approximately 270°. Wing came up good with good stability. Leaned back, full throttle. Pilot was off the ground 50'-100' at height of 10'-15' and starting to climb when felt a thud. Tilted to the left and wing turned hard to the right. Let off power, pulled full brakes and was on ground before prop stopped spinning. After shutdown, discovered left swingarm hanging from backup strap. The internal swing arm 'puck' from the ACS system had broken from its mount. Part was found in the dirt.
Hardware failure - the left swing arm attachment point (ACS system internal 'puck') broke during takeoff. The manufacturer (Gravity Paramotors) is no longer in operation, making maintenance and replacement parts increasingly difficult to obtain.
Not deployed
dirt
Mostly correct inputs while reacting
July 26, 2025
09:00:00
United States
Gunnison, Colorado (KGUC)
Footlaunch
Gravity Paramotors Defy
Moster 185+
Ozone
Mojo Pwr 2
28
4 m
41 years old, male, 195 lbs, PPG 2 rated, 10-50 hours experience
1.3 m/s
Light Wind (1-5 mph), light and variable
Morning flight, light and variable winds
Morning flight out of KGUC on the dirt strip (17/31), Field Elevation 7680', Preflight spotted nothing (see attached preflight check list, I carry with me even during flight) ran my checklist the day before as my day of checklist Specific part is covered under the "ACS System…….. check" portion of the check list. No faults found with the equipment. Tuned motor for elevation/temp, final run up was good. Forward, power on launch heading aprox 270. Wing came up good, stability was good, leaned back, full throttle. I was off the ground for no more than 50'-100' at a height of no more than 10'-15' and started to feel the beginning of a climb when I felt a thud, I was tilted to the left and the wing turned hard to the right, let off the power, pull full brakes and was on the ground before the prop even had time stop spinning. I sustained no injuries. After killing motor, unhooking and taking a moment, I began to figure out what had happened. I noticed that my left swingarm was hanging from its backup strap. I quickly figured out that it had broken its mount, gravity calls it the "ACS". All but one part was still with the frame. I found the internal swing arm "puck" was missing. After a quick search in the dirt, I located it. I began to take stock of myself and make sure I wasn't overlooking a possible injury. Further inspection of my equipment has not revealed any additional damage. Maintenance on this frame has become increasingly complex since the manufacturer of the product is no longer in operation, and replacement parts are becoming increasingly difficult to find.