CubCrafters Reveal 30% Gross Weight Increase for Piper PA-18 Super Cubs

CubCrafters has secured a Supplemental Type Certificate (STC) that increases the gross weight capacity of the Piper PA-18 Super Cub to 2,300 lbs. Initially acquired by CubCrafters in 2007 and revised in 2012, this STC was predominantly utilised for internal projects. However, the company is now expanding its offering to the wider market, enabling its inclusion in a greater number of Super Cub restorations and overhauls.

“This STC was a critical part of our internal certification program for the Top Cub almost two decades ago,” said Brad Damm, CubCrafters Vice President. “Given the increasing demand for performance enhancements in legacy Super Cubs, we believe the time is right to make this valuable capability more easily available to qualified aircraft owners, operators, and shops.”

“Our mission has always been to blend innovation with heritage,” added Patrick Horgan, CubCrafters President and CEO. “We’re committed to giving classic aircraft like the Super Cub new life by applying modern engineering solutions that significantly enhance performance, safety, and mission capability.”

The Supplemental Type Certificate (STC) raises the certified gross weight of eligible PA-18 aircraft from 1,750 lbs. to 2,300 lbs., providing an increase in payload capacity of over 30%. This enhancement is especially beneficial for backcountry pilots and operators who rely on maximising every available pound for gear, fuel, and safety margins. Additionally, owners of float-equipped aircraft will find this STC advantageous, as the increased legal useful load allows for the comfortable transport of two people, fuel, and baggage—capabilities often challenging or unattainable under the previous weight restrictions of the Super Cub.

To qualify for the 2,300 lb. gross weight increase, the aircraft requires comprehensive overhaul work. This includes a structurally enhanced airframe, new wings and landing gear assemblies, a 180 HP engine with a reinforced engine mount, and specialised aerodynamic features such as tail strakes and vortex generators. These upgrades have been designed and tested to modernise Piper's original Super Cub design, enhancing both performance and safety.

CubCrafters is providing this STC to interested customers as part of comprehensive aircraft overhauls conducted by its factory Services department in Yakima, WA. Additionally, the company plans to offer the STC along with the necessary structurally upgraded parts and assemblies for use by external third-party aircraft maintenance and restoration professionals.

Johnny McKinney, CubCrafters’ Aircraft Maintenance Services Manager, notes that most other popular Super Cub STCs are complementary to the 2,300 lb. GW increase STC. “Our customers will often incorporate modern avionics, a constant speed propeller, tundra tires, or a belly pod as part of their overhaul project — all of which can also be incorporated into a 2,300 lb. gross weight Super Cub project.”