Timberline Aerospace, LLC, based in Sandpoint Idaho, certifies and manufactures aircraft upgrades and modifications with a focus on utility helicopters and equipment.

Founded in 2018 as a wholly owned subsidiary of Timberline Helicopters, Inc., we have received several STC’s and have several more pending to modify the UH-60, MD500, Bell 205, 206, 407, 212, 412, and Airbus AS-350 helicopters to better equip them for utility missions.  Timberline’s in-house design and engineering capabilities include certification personnel who work with local Designated Engineering Representatives and the Aircraft Certification Office to move projects through the STC process efficiently.

Our manufacturing capabilities have grown to include CNC machining, composite construction, and complex structural assemblies. In 2019, we received FAA Parts Manufacturing Approval allowing in-house production of our STC kits.





UH-60A Purge Fuel Collector System




During shutdown of the GE T-700/701 engines installed in the UH-60 helicopter, the fuel nozzles are purged with bleed air to prevent coking. This fuel is vented overboard and dumped on the ground creating an environmental issue in many jurisdictions. Timberline Aerospace has developed the Purge Fuel Collector System to capture this fuel and prevent it from being released into the environment. The system meets US Forest Service Call When Needed and Exclusive Use contract requirements. Installation is approved via an STC Approved Model List currently including UH-60A, EH-60A, and HH-60L models for various Type Certificate holders.

Locking Fuel Cap Cover




Developed as an alternative to expensive and problematic locking fuel caps, the locking fuel cap cover is an economical and simple solution. It helps prevent introduction of foreign materials into the fuel system as well as deterring unauthorized access to fuel ports. For fleet operators there is an option for all keys to be alike reducing the burden of lost/misplaced keys. 

UH-60A 34.5 Beam Modification




Operators of the UH-60A have long known of cracks developing in the stress concentration where the Station 308 frame joins the 34.5 cabin roof beam. Previously repairing this cracking required the replacement of the entire 308 Frame, a time consuming and expensive process. Timberline Aerospace has engineered a modification kit that is more economical and much simpler to install. This modification can be installed prior to cracks being detected or, in specific cases, after a crack in the 308 Beam Tab has been discovered. Installation requires approximately 50 man hours for each 308 to 34.5 junction and must be completed by or supervised by Timberline approved personnel. Install teams are available to expedite the process and ensure maximum availability of an aircraft. The modification is currently approved via STC Approved Model List on 11 different models of the UH-60 for different Type Certificate Holders.

Flight Control Rigging Pin Kit 


Timberline Aerospace’s flight control rigging pin kit is designed by operators for operators. This complete kit provides a quick and easy method of pinning the flight control linkages so that they can be adjusted correctly before installing flight fasteners, meeting all repair manual rigging requirements for PMI 1, PMI 2, reset and refurbishment.

UH-60 Rotor Blade and Hub Covers Kit


Timberline Aerospace’s rotor blade and hub covers kit provides a quick and easy method of installing waterproof covers on both the main and tail rotor blades and main and tail rotor hubs. These covers prevent frost and ice forming during cold icing conditions by using an open bottom design allowing water to drain freely. The covers are designed with the operator in mind featuring a quick and easy installation and removal using a pull strap and snap connector.

Benefits of the Hub and Rotor Cover:

  • Easy to install and remove
  • Open bottom design to allow water drainage
  • Reduces deicing time before startup
  • Prevents frost and ice from forming 
  • Pull strap and snap connection tightening 
  • K-MAX version also available

UH-60A External Fixed Provisions Kit


STC Pending


Utility helicopter missions often require externally mounted equipment. The Timberline Aerospace External Fixed Provisions Kit gives operators multiple approved external mounting points to attach mission related equipment and furnishings. Consisting of a set of five separate belly mounted points and two points mounted outside the cabin 308 beam, the options are endless.