Project History

Evergreen Super Tanker

Sel-Tech was contracted by Evergreen International Airlines to build Fire Retardant Pressure Vessel Tanks for their 747 Supertanker, the largest tanker in the world. Fabricated from aircraft grade Aluminum, the tanks required extensive use of fixtures,and precision sheet metal skills. Working closely with the engineers on the project, Sel-Tech was able to effectively build a quality airworthy product in a relatively short amount of time. All parts of the project are documented and certified by an FAA approved DAR.When fabrication was complete, Sel-Tech performed pressure test on each tank at 120 PSI. We fabricated 6 custom tanks ranging in size from 900 to 2500 gallons, to fit inside the 747 aircraft and provide a total of 20,000 gallons of storage.

TronosJet Hopper

The BAe-146 is one of the first of the next generation firefighting aircraft. Its medium size and four jet engines make it a versatile enough to handle the challenging environment of forest firefighting. The continuous flow tank system on the BAe-146 allows for much more consistent flow of retardent than conventional door systems. Sel-Tech has manufactured all of the hopper systems for the TronosJet fleet of Air Tankers. These hopper systems required an extensive amount of complex CNC bending as well as TiG welding and assembly. All welding on the project was required to pass fluroescent penetrant inspection. These projects are a good example of the versatility that Sel-tech offers its customers.


The Multi-Mission Pod has been one of our most recent projects which relied heavily on our precision CNC machining and assembly capabilities. This project required the extensive use of Boeing specs and very tight assembly tolerances. The unit consists of two complex assemblies which hang from the belly of the aircraft for storage of various electronics. The unit is 17 inches by 4 feet by 13 feet in size.

Air Stairs

Sel-Tech was originally established to meet the increasing demand for the Air Stair systems and these products are still a significant portion of our business. These units are automatic hydraulically powered accordion style stair assemblies which fold inside of the aircraft for storage. The assembly relies on complex kinematic motion to lock all segments into place and deploy handrail systems at the correct time.Air Stair systems range in size but some are as long as 27 feet.