Archangel's core philosophy is simple: when you purchase our products, we serve as the Inertial-Sensing Division of your company. As such, we are committed to applying our knowledge and expertise to the benefit of our clients, including OEMs, Upgraders, and organizations facing issues with obsolescence.
We invite you to read some of the stories below to see how other companies have relied on Archangel.
S-64 / OEM Client (AHR150A)
The Erickson Air-Crane S-64 is a truly iconic heavy-lift helicopter. After securing the Type Certificate from Sikorsky, Erickson began a significant upgrade of the entire platform. As a part of this upgrade, Erickson Air-Crane selected Archangel’s AHR150A ADAHRS to replace antiquated spinning mass gyros, flux gate, and air data computer.
The result was significant reductions in weight and power while enhancing the reliability of the attitude subsystem, but there is more to the story.
During flight tests, Erickson Air-Crane discovered that the S-64 is a beast (high vibration environment) and a dancer (not exactly a rigid body). The AHR150A handled the vibration, but the autopilot created pitch oscillations that grew in intensity. Working together, Erickson and Archangel used simulations and analyses of collected data to isolate the cause. We found that oscillations in the aircraft body were strong enough to induce oscillations in the autopilot commands. After an engineering review, Archangel recommended moving the ADAHRS closer to the aircraft's center of gravity, which solved the problem.
In addition, the S-64 autopilot is analog while the AHR150A outputs are digital. To accommodate this difference, Archangel developed the AFC001 Flight Controller for Erickson. The AFC001 is one of the few DO-178B Level B data translators in the industry, but that’s another story.