Air Data Attitude Heading Reference System (ADAHRS)
Archangel Systems Inc. announced today it has received FAA TSO C4c, C5f, C6e, C88b and C106 approval to manufacture its family of Air Data Attitude Heading Reference Systems (ADAHRS). The ADAHRS family consists of the AHR150A and AHR300A with maximum gyro output rates of 128°/s and 256°/s respectively. Each system is composed of two boxes: an Inertial Sensing Unit (-1) and a Magnetic Sensing Unit (-2).
These ADAHRS meet all the requirements of TSO C5f for an Unslaved Direction Gyro (using all solid state MEMS sensors), C4c for Pitch and Bank, and C6e for Gyro Stabilized Magnetic Heading. The systems also meet the requirements of C106 for an Air Data computer as well as C88b for Altitude Reporting Equipment, using an 11 wire discrete interface compatible with most transponders.
Developed originally for fly-by-wire aircraft, Archangel's ADAHRS have 100% DO178b Level A operating software in all five processors used in both the ISU and MSU. The ISU has multiple, redundant, dissimilar processors computing both air data and attitude data to ensure data validity.
The ISU measures 4.25" by 4.25" by 5.25", weighs 3.1 lbs and operates from 16 to 36 VDC using less than 20 Watts maximum. The MSU is approximately 3" round by 0.75", weighs 0.5 lbs and is powered by the ISU.
The ISU has 8 data ports for transmission and 2 for reception: 4 Hi speed and 4 Lo speed ARINC 429 transmission ports and 1 Hi speed and 1 Lo speed for data reception. ARINC 705-5 and 706-4 data are transmitted on the Hi speed ports and ARINC 706-4 is transmitted on the Lo speed ports. An RS232 maintenance port is also provided on the ISU for field calibration of the MSU, using a Windows™ based calibration routine which is provided with each unit. The maintenance port uses a protective cap with lanyard and contains lockout protect during flight. All connectors are Mil Spec 35899. An AN4 fitting is provided for pitot pressure and an AN6 for static pressure.
Strapping allows the unit to be oriented in 16 varying positions as well as to use 4 different static source error correction tables, all with parity strapping. Discrete inputs are provided for Outside Air Temperature, Angle of Attack as well as DG mode select and CW/CCW compass slewing (both of which can be done via the Lo speed ARINC buss). A master fault discrete output is also provided. For complete information, see the Interface Control Document and Specifications.
The AHR150A system has been chosen by Bell Helicopter Textron Industries for the Bell 609 Tilt Rotor Aircraft. Three AHR150A systems are used as an integral part of the Bell 609 fly by wire system and communicate with the 3 flight control computers as well as the flight displays. The three ISUs are mounted in the nose area while the three MSUs are mounted on the empennage bulkhead.
Jack Gallagher, Program Director for Bell/Agusta 609, expresses the importance of Archangel's long-term agreement with Bell. He says: "Key to the success of the 609 is cost, performance, weight and schedule; Archangel Systems meets these critical elements and we welcome them to our Team."
ADAHR ICD 
(User must confirm this is latest Rev. prior to use).
ADAHR Installation Manual (User must confirm this is latest Rev. prior to use).
Pricing & Delivery Information
These files require Adobe Acrobat Reader. Download Adobe Reader