FAA TSO C106 PDF

a. Applicability.

(1) Minimum Performance Standard. This technical standard order (TSO) prescribes the minimum performance standard that air data computers must meet in order to be identified with the applicable TSO marking. New models of air data computers that are to be so identified and that are manufactured on or after the date of this TSO must meet the standard set forth in Society of Automotive Engineers (SAE), Aerospace Standard (AS) 8002, "Air Data Computer - Minimum Performance Standard," dated October 30, 1981.

(2) Environmental Standard. The conditions and procedures prescribed in Radio Technical Commission for Aeronautics (RTCA), Document No. DO-160B, "Environmental Conditions and Test Procedures for Airborne Equipment," dated July 1984 are to be used in lieu of RTCA Document No. DO-160A, "Environmental Conditions and Test Procedures for Airborne Equipment," dated January 1980, which is incorporated as a reference in SAE AS 8002.

(3) Deletion. Paragraph 4.2.

(4) Addition. The following shall be used in place of paragraph 4.2:

Static Source Error Correction (if applicable)

Unless otherwise noted, outputs may be corrected for static source errors of the specific aircraft model in which the computer is intended to be used.

The tolerance of the correction value produced form the correction profile (correction curve) residing in the computer shall be the sum of the following:

A. ±15% of theoretical value of correction or equivalent of ±.0025 in Hg static pressure, whichever is greater.

B. Value of correction curve slope times the tolerance of independent variable programming the correction curve.

When testing corrected parameters (altitude, airspeed or mach) the nominal value of the parameter at each test point indicated in Tables 1, 3 or 4 shall be adjusted to include the correction value with tolerance limits set per (A) and (B) above.

(5) Exception. TABLE 3, CALIBRATED AIRSPEED: A looser tolerance of ±3.5 knots may be used at the 80 knots reference point.

(6) Computer Software. If the equipment design implementation includes a digital computer, the computer software must be verified and validated in an acceptable manner. One acceptable means of compliance for the verification and validation of the computer software is outlined in RTCA Document No. DO-178A, "Software Considerations in Airborne Systems and Equipment Certification," dated March 1985. For those applicants who elect to use RTCA Document No. DO-178A to demonstrate compliance for the verification and validation of the computer software, the following requirements must be met:

(i) RTCA Document DO-178A defines three levels of software: Level 1, Level 2, and Level 3. The applicant must declare the level (or levels) to which the computer software has been verified and validated. This equipment may incorporate more than one software level. The software for navigation functions must be verified and validated to at least Level 2.

(ii) The applicant must submit a software verification and validation plan for review and approval.

NOTE: The Federal Aviation Administration (FAA) strongly recommends early discussion and agreement between the applicant and the FAA on the applicant's proposed software verification and validation plan, and the applicant's proposed software level or levels.