(c) For INS installations that do not have memory or other inflight alignment means, a separate electrical power source (independent of the main propulsion system) must be provided which can supply, for at least 5 minutes, enough power (as shown by analysis or as demonstrated in the airplane) to maintain the INS in such condition that its full capability is restored upon the reactivation of the normal electrical supply.
(d) The equipment must provide such visual, mechanical, or electrical output signals as may be required to permit the flight crew to detect probable failures or malfunctions in the system.
4. Equipment and equipment installation -- Doppler Radar Systems. (a) If an applicant elects to use a Doppler Radar System it must be at least a dual system (including dual antennas or a combined antenna designed for multiple operation), except that:
(1) A single operating transmitter with a standby capable of operation may be used in lieu of two operating transmitters.
(2) Single heading source information to all installations may be utilized, provided a compass comparator system is installed and operational procedures call for frequent cross-checks of all compass heading indicators by crewmembers.
The dual system may consist of either two Doppler Radar units or one Doppler Radar unit and one INS unit.
(b) At least two systems must be operational at takeoff.
(c) As determined by the Administrator and specified in the certificate holder's operations specifications, other navigational aids may be required to update the Doppler Radar for a particular operation. These may include Loran, Consol, DME, VOR, ADF, ground-based radar, and airborne weather radar. When these aids are required, the cockpit arrangement must be such that all controls are accessible to each pilot seated at his duty station.
5. Training programs. The initial training program for Doppler Radar and Inertial Navigation Systems must include the following:
(a) Duties and responsibilities of flight crewmembers, dispatchers, and maintenance personnel.
(b) For pilots, instruction in the following:
(1) Theory and procedures, limitations, detection of malfunctions, preflight and inflight testing, and cross-checking methods.
(2) The use of computers, an explanation of all systems, compass limitations at high latitudes, a review of navigation, flight planning, and applicable meteorology.
(3) The methods for updating by means of reliable fixes.
(4) The actual plotting of fixes.
(c) Abnormal and emergency procedures.
6. Equipment accuracy and reliability. (a) Each Inertial Navigation System must meet the following accuracy requirements, as appropriate:
(1) For flights up to 10 hours' duration, no greater than 2 nautical miles per hour of circular error on 95 percent of system flights completed is permitted.
(2) For flights over 10 hours' duration, a tolerance of ±20 miles cross-track and ±25 miles along-track on 95 percent of system flights completed is permitted.
(b) Compass heading information to the Doppler Radar must be maintained to an accuracy of ±1° and total system deviations must not exceed 2°. When free gyro techniques are used, procedures shall be utilized to ensure that an equivalent level of heading accuracy and total system deviation is attained.
(c) Each Doppler Radar System must meet accuracy requirements of ±20 miles cross-track and ±25 miles along-track for 95 percent of the system flights completed. Updating is permitted.
A system that does not meet the requirements of this section will be considered a failed system.
7. Evaluation program. (a) Approval by evaluation must be requested as a part of the application for operational approval of a Doppler Radar or Inertial Navigation System.
(b) The applicant must provide sufficient flights which show to the satisfaction of the Administrator the applicant's ability to use cockpit navigation in his operation.
(c) The Administrator bases his evaluation on the following:
(1) Adequacy of operational procedures.
(2) Operational accuracy and reliability of equipment and feasibility of the system with regard to proposed operations.
(3) Availability of terminal, gateway, area, and en route ground-based aids, if required, to support the self-contained system.
(4) Acceptability of cockpit workload.
(5) Adequacy of flight crew qualifications.
(6) Adequacy of maintenance training and availability of spare parts.
After successful completion of evaluation demonstrations, FAA approval is indicated by issuance of amended operations specifications and en route flight procedures defining the new operation. Approval is limited to those operations for which the adequacy of the equipment and the feasibility of cockpit navigation has been satisfactorily demonstrated.
[Doc. No. 10204, 37 FR 6464, Mar. 30, 1972, as amended by Amdt. 121-207, 54 FR 39293, Sept. 25, 1989]
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