Document ID: chunk:federal_register_of_legislation:F2021C01280:reg:5:p13
Version: federal_register_of_legislation:F2021C01280
Segment Type: reg
Provision Reference: reg 5 (pt 13/26)
Character Range: 38130–40878

in accordance with subclause 5.3.
       5.3For subclause 5.2, the scale errors at the major graduations of the scale must not exceed ± 4 knots up to the maximum speed of the aircraft, when tested first with the pressure increasing, and then with the pressure decreasing. During the test, operation of the airspeed indicator must be smooth and continuous.
       5.4Airspeed indicator tests, including determination of the scale error of the aircraft's installed airspeed indicator, must be performed at intervals not exceeding every 48 months.

6 Fuel quantity gauges
 6.1 Subject to subclause 6.1A, this clause applies to an aircraft if the aircraft's fuel quantity indicating system:
(a) relies on float type devices to measure tank fuel levels; and
(b) does not have a self-test function that can verify that the system is working within the manufacturer's stated tolerances.
6.1A This clause does not apply to an aircraft that is maintained in accordance with a maintenance program that adheres to MSG-2 or MSG-3 principles, as in force from time to time.
       6.2The accuracy of an aircraft-installed system for measuring fuel (the system) must be tested and determined.
       6.3For subclause 6.2, the determination must be made in accordance with the following test requirements:
(a) subject to the tolerances mentioned in this subclause — the indicated quantity of fuel must equal the actual fuel in the fuel tank less the unusable quantity of fuel;
(b) fuel quantity gauges must be checked for accuracy at all major graduations;
(c) subject to paragraph (d) — scale errors at empty must not exceed + 0.5% or – 5% of the nominal fuel tank capacity;
(d) for a system where it is impracticable to correct the empty reading — scale errors at empty must not exceed + 0.5% or – 8% of the nominal fuel tank capacity;
(e) if either of the following apply:
           (i) scale errors or the ungaugeable quantity of fuel exceeds ± 5% of the nominal fuel tank capacity; or
 (ii) the gauge is calibrated in fractions of fuel tank capacity;
 then, a placard must be displayed adjacent to the fuel quantity gauge showing:
 (iii) the corrected readings at all major graduations; and
 (iv) the ungaugeable quantities of fuel;
(f) fuel quantity gauges must be checked with the aircraft positioned to simulate level flight attitude;
(g) for paragraph (f):
 (i) electrically operated gauges must have normal system voltages applied; and
 (ii) the fuel quantity at each calibration point must be made by:
(A) measurement of the fuel added to the fuel tank; or
(B) a dip or drip stick previously calibrated for the fuel tank;
(h) during the test, the motion of any fuel quantity gauge must be smooth and continuous.
       6.4Determination of the accuracy