I, WILLIAM BRUCE BYRON, Director of Aviation Safety, on behalf of CASA, make this instrument under subregulation 21A (1) of the Civil Aviation Regulations 1988.
[Signed Bruce Byron]
Bruce Byron
Director of Aviation Safety and
Chief Executive Officer
17 December 2007
Civil Aviation Order 103.27 Instrument 2007
1 Name of instrument
This instrument is the Civil Aviation Order 103.27 Instrument 2007.
2 Commencement
This instrument commences on the day after it is registered.
3 New Civil Aviation Order 103.27
Civil Aviation Order 103.27 is repealed and a new Civil Aviation Order 103.27 substituted as set out in Schedule 1.
Schedule 1 Civil Aviation Order 103.27
Equipment standards — for navigation receiving equipment
Note: This Order is to be read in conjunction with Civil Aviation Order 103.21.
1 Application
1.1This Civil Aviation Order specifies standards for airborne VOR navigation receiving equipment operating within the frequency range from 108 to 117.95 MHz.
1.2These standards apply to the approval of equipment for use in Australian registered aircraft for the purpose of providing information for the navigation of the aircraft.
2 Design requirements
2.1The receiving and indicating functions of the equipment must be designed for compatibility with the Standards and Recommended Practices for VOR specified by the International Civil Aviation Organization current at the time of application for approval.
2.2The frequency range and number of channels must be adequate for the intended operational purpose of the equipment.
Note Australian domestic VOR channels are allocated from 0.1 MHz increments within the range 112 to 117.9 MHz.
2.3Not more than 2 controls must be used for frequency selection and tuning. These controls must switch into operation preset frequency determining circuits.
Note Continuously tunable receivers will not be approved.
2.4The minimum instrumentation arrangement must provide indication of deviations from VOR courses and unambiguous indication of the received VOR radial.
Note A radio magnetic indicator or similar device or a deviation indicator with TO/FROM indicator and omnibearing selector are acceptable alternative means of compliance with this requirement.
2.5Means to verify the quality of the received VOR signal and, as far as practicable, the correct functioning of the equipment, must be provided. For equipment with an I or L rating an alarm device complying with the requirements of paragraph 4.4 must be provided.
Section 1 - Civil Aviation Order 103.27 Instrument 2007 - Civil Aviation Order 103.27 Instrument 2007 | Zoe
Note The alarm function may be combined with the TO/FROM indicator providing that such combination meets all applicable requirements specified in this Equipment Standard.
2.6For equipment with an I or L rating, the indicator dial marking, TO/FROM indicator and alarm device indicator must be visible from any point within the frustum of a cone, the side of which makes an angle of 30 degrees with the perpendicular to the dial and the small diameter of which is the indicator window.
2.7The course deviation indicator pointer must be capable of deflecting at least 0.5 inch from its centred position to the positions corresponding to 10 degrees left and right deviation. For cross-pointer ILS type indicators, and indicators with similar markings, but without a glideslope deviation pointer, the deflection must be measured along the line corresponding to the centred position of a glideslope deviation pointer. Except in certain special cases accepted by the Director (e.g. non‑linear deflection systems associated with flight directors), the full scale deflection positions of the deviation indicator pointer must correspond to a nominal 10 degrees deviation from course.
2.8The performance of the equipment in its navigation functions must not be degraded by the operation of squelch circuits. The effect of squelch circuits must be confined to the muting of audio output.
2.9Navigation functions, including those of TO/FROM indicators and alarm devices, must not be affected by the operation of manual gain controls.
2.10Audio level controls must be connected in such a manner that variation of the controls will not cause a significant change in audio output level of other equipment with which its audio output may be paralleled.
2.11The manufacturer must state the load requirements for instrument and indicator output circuits.
2.12The operation of instrument and indicator circuits must not be affected when the audio output load impedance is varied within limits stated by the manufacturer.
2.13Controls not intended for use during flight must not be readily accessible to the flight crew.
2.14All indicators, controls and test points must be clearly marked or readily identifiable as follows:
(a) indicators and controls for in-flight operation must be marked in English symbols;
(b) indicators, controls and test points for maintenance adjustments to installed equipment must be marked in English or recognised technical symbols;
(c) controls and test points used only during maintenance at the test bench must be identifiable by means of suitable markings or other means of providing unambiguous identification, e.g. overlays, photographs.
2.15The equipment must be designed so that a possibility of incorrect mating of connectors is minimised. Plugs and sockets without positive means to prevent incorrect mating must be suitably marked or readily identifiable with their function or suitable circuit reference.
2.16The equipment must be so designed that the possibility of electric shock to passengers or crew is negligible.
2.17The equipment must be so constructed that normal methods of mounting and the application of vibration and shock under the most severe conditions likely to be encountered by the equipment will not cause detuning or other malfunctions to occur or otherwise damage the equipment.
2.18The equipment must be designed so that the rating of each component, with appropriate derating, is not exceeding in any localised component environment which may occur during operation of the equipment in any overall environment implied by its classification.
2.19The attachment of components and the restraint of plug-in components, adjustments and tuning devices, must be adequate to ensure their security and permanence of adjustment under the vibration conditions within which the equipment may be operated.
2.20The performance characteristics of the equipment must be unaffected by operation of panel and indicator lamps incorporated in the equipment.
Note It is recommended that lamps be fitted with a dimming device or provision made for their connection into a suitable dimming circuit.
3 Conditions of test
3.1Compliance with this Civil Aviation Order must be substantiated by tests conducted on 1 or more sets of equipment to the extent appropriate to the desired classification.
Note 1 The Director may allow some departure from individual requirements provided that, in his opinion, overall performance is consistent with the intended purpose of the equipment and is generally satisfactory throughout the range of environmental conditions mentioned in this Order.
Note 2 The Director may require additional tests to be conducted if particular designs or performance characters appear to warrant special assessment.
3.2During, and subsequent to the application of, the specified tests, the equipment must not exhibit evidence of any condition which would be detrimental to its continued satisfactory performance.
3.3Unless otherwise specified or required, tests must be conducted under room ambient conditions.
Note Room ambient conditions should be:
Note: atmospheric pressure — 810 to 1050 mb or 24 to 31 inches Hg;
Note: air temperature — +10 to 40C;
Note: relative humidity — less than 85%.
3.4Unless otherwise specified or required, the equipment must be operated at normal rated power supply voltage and frequency. Variations up to ± 2% of voltage and ± 2% of frequency will be accepted.
Note 1 Normal rated voltage and frequencies are those specified by the manufacturer for continuous or stated duty cycle operation of the equipment. Usual ratings will be 13.75 or 27.5 volts for DC and 115 volts at 400 Hz for AC operated equipment.
Note 2 For equipment designed to operate on a variable frequency AC supply, the terms “selected test frequency” and “critical test frequency” should be used and noted in the test reports.
3.5The input signal level must be interpreted as the “open circuit” voltage (EMF) of the signal source. The signal source output impedance must comprise a resistance within 10% and a reactance of not more than 10% of the characteristic impedance of the transmission line for which the receiver is designed. The input signal levels specified in this Equipment Standard are for receivers designed for a transmission line having a nominal characteristic impedance of 52 ohms. In the case of a receiver designed for a transmission line having a nominal characteristic impedance other than 52 ohms, the input signal levels must be computed according to the following equation:
E2 = Image unavailable in extracted text
where:
E2 is the input signal level to be used for a receiver designed for a transmission line having a nominal characteristic impedance other than 52 ohms;
E1 is the applicable signal level;
R2 is the nominal characteristic impedance of the transmission line for which the receiver is designed.
3.6Where a voltage level at radio frequency (other than an input signal level) is specified, it must be interpreted as the voltage actually occurring between the points stated, or the point and equipment frame, as appropriate.
3.7Unless otherwise agreed by the Director, equipment covered by these Equipment Standards must be capable of continuous operation.
3.8Accepted test procedures must be used for the conduct of the performance tests required by these Equipment Standards. Unless otherwise agreed by the Director, the same procedures must be used for the conduct of similar tests under environmental, low voltage and normal test conditions.
Note Suggested test procedures are contained in Appendix 2.
3.9Evidence that test equipment is properly calibrated and checked must be made available at the Director’s request.
3.10Minor modifications to correct deficiencies noted as a result of the tests may be made at any stage of the tests if such tests as the Director considers necessary are repeated.
Note Results of repeated tests should be identifiable with the specific modification.
4 Minimum performance requirements under normal test conditions
Note 1 Statistical analysis of the effect of several independent variables on VOR bearing accuracy is required in determining compliance of rating I equipment with paragraph 4.1. As the results of several tests from section 6 of this Equipment Standard are required for the analysis, the test program may be conducted in a sequence convenient to this requirement.
Note 2 Standard test signals and special terminology are defined in Appendix 1.
4.1Bearing accuracy
(a) The bearing error must not exceed the values mentioned in Table 1 when the equipment is subjected to each of the applicable variable conditions in Table 2 (marked X or (X)) while a standard VOR on-course signal at a level of 100 microvolts (unless otherwise specified) is applied to the receiver input.
In demonstrating compliance with this requirement, the equipment must be tested at VOR bearing intervals not exceeding 30 degrees and, for equipment designed to incorporate a bearing selector and course deviation indicator, on courses TO and FROM.
Table 1
VOR bearing accuracy
Operating rating
I5, I4, I3, I2
I1
V
Permissible bearing error (degrees)
2.7
4.2
5.0
(b) Additionally, for rating I equipment, the bearing accuracy must be within the limits mentioned in Table 1, with a statistical probability of 95%, under all combinations of the variable conditions marked (X) in Table 2.
Note It is not necessary to conduct tests under all combinations of the variable conditions applied simultaneously. Statistical methods of determining compliance with this requirement are set out in RTCA DO‑196 or later amendment.
Table 2
<table cellspacing="0" cellpadding="0" style="width:401.15pt; margin-left:37.2pt; border-collapse:collapse"><tbody><tr><td style="width:16.05pt; border-top:0.75pt solid #000000; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTableheading" style="margin-top:3pt"><span></span></p></td><td style="width:286.45pt; border-top:0.75pt solid #000000; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTableheading" style="margin-top:3pt"><span>Bearing </span><span>accuracy test</span><span> </span><span>—</span><span> </span><span>variable conditions</span></p></td><td colspan="2" style="width:66.55pt; border-top:0.75pt solid #000000; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTableheading" style="margin-top:3pt"><span>Operational </span><span>r</span><span>atings</span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext"><span></span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext"><span></span></p></td><td style="width:26.4pt; border-top:0.75pt solid #000000; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext"><span>I</span></p></td><td style="width:29.45pt; border-top:0.75pt solid #000000; border-left:0.75pt solid #000000; border-bottom:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext"><span>V</span></p></td></tr><tr><td style="width:16.05pt; border-top:0.75pt solid #000000; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>1</span></p></td><td style="width:286.45pt; border-top:0.75pt solid #000000; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>Variation of RF signal level over the range from 10 microvolts (</span><span>rating</span><span> I) or 20 microvolts (rating V) to 10</span><span> </span><span>000 microvolts</span></p></td><td style="width:26.4pt; border-top:0.75pt solid #000000; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>(X)</span></p></td><td style="width:29.45pt; border-top:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span></span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>2</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>Variation of RF carrier frequency above</span><span> </span><span>and below the assigned channel frequency by 0.005% of the assigned frequency channel</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>(X)</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span></span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>3</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:5.5pt"><span>When a 2</span><span> </span><span>000 microvolt undesired signal modulated 30% by a 30Hz signal that is 90</span><span style="font-family:Symbol, serif"></span><span> out of phase with the variable phase component of a simultaneously applied desired standard VOR test signal</span><span>,</span><span> and:</span></p><p class="LDTabletext" style="margin-top:5.5pt; margin-left:19.8pt; margin-bottom:5.5pt; text-indent:-19.8pt"><span>(a)</span><span style="width:6.48pt; text-indent:0pt; display:inline-block"> </span><span>the desired VOR signal level is varied from 10 to 10</span><span> </span><span>000 microvolts; and</span></p><p class="LDTabletext" style="margin-top:5.5pt; margin-left:19.8pt; margin-bottom:2.5pt; text-indent:-19.8pt"><span>(b)</span><span style="width:5.81pt; text-indent:0pt; display:inline-block"> </span><span>the undesired signal is set to any VOR frequency from 108 to 118 MHz, 100 kHz or more removed from the desired signal</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>(X)</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>Z</span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>4</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>Variation of the 30 Hz reference and a variable phase signal frequency by </span><span style="font-family:Symbol, serif"></span><span> 1.00%</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>(X)</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>Z</span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>5</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>Variation of the percentage modulation of the RF carrier by the variable phase signal from 25% to 35%</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>(X)</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>Z</span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>6</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>Variation of all primary power input voltages from 90% to 110% normal rated, or any greater range for which the equipment is designed</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>(X)</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>X</span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>7</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>Variation of primary power input frequency (if applicable) over the range for which the equipment is designed</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>(X)</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>X</span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>8</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>During the altitude test</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>(X)</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>X</span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>9</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>During the high temperature test</span><span style="width:14.15pt; display:inline-block"> </span><span style="width:21.3pt; display:inline-block"></span><span>(X)(T)</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>X</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span></span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>10</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>During the temperature variation test</span><span style="width:14.13pt; display:inline-block"> </span><span>(X)(T)</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>X</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span></span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>11</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>During the low temperature test</span><span style="width:17.48pt; display:inline-block"> </span><span style="width:21.3pt; display:inline-block"></span><span>(X)(T)</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>X</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>X</span></p></td></tr><tr><td style="width:16.05pt; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>12</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>After the humidity test</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>X</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span></span></p></td></tr><tr><td style="width:16.05pt; border-bottom:0.75pt solid #000000; padding-right:5.35pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>13</span></p></td><td style="width:286.45pt; border-right:0.75pt solid #000000; border-left:0.75pt solid #000000; border-bottom:0.75pt solid #000000; padding-right:4.97pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>During the vibration test</span></p></td><td style="width:26.4pt; border-right:0.75pt solid #000000; border-bottom:0.75pt solid #000000; padding-right:4.97pt; padding-left:5.35pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span>X</span></p></td><td style="width:29.45pt; border-left:0.75pt solid #000000; border-bottom:0.75pt solid #000000; padding-right:5.35pt; padding-left:4.97pt; vertical-align:top"><p class="LDTabletext" style="margin-bottom:2.5pt"><span></span></p></td></tr></tbody></table>
Note Symbols used in Table 2 have the following significance:
Note: X means that the test is required for determination of compliance with paragraph 4.1 (a);
Note: (X) means that the test is required for determination of compliance with paragraphs 4.1 (a) and (b);
Note: (T) as these conditions are not independent of each other, the maximum errors to be used in the statistical analysis are the maximum “left” and “right” errors occurring in the group of tests;
Note: (Z) although the application of conditions 3, 4 and 5 is not specified for equipment with V rating, a similar standard is desirable.
4.2Course deviation indication
Note The requirements of this paragraph apply to moving pointer course deviation indicators which are activated by a reversible polarity, direct current output from the receiving equipment. Where feasible, the sense of the requirements must be applied to other types of indicator or display which may also be used.
4.2.1Deflection sensitivity
The course deviation pointer must visibly deflect at least 12.7 mm along its scale when the phase difference between the reference and variable phase components of a standard VOR test signal is changed 10 degrees from that producing an “on‑course” indication. This requirement must be met throughout the range of input signal levels from 10 microvolts (rating I) or 20 microvolts (rating V) to 10 000 microvolts.
Note 1 This requirement applies to both left and right deflection.
Note 2 Refer also to paragraph 2.7.
4.2.2Deflection linearity
These requirements apply to equipment for which an I or L rating is desired.
As the phase difference between the reference and variable phase components of a standard VOR test signal is changed from plus 10 degrees to minus 10 degrees with respect to that producing an “on-course” indication, the deflection must be proportional to the phase change within 20% of standard deflection.
Additionally, as the phase difference is increased beyond ± 10 degrees to ± 80 degrees, the pointer deflection must not decrease at any stage of the variation.
These requirements must be met throughout the range of input signals levels from 20 to 10 000 microvolts.
4.2.3Deflection response and damping
This requirement applies only to equipment for which an I rating is desired.
When the difference in phase between the reference and variable components of a standard VOR “on-course” signal at a level of 100 microvolts is abruptly changed by 10 degrees, the pointer must reach 67% of its ultimate deflection within 3 seconds and the pointer overshoot must not exceed 20%.
Note 1 The manufacturer may choose to provide all or part of the damping within the equipment or provide for externally connected damping capacitors, etc.
Note 2 A similar standard is desirable for all equipment.
These requirements apply to equipment for which an I rating is desired.
4.3.1Deflection sensitivity
When the equipment has been initially adjusted to produce standard deflection with a standard VOR deviation signal at a level of 100 microvolts and the level is then varied over the range from 20 to 10 000 microvolts, the deviation current must not vary more than:
20%
of standard deflection
for rating
I
4.3.2Deflection linearity
(a) As the phase difference between the reference and variable phase components of a standard VOR test signal is changed from plus 10 degrees to minus 10 degrees with respect to that producing zero “on-course” indicator current, the output current must be within 20% of being proportional to the phase change.
(b) Additionally, as the phase difference is increased beyond ± 10 degrees to ± 80 degrees, the output current must be not less than standard deviation current.
4.3.3Deflection response
When the difference in phase between the reference and variable components of a standard VOR “on-course” signal at a level of 100 microvolts is abruptly changed by 10 degrees, the output current must reach 67% of its ultimate value in from 0.5 to 3 seconds.
Note Provision should be made for subsequent adjustment of response to suit operational conditions.
4.4Alarm device
This requirement applies to all equipment for which an I rating is desired (see paragraph 2.5).
(a) The alarm device must be fully visible or otherwise indicate system failure:
(i) in the absence of an RF signal; and
(ii) when the unmodulated RF carrier at the selected frequency is applied to the receiver input and its level varied from zero to 20 000 microvolts; and
(iii) when an RF carrier at the selected frequency and modulated 30% by an audio signal varied over the range 300 to 3 000 Hz is applied to the receiver input; and
(iv) when the 9 960 Hz modulation is removed from an otherwise standard VOR test signal varied over the range 20 to 10 000 microvolts; and
(v) when the 30 Hz modulation is removed from an otherwise standard VOR test signal varied over the range 20 to 10 000 microvolts.
(b) The alarm device must at least begin to appear, or otherwise indicate system degradation, when only 50%, or less, of standard deflection is produced by a standard VOR deviation signal due to variation of its RF carrier level.
(c) The alarm device must not be visible and must not otherwise indicate unsatisfactory operation of a properly functioning system when the level of a standard VOR test signal is varied over the range from not more than 10 microvolts (rating I) to 10 000 microvolts.
4.5TO/FROM indicator
Note Refer also to paragraph 2.4.
When the equipment incorporates, or is intended to operate with, a course deviation indicator, course selector and TO/FROM indicator, the TO/FROM indicator must provide positive TO or FROM indications at all bearings within 60 degrees (for rating I) or 45 degrees (for rating V) of the selected radial or its reciprocal.
4.6Selectivity
This requirement is included to provide a standard for rating V equipment for which tests providing an indication of bandwidth and adjacent channel characteristics are not included in the tests and analysis mentioned in paragraph 4.1.
(a) The level of an input signal, modulated 30% at 1 000 Hz, required to produce constant output must not vary more than 6 dB when its frequency is varied above and below the assigned channel frequency by 15 kHz.
(b) When the level of an input signal, modulated 30% at 1 000 Hz, is increased by 40 dB, the amount by which the input frequency must be changed to restore a selected output must be not more than 100 kHz.
4.7Spurious responses
This requirement applies to equipment for which an I rating is desired.
Over the frequency range from 190 kHz to 1 200 MHz, excluding the band 108 to 117.95 MHz, the response of the receiver must be at least 60 dB (rating I) below that at the assigned channel frequency.
4.8RF sensitivity
The level of a standard VOR audio test signal required to produce an audio output with a signal-plus-noise to noise ratio of 6 dB must not exceed:
5
20
microvolts
for ratings
I
V
4.9Audio AGC
The audio output must vary not more than:
6
12
dB
for ratings
I
V
as the level of an RF signal modulated 30% at 1 000 Hz is varied from 6 dB above the RF sensitivity level to 10 000 microvolts.
4.10Audio output
With an RF input signal modulated 30% at 1 000 Hz, the audio output capability must be not less than the rated power output published by the manufacturer. This requirement must be met over the input signal level range from the RF sensitivity level mentioned in paragraph 4.8 to 10 000 microvolts.
Note To ensure satisfactory performance in a wide variety of installations, an audio output capability not less than 50 milliwatts for the headset output circuit and 3 watts for the speaker output circuit (if provided) is recommended.
4.11Distortion
With an RF input signal modulated 30% by an audio frequency varied over the range 350 to 2 500 Hz and the audio output set to produce rated output at 1 000 Hz, the total harmonic distortion must not exceed 25%. This requirement must be met as the input signal level is varied over the range from 100 to 10 000 microvolts.
4.12Audio frequency response
The overall audio frequency response must be such as to produce clearly intelligible reception of any normal human speaking voice and attenuation of those frequencies which may detract from, or not significantly contribute to, intelligibility.
4.13Audio output regulation
The manufacturer must declare the effect of variation of audio load impedance on audio output power or voltage.
Note Although no specific values of acceptability are set down for this requirement, the information is necessary to the design and approval of aircraft audio installations. The information should cover load impedance variations from 0.25 to 2 RL for headphone circuits and 0.5 RL for speaker circuits.
4.14Manual gain control
The manual gain control must be capable of varying the audio output of the receiver by at least 24 dB with any level of standard VOR audio test signal from 20 to 10 000 microvolts applied to the receiver input.
4.15Spurious emissions
Note 1 Equipment which complies with the requirements for either Category A or B equipment specified in RTCA DO-160 or later amendment will be taken to comply with this paragraph.
Note 2 The emission of spurious radio frequency energy of a transient nature resulting from the manual operation of switches, but not including emissions from circuits operating as a result of that manual operation, may exceed the limits mentioned in this paragraph if its duration does not exceed 1 second.
4.15.1Emissions from antenna
The power of any spurious emission present at the antenna terminal on any discrete frequency between 190 kHz and 1 200 MHz must not exceed 1 nanowatt (for rating I) or 20 nanowatts (for rating V).
4.15.2Emissions from interwiring
This requirement applies only to equipment for which an I rating is desired. Unwanted radio frequency energy on any cable must be of such level, or must be contained in such manner, that the level of signals on discrete frequencies from 190 kHz to 1 200 MHz induced in another cable run with it does not exceed 1 000 microvolts. (Refer to Appendix 2 for suggested test procedure.)
Note Although this requirement does not apply to receivers with V rating, a similar standard is desirable. Particular attention should be given to minimising spurious emissions within the frequency ranges from 190 kHz to 20 MHz and 117.975 to 137 MHz in order to provide reasonable assurance that mutual interference limits, mentioned in other Civil Aviation Orders, can be met. Transistorised inverters in power supply circuits are frequently responsible for unacceptable emissions.
4.16Channel selection time
The maximum time for the equipment to change from 1 channel to any other must not exceed 10 seconds.
4.17RF input impedance
This requirement applies to equipment for which an I rating is required.
Over the frequency range for which the receiver is designed, the VSWR produced on the antenna transmission line by the receiver must not exceed 10:1.
4.18Operation of mechanical devices
Mechanical devices must perform their intended function. Marginal operation must be avoided.
4.19Variation of primary power frequency
The equipment must comply with this Equipment Standard when the primary power frequency is varied throughout the range for which the equipment has been designed. For equipment designed to operate from a nominally constant frequency supply, it must be assumed that the frequency will vary by at least ± 5%.
4.20Application of conducted voltage transients
This requirement applies only to equipment for which an I rating is desired.
Note 1 Although specified for I rating equipment only, it is desired that this requirement be applied, where practicable, to all equipment, especially that which incorporates solid state devices susceptible to damage by foliage transients.
Note 2 This requirement is expressed in this interim form pending further investigation of the magnitude and effects of aircraft electrical system voltage transients.
4.20.1Intermittent transients
After application of intermittent transients as specified in RTCA DO-160 or later amendment, the equipment must not exhibit evidence of damage and must continue to function without degradation.
4.20.2Repetitive transients
When the equipment is subjected to the repetitive transients test specified in RTCA DO-160 or later amendment, the requirements of both paragraphs 4.2.1 and 4.3.1 (Deflection sensitivity) and 4.4 (c) (Alarm device), each of this Order, must be met.
4.21Conducted and radiated interference susceptibility
These requirements apply only to equipment for which an I rating is desired.
Note Although these requirements do not apply to equipment with V rating, a similar standard is desirable, especially for the former, in order to provide reasonable assurance that mutual interference limits, mentioned in other Civil Aviation Orders, can be met.
4.21.1Conducted audio frequencies
The bearing error must not exceed the limits mentioned in Table 1 when the equipment is subjected to the test specified in RTCA DO-160 or later amendment.
4.21.2Audio frequency magnetic fields
The bearing error must not exceed the limits mentioned in Table 1 when the equipment is subjected to the test specified in RTCA DO-160 or later amendment.
4.21.3Radio frequencies (conducted and radiated)
The bearing error must not exceed the limits mentioned in Table 1 when the equipment is subjected to the tests specified in RTCA DO-160 or later amendment.
5 Minimum performing requirements at low primary voltage
5.1When all primary power input voltages are simultaneously reduced to 80% of normal rated for DC and 90% of normal rated for AC supplies:
(a) bearing accuracy must be within the limits mentioned in Table 1 as the level of a standard VOR on-course signal is varied over the range from 20 microvolts (rating I) or 40 microvolts (rating V) to 10 000 microvolts; and
(b) the requirements of paragraphs 4.2 (Course deviation indication), 4.4 (Alarm device), 4.16 (Channel selection time) and 4.18 (Operation of mechanical devices) must be met; and
(c) for rating I equipment, the requirements of paragraph 4.3 (Course deviation output characteristics) must be met.
6 Minimum performance requirements under environmental test conditions
Note Environmental test procedures are mentioned in Civil Aviation Order 103.21.
6.1Altitude test
When the equipment is subjected to this test:
(a) there must be no evidence of arcing, burning or other deleterious effect; and
(b) the requirements of paragraphs 4.1 (Bearing accuracy), 4.2 (Course deviation indication) and 4.3 (Course deviation output characteristics) must be met.
6.2Depressurisation test
6.2.1When the equipment is subjected to this test, it must continue to function as intended. Some degradation of performance may be permitted.
6.2.2There must be no evidence of any condition occurring as a result of this test which may cause complete failure of the equipment.
6.3Short time operating high temperature test
When the equipment is subjected to this test:
(a) there must be no evidence of overheating of any component or exudation of grease or other compounds; and
(b) the equipment must continue to function as intended. Some degradation of performance is permitted.
6.4High temperature test
When the equipment is subjected to this test:
(a) there must be no evidence of overheating of any component or exudation of grease or other compounds; and
(b) the requirements of paragraphs 4.1 (Bearing accuracy), 4.2 (Course deviation indication), 4.3 (Course deviation output characteristics), 4.4 (Alarm device), 4.5 (TO/FROM indicator) and 4.11 (Distortion) must be met.
6.5Temperature variation test
When the equipment is subjected to this test, the requirements of paragraphs 4.1 (Bearing accuracy), 4.2 (Course deviation indication), 4.3 (Course deviation output characteristics), 4.4 (Alarm device), 4.5 (TO/FROM indicator) and 4.8 (RF sensitivity) must be met.
6.6Low temperature test
When the equipment is subjected to this test:
(a) the requirements of paragraphs 4.1 (Bearing accuracy), both paragraphs 4.2.1 and 4.3.1 (Deflection sensitivity), 4.11 (Distortion), 4.16 (Channel selection time) and 4.18 (Operation of mechanical devices) must be met; and
(b) RF sensitivity must be not more than 6 dB below that mentioned in paragraph 4.8; and
(c) audio output capability must be not more than 3 dB below that mentioned in paragraph 4.10.
6.7Humidity test
6.7.1After the equipment has been subjected to this test, and immediately following the 15 minute warm-up period:
(a) bearing accuracy must be within + 8.0 degrees for rating I5, I4, I3 and I2 or 10.0 degrees for rating I1 equipment; and
(b) the equipment must continue to function electrically and mechanically.
6.7.2Within 4 hours from the time primary power is applied, the requirements of paragraphs 4.1 (Bearing accuracy), both paragraphs 4.2.1 and 4.3.1 (Deflection sensitivity), 4.4 (Alarm device), 4.5 (TO/FROM indicator), 4.8 (RF sensitivity), 4.16 (Channel selection time) and 4.18 (Operation of mechanical devices) must be met.
6.8Resonance search
When the equipment is subjected to the resonance search, there must be no evidence of excessive flexure of the chassis or mounting and components must not develop independent movement which would be likely to result in failure of the component or its attachment to the equipment.
6.9Anti-vibration mounting attenuation test
When the equipment is subjected to this test:
(a) the mountings must not attain their limit of displacement in any direction; and
(b) magnification of vibration amplitude must be confined to frequencies below 20 Hz.
6.10Vibration test
When the equipment is subjected to this test:
(a) there must be no evidence of detuning, upset of adjustments or other malfunction; and
(b) the requirements of paragraphs 4.1 (Bearing accuracy), both paragraphs 4.2.1 and 4.3.1 (Deflection sensitivity), 4.4 (Alarm device), 4.5 (TO/FROM indicator) and 4.8 (RF sensitivity) must be met.
6.11 Acceleration test
After the equipment has been subjected to this test, there must be no evidence of it breaking free from its mountings.
Appendix 1
Definitions
1 Standard test signals
Standard VOR test signals must have the characteristics mentioned below. It is permissible to use any type of signal generator which produces signals within the specified tolerance.
RTCA DO-52, Calibration procedures for signal generators used in the testing of VOR and ILS receivers, describes acceptable procedures for calibrating and checking several types of VOR signal generator.
2 Standard VOR test signal
An RF carrier, amplitude modulated simultaneously:
(a) 30 1% by a 9 960 Hz 1% subcarrier of constant amplitude which is, in turn, frequency modulated at a deviation ratio of 16 ± 1 by a 30 Hz ± 0.1% “reference phase signal”; and
(b) 30 1% by a 30 Hz ± 0.1% “variable phase signal”, derived from the same signal source as the reference phase signal, and which can be varied in phase with respect to the reference phase signal.
3 Standard VOR on-course signal
A standard VOR test signal in which the difference in phase between the reference phase and variable phase signals is within 0.3 degrees of the setting of the equipment course selector.
4 Standard VOR deviation signal
A standard VOR test signal in which the difference in phase between the reference phase and variable phase signals differs by 10 ± 0.3 degrees from the setting of the equipment course selector.
5 Standard VOR audio test signal
A standard VOR test signal to which is added a 1 000 Hz tone amplitude modulating the carrier 30%.
6 Standard deflection
(a) in the case of a course deviation indicator (or equivalent), standard deflection must be that deflection of the pointer which corresponds to a deviation of 10 degrees from the selected course; and
(b) in the case of an electrical output from the equipment, standard deflection must be the current which corresponds to a deviation of 10 degrees from the selected course;
when the equipment is adjusted to produce standard deflection and the input signal is a standard VOR deviation signal at a level of 100 microvolts.
7 VOR radial
A specific course emanating from the VOR facility. The radial is identified by its magnetic bearing from the facility.
8 Course selector
The course selector (track selector, omnibearing selector) is the device which permits selection of any VOR radial.
9 Selected radial
The VOR radial which has been selected on the course selector.
10 Course
In this Equipment Standard, course refers to a line through the VOR facility and identified by its magnetic bearing in whichever direction is chosen. Thus, a 60 degree TO course corresponds with the 240 degree radial, but toward the facility; and 060 degree FROM course corresponds with the 060 degree radial.
Appendix 2
Test procedures
1 It is recognised that compliance with some of the minimum performance requirements mentioned in this Civil Aviation Order may be determined using alternative test procedures. However, paragraph 3.8 stated that “accepted” test procedures are to be used and the Director may require a full description of the procedures actually used should there by any doubt as to the validity of the results of any test.
2 Procedures suitable for the conduct of most of the tests mentioned in this Civil Aviation Order are contained in RTCA DO-196 or later amendment. In some instances, suitable procedures may be determined from the wording of the requirement.
3 For the convenience of manufacturers who do not have ready access to RTCA DO‑196 or later amendment, or certain of the test equipment mentioned in it, the following information on acceptable test procedures may be useful.
3.1 Simultaneous application of 2 signals to the receiver input
Test 3, Table 2, paragraph 4.1 requires the simultaneous application of 2 signals to the receiver input. It is important that the 2 signal generators and the receiver be properly interconnected and terminated for these tests. The preferred procedure for these tests is as follows:
Connect 2 signal generators via a suitable “T” pad to the receiver input. The pad must provide suitable termination and isolation for the signal generators and receiver. One signal generator will supply the “desired” signal, the other the “undesired” or “interfering” signal.
Image unavailable in extracted text When both signal generators and the receiver are designed for a nominal 52 ohm RF termination, the “T” pad should be as shown in Figure 1.
Figure 1 R1 = R2 = R3 = 17 ohms
“T” Pad for 52 OHM equipment (non-inductive)
When using the “T” pad, the RF signal levels specified are the “open circuit” levels at the output of the “T” pad with the receiver disconnected.
3.2 Spurious Emissions (paragraph 4.15 refers)
3.2.1 Emission from antenna
Connect a suitable tunable receiver — such as a field intensity receiver — to the antenna terminal of the receiver under test. Ensure that correct impedance matching is achieved. The receiver under test may be set to approximately 110 MHz.
Tune the tunable receiver across the specified frequency range and note the presence and level of a signal indications.
A signal generator in place of the receiver under test may be used to determine the levels of noted signals and these converted to power by calculation.
3.2.2 Emissions from interwiring
The test conditions should simulate a typical installation in an aircraft.
Mount the equipment by its normal means, approximately centrally, on a copper, brass or aluminium groundplane measuring at least 0.76 metre wide and having an area of at least 1.1 square metres.
This test should preferably be conducted in a screened room with the groundplane connected to the room shielding by low reactance paths from at least both ends of the groundplane.
Where the length of interconnecting cables is not specified by the manufacturer, these should be at least 1.52 metres long and arranged as in a typical installation. Cables should be raised about 50 mm above the groundplane to reduce shunt capacitance effects. Only those cables so specified by the manufacturer in wiring diagrams applicable to the equipment may be screened.
Bonding straps across vibration isolators, etc should be fitted where these would be used in a normal installation. Bonding must not be used in any place where it would not normally be used in an installation.
Tie in with each bundle of cables in the simulated installation an 18 or 20 gauge insulated cable, unterminated at both ends. Connect a suitable tunable receiver — such as a field intensity receiver — to this “pick-up” cable.
Tune the tunable receiver across the specified frequency range and note the presence and level of signal indications. A signal generator may then be used to determine the levels of noted signals.
Appendix 3
Bearing accuracy analysis
A statistical analysis of VOR bearing accuracy is mentioned in paragraph 4.1 (b). For rating I equipment, for which the analysis must include the effects of a large number of variable conditions, the analysis should be made along lines similar to those described in RTCA DO-196 or later amendment.
Where only a few variable conditions have to be taken into account, the following procedures, although sometimes yielding a slightly pessimistic result, greatly shortens the computation time:
(a) Tabulate, as in Columns 2 and 4 of the following table, the maximum “left” and “right” bearing errors due to each of the applicable variable conditions in Table 2, paragraph 4.1. Note, however, that the temperature tests are grouped for determination of the maximum errors resulting from any temperature condition.
(b) Calculate the square of each maximum error and enter in Columns 3 and 5.
(c) Add Column 3 and calculate the square root of the sum. Do likewise for Column 5.
(d) Compute two-thirds of the root-sum-squares thus found. (It is assumed that these results are the 95% (2 sigma) probability levels for bearing accuracy as required by the specification.)
Note 1 A similar tabulation and calculation will be required for each type of readout, e.g. RMI, Course deviation indicator/OBS, that may be used with the equipment.
Note 2 The figures have no significance and serve only as an example of the method.