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Pt. 27, App. D
Appendix D to Part 27—HIRF Environments and Equipment HIRF Test Levels
This appendix specifies the HIRF environments and equipment HIRF test levels for electrical and electronic systems under § 27.1317. The field strength values for the HIRF environments and laboratory equipment HIRF test levels are expressed in root-mean-square units measured during the peak of the modulation cycle.
(a) HIRF environment I is specified in the following table:
Table I.—HIRF Environment I
Frequency
Field strength(volts/meter)
Peak
Average
10 kHz-2 MHz
50
50
2 MHz-30 MHz
100
100
30 MHz-100 MHz
50
50
100 MHz-400 MHz
100
100
400 MHz-700 MHz
700
50
700 MHz-1 GHz
700
100
1 GHz-2 GHz
2,000
200
2 GHz-6 GHz
3,000
200
6 GHz-8 GHz
1,000
200
8 GHz-12 GHz
3,000
300
12 GHz-18 GHz
2,000
200
18 GHz-40 GHz
600
200
In this table, the higher field strength applies at the frequency band edges.
(b) HIRF environment II is specified in the following table:
Table II.—HIRF Environment II
Frequency
Field strength(volts/meter)
Peak
Average
10 kHz-500 kHz
20
20
500 kHz-2 MHz
30
30
2 MHz-30 MHz
100
100
30 MHz-100 MHz
10
10
100 MHz-200 MHz
30
10
200 MHz-400 MHz
10
10
400 MHz-1 GHz
700
40
1 GHz-2 GHz
1,300
160
2 GHz-4 GHz
3,000
120
4 GHz-6 GHz
3,000
160
6 GHz-8 GHz
400
170
8 GHz-12 GHz
1,230
230
12 GHz-18 GHz
730
190
18 GHz-40 GHz
600
150
In this table, the higher field strength applies at the frequency band edges.
(c) HIRF environment III is specified in the following table:
Table III.—HIRF Environment III
Frequency
Field strength(volts/meter)
Peak
Average
10 kHz-100 kHz
150
150
100 kHz-400 MHz
200
200
400 MHz-700 MHz
730
200
700 MHz-1 GHz
1,400
240
1 GHz-2 GHz
5,000
250
2 GHz-4 GHz
6,000
490
4 GHz-6 GHz
7,200
400
6 GHz-8 GHz
1,100
170
8 GHz-12 GHz
5,000
330
12 GHz-18 GHz
2,000
330
18 GHz-40 GHz
1,000
420
In this table, the higher field strength applies at the frequency band edges.
(d) Equipment HIRF Test Level 1.
(1) From 10 kilohertz (kHz) to 400 megahertz (MHz), use conducted susceptibility tests with continuous wave (CW) and 1 kHz square wave modulation with 90 percent depth or greater. The conducted susceptibility current must start at a minimum of 0.6 milliamperes (mA) at 10 kHz, increasing 20 decibels (dB) per frequency decade to a minimum of 30 mA at 500 kHz.
(2) From 500 kHz to 40 MHz, the conducted susceptibility current must be at least 30 mA.
(3) From 40 MHz to 400 MHz, use conducted susceptibility tests, starting at a minimum of 30 mA at 40 MHz, decreasing 20 dB per frequency decade to a minimum of 3 mA at 400 MHz.
(4) From 100 MHz to 400 MHz, use radiated susceptibility tests at a minimum of 20 volts per meter (V/m) peak with CW and 1 kHz square wave modulation with 90 percent depth or greater.
(5) From 400 MHz to 8 gigahertz (GHz), use radiated susceptibility tests at a minimum of 150 V/m peak with pulse modulation of 4 percent duty cycle with a 1 kHz pulse repetition frequency. This signal must be switched on and off at a rate of 1 Hz with a duty cycle of 50 percent.
(e) Equipment HIRF Test Level 2. Equipment HIRF test level 2 is HIRF environment II in table II of this appendix reduced by acceptable aircraft transfer function and attenuation curves. Testing must cover the frequency band of 10 kHz to 8 GHz.
(f) Equipment HIRF Test Level 3.
(1) From 10 kHz to 400 MHz, use conducted susceptibility tests, starting at a minimum of 0.15 mA at 10 kHz, increasing 20 dB per frequency decade to a minimum of 7.5 mA at 500 kHz.
(2) From 500 kHz to 40 MHz, use conducted susceptibility tests at a minimum of 7.5 mA.
(3) From 40 MHz to 400 MHz, use conducted susceptibility tests, starting at a minimum of 7.5 mA at 40 MHz, decreasing 20 dB per frequency decade to a minimum of 0.75 mA at 400 MHz.
(4) From 100 MHz to 8 GHz, use radiated susceptibility tests at a minimum of 5 V/m.
[Doc. No. FAA-2006-23657, 72 FR 44027, Aug. 6, 2007]