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Appendix D – HIRF Environments and Equipment HIRF Test Levels

ED Decision 2016/024/R

This Appendix specifies the HIRF environments and equipment HIRF test levels for electrical and electronic systems under CS 27.1317. The field strength values for the HIRF environments and 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 (V/m)

PEAK

AVERAGE

10 kHz–2 MHz

50

50

2–30 MHz

100

100

100–400 MHz

100

100

400–700 MHz

700

50

700 MHz–1 GHz

700

100

1–2 GHz

2000

200

2–6 GHz

3000

200

6–8 GHz

1000

200

8–12 GHz

3000

300

12–18 GHz

2000

200

18–40 GHz

600

200

 

In this table, the higher field strength applies to the frequency band edges.

(b)     HIRF environment II is specified in the following table:

Table II — HIRF Environment II

FREQUENCY

FIELD STRENGTH (V/m)

PEAK

AVERAGE

10–500 kHz

20

20

500 kHz–2 MHz

30

30

2–30 MHz

100

100

30–100 MHz

10

10

100–200 MHz

30

10

200–400 MHz

10

10

400 MHz–1 GHz

700

40

1–2 GHz

1300

160

2–4 GHz

3000

120

4–6 GHz

3000

160

6–8 GHz

400

170

8–12 GHz

1230

230

12–18 GHz

730

190

18–40 GHz

600

150

 

In this table, the higher field strength applies to the frequency band edges.

(c)      HIRF environment III is specified in the following table:

Table III — HIRF Environment III

FREQUENCY

FIELD STRENGTH (V/m)

PEAK

AVERAGE

10–100 kHz

150

150

100 kHz–400 MHz

200

200

400–700 MHz

730

200

700 MHz–1 GHz

1400

240

1–2 GHz

5000

250

2–4 GHz

6000

490

4–6 GHz

7200

400

6–8 GHz

1100

170

8–12 GHz

5000

330

12–18 GHz

2000

330

18–40 GHz

1000

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 % 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 % 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 % duty cycle with 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 %.

(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.

[Amdt 27/4]