14 CFR Part 25, Appendix L to Part 25 - HIRF Environments and Equipment HIRF Test Levels

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View PDF at GPO Pt. 25, App. L
Appendix L to Part 25—HIRF Environments and Equipment HIRF Test Levels
This appendix specifies the HIRF environments and equipment HIRF test levels for electrical and electronic systems under § 25.1317. 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(volts/meter)
Peak Average
In this table, the higher field strength applies at the frequency band edges.
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
(b) HIRF environment II is specified in the following table:
Table II.-HIRF Environment II
Frequency Field strength(volts/meter)
Peak Average
In this table, the higher field strength applies at the frequency band edges.
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
(c) 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.
(d) 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.
(e) 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 44026, Aug. 6, 2007]

Title 14 published on 2014-01-01

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  • 2014-09-12; vol. 79 # 177 - Friday, September 12, 2014
    1. 79 FR 54571 - Special Conditions: Bombardier Aerospace, Models BD-500-1A10 and BD-500-1A11 Series Airplanes; Automatic Speed Protection for Design Dive Speed
      GPO FDSys XML | Text
      DEPARTMENT OF TRANSPORTATION, Federal Aviation Administration
      Final special conditions.
      Effective Date: October 14, 2014.
      14 CFR Part 25

Title 14 published on 2014-01-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 14 CFR 25 after this date.

  • 2014-09-12; vol. 79 # 177 - Friday, September 12, 2014
    1. 79 FR 54571 - Special Conditions: Bombardier Aerospace, Models BD-500-1A10 and BD-500-1A11 Series Airplanes; Automatic Speed Protection for Design Dive Speed
      GPO FDSys XML | Text
      DEPARTMENT OF TRANSPORTATION, Federal Aviation Administration
      Final special conditions.
      Effective Date: October 14, 2014.
      14 CFR Part 25