10.0 Conducted Voltage Transient Test.

10.1 Intermittent Transients. With the equipment operating at its normal input voltage(s), apply to each of the d.c. primary input power leads a series of positive and negative voltage transients having the characteristics (amplitude and wave form) appropriate to the applicable normal d.c. input voltages specified in Figure 1, for a period of at least ten (10) seconds and at a rate of not less than two (2) transients per second. Immediately after the 10-second period, determine compliance with the applicable standards of paragraph 3.0, "Minimum Performance Standards under Environmental Test Conditions," of the appropriate FAA Airborne Electronic Equipment Minimum Performance Standards. The positive and negative transients should be developed, applied and monitored in a manner similar to that shown in Figures 2 and 3.

10.2 Repetitive Transients. With the equipment operating at its normal input voltage(s), apply to each of the d.c. primary input power leads a series of positive voltage transients having the characteristics (amplitude and wave form) appropriate to the applicable normal d.c. input voltages specified in Figure 1 at a rate of not less than two (2) transients per second and, simultaneously, determine compliance with the applicable standards of paragraph 3.0, "Minimum Performance Standards under Environmental Test Conditions" of the appropriate FAA Airborne Electronic Equipment Minimum Performance Standards. The positive voltage transients should be developed, applied and monitored in a manner similar to that shown in Figure 2.12

11.0 Conducted Audio-Frequency Susceptibility Test.

11.1 D.C. Input Power Leads. Apply a sine wave audio frequency signal in series with each ungrounded d.c. input power lead. While varying the audio frequency of the applied signal between 200 and 20,000 cycles per second, maintain the r.m.s. amplitude of this signal at not less than 5 percent of the nominal d.c. input voltage and determine compliance with the applicable standards of paragraph 3.0, "Minimum Performance Standards Under Environmental Test Conditions" of the appropriate FAA Airborne Electronic Equipment Minimum Performance Standards. When conducting this test, all equipment interconnecting cables and RF transmission lines shall be in accordance with the manufacturer's installation wiring diagram and shall use shielded or twisted wires only where specified. Where no length

12 This test applies to equipment designed to utilize d.c. primary power which is furnished by the aircraft's electrical system. Equipment designed to operate solely on a.c. primary power need not be subjected to this test.

of interconnecting cables is specified, the cables shall be at least five (5) feet long. Any inputs or outputs from or to other equipment(s) normally associated with the equipment under test shall be adequately simulated.

11.2 A.C. Input Power Leads. Apply a sine wave audio frequency signal in series with each ungrounded a.c. input power lead. With the frequency of this signal successively adjusted to the second harmonic of the a.c. power frequency and to each next higher order harmonic up to 9,000 cycles, maintain the r.m.s. amplitude of this signal at not less than 5 percent of the nominal a.c. input voltage and determine compliance with the applicable standards of paragraph 3.0 "Minimum Performance Standards Under Environmental Test Conditions" of the appropriate FAA Airborne Electronic Equipment Minimum Performance Standards. When conducting this test, all equipment interconnecting cables and RF transmission lines shall be in accordance with the manufacturer's installation wiring diagram and shall use shielded or twisted wires only where specified. Where no length of interconnecting cables is specified, the cables shall be at least five (5) feet long. Any inputs or outputs from or to other equipment(s) normally associated with the equipment under test shall be adequately simulated.

12.0 Audio Frequency Magnetic Field Susceptibility Test.

12.1 Categories of Equipment. For the purpose of this test, equipment is categorized as follows:

Category A-Equipment which is intended for installation in an aircraft which has an a.c. power source having a rating of 250 VA (volt-amperes) or greater.

Category B-Equipment which is intended for installation in an aircraft which has an a.c. power source having a rating of less than 250 VA, or which has no a.c. power source whatever.

12.2 Test Procedure.

Category A-Expose the equipment under test to an audic frequency magnetic field which is generated by a 400 c.p.s. current of at least 20 amperes (r.m.s.) flowing in a straight wire radiator, which is within 12 inches of the periphery of the unit of equipment under test, and determine compliance with the applicable standards of paragraph 3.0 "Minimum Performance Standards Under Environmental Test Conditions" of the appropriate FAA Airborne Electronic Equipment Minimum Performance Standards. During this test, the radiator shall be so oriented with respect to each external surface of each unit as to cause maximum interference. The length of the radiator shall be such that it extends a distance of at least 2 feet (laterally) beyond the exposed surface of the unit under test. The leads supplying current to the radiator shall be routed at least 2 feet away from any part of the unit

under test and from the radiator itself. All units of the equipment under test shall be individually tested.

Category B-No test of Category B equipment is required.

13.0 Radio Frequency Susceptibility Test (Radiated and Conducted). For the purposes of this test,13 equipment is categorized as follows:

Category A-Equipment which is intended for installation in aircraft having a Maximum Weight of more than 12,500 pounds.

Category B-Equipment which is intended for installation in aircraft having a Maximum Weight of 12,500 pounds, or less.

13.1 General Requirements.

(a) The equipment under test shall be set up on a ground plane and operated in accordance with the following criteria:

(1) Ground Plane.-A copper or brass ground plane, 0.01 inch thick minimum for copper, 0.025 inch thick minimum for brass, 12-square feet or more in area with a minimum width of 30 inches, shall be used. In all cases where a shielded room is employed, the ground plane shall be bonded to the shielded room at intervals no greater than 3 feet, and at both ends of the ground plane. (2) Shock and Vibration Isolators.-The equipment under test shall be secured to mounting bases incorporating shock or vibration isolators, if such mounting bases are specified by the equipment manufacturer. The bonding straps furnished with the mounting base shall be connected to the ground plane. Where mounting bases do not incorporate bonding straps, bonding straps shall not be used in the test setup.

(3) Bonding.-Only the provisions included in the design of the equipment and specified in the installation instructions shall be used to bond units, such as equipment case and mount, together or to the ground plane. Where bonding straps are required to complete the test setup they shall have a length not greater than 5 times the width, shall have a minimum thickness of 0.025 inch, and shall be copper or brass metal straps, not braid. Connections made with such bond straps shall have clean metal-to-metal contact.

(4) External Ground Terminal.-When an external terminal is available for a ground connection on the equipment under test, this terminal shall be connected to the ground plane if the terminal is normally grounded in the installation. If the installation conditions are unknown, the terminal shall not be grounded.

(5) Interconnecting Cables.-All equipment interconnecting cables and RF trans

13 See "Introduction" of Appendix A for information on the relationship between the emission of spurious radio frequency energy from electrical and electronic equipment installed in an aircraft and the levels of radio frequency susceptibility signals used in this test procedure.

mission lines shall be in accordance with the manufacturer's installation wiring diagram and shall use shielded or twisted wires only where specified. Where no length of interconnecting cables is specified, the cables shall be at least five (5) feet long. Any inputs or outputs from or to other equipment associated with the equipment under test shall be adequately simulated.

(6) Dummy Antennas.-The dummy antenna shall have electrical characteristics which closely simulate those of the normal antenna, and should be shielded. It shall contain electrical components which are used in the normal antenna (such as filters, crystal diodes, synchros, motors, etc.).

b. Test instruments shall be set up and operated in accordance with the following criteria:

(1) Bonding.-Interference meters used for measurement during the "conducted" test shall not be bonded to the ground plane except through the interconnecting coaxial cable. The counterpoise on rod antennas shall be bonded to the ground plane with a strap of such length that the rod antenna can be positioned correctly. The strap shall be as wide as the counterpoise.

(2) Powerline Stabilization Network.-One stabilization network shall be inserted in each ungrounded primary input power lead of the equipment under test. The network enclosure shall be bonded to the ground plane. The network shall be constructed in accordance with Figure 4. The input impedance characteristics of the stabilization network are shown in Figure 5.

(3) Antenna Orientation and Positioning in Shielded Enclosures.-The rod or dipole antenna shall be located as shown in Figures 6 or 7. The rod antenna shall be so placed that the antenna is in a vertical position. The rod antenna shall be located at the point where maximum radiation pickup is obtained when it is moved along a line parallel with the edge of the ground plane. Those measurements which use a resonate dipole antenna shall have the dipole positioned parallel with the edge of the ground plane. The dipole antenna shall be centered 12 inches ±1 inch above the level of the ground plane. The rod or the dipole antenna shall be located at the distance from the equipment under test specified in Figures 6 and 7. When the dimensions of the dipole antenna become smaller than the test layout, the antenna shall be moved parallel to the edge of the ground plane to keep its sensitive elements. adjacent to the point of maximum radiation. At frequencies from 25 up to and including 35 megacycles, the measurements shall be taken with the dipole antenna adjusted to resonance at 35 megacycles. The dipole antenna shall be adjusted to resonance at all frequencies above 35 megacycles. In screen room tests, the antennas shall be at least 1 foot away from any wall.

13.2 Conducted Radio Frequency Susceptibility Test. With the equipment under test arranged in a manner similar to that shown

in Figure 8 apply through the powerline stabilization network an RF signal modulated 30 percent at 1,000 c.p.s. between each ungrounded primary input power lead and ground. Determine compliance with the applicable standards of paragraph 3.0 "Minimum Performance Standards under Environmental Test Conditions" of the appropriate FAA Airborne Electronic Equipment Minimum Performance Standards when the signal level is varied (versus frequency) over the range specified in Figure 9 or Figure 10 for Category A and Category B installations, respectively. The output impedance of the

signal generator shall be 50 ohms. The voltages specified shall be those which exist across the 50 ohm signal generator output when no load is connected to the signal generator. All equipment interconnecting cables shall have 4 feet of their length bundled together and supported 2 inches above the ground plane, as shown in Figure 8.

13.3 Radiated Radio Frequency Susceptibility Test. Expose the equipment under test to a radio frequency field, the levels of which (versus frequency) are specified in Figures 11 and 12 for Catagory A and Catagory B installations, respectively. The voltages spec

COIL DATA:

WIRE DATA:

CAPACITOR:

CAPACITOR DATA:

RESISTOR DATA:

14.0 Explosion Test.

14.1 Application and Conditions of Test. a. Application and Categories of Equipment.

(1) It is recognized that installation practices in civil aircraft and in many noncivil transport aircraft normally do not require the installation of equipment in locations where an explosive atmosphere may exist in the course of normal aircraft operations. For such installations, the Explosion Test is not applicable and the equipment is designated as Category "X" equipment.

(2) It is also recognized that, in special applications and in special purpose aircraft, equipment may be installed in locations

where an explosive atmosphere may exist in the course of normal aircraft operations. For these installations, the Explosion Test is applicable and the equipment is designated as Category "E" equipment.

b. Apparatus. The test chamber shall be a type capable of providing the test environment. A suitable test chamber is described in Military Specification MIL-C-9435.

c. Fuel. The fuel used shall be 100/130 octane gasoline.

d. Failure Criteria. If the equipment causes explosion at any of the test altitudes, it shall be considered to have failed to pass the test and no further trials need be attempted.