Avionics Indirect Lightning
Overview Flight Facts Worldwide Lightning Mechanism Indirect Lightning Standards Bodies Waveforms DO160 Testing Application MIL 461 CS117 Testing Application
IATA study for 2008: A daily average of 4.5 million passengers travel by airplane. An average of 93,000 commercial flights scheduled every day from 9000 airports. At any given time 8000-13000 planes were in flight
According to a 2014 published Boeing study In 2013 there were 54.9 million registered flight hours across the global. A total of 1.2 billion flight hours have been registered across the globe between 1959 and 2013.
On average an aircraft is struck by lightning every 1000 flight hours. In 2013 there were approximately 54,900 lightning events involving airplanes. Approximately 1.2 million lightning strikes events involving planes between 1959 and 2013.
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Lightning Mechanisms E/H
Indirect Lightning
Standards Bodies DO 160 G Environmental Conditions and Test Procedures for Airborne Equipment Section 22 ARP 5413 Aerospace Recommended Practice and other SAE documents Advisory Circular 20-136: Protection of Aircraft Electrical Electronic Systems against the indirect lightning effects. ED-14: Environmental conditions and test procedures for airborne equipment Section 22
Purpose of Tests Apply idealized waveforms to verify the capability of equipment to withstand effects of lightning induced electrical transients Can be applied anywhere in the world and at the test lab around the corner Use defined reproducible tests
Test Types of Test 1. Damage Tolerance Tests Lightning Damage Test PIN Injection 2. Immunity tests Functional upset tests Cable bundle EUT
Waveform 1 This is a CURRENT waveform for cable bundle tests only
Waveform 2 This is a VOLTAGE waveform for cable bundle tests
Waveform 3 This is a VOLTAGE/CURRENT waveform for cable bundle tests
Waveform 4 This is a VOLTAGE waveform PIN and ground injection tests
Waveform 5A This is a VOLTAGE/CURRENT waveform PIN and ground injection tests
Waveform 5B This is a VOLTAGE/CURRENT waveform mostly used for component testing
Waveform 6 This is a VOLTAGE waveform for cable bundle tests
Waveform Event Types Single Stroke Multiple Stroke Multiple Burst
Single Stroke Test
Multiple Stroke Source
Multiple Stroke Max 50%
Alternative Multiple Stroke Single Stroke Level Multiple Stroke at 40% / 20%
Multiple Burst Source
60 STROKE MULTIPLE BURST 3 Bursts 3 second repetition 5 minutes duration 20 STROKE BURST PACKAGE 20 Pulses 50 to 1000us Randomly spaced SINGLE IMPULSE Multiple Burst Sequence Damped Oscillatory Waveform 3
Pin Injection Voc = open circuit voltage Isc = short circuit current Zgenerator impedance = Voc / Isc
Cable Bundle Single Stroke VL = voltage limit IL = current limit VT = voltage test level IT = current test level Vx/Ix = ZEUT only then can V/IL or V/IT be reached
Cable Bundle Multiple Stroke
Cable Bundle Multiple Burst Waveform Waveform 3 6 Level V T /I L V L /I T 1 60/1 70/5 2 150/2.5 180/12.5 3 360/6 430/30 4 900/15 1080/75 5 1920/32 2290/160
Calibration Setup Calibration is performed with the above setup. Voltage pulse and current pulse may not be from the same generator. Open Loop = Voltage Closed loop = Current
Test Setup
Indirect Lightning CS117 CS117 Indirect Lightning Most waveforms as in DO-160 section 22 Multiple stroke Multiple Burst Specific Test Levels NO PIN or Single Stroke 33
CS117 Proposed Levels MIG-OS-MB w/ext MIG0600MS 34
CS117 Proposed Levels MIG-OS-MB w/ext MIG0600MS V L = Voltage Limit I T = Current Test I L = Current Limit for 1 wire* Test to the Test level in this case Current unless voltage is hit first then switch pulses and test to Voltage waveform. * For cable bundle with 1 wire test only to I L 35
CS117 Proposed Levels MIG-OS-MB w/ext 36
CS117 Proposed Levels V T = Voltage Test I L = Current Limit I T = Current Test for 1 wire* Test to the Test level in this case Voltage unless Current is hit first then switch pulses and test to Current waveform. NOTE: Voltage is hit in most configurations. MIG-OS-MB w/ext * For cable bundle with 1 wire test only to I T 37
CS117 Proposed Levels MIG0600MS 38
CS117 Proposed Levels MIG-OS-MB w/ext 39
CS117 Calibration Calibration is performed with the above setup. Voltage pulse and current pulse may not be from the same generator. Open Loop = Voltage Closed loop = Current 40
CS117 Test Setup Like other MIL-STD tests power leads are tested both with the return and without the return. 41
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