RTCA DO-160: temperature, humidity, electrical interference and shock resistance

 

As one of the largest testing providers in the global aerospace sector, Element are a single-source partner for every section of RTCA DO-160 testing.

RTCA DO-160 (Environmental Conditions and Test Procedures for Airborne Equipment) covers standard procedures and environmental test criteria for testing airborne electronic equipment and mechanical systems. The most current revision, RTCA DO-160G, specifies tests that are typically performed to meet the requirements of the Federal Aviation Administration (FAA) and other regulatory bodies for equipment installed on aircraft.

RTCA DO-160 is used by all major aircraft manufacturers to ensure that electronic systems and components are safe and reliable in any environmental condition. It is applicable for any aircraft, from business jets and helicopters to full-scale airliners.

 

Our RTCA DO 160 testing services

 From vibration testing and environmental simulation to EMC testing and direct lightning strike, our laboratories provide RTCA DO-160 testing for virtually every type of aircraft.

In most cases we can perform the full suite of RTCA DO-160 testing at one location. Using state-of-the-art equipment and parallel test setups, we deliver fast test setups, easier witness testing, and better turnaround times, to help you reduce time to market and minimize test program error.  

With experts in active service on RTCA Special Committee 135, we are constantly on the forefront of evolving standard updates, and can provide support and guidance on even the most challenging technical issues. We work with you to create a specialized test program that that project manages all of your testing requirements.

 

Element Aerospace testing services

In addition to RTCA-DO 160, we test and qualify your products to a wide range of aerospace equipment testing standards, including Airbus, Boeing, Eurofighter, EUROCAE, and specialist military and defense sector testing including Def Stan 00-35, Def Stan 59-411, MIL-STD-461 and MIL-STD-810.

We have over 100 years’ experience in a wide range of product qualification testing, from mechanical and structural testing of full-size airframes to operational, functional, and performance testing.

For more information about our RTCA DO-160 testing services, or to request a quote, contact us today.

Section 4

Temperature and Altitude Testing

Sections 4 and 5 of RTCA DO 160 combine an aircraft's cruising altitude with the test unit's onboard position to create equipment categories that set requirements for temperature, altitude, and rates of change for testing. 

Equipment Categories

There are 21 categories associated with temperature and altitude.  Temperature testing consists of non-operational ground survival temperatures as low as -55 C and operational high temperatures of 70 C.  Altitude testing as high as 70,000 feet as well as decompression (emergency descent) and overpressure testing (routine aircraft pressurization system testing) is also required.

Section 5

Temperature Variation 

This section covers equipment performance during high and low operating temperature variation. Testing can be performed while the unit is operational or non-operational, or at different points in the operation cycle, demonstrating that the equipment can function under any temperature condition.

Equipment Categories

There are three categories of operational temperature variation (A, B, or C) and two categories of thermal shock (S1 and S2). The Categories are for various rates of change (Degrees / Minute) depending on the expected thermal changes the unit will experience in actual use. Category A = 10 Deg C / minute, B = 5 Deg C / minute, C = 2 Deg C / minute, while Categories S1 and S2 are for known or unknown rates of change > 10 Deg C / minute. S2 is the most severe and is an actual Thermal Shock with as quick a transition from one extreme temperature to the other extreme temperature as possible.

Section 6

Humidity Testing

RTCA DO 160 humidity testing determines a product's ability to withstand naturally occurring or induced humid atmospheres. We test against corrosion, mechanical failures, electrical malfunction and chemical degradation to ensure that the unit continues to operate safely, no matter its location on the aircraft.

Equipment Categories

Humidity testing has three Categories, A, B, and C (Standard, Severe, and External). Category A has a high temperature of 50 Deg. C and a duration of two days; Category B has as high temperature of 65 Deg C and a duration of 10 days; and Category C has a high temperature of 55 Deg C and a duration of six days. Operational ‘Spot’ checks are often required.

Section 7

Operational Shock and Crash Safety Testing 

Operational shock verifies that equipment will continue to function after exposure to shocks experienced during normal aircraft operations.  Crash safety shock verifies that equipment will not detach from its mountings during an emergency landing.

Equipment Categories

There are four basic Categories in the Shock section, A, B, D and E. These are based on the unit’s resonant frequency and expected shock exposures during the operational life of the unit.

Usually combined with Vibration testing, Standard Operational Shock (high or low frequency) as well as Crash Safety (impulse) are performed on our electrodynamic shakers.  Crash Safety (sustained) is performed using one of our multiple large centrifuges (largest 30 foot arm).

Section 8

Vibration Testing

This test verifies that equipment can operate or will not be damaged when subjected to vibration levels depending on the installation and location in the aircraft.

Equipment Categories

The Vibration section has many Categories of vibration (S, H, Z, and R for Fixed Wing; and R, U and U2 for Helicopter). Depending on the type of aircraft, the location of the unit in the aircraft, and proximity to the engines (based on ‘Zones’) the test levels and durations are determined.

Our facilities offer a full range of capabilities using both electrodynamic and hydraulic systems capable of the many combinations of frequency and displacement required to meet any of the various Categories within RTCA/DO-160.  We can help with the design and fabrication of your fixture if needed. 

Section 9

Explosive Atmosphere Testing

This test verifies that equipment that may come into contact with flammable fluids and vapors  through normal and/or fault conditions will not cause an explosion. 

Equipment Categories

There are three environments (I, II, III) and three Categories (A, E, H). These take into account the area that the equipment will be on the aircraft (possible or expected flammable fluids), fault conditions, or high surface temperatures.

Element's explosion  chambers are capable of attaining altitudes of 50,000 feet and temperature up to 500°F. A wide variety of remote configurations are available to facilitate the operation of units under test. High speed photography can also be used to determine point of failure (capture flame ignition source).

Section 10

Waterproofness Testing

Condensing, Drip, Spray, and Continuous Stream Proof testing are performed on units while operating with tightly controlled unit and water temperatures.

Equipment Categories

There are four Categories (Y, W, R, and S) and they determine whether the equipment can withstand the effects of liquid water being sprayed, falling, or from condensation, depending on the  different type of exposure the test units will see in actual use on the aircraft. Category Y is for Condensing water on the unit while Category W is for falling drops of water from condensation on the aircraft.

Section 11

Fluids Susceptibility Testing

This determines whether the materials used in the construction of equipment can withstand the effects of fluids that are representative of those commonly used in airborne and ground operations.

Equipment Categories

While there is only one Category, F, however there are two different methods: Spray and Immersion.

Our inventory of fluids is kept up-to-date with each airframe/airline specific fluids and we can safely perform this test at elevated temperatures. Our Engineers and Technicians can perform the required ‘Operational Checks’ during this multi-day test which can save you travel time and associated costs.

Section 12

Sand and Dust Testing 

This test determines the resistance of equipment to the effects of blowing sand and dust.  Adverse effects include: penetration into cracks, bearings, clogging of moving parts and filters, and formation of electrically conductive bridges.

Equipment Categories

There is only one Category, F.  This test requires 28 days of testing in an environment conducive to rapid fungal growth.

Element's experts are highly experienced and spores are kept active which allows us to start a test with minimal notice.  As the inspection can be subjective, magnified photos of any growth are included in our test reports.

Section 13

Fungus Resistance Testing

This test determines whether material used in the construction of equipment can be adversely affected by fungi. 

Section 14

Salt Fog Testing

This test determines the effects on equipment of prolonged exposure to a salt atmosphere. Salt fog can be a destructive test and will show corrosion, clogging or binding of moving parts, as well as insulation faults.  

Equipment Categories

There are two Categories. S for locations where corrosive atmosphere is encountered during normal aircraft operation and T for locations where severe salt atmosphere is encountered (hovering aircraft over sea).

Section 15

Magnetic Effect Testing

This test is performed to determine how much the Equipment Under Test (EUT) will deflect a compass needle, or effect the indication from a magnetic field sensor, also known as a “Flux Gate”.

Equipment Classes

There are five equipment Categories (Y, Z, A, B, and C) that apply to installation separation distances between the EUT and compass (or compass sensor) of less than 30 centimeters to more than 300 centimeters.

Section 16

Power Input Testing

To support the most stringent EMC requirements of RTCA DO 160, MIL-STD-461 and others, we offer power quality testing at extremely high voltage and current levels.

Equipment Categories

There are four Equipment Categories (A, B, D, or Z) that indicate the type of power used by the equipment and the type of AC and/or DC power source with which the equipment is compatible.  For AC powered equipment, an additional designator, placed in parenthesis following the Category designator, is a two character code indicating that the equipment has been tested for use with Constant Frequency (CF), Narrow Variable Frequency (NF), or Wide Variable Frequency (WF).

Up to four additional category designators are also used to indicate testing for:

  • AC current harmonics (H)
  • AC current modulation (L)
  • AC power factor (P)
  • DC current ripple (R)
  • AC or DC inrush (I)

Learn more about our EMI/EMC services.

Section 17

Voltage Spike Testing

This test determines if the unit can operate as required during and/or after voltage spikes are applied to AC and/or DC power units. Any method can be used, as long as the pulse produced has a duration of at least 10 microseconds, a rise time of less than 2 microseconds, and a source impedance of 50 ohms. During testing, a minimum of 50 voltage spikes are applied within 1 minute.

Equipment Categories

There are two equipment Categories.  The Category B test level is twice the AC (rms) and/or DC line voltage (or 200 volts, whichever is less).  The Category A test level is 600 volts.

Learn more about our EMI/EMC services.

Section 18

Audio Frequency Conducted Susceptibility - Power Inputs Testing

This test is performed to verify that the unit will operate as specified when audio frequency interference is applied to the AC and/or DC power input.

Equipment Categories

There are three DC power equipment Categories (R, B, and Z) that indicate the type of power used by the equipment and the type of DC power source with which the equipment is compatible.

Two AC power equipment Categories are specified (R & K).  Category R is used with an additional designation (a two character code), placed in parenthesis following the Category designator, indicates that the equipment has been tested for use with Constant Frequency (CF), Narrow Variable Frequency (NF), or Wide Variable Frequency (WF).  Category K designates that the EUT has been tested for use with any type of AC power input, and tested to a higher level of voltage distortion than category R.

Section 19

Induced Signal Susceptibility Testing

Tests in this section are performed to determine if the unit and its interconnecting cables can operate as required when exposed to RF interference. Continuous Wave (CW), Square Wave AM (SW) and Pulse Modulated (PM) signals are all required.

Equipment Categories

The equipment Categories are comprised of two characters.  The first character (A, B, C, or Z) indicates the tests performed and severity level of the tests.  The second character (C, N, or W) indicates the AC power system operating frequency (Constant, Narrow Variable, or Wide Variable) with which the EUT is compatible.

Section 20

Radio Frequency Susceptibility (Radiated and Conducted) Testing

These tests are performed to determine that equipment will operate as specified when the EUT and its interconnecting cables are exposed to Radio Frequency interference.  Continuous Wave (CW), Square Wave AM (SW), and Pulse Modulated (PM) RF signals are required.  

Equipment Categories

Equipment Category designation for Section 20 consists of two letters.  Conducted susceptibility test levels are designated with the first category character and radiated susceptibility test levels with the second category character.  There are 7 Equipment Categories for conducted susceptibility, and 10 Equipment Categories for radiated susceptibility.  These categories indicate the severity level of the tests performed, and/or the type of modulation used.  Category S is the least severe at 1 V/m, and Category L is the most severe, with test levels as high as 7200 V/m.

Learn more about our EMI/EMC testing services.

section 21

Emission of Radio Frequency Energy Testing

This section of RTCA DO 160 ensures that the unit does not emit radiofrequency interference in excess of accepted limits. Testing measures conducted RF and radiated RF appearing on interconnected cables and power leads.

Equipment Categories

There are 6 equipment Categories (B, L, M, H, P, and Q) that indicate the location of the equipment and the separation between the equipment and aircraft antennas.  In general, the closer the equipment is to an aircraft antenna, and the more it approaches a "direct view" of an aircraft antenna, the tighter the emissions limits.

section 22

Lightning Induced Transient Susceptibility Testing

These tests determine whether a unit can operate as specified during and/or after various lightning induced transient waveforms are injected into connector pins, interconnecting cables, and power leads using pin injection or cable bundle tests. Pin injection is normally used to show damage tolerance, while cable bundle tests are normally used to show upset tolerance.

Equipment Categories

Category designations consist of five characters that describe the pin and cable test Waveform Sets and test levels. The 3 Pin Injection test waveforms are grouped together in two Waveform Sets (A & B).  The 6 Cable Bundle test waveforms are grouped together in four Single Stroke Waveform Sets (C through F), and four combined Single Stroke and Multiple Stroke (G through K), and two Multiple Burst Waveform Sets (L& M).

Learn more about our EMI/EMC testing services.

section 23

Lightning Direct Effects Testing

Tests in this section determine the ability of externally mounted electronic equipment to withstand the direct effects of a severe lightning strike. Equipment is not normally operational, and testing usually causes damage to the unit. High voltage and/or high current tests at thousands of kilo-Volts and/or hundreds of kilo-Amps are applied.

Equipment Categories

Category designations consist of four characters that describe the nature and severity of the test waveforms applied.  The first 2 characters designate the High Voltage Strike Attachment test category, and the last two characters designate the High Current Physical Damage test category.  The designated test category for the EUT should correspond to the lightning strike zone in which the EUT will be installed on the aircraft.

section 24

Icing Testing

Icing testing determines a product's ability to withstand naturally occurring ice and frost conditions, and helps evaluate the need for de-icing operations. All sections can be performed at Element, using automated chambers that perform the 25-cycle Category B test that combines altitude, humidity and freezing temperatures.

Equipment Categories

There are three equipment Categories: A, B, and C. Category A is for equipment located externally or in non-climate controlled areas of the aircraft where Ice and Frost may occur due to condensation. Category B is a 25 cycle test which mimics the effects of multiple ascents and descents where the accumulation of water can cause structural or functional damage to moving parts and electronic systems. Category C is used for external areas where standing water could freeze and where ice could build up over time impeding normal operation of the test unit.

section 25

Electrostatic Discharge Testing

Electrostatic discharge testing per RTCA DO 160 determines if a unit can operate as specified during and after an electrostatic discharge event. Test points are chosen based on their accessibility to personnel, with 10 positive and 10 negative polarity discharges at 15 kV applied to each one.

Equipment Categories

There is only one Category (A), with a test level of 15 kV.

section 26

Fire, Flammability Testing 

This section defines the flammability and fire resistance procedures located in the aircraft engine, as well as electronic enclosures. In addition to the Bunsen burner type testing required by category C, Element has extensive aircraft engine fire simulation capabilities required by categories A and B, as well as smoke and toxicity testing required by certain airframers.

Equipment Categories

There are three categories, A, B, and C.  Categories A and B are intended for equipment located in fire zones (engine) and uses a large kerosene burner to simulate an aircraft engine fire.  Category C uses a Bunsen burner and is used to check the non-propagation of the flame in cases where ignition would appear inside or outside of the equipment.  Typically, this test is performed on materials only.  Element has extensive capabilities required by all categories as well as smoke and toxicity required by various airframers.

Our team of over 9,000 Engaged Experts in North America, Europe, The Middle East, Australia, Asia and Africa are ready to help you.