The Basics regarding Defence and Aerospace Product Testing

We’ve put together the following summary to assist companies that may be tendering for defence or aerospace projects.   This info is aimed to ensure:

1. We provide you an accurate quote covering all required tests.
2. You satisfy your customer with a test plan and test report that meets their requirements.

Before entering the qualification process with Austest for defence equipment – whether aerospace, naval, land or transport related – or avionics equipment, you will need to gather substantial background information, both on your product, its intended location and the standards you need to comply against. The test standards will dictate the level of additional input required, as some are with rigid procedures and levels, while others rely on you or your client to decide which tests and severity levels apply.

Environmental Testing for Defence – Aerospace, Naval, Land & Transport

Environmental standards such as MIL-STD-167-1A for Vibration testing, strictly define test procedures and test levels. Likewise RTCA DO160 defines test levels and procedures, which vary according to the exact application of the unit under test (UUT). For example if your customer requires vibration testing performed to Section 8 of RTCA DO-160G, you will need to provide us with the location/s in the aircraft that your UUT will be installed in, the type of aircraft/s that your UUT will be installed in and if it is to be used in helicopters then the various rotor, engine and gearbox RPMs. We can then determine test levels (and test costs).

In comparison, MIL-STD-810G (and its earlier revisions), is the most commonly used standard for qualifying military equipment and is far more generic. Contacting us for MIL-STD-810G testing should be preceded by a discussion with your end customer, who will specify the clauses you need tested and the parameters/severity levels you need applied to each for the tests. If your end customer is unsure, we are happy to provide guidance based on the many years of experience our team has.

MIL-STD-810G has 28 different tests and as mentioned, typically your end customer decides which of these are relevant to their end application for your UUT. Typically the MIL-STD-810 tests performed on most UUTs (Units Under Test) are High Temperature testing to Method 501.5 (of MIL-STD-810), Low Temperature testing to Method 502.5, Humidity testing to Method 507.5, Vibration testing to Method 514.6 and Shock testing to Method 516.6. You must then consider whether your UUT requires qualification to other environmental hazards such as Temperature Shock, Rain, Dust, Immersion Salt Fog, Solar Exposure, Altitude/Pressure, combined Altitude/Temperature and Acceleration. Each of these environmental hazards are covered by a MIL-STD-810 test method and Austest can perform all of these tests in-house. Given the test methods in MIL-STD-810 are often highly generic, you will need to specify the test parameters applied to each method (or if the method specifies a choice of parameters then which one of these). These parameters involve not only test severities but also test duration.

MIL-STD-810G and RTCA DO160 are highly complex, with some major defence contractors having entire departments devoted to their interpretation. Customers qualifying a new type of product or a highly complex one can find it hard to determine which methods need to be invoked and what test parameters should be applied. That is why Austest offers a service where, for a fee, we can assist you in working through these standards to develop a suitable environmental test program for your product based on either of these standards. To develop such a test program we need basic details and dimensions of your product as well as details of all the different applications, terrains and installations that your UUT may be placed in. We would then provide you with a draft test plan so that you can discuss it with your customer and give us feedback. This will ensure that the final test plan can be signed off by your customer and thus give you certainty that the testing program you are undertaking will meet your customer’s requirements.

EMI/EMC Testing for Military & Avionics Applications

As with environmental testing, requests to Austest for quoting for EMI/EMC testing should be preceded by a discussion with your end-customer in order to specify the version of the standard, test categories and test levels that apply to your product.

Unlike commercial testing where a product is tested to the latest version of a standard, defence and aviation EMC testing is performed against the version of the standard that existed at the time the original infrastructure was commissions, be it a ship, vehicle, submarine or plane.

MIL-STD 461F was issued in 2007 and is the current version. MIL-STD 461F contains 18 tests in total, however all are not applicable. Required tests are usually determined by the end customer, who will specify the environment/platform that the product will be installed and operate from. Typical tests that are applicable across all Categories in MIL-STD 461F include CE102 and RE102 (Conducted and Radiated Emissions) and CS101, CS114, CS115, CS116, RS103 (Conducted and Radiated Susceptibility). Again, applicability of these tests plus other platform-specific tests are dependent on end-customer requirements – which would normally culminate in the form of an EMI test procedure (EMITP).

Once the test procedure has been reviewed and approved by all parties, Austest can then provide a quotation for formal testing. Austest also recommends performing pre-compliance testing on prototype designs or during the product design phase in order to mitigate any issues that may cause the product to fail the required tests. Ideally you should have confidence that your product will comply when placed under formal testing as failure investigation can be a time consuming, expensive process that will have significant impact on tight deadlines of you or your customer.

Austest can assist in the creation of an EMITP with our consultancy service, through to EMI/EMC pre-compliance and formal testing, culminating with the formal test report.

Austest can also perform accredited testing to legacy versions of MIL-STD 461 B & C to cater for equipment undergoing retrofit activities within military legacy systems.

The above process is also applicable to aircraft EMC to the RTCA DO160 avionics test standard, the latest version being DO160G. Some of the applicable sections of this standard covering EMC-related tests include Sections 20 & 21 (Radiofrequency Susceptibility and Emissions) & Section 25 (Electrostatic discharge). Again, in order to provide a quotation we will require a test procedure stating the relevant product categories called up by the standard.

Austest is currently accredited to RTCA DO160 versions F & G Section 20 – Radio Frequency Susceptibility (Radiated & Conducted). Other sections earmarked for inclusion to our scope in the next 2 months include Sections 21 & 25.