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Avionics & Aircraft Equipment

Testing avionics LRUs, ground power units, aircraft actuators and converters on 115/200 V 400 Hz AC, 28 VDC, 270 VDC. What you are proving is that the box keeps working when the aircraft bus misbehaves.

Device under test
avionics LRUs, ground power units, aircraft actuators and converters
Bus
115/200 V 400 Hz AC, 28 VDC, 270 VDC
Who buys this
airframe and avionics suppliers qualifying to a platform spec

The 400 Hz bus is the whole game here, and the transient envelopes are what separate a source that can run this test from one that merely reaches the voltage.

Where programmes get caught out

  • Peak, not RMS, sizes the source

    The transient envelope reaches well above nominal. A source rated only on steady-state RMS will clip the surge and the test is invalid before it starts.

  • Frequency has to move, not just sit

    Variable-frequency platforms need programmable df/dt, and a fixed-400 Hz source cannot run those clauses at all.

  • The DC bus is a second test programme

    28 V and 270 V clauses are a separate rig from the AC work. Programmes routinely budget for one and discover the other late.

Where the standards have moved

Revision status changes what your report has to cite. Every note below carries the record it came from, retrieved on the date shown.

  • DO-160 Revision H is in disposition, and Section 16 was rewritten

    RTCA SC-135 closed its Review and Comment on Revision H during 2025 with more than 2,000 member comments across all 26 sections. Section 16, Power Input, was revised specifically to be easier to apply across all aviation equipment, and the committee is dispositioning comments through the first half of 2026 with publication expected in the autumn. Nothing here changes the levels your source has to produce — it changes which document your test plan will cite by the time the report is written.

    Source: RTCA 2025 Year-In-Review — RTCA. Retrieved 2026-08-24.

  • Revision H will expressly prohibit LISNs in Section 16

    A line impedance stabilisation network distorts the waveform the equipment sees and gives the unit under test an unfair advantage, so it should not be used for Section 16 under any revision. Revision H makes that explicit. If your bench inherited a LISN from the Section 21 emissions setup, it comes out for power input work.

    Source: EMC Testing to DO-160: Practical Insights for Sections 16, 18, and 19 — AE Techron, summarising a webinar with Patrick Andre, RTCA SC-135. Retrieved 2026-08-24.

  • MIL-STD-704F is still current, and it is not the test document

    Revision F dates from 12 March 2004 with Change 1 of 5 December 2016. The DLA ASSIST record carries a Revision F Notice 4 validation dated 24 June 2026 and a next review due in June 2036 — there is no Revision G to design against. What 704 defines is the power at the equipment terminals; the test methods live in MIL-HDBK-704-1 through -8 and are individually numbered by power type (the SAC, TAC, SVF, TVF and SXF series). A statement of work that says "tested to 704F" without naming those method numbers has not specified a test.

    Source: MIL-STD-704 document record — Defense Logistics Agency, ASSIST QuickSearch. Retrieved 2026-08-24.

Testing to a standard

The clause-by-clause limits, and what each standard deliberately says nothing about.

Equipment for this work

Specifying a bench for aviation?

Send the clause you have to satisfy rather than a shopping list. An engineer will tell you what the rig has to do — including the parts of the programme this equipment does not cover.

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