// RESOURCES
Understanding the subjects behind our systems.
Anonymised case studies and in-depth articles written by our engineers on the standards and techniques of airborne acquisition and recording — no filler, no sales pitch in disguise.
Case studies
As a matter of principle we do not name our customers. The configurations described are real; the identities are not.
Over a thousand parameters, live, from one aircraft
A new variant of a high-performance light aircraft, a full flight-test installation, and a constraint that decides the architecture before anything else: all of it live, on one time reference.
A test track, six units and one megahertz
Sampling at a megahertz is not difficult. Doing it in six places spread over several kilometres, and having every channel land on the same timeline, is the whole problem.
A secure audio recorder that changed nothing on the aircraft
Sixty-four audio channels, an encrypted medium, full TEMPEST certification — and the hardest requirement of all: fit inside the envelope and the interfaces of the system being replaced.
Instrumenting a production trainer without freezing the configuration
A European airframer needed instrumentation that could ship with every aircraft and still differ from one customer to the next. The answer was not a bigger unit — it was one that could be assembled differently.
Design & architecture
Designing a flight-test instrumentation chain: from sensor to report
Nine stages, one time reference and a single governing rule: every stage can lose information and no stage can add any. A guide to the whole chain, and to knowing which link is your weakest.
Sizing an airborne acquisition system: a worked example
Four budgets have to close at once — bit rate, storage, telemetry and mass — and they are coupled. Here is the arithmetic, done all the way through on a real-shaped installation.
Centralised or distributed: where to put the acquisition units
The question looks like an architecture debate. It is mostly geometry: how far your sensors are from each other, and who owns the mass of the harness.
Time and synchronisation: IRIG-B, GPS and PTP
Every other measurement can be repeated. A timing error cannot: it is discovered months later, during analysis, and it invalidates every comparison that was built on it.
History & heritage
Standards & formats
IRIG 106 Chapter 10, explained
Why flight-test data ends up in a .c10 file, what the standard actually specifies, and what it deliberately leaves to the vendor — a practical guide for engineers who record, download and analyse airborne data.
The D.T.MUX format, and how it compares to Chapter 10
Why a recorder still has a house format, how a D.T.MUX recording is built, and where it lines up with — and deliberately departs from — IRIG 106 Chapter 10.
Reading an avionics bus: MIL-STD-1553 and ARINC 429
Two buses designed half a century ago, still being installed on new aircraft — how they work, what it takes to record them honestly, and why the hard part is never the recording.
Telemetry
PCM telemetry: frames, sync and link budget
How several hundred sensors end up as a single serial bit stream, how a ground station finds its way back into that stream, and how far it will actually reach — the practical mechanics of PCM/TDM telemetry.
Satellite links and telemetry: what Starlink actually changes
A low-orbit constellation will not replace the range telemetry link. It replaces the absence of a link everywhere else — and it brings something telemetry has never had: a way back up.
Anatomy of a telemetry ground station
Six stages between a radio signal and a decision, and a hard deadline: the test conductor has to be able to say continue or abort while the aircraft is still on the point.
Acquisition & recording
Sampling, quantisation and aliasing: how not to record a false measurement
Most defects in a measurement chain announce themselves. Aliasing does not: it produces a clean, plausible, entirely fictitious signal, and it is the only error in the chain that cannot be repaired afterwards.
Sensor conditioning: strain gauges, thermocouples, IEPE and LVDT
Everything upstream of the converter decides the ceiling. A guide to what each sensor family actually demands, and to the errors that survive all the way into the report.
Onboard video: H.264, bandwidth and staying in sync
Video is the cheapest witness on a test aircraft and the easiest data to get subtly wrong — a practical look at compression, bit rate, timing and installation.
Onboard memory: SSD, cartridges and erasing for real
The specification that matters is not how fast the memory can write, but how slowly it is allowed to write on its worst millisecond — and what happens to the data when the campaign is over.
Data integrity: detecting losses, drifts and truncated recordings
The file exists, it opens, and the curves look plausible. None of that is evidence. Here is the list of things that can be wrong with a recording, and which of them you can actually detect.
Recovering data after a power cut or a corrupted recording
A recording that was never closed is not a recording that is lost. What decides how much comes back is a design decision taken long before the flight — and a few rules about what you do in the first hour.
FDR, flight-test recorder, mission recorder: what actually differs
They all record flight data onto solid-state memory in an aircraft. Beyond that they have almost nothing in common — and the differences are not technical, they are about who is asking.
Coming next
- Decommutation and calibration: from raw counts to engineering units
- Onboard Ethernet: IENA, iNET-X and real-time acquisition
- Writing the specification for an airborne recorder: the checklist
A subject you would like us to cover?
Tell us what is missing — our engineers write these articles from the questions they get asked.
Suggest a subject →