E. Ashworth
Managing director & co-founder
Ex-automotive powertrain lead. Owns the thesis that a crankshaft should cost what a crankshaft costs.
The bird with no feet.
Martlet Aero builds high-performance piston engines for small aircraft at Filton, on the northern edge of Bristol. The company was founded in 2019 by three engineers — two from automotive powertrain, one from aero certification — around a single irritating fact: a light-aircraft engine cost four times what its parts justified.
- Founded
- 2019
- Works
- Filton, Bristol, United Kingdom
- Engines flying
- 467
- Countries
- 23
The story
The name is heraldic. The martlet is the bird drawn without feet — it never lands — and it marked the fourth son, who inherited no land and had to earn his own way. We put it on the crankcase because it is the whole thesis in one glyph: relentless flight, nothing inherited, everything earned.
The engineering follows the heraldry. We build at automotive scale with automotive-grade sensors and FADEC silicon, we run unleaded mogas, and we publish the entire parts catalog with prices. The engines are affordable because they are honest and serviceable — not because they are cheap.
The martlet is drawn without feet. It never lands.
Works ledgerUPDATED NIGHTLY
- Test cell hours
- 31,427
- Engines shipped
- 467
- Fleet hours
- 128,740
- Countries flying
- 23
- Works
- Filton, Bristol, United Kingdom
Cumulative dyno + flight hours across all cores, updated nightly from the cell logger.
Seven years, in order
From a borrowed dyno to 467 engines flying.
- 2019Founded at Filton. First core — a cut-down automotive flat-four — runs on the borrowed dyno in November.
- 2021Clean-sheet M120 architecture frozen. Own test cell commissioned in the old No. 3 fitting shop.
- 2022M120 first flight on the company Redshank 2. Parts catalog published openly — prices included, to some industry alarm.
- 2023First 100 customer engines shipped. M160T runs to 15,000 ft equivalent on the altitude rig.
- 2024M160T deliveries begin. Fleet passes 25,000 flying hours; DOA application filed.
- 2025M120H hybrid conforming prototype flies. First UAV OEM contract signed.
- 2026467 engines flying in 23 countries. Test cell passes 31,000 hours. CS-23 certification programme in full swing.
The people
Each shown beside the thing they are responsible for.
N. Osei
Chief engineer & co-founder
Clean-sheet architect of the M-series core. Insists every tolerance in the manual is one we actually hold.
H. Brandt
Head of certification & co-founder
Twenty years of CS-23 paperwork. Believes certification is a design input, not an afterthought.
F. Iwu
Head of test
Runs the cell. Personally signed off 31,000 hours of dyno time and still listens for the one wrong noise.
M. Calder
Head of manufacturing
Built the Filton line cell by cell. Measures success in first-pass yield and clean floors.
S. Devlin
Customer engineering
The voice on the phone when a builder torques the first head bolt. Writes the manuals people actually read.