AS350 B3e course · The aircraft
Meet the Astar
One aircraft, several names — and a rotor that turns the other way
The essentials
The AS350 is a single-engine, light utility helicopter: one turboshaft engine, a three-bladed main rotor that turns clockwise seen from above, and a two-bladed tail rotor.
It is sold today as the Airbus H125. Most pilots call it the Astar or, for the current version, the B3e.
The one habit to re-learn if you come from American types: everything to do with torque is mirrored. Power in means right pedal.
One aircraft, three names
Airbus calls it the H125; the type certificate calls it an AS350 B3; almost everyone who flies it says B3e.
Legally, a B3e is an AS350 B3 fitted with the Safran Arriel 2D engine and a set of tail-rotor modifications; the type certificate gives its commercial name as H125. The B3e was unveiled at Heli-Expo 2011 with the new engine and a new digital engine control, and the name H125 arrived with Airbus's renaming in March 2015.
Where it came from
The AS350 was designed at Aérospatiale in France in the early 1970s as a cheaper, simpler successor to the Alouette family. The prototype first flew on 27 June 1974.
In France it is the Écureuil — the squirrel. In North America it was marketed as the AStar, initially with a Lycoming engine. Aérospatiale's helicopter division became part of Eurocopter, and Eurocopter became Airbus Helicopters.
Two prototypes, two engines
The first AS350 prototype flew on 27 June 1974 with a Lycoming LTS101 turboshaft. The second, which followed on 14 February 1975, had a Turboméca Arriel.
The split carried into production. Aircraft for North America were built around the Lycoming and sold as the AStar; elsewhere the Arriel became standard, and the Arriel-powered AS350 B was certified in France on 27 October 1977.
That is why the family has two engine lines, and why an old airframe's logbook can hold surprises.
Built to be simple
The design brief was a helicopter that was cheap to buy and cheap to keep flying. Its answers are still visible in the aircraft you fly:
- a Starflex main-rotor hub with no conventional hinges
- composite main-rotor blades
- a modular turboshaft that maintenance can change in sections
Those choices are why the Astar became the default light utility helicopter for work such as external load, firefighting, EMS, law enforcement and tourism.
Milestones
| First flight | 27 June 1974 — prototype with Lycoming LTS1018 |
|---|---|
| AS350 B certified | 27 October 1977 — Arriel 1B4 |
| AS350 B3 first flight | 1 March 1997 — Arriel 2B10 |
| Everest summit landing | 14 May 2005 — AS350 B314 |
| AS350 B3e flight manual approved by EASA | 17 June 2011 — Arriel 2D4 |
| Renamed H125 | March 20157 |
| US final assembly line | Columbus, Mississippi — announced 2014, first delivery December 201515 |
| 7,000th Écureuil-family delivery | July 2022 (Airbus figure)16 |
A family in numbers
Airbus delivered its 7,000th Écureuil-family helicopter in July 2022 — an H125 for a French operator specialising in high-altitude sling work. Airbus counted 2,014 customers in 124 countries and 37 million flight hours, civil and military (Airbus figures).
H125s are assembled in Marignane, France, and also in Columbus, Mississippi; the first US-assembled aircraft went to the Ohio State Highway Patrol in December 2015.
Scale helps you: parts, maintenance experience, training and accident lessons all exist in volume. Its cost is variety — five decades of versions and modifications under one name.
Everest, 14 May 2005
Eurocopter test pilot Didier Delsalle landed an AS350 B3 on the summit of Everest, 8,848 m, and stayed long enough for it to count as a record. He landed there twice.
His account of the wind is the useful part. On the upwind side the aircraft kept climbing with the collective fully down; on the downwind side it was carried away from the summit even at full power. The summit wind was reported at about 65 kt.
A demonstration shows what a design can do, in expert hands, on one day. It is not a limit, and not a reason to expect the same of your aircraft. The account is also a mountain-flying lesson: near terrain, wind can overpower both ends of the collective.
Source 14
At a glance
It turns the other way
Rotor direction and torque, with the American layout for comparison. This diagram needs JavaScript.
Seen from above, the AS350's rotor turns clockwise — the opposite of every American type. Flip the switch to compare.
Nearly everything downstream is a mirror image: the advancing blade is on the left, and torque swings the nose left.
The mirror, in full
If your hours are on American types, these all swap:
- Power in: nose yaws left; hold it with right pedal.
- Power off or engine failure: nose yaws right; left pedal.
- Advancing blade: on the left in forward flight.
- Translating tendency: the tail rotor pushes the aircraft left, so it drifts left in the hover and is held with a little right cyclic.
- Loss of tail-rotor effectiveness: an unanticipated yaw to the left.
None of this is hard. It only bites when you are busy and old habits take over.
Seen from above, which way does the AS350's main rotor turn?
Clockwise — the European convention, and the opposite of American types. It's why the advancing blade is on the left.
You raise the collective in an AS350. Which way does the nose want to yaw?
Left. Torque reaction turns the fuselage opposite to the rotor: a clockwise rotor pushes the fuselage anticlockwise, nose left. Right pedal holds it.
The engine fails in cruise. Which way does the nose yaw?
Right. With the engine driving, torque reaction pushes the nose left and you hold it with right pedal. When power is lost that torque disappears, the right pedal you were holding is now too much, and the nose swings right.
In the hover, tail-rotor thrust makes the AS350 tend to drift which way?
Left. To hold the nose against the clockwise rotor's torque, the tail rotor pushes the tail to the left, and that thrust moves the whole aircraft left. It is held with a little right cyclic — the mirror of American types.
Which engine powered the first AS350 prototype in 1974?
The Lycoming LTS101. The second prototype had the Arriel. Both engine lines went into production, which is why the North American AStar and the Arriel-powered Écureuil differ.
An AS350 B3 landed on the summit of Everest in 2005. What does that tell you about your B3's altitude limit?
Nothing. A record flight by a manufacturer's test pilot shows what the design could do on one day. Your operating limits are in the RFM for your aircraft.
Sources
- Airworthiness Factual Report (AS350 B3e investigation docket) · NTSB
- H125 technical information · Airbus Helicopters
- Clockwise-rotating helicopter differences · Helicopter Ground
- Type-Certificate Data Sheet R.008, AS 350 / EC 130 · EASA
- Eurocopter gives AS350, EC135, AS365/AS565 and AS332 the 'e' treatment · HeliHub · 7 March 2011
- Eurocopter falls back on load compensator as fix for AS350 B3e · Vertical
- New names for Airbus Helicopters models · Vertical · 2015
- Aérospatiale AS 350 AStar · This Day in Aviation
- Proven pedigree: low cost, low noise and low vibration led Eurocopter's design priorities for its AS350B3 · Flight International · 1 September 1999
- Eurocopter AS350 Écureuil — development and variants · Wikipedia · Development; Variants (AS350 BA, B1, B2, C, D)
- Program history of the AS350 (in a review of the Nemeth AS350) · HeliSimmer.com
- Starflex rotor hub — European Rotorcraft Forum paper · European Rotorcraft Forum
- The greatest guide: Airbus AS350 helicopter · Winair
- Didier Delsalle: AS350 B3 landing on the summit of Mount Everest · This Day in Aviation · 14 May 2005
- Ohio State Highway Patrol takes first U.S.-made H125 AStar · AVweb · 3 December 2015
- Airbus delivers the 7,000th Ecureuil helicopter · Airbus Helicopters · July 2022
- AC 90-95, Unanticipated Right Yaw in Helicopters · FAA · 26 December 1995
- Helicopter Flying Handbook (FAA-H-8083-21B) · FAA · Chapter 2, Aerodynamics of Flight
Educational only. Not approved training material, and never a substitute for the Rotorcraft Flight Manual, an instructor, or your operator's procedures. Figures marked as manufacturer data or test results are not limitations. This content is a draft and has not yet been reviewed by an instructor.