Diamond DA42 Twin Star

Updated: October 2026 – A white twin taxis toward the runway, the horizontal stabilizer perched on top of the fin, the wings long and slender like those of a motor glider. On the takeoff roll it doesn’t sound like the deep burble of classic flat-opposed engines but more like a strong turbodiesel: chances are you are looking at a Diamond DA42 Twin Star. The four-seater from Austria has been one of the world’s most important multi-engine trainers for a good two decades. Here you will learn how to recognize it, what sets the many variants apart and where to get it in front of your lens.

What is the Diamond DA42 Twin Star?

The DA42 is a four-seat, twin-engine light aircraft from Diamond Aircraft of Wiener Neustadt in Lower Austria. The airframe is made almost entirely of carbon fiber composite – an approach Diamond brought over from glider construction and had already tried out on the single-engine DA40 and the two-seat DA20 Katana. Since 2017, Diamond has belonged to the Chinese Wanfeng group, but headquarters and development remain in Austria.

What made the DA42 special at launch was its powerplant: instead of air-cooled gasoline flat-opposed engines from Lycoming or Continental, as found in almost all piston twins, Diamond chose turbocharged diesel engines that run on jet fuel. Today these are two Austro Engine AE300 units from the company’s in-house engine subsidiary, each producing 168 hp according to Diamond. Each engine is controlled by a single power lever; an electronic engine control unit manages mixture and propeller speed.

Add everything that makes a “complex” multi-engine aircraft: three-blade constant-speed propellers with feathering, hydraulic retractable landing gear and a glass cockpit – today the Garmin G1000 NXi with GFC 700 autopilot. According to Diamond, the current version is certified for instrument flight and can be equipped with TKS de-icing for the wings, tail, propellers and windshield.

Origins and development

The DA42 made its first flight on December 9, 2002. European type certification followed in April 2004, US certification in July 2005. As early as August 2004, the type made headlines: Frenchman Gérard Guillaumaud flew a DA42 nonstop across the North Atlantic – by common account the first Atlantic crossing by a diesel-powered fixed-wing aircraft, in around twelve and a half hours.

The early aircraft flew with Thielert Centurion diesels, first at 1.7 liters of displacement, from 2007 at 2.0 liters. Then came the turning point: Thielert filed for insolvency in April 2008, and Diamond paused DA42 production in the summer of 2008. The answer was an engine of its own. The subsidiary Austro Engine, founded in Wiener Neustadt in 2007, got the AE300 certified by EASA in January 2009. It led to the DA42 NG, which received European certification in March 2009 and US certification in April 2010. In 2012 came the further improved DA42-VI, which is still being built today.

Date	Milestone
December 9, 2002	First flight
April 2004	EASA type certification
August 2004	Nonstop Atlantic crossing with diesel power
July 2005	FAA certification
2007	Switch to the 2.0-liter Thielert diesel
April 2008	Insolvency of engine supplier Thielert
July 2008	Production pause
March 2009	EASA certification of the DA42 NG with Austro AE300
April 2010	FAA certification of the DA42 NG
March 2012	Introduction of the DA42-VI

Diamond itself calls the DA42 one of the best-selling piston twins in the world. The manufacturer does not give a current total on its type page; as early as 2010, there were more than 600 aircraft.

Why flight schools choose the DA42

Anyone who wants to become a professional pilot needs experience on multi-engine aircraft. The class rating for multi-engine piston aircraft, MEP for short, and instrument flight training on two engines are fixed building blocks on the way into an airline cockpit. Becoming a pilot explains the paths there, and ATPL training and costs covers what it costs.

The DA42 fits this phase perfectly:

Major operators include Embry-Riddle Aeronautical University in the US and Lufthansa Aviation Training; Air India has also ordered DA42 NGs for its training. For spotters, that means: wherever a multi-engine flight school is based, the DA42 is often in constant use – with traffic patterns, go-arounds and instrument approaches. VFR and IFR explains the difference between visual and instrument flight.

The features that are enough to identify it

The DA42 has a few distinctive traits that give it away even from a distance.

The sound helps too: the diesels sound smoother and less bassy than the big flat-opposed engines of a Seneca. In the end, the registration confirms the type. With a maximum takeoff weight just under two tonnes, German DA42s carry registrations in the D-G group – see more in German aircraft registrations and, in general, Understanding aircraft registrations. In Austria, the type’s home country, the OE registrations help with classification.

Variants: from the Thielert diesel to the sensor platform

All versions share the basic layout, fuselage and wings. The differences lie in engines, weight, equipment and mission.

Version	Features
DA42 (first production series)	Thielert Centurion 1.7, from 2007 Centurion 2.0; diesel for jet fuel
DA42 NG	Austro Engine AE300, higher maximum takeoff weight, EASA certification 2009
DA42-VI	Further developed production version since 2012, now with G1000 NXi
DA42 L360	Lycoming IO-360 with 180 hp for avgas, mainly for training in North America
DA42 M / M-NG	Special-mission versions of the Thielert and Austro variants respectively
DA42 MPP (Guardian)	Multi-Purpose Platform for surveillance, survey and remote sensing
DA42T	Trainer version for Russia
Centaur OPA	Optionally piloted version by Aurora Flight Sciences

From the outside, the DA42, NG and VI are hard for spotters to tell apart. You can only be sure from the registration and register data. Finding out an aircraft’s age shows how to trace an airframe’s history.

The special-mission versions

The special versions are more exciting for spotters. Diamond markets the DA42 MPP as a GUARDIAN platform for remote sensing and surveillance. According to the manufacturer, it manages up to eight hours of endurance and carries up to 634 kg of payload, burning around 24 liters per hour at 35 % power. Diamond delivers such packages turnkey, with sensors, data links, ground station and training.

From the outside, you recognize an MPP by sensor turrets or camera pods under the fuselage or on the nose, often also by additional antennas. It is operated by border protection, government agencies and air forces – the British Royal Air Force used two DA42 MPPs in 2008 and 2009, and Turkmenistan ordered five Guardians. In addition, standard DA42s fly as trainers with several air forces, for example in Poland.

Two spin-offs go even further: the Centaur OPA from Aurora Flight Sciences can fly either with or without a pilot on board, and the Israeli company Aeronautics developed the unmanned Dominator II based on the DA42. Tracking military aircraft online explains how to find government and military aircraft online.

DA42, DA62, P2006T, Seneca or Baron?

At training airfields you will meet several light twins. The finder helps narrow it down.

The Diamond DA62 is the closest relative: the same concept, but noticeably larger at around 9.2 m in length and about 14.6 m in wingspan, with more powerful AE330 engines and up to seven seats. The Tecnam P2006T is the direct competitor in training, but a high-wing aircraft with Rotax engines. The Piper PA-34 Seneca and the Beechcraft Baron are all-metal low-wing aircraft with a conventional tail and gasoline engines.

There is a real risk of confusion with the Piper PA-44 Seminole: it is also a training twin with a T-tail. But it has a metal fuselage with rivets, shorter, broader wings and a conventional side door instead of the large canopy. For general identification help in small-aircraft flying, see Identifying small aircraft.

Where to find the DA42

The DA42 doesn’t follow a schedule. It flies wherever flight schools and academies offer multi-engine and instrument training: at regional airports, at general aviation airfields with instrument approaches and at some commercial airports with little scheduled traffic. Typical are several approaches in a row, often in fixed morning and afternoon slots.

Germany, Austria and Switzerland

In the German-speaking region, the DA42 is in use at numerous flight schools and clubs, but fleets change constantly. The most reliable approach is to search the tracking service for the code DA42 and see at which airfields the aircraft regularly take off and land. Tracking an aircraft by registration shows how to follow a specific aircraft.

In Austria, the area around Wiener Neustadt is worth a look, where Diamond builds and test-flies its aircraft. Anyone there can combine the visit with the Aviaticum aviation museum in Wiener Neustadt. You can find small airfields with Finding small airfields on maps; worthwhile destinations are listed in Regional airports in Germany for spotters and Spotting at small regional airports. Spotting general aviation is the entry point to small-aircraft flying.

Trade shows and special cases

A sure bet is AERO in Friedrichshafen at Friedrichshafen Airport: Diamond regularly exhibits its aircraft there, and with a bit of luck a DA42 is among them. Special-mission versions, on the other hand, are hard to predict – only tracking and tips from the community help here.

Place	Chance of a hit	Why
Airfields with multi-engine flight schools	high	Daily training with many approaches
AERO Friedrichshafen	high	Diamond regularly exhibits there
Area around Wiener Neustadt	medium	Manufacturer’s plant and flight testing
Regional airports with instrument approaches	medium	Practice approaches by training aircraft
Large hubs	low	Hardly any training; at most ferry flights

Photo tips for the DA42

Common mix-ups and how to rule them out

Conclusion

The Diamond DA42 Twin Star reimagined the light twin: carbon fiber instead of aluminum, jet-fuel diesel instead of gasoline flat-opposed engines, glass cockpit and single-lever operation. That made it the standard trainer of many academies and the basis for surveillance platforms. T-tail, long glider-style wing and far-forward nacelles give you the type, the registration the variant.