Grob G 115

Updated: October 2026 – A small white low-wing aircraft banks over a British military airfield, the landing gear fixed and with wheel fairings, two heads sit side by side under the broad glass canopy, an RAF roundel adorns the fuselage – and yet it carries a civil registration: that is very likely a Grob G 115E, known to the Royal Air Force as the Tutor T1. Here you will learn where the trainer from the Allgäu comes from, how to tell the variants apart and where to get it in front of your lens.

What is the Grob G 115?

The G 115 is a two-seat piston-engine trainer built by the Bavarian manufacturer Grob. The company is based in Tussenhausen-Mattsies in the Lower Allgäu, right at Mindelheim-Mattsies airfield. Grob first became known for gliders and motor gliders in plastic construction, and exactly this know-how is in the G 115 too: the airframe consists entirely of fiber composites, an approach still unusual in the 1980s for a powered aircraft of this class.

The road to the G 115 led through two predecessors: the G 110, which flew in 1982 and was lost in spin tests the same year, and the G 112. The G 115 prototype took off on November 15, 1985, German certification followed in March 1987 and certification under US regulations (FAR Part 23) at the end of 1988. That cleared the way for customers worldwide – from flying clubs to commercial flight schools to air forces.

The concept is plain and robust: low wing, fixed nosewheel gear with spring-steel main legs, wheel fairings, a short engine nose and a broad canopy under which instructor and student sit side by side. The side-by-side arrangement is practical for basic training because the instructor sees every move directly. Today Grob builds mainly the G 120TP turboprop trainer and the G 520 high-altitude reconnaissance aircraft.

Technology in brief

The best-known version today, the G 115E, is powered by a Lycoming AEIO-360. That is a four-cylinder flat engine with fuel injection and around 180 hp, designed for aerobatics with an inverted-flight system for oil and fuel. It drives a three-blade constant-speed propeller. The wingspan is 10 meters, the maximum takeoff weight 990 kilograms. Reference works give the fuselage length slightly differently; it is just under eight meters.

For aerobatics, the G 115 is approved from version D onward with load factors of +6 g and −3 g. That is enough for loops, rolls and spins – exactly the program a budding military pilot gets to know in basic training. The early civil versions G 115 and G 115A, by contrast, with a smaller engine and a two-blade propeller, were intended as classic club and training aircraft.

Identifying the G 115 in the field

On an airfield full of small aircraft, you need a second look. These three steps lead you reliably to the G 115.

In the end, the registration confirms the identification. On the British Tutors that is especially easy: they carry civil registrations of the G-BY.. series, which you can look up in any register database. Civil G 115s in Germany fly with a D-E registration, as is usual for single-engine aircraft up to two tonnes.

Variants at a glance

Over the years Grob gradually made the G 115 more powerful and more robust. For spotters, the difference between the early civil versions and the aerobatic trainers is the most important.

Variant	Features	Typical users
G 115 / G 115A	First series, smaller engine, two-blade propeller, upright vertical fin	Clubs and flight schools, including in Germany and Great Britain
G 115B	More powerful engine	Flight schools
G 115C	Revised airframe with tanks in the wings	Flight schools
G 115D	Aerobatic, three-blade constant-speed propeller	Military and civil training
G 115D2 “Heron”	Training version for the Royal Navy	Royal Navy, later a civil school
G 115E “Tutor T1”	Military version with AEIO-360 and three-blade propeller	RAF, Royal Navy, other air forces

According to German-language reference works, around 360 had been built by March 2006. Production did not run continuously, though: Grob interrupted it in 1990, resumed in 1993 and had to stop again after the insolvency in 2008. In 2009 it continued under new owners as Grob Aircraft. A project with retractable gear, the G 115T, later developed into the successor G 120A – the cornerstone of today’s turboprop line.

Tutor T1: the G 115 with the RAF and Royal Navy

The G 115 had its big moment in Great Britain. In the late 1990s the Royal Air Force was looking for a successor to the Scottish Aviation Bulldog, which flew with the University Air Squadrons (UAS) and the Air Experience Flights (AEF). The choice fell on the G 115E. From 1998 the first aircraft reached the squadrons, and according to reference works the Cambridge University Air Squadron was the first unit to get its Tutor. A total of 99 aircraft were ordered.

What made it special was the operating model: the Tutors do not belong to the Ministry of Defence but to a civil contractor that provides and maintains them under a Private Finance Initiative. Originally that was VT Aerospace, later the business ran under Babcock. That is why the aircraft wear civil British registrations of the G-BY.. series, but also the white livery with blue accents and RAF roundels – a combination that spotters who log their sightings love.

The Tutor fulfills several tasks:

• University Air Squadrons: Students interested in a career with the RAF gain their first flying experience here.
• Air Experience Flights: Air Cadets get their first flying hours on the Tutor. One example is 8 AEF at RAF Cosford, which flies together with the University of Birmingham Air Squadron.
• Elementary flying training: Until 2018, basic training of military pilots at RAF Cranwell and RAF Barkston Heath ran on the Tutor; then the turboprop G 120TP Prefect took over. According to reference works, parts of this training continued on the Tutor at Wittering afterwards.
• Royal Navy: 727 Naval Air Squadron at Yeovilton uses the Tutor for the aptitude assessment of prospective naval aviators. Before that, the squadron flew the G 115D Heron from 2001, which was replaced from 2004 by former RAF Tutors.

The Tutor has also written sad chapters during its service. In February 2009 two Tutors collided in the air on a flight from RAF St Athan; all four occupants were killed, including two teenage cadets. In June 2009 a Tutor collided with a glider, and both occupants of the Tutor died. In 2004 a detached propeller blade had already led to an emergency landing and a temporary grounding of the fleet.

Other users worldwide

Besides Great Britain, several air forces rely on the G 115E. Reference works name Egypt with a large fleet of over 70 aircraft and the United Arab Emirates, among others. Finland took over 28 former British G 115Es as a replacement for the Valmet L-70 Vinka, which was retired in 2022 after more than 40 years. There, at the Air Force Academy, the G 115 is now the first military aircraft of Finnish pilot students.

In the civil sector, the G 115 was especially widespread in Australia: several flight schools used it, including, from 1996, a large commercial flight school at Jandakot near Perth. In Germany you find civil G 115s occasionally with clubs and flight schools – a rare but typically German find at small airfields.

Where you find the G 115

Your best chances are in Great Britain. At airfields with UAS or AEF operations, Tutors are in the traffic pattern, often on weekends and during semester breaks when cadets and students fly. A good starting point is RAF Cosford: the RAF Museum Cosford is at the airfield, and from the museum grounds you can watch flight operations along with a visit to the exhibition. In Somerset, a detour to the Fleet Air Arm Museum in Yeovilton is worthwhile, where the Royal Navy used its Tutors for the aptitude flights.

At airshows, too, the Tutor was represented for years with its own RAF display. Whether it is currently on the program at the Royal International Air Tattoo in Fairford or at other British airshows is revealed by the respective flight schedule; you will find an overview of the big dates under Airshows in Europe.

Place	Chance of a hit	Why
British airfields with UAS/AEF	medium to high	Tutors in training and cadet flying operations
British airshows	low to medium	Display or static exhibit, depending on the program
Tikkakoski (Finland)	medium	Training fleet of the Finnish Air Force
Small airfields in Germany	low	Occasional civil G 115s
Mindelheim-Mattsies	low to medium	Grob’s factory airfield, but mainly newer types are seen there

For southern Germans, Grob’s factory airfield is practically on the doorstep; the nearest commercial airport is Memmingen Airport. Do not count on a sure G 115 sighting there, though – the factory focuses on the G 120TP and other projects today.

Easily confused: G 115, Diamond and Prefect

Small trainers look alike at first glance. The finder helps you separate the G 115 from the most common look-alikes.

The Diamond DA20 Katana is the most obvious kindred spirit: also composite construction, also two seats side by side, also a popular military primary trainer. Its T-tail and the very stretched wings give it away immediately, though. The four-seat Diamond DA40 looks longer and has side windows at the rear for the passengers. If you want to know more about the Austrian competitor, see Diamond Aircraft.

The Cessna 172 is ruled out from afar as a high-wing aircraft with wing struts. And with the North American T-6 Texan, the G 115 shares only the role: the warbird is much larger, has a radial engine and tailwheel landing gear.

Photo tips for small trainers

The G 115 is small, fast in the traffic pattern and often only briefly in the frame. A few tricks help.

You will find more basics on photographing at small airfields in the article Spotting general aviation. If you are interested in flying yourself, read on at Private pilot license PPL(A) or, for the military route, at Becoming a pilot in the Bundeswehr.

Conclusion

The G 115 is no star of airshow posters, but a type with history: from the gliding tradition of the Allgäu came a robust composite trainer that, as the Tutor T1, took British cadets and students into the air for a quarter of a century and today trains military pilots in Finland or Egypt. For spotters it is a worthwhile tick in the collection, especially because of the mix of civil registration and military markings.