Grob Aircraft

Grob Aircraft has flown its new turboprop-powered trainer for potential buyers in regions including the Middle East

If acquiring the assets of the failed Grob Aerospace company from receivership three-and-a-half years ago was a gamble, then the current level of interest in the reborn Grob Aircraft's new-generation G120TP trainer appears to have more than justified the risks taken by its German backers.

Combining the fuselage outer mould line of the company's G120A two-seater and the lessons learned from integrating the Rolls-Royce M250 turboprop engine with the abandoned four-seat G140, the TP was first flown in 2010 and swiftly attracted a buyer.

Having selected the type in September 2011, Indonesia's first of 18 examples is now on the assembly line at Grob Aircraft's Tussenhausen-Mattsies site, nestled deep in the Bavarian countryside around a 90min drive away from Munich airport.

Equipped with analogue cockpit instruments, it will be part of a first batch of trainers, which is on schedule for delivery to Jakarta later this year. The company has not released a contract value for the deal. Around five more G120TPs were waiting to go into the paint shop when Flight International visited the company on 15 June, with these expected to be on the assembly line within weeks.

A second batch of trainers will go to Indonesia in the first quarter of 2013. The nation's air force will employ the type beneath its Korea Aerospace Industries (KAI) KT-1s and the same manufacturer's future T-50 aircraft in a training pipeline leading to assets including armed Embraer EMB-314 Super Tucanos, Lockheed Martin F-16As and Sukhoi Su-27/30s. More of the German-built type could be acquired later.

By using an existing composite airframe, Grob Aircraft has greatly simplified the task of developing the new platform, which co-chief executive and chief sales officer André Hiebeler says reflects a major change of strategy from his family-owned H3 group and other investors since January 2009 than that of the previous management. Major investments in aircraft such as the fully aerobatic G140 and G160 Ranger general aviation aircraft, both of which failed to secure buyers, took their toll on Grob Aerospace's health, before a massive gamble on the SPn business jet killed it.

Hiebeler says his predecessors performed rapid development and prototyping work rather than consult with their intended business sectors to see whether their designs could find a home. The G160 was intended to sit between the Daher-Socata TBM 850 and Pilatus PC-12 and taken from concept to first flight in about 13 months, but it threatened neither.


Explaining the company's decision to refocus its efforts on the military training sector, Hiebeler comments: "We didn't need to reinvent the wheel - we already had it."

Formed in 1971, Grob was the first firm in the world to produce all-composite aircraft, ranging from powered gliders such as the G109 to two-seat trainers optimised for the military market, such as the G115 and G120. More than 3,500 have been delivered to date, without a single structural failure.

Maximum take-off weight for the side-by-side-crewed G120TP is a little over 1,500kg (3,300lb), or just 75kg less for an aerobatic flight profile to use its full +6/-4g handling envelope.

"It's an evolution, so people know what to expect," says Jan Krausko, director of operations for Grob Aircraft's training aircraft programmes, who started working for the predecessor company in 1996.

A first example of the G120TP has been busy during its short life. Its manufacturer has already deployed the aircraft to support assessments in nations including India, Malta, Saudi Arabia and the United Arab Emirates, while pilots from several others have tested its capabilities from its German home. It has performed "flawlessly" throughout, Hiebeler says, while feedback from guest pilots, including Flight International's Peter Collins, is that it "feels like a fighter".


 Grob Aircraft

The G120TP is now being offered under a company-backed service provision model


While Indonesia wants its examples to have analogue flight instruments, the company is continuing to work towards the European certification of an enhanced configuration with glass cockpit displays, which is being offered to potential customers around the world.

"We're bullish," says Hiebeler, who points to possible future success throughout Africa, Asia, Latin America and the Middle East, with key targets including Australia, New Zealand and the UK. As the head of a six-strong sales team, the executive spent 250 days on the road in 2011 promoting the company's products, with further support from a growing network of in-country representatives. "We're really out there doing everywhere," he says. "Our main marketing task is to be there before the request for proposals. If our product is as good as we think it is then this will be reflected in the request for information."

The company recently lost out to the Pilatus PC-7 Mk II in a fiercely fought battle to supply the Indian air force with 75 basic trainers. The service's preference for a tandem seat configuration aircraft was one contributory factor to the defeat, along with the G120TP still being in its development phase at that time.

Hiebeler says that acquiring a composite aircraft offers users a major benefit. While each airframe's unit cost will be higher than that of a metal-structured rival, through-life maintenance advantages are clear. Grob Aircraft quotes a maintenance activity of just under 30min per flight hour for its G115 and G120 products, versus perhaps 3h for rival systems. Zero work is also required through the first 3,500 flight hours: potentially around five years of use.

"We have fewer inspections, and none for fatigue and corrosion - straight away that's one-third off the maintenance costs," Krausko says. As its aircraft are manufactured using low-pressure composites, users are able to make minor repairs in the event of airframe damage in the field, reducing fleet down-time. More extensive work can be performed at Tussenhausen-Mattsies, with one G120A from the French air force's EADS-run flight training school at Cognac air base now being fixed following an inadvertent wheels-up landing.

Production lessons have been learned from the work conducted so far under Indonesia's order for the TP, with their benefits to be felt from next year. These include transforming the company's previously inflexible production techniques to allow up to 10 people to work on the aircraft at the same time, and less variation in specification.

"It's about process," Krausko says. "G120As were available in five different configurations - now we have a standard aircraft with options. So the production rate and efficiency are better, making a cost saving for the company and the customer."

With its first marketing blitz already performed, the company has decided against bringing its G120TP to Farnborough this year. But visitors to its outside exhibit who look closely at its full-scale main fuselage and cockpit mock-up with flight-simulation capability will notice two major changes.

During its first visit to the UK show in 2010, Grob Aircraft announced a teaming agreement with Elbit Systems, under which the Israeli partner was to provide the TP's avionics suite. This arrangement has now ended, Hiebeler reveals, with the trainer to receive the CMC Electronics Cockpit 4000 suite, already fitted with types including the Hawker Beechcraft T-6 Texan II and KAI KT-1. Export considerations and schedule issues led to the decision.

Also in the cockpit, the type's previously planned dual Martin-Baker Mk15B ejection seats will be replaced with a new Mk17 design created by the UK company specifically for the German trainer. To be unveiled at Farnborough, this is lighter and sleeker in profile than the earlier model.

Hiebeler says the dual cockpit design is an important part of his company's training philosophy, as it enables an instructor in the left-hand seat to more accurately monitor a student's activity and progress than in a tandem-configured type. With the numbers of fighter aircraft in many air forces falling as a percentage against other types, it is also more typical of the multi-crew cockpit environment that many will experience operationally when flying transport aircraft or helicopters.

"You need to have a training system that accommodates not just the fighter pilot, but all of them," says Hiebeler, whose ambition is to replicate the success of the Pilatus PC-7 and Shorts Tucano in the 1980s. He believes that this goal could be helped by what he describes as "a worldwide generation change", where "countries are not prepared any more to build new aircraft for their own needs".

Likening the G120TP to Apple's multifunctional iPhone, Hiebeler notes that the aircraft's performance can be rated according to the student's experience. Early on, its engine power can be reduced and its reverse thrust locked, with the flight envelope to be expanded only as the pilot gains in skill and confidence.

The cockpit design also gives students an early grounding in the use of the hands on throttle and stick (HOTAS) controls which they will use on frontline types. "Our concept is to give them HOTAS at the very beginning and build up," Hiebeler says. Likewise, a trainee pilot would initially use a primary flight display and have engine information shown on the aircraft's large central display, before going on to use electronic checklists and the simulated carriage of weapons.


"Our aircraft allows a student to train in a neutral environment, learning about mission management, and observing and managing information. These are the main tasks now," Hiebeler says. He adds that the G120TP's 240kt (444km/h) maximum speed exceeds that typically flown by the UK Royal Air Force's current Tucano T1, and that larger and significantly more expensive rivals such as the Hawker Beechcraft T-6B and Pilatus PC-21 have "only speed as a differentiator".

Such is the company's confidence in the TP that it has already begun offering the type to potential users under a proposed service provision model, which is expected to soon be selected by a Latin American customer. 

Grob tp120 3view

G120TP specs

Under such an arrangement, it would provide aircraft, computer-based training systems, simulators, instructors, spare parts and conduct maintenance work with a local partner. It could even buy back earlier Grob aircraft and replace them with the new variant under the scheme, which would help it become less reliant on manufacturing by upping its in-service support activities.

Commercial user Lufthansa Fight Training has six G120As with an availability rate of over 98%, with five always available on the flight line. "That's the same that we expect from the TP: the systems are reliable and the engine is proven," Hiebeler says.


During its last several months of operations, the ill-fated Grob Aerospace massively expanded its workforce to around 500 people. Today, Grob Aircraft has gone back to the pre-SPn level of around 150, including roughly 30 contract workers. "The work process is more or less set for 200 people. The company was not accustomed to 500," Krausko notes.

"The people who are working here are really experienced - they really know the products," Krausko says. The company also manufactures its aircraft's landing gear, and prepares systems such as wiring looms in situ. "For our customers, this guarantees that we have a very stable lifetime support capability," he adds.

Adding only five or 10 more staff to the assembly line would enable the delivery of a maximum of 30 to 40 aircraft per year, but going above this level would require investment in additional aircraft moulds, says Krausko.

After a profitable first two years, 2011 brought a loss for Grob Aircraft, but Hiebeler says that this was anticipated while it paused to prioritise the development and marketing of its new poster child. He expects it to have a turnover in the region of €100 million ($126 million) this year, including a return to profit. "In year four we will make a very solid profit," he predicts. The company's current backlog represents around two and a half years of work, he adds.

"We've written a small but very successful story," says Hiebeler. Only history will show what lies ahead, but the G120TP looks certain to attract new customers to put their faith in the Grob Aircraft brand.


  • Craig Hoyle is a contributor to our dedicated defence sector blog, The DEW Line.

Source: Flight International