"The only piston helicopter designed from scratch with the safety of its occupants as top priority.” - Guimbal
FENESTRON TAIL
Whilst many other helicopters use a tail rotor mounted to the side of the tail boom, the Fenestron Tail Rotor, a patented design from Guimbal, is built within the tail itself. The main purpose of course is safety. When protected by a shroud the fan poses much less of a threat to crew operating on ground and from foreign objects impacting it. Noise abatement is improved; the blades are enclosed and mounted asymmetrically, dispersing vibrations over various frequencies. Anti torque effectiveness is enhanced as the blades are shielded from their own wing tip vortices, creating a more reliable production of anti-torque force; this lessens a pilot's workload. There is the added bonus of it looking rather sleek too.
COMPOSITE STRUCTURE
The fuselage is monocoque (single shell) and made of carbon fibre, giving it supreme energy absorbing characteristics. The composite construction provides extra safety in a crash scenario in that the body of the helicopter primarily absorbs the impact; instead of crumpling, energy ripples around the structure in order to dissipate. Aerodynamics is improved with a composite structure. Less is more in this case, without numerous panels and their corresponding bolts increasing the drag element, more power is available to the pilot. The fuselage has no calendar-limited components, meaning its extremely durable. Fun fact, the helicopter is certified to direct lightning strike, not that we would encourage flight in those sorts of conditions.
ENERGY ABSORBING SEATS
The focus on occupant safety continues with the Cabri’s energy absorbing seats. Crash tests on the G2 have ensured occupants would survive a vertical impact of up to 2000ft/minute; a remarkable figure. The Cabri is the only piston engine helicopter certified to EASA CS27 and FAR 27 regulations for high impact absorption. Instead of the crumpling action typically incorporated in crash technology, Guimbal have instead attached two rail-like structures to the backs of the seats, like a dual spine. In a hard impact scenario the seats slide down the rails to absorb the impact.
MULTI LIMIT INDICATOR
The core of the Cabri's electronics is the Electronic Pilot Management (EPM). The EPM allows monitoring of up to 36 system and engine elements, displaying them on a digital platform instead of analogue. The system gives an accurate account of fuel levels and endurance down to the minute, it automatically controls the carburettor anti-icing system, and has remote central locking with an immobiliser. Instead of the traditional warning lights that come on in a helicopter when something goes awry, the G2 will present a warning indicator on the screen highlighting the problem. The overall effect being a reduced workload. The numbers are clear and the interaction is ergonomic and intuitive.
ELECTRIC TRIM
A multidirectional trim function has been added to the design of the cyclic control. It is activated by a small joystick that sits atop the cyclic, close to where the pilot’s thumb might sit. It allows pilots to ease any control forces typically felt through the cyclic. Think of it like power steering for helicopters. When less effort is used to hold the controls in place, pilots have more freedom to focus on other aspects in flight.
The Cabri G2 embodies many of the technological advances of larger helicopters from the Fenestron anti-torque tail rotor to the three-bladed fully articulated main rotor head, glass cockpit, and plasma ignition system to name a few. Whilst increasing operational safety these elements also improve the helicopter's manoeuvrability and tolerance to bad weather, endearing it to the name ‘the little big helicopter’.
The G2 fully adheres to all safety requirements for a crash-resistant fuel system in accordance with the Federal Aviation Administration Regulations. Only a few helicopters in the world have made this list and the G2 is the only piston engine helicopter amongst them.
BUILT FOR AUTOROTATION
Autorotation is a manoeuvre routinely practiced throughout training. As an emergency procedure it is considered to be of higher risk than other manoeuvres performed throughout flight training. We consider employing a helicopter that has incorporated as many safety elements as possible with regard to autorotation to be the most responsible choice; and the Cabri exhibits excellent autorotating capabilities. Retaining lift via rotor RPM is the most important factor in a successful auto. Designed with high inertia blades, meaning they retain their kinetic energy well, the Cabri’s safe rotor RPM envelope is much larger than other existing two seater training helicopters. As autorotation is considered a low-G manoeuvre, the fully articulated rotor head negates any threat of mast bumping that is seen in semi-articulated two bladed rotor heads. Superior manoeuvrability is also possible when having to autorotate in turbulent and strong weather conditions.
WEATHER TOLERANT
The Cabri G2 handles poor meteorological conditions exceptionally well, namely turbulence, gusting winds of up to 40kts, and rain. This is due to its three composite blades made from fibreglass reinforced carbon, mounted to a fully articulated rotor head system. In a fully articulated system each blade is allowed to lead/lag and flap independently of each other, with the addition of feathering. In this case the aerodynamic pressures on the blades are eased. Mimicking feathers on a bird, the strength lies in yielding to the wind. This system greatly lessens the chance of the rotor blades coming into contact with the tail boom as an additional safety feature. The ability to fly in poor weather conditions gives students the opportunity to gain invaluable experience.
