Merlin GTS Autogyro


	This single seat Autogyro has an excellent safety record and is the latest development of this type of Aircraft, based on our well proven “Kit Build” Airframe. It was designed, built and tested by Jim Montgomerie, and is the result of continuous research and development over a 20 year period.


	The Airframe is constructed from aluminium alloy rectangular hollow section tubes. These tubes have been pre-drilled in our jigs here at Crosshill, and are fastened together with Aircraft type approved fixings by either direct throughbolting, or in some cases braces with fillet plates which have been pre-drilled and cut to size with modern C.A.D. laser technology and precision. The Merlin Pilot enclosure will accommodate a Pilot over 6 feet tall and is manufactured by us at Crosshill from polyester resin strengthened with E-glass and a Kevlar fibre reinforcing matrix.


	The latest version of the Merlin incorporates various new developments that have been tried and tested on various aircraft over recent years, most of this work being done on my own Two Seat Autogyro G-BRFW. The new Merlin comes with fully sprung and dampened main wheel suspension to reduce fatigue on the airframe and pilot, and reduce the take-off run.


	It is pretty obvious that the compression strut springs absorb most of the shocks when taking off and landing from rough ground, but how does it reduce the take off run? If you visualise the rotors beginning to rotate very slowly initially and gradually building up to take-off speed, which will be around 350-400 RPM depending on make and diameter, the two bladed flexible wing becomes a relatively rigid disc and a very large gyroscope. Whilst the rotor is doing this it wants to travel in a straight path, as is the nature of a gyroscope. Any outside interference that tries to deviate it from this straight path, like a gimbal head bumping up and down trying continually to alter the disc axis only lengthens the process. Therefore the more we can stabilise the gimbal head on the take-off run, the quicker the disc will form and reach flying RPM. The most recent modification to my Merlin design is the alteration of the propeller thrust in relation to the centre of mass of the aircraft. This new lowered thrust line now passes directly through the centre of mass (depending on pilot weight and fuel load) of the aircraft to improve efficiency but more importantly to improve safety by reducing the risk of a powered push over in the event of pilot mishandling.

This new thrust line has been achieved basically by raising the engine further up the mast and turning the gearbox around to the down position with the propeller clearance maintained by incorporating a stepped joint in the keel tube. Some minor modifications had also to be made to the nacelle to accommodate this new engine position with the exhaust now passing through the nacelle to improve aerodynamic efficiency.

The Fuel Tanks are factory fitted behind the seat bulkhead area. This area was chosen to keep the varying fuel weight as close to the centre of gravity as possible and also to keep the Pilot and his fuel as remote from each other as possible with three boundary layers between them.

Does it fit the garage? The overall width to the outside of the Main wheel covers is 5’ l0” (1.800m) the height from floor to the highest point of the Gimbal Head is 7’5” (2.250m) and the overall length from nose to tail is 11 ‘6” (3.500m).

Weight. Empty weight depends on the final specification and extras you have fitted to the Aircraft but the average is around 320lbs (145kg), which gives you a useful payload of approx 3301bs (150kg) for Pilot and fuel.

Fuel Capacity. Approx 11 gal. (50ltr).

The original Merlin design pictured here holds the following endurance records:

1)   First Autogyro to fly from Scotland to Ireland.
2)   First Autogyro to fly from Ireland to Isle of Man.
3)   First Autogyro to fly from Isle of Man to Mainland Britain.
4)   First Autogyro to fly to all 5 Countries of the British Isle.
(Scotland, England, Ireland, Wales & Isle of Man) in one day.

Performance:

                     Take off distance.           Depending on wind conditions 20 to 150ft (6m-55m).
                     Landing distance.            Depending on wmd conditions 0 to 65ft (0-20m)
                     Rate of climb.                 Over 900ft per min. (275mpm).
                     Stall Speed                     None, fully controllable to zero airspeed, maintains altitude at 20mph
                     VNE.                             90mph.
                     Cruise.                           75mph on 20 ltr. per hr.

Our latest policy is to supply the Gyro without engine, rotors, propeller or instruments as we have discovered Over the years that most of our customers have there own preference as to rotor make, new or second hand Rotax engine, fixed or variable pitch propeller and customised instrumentation.