Back Monte-Copter Model 15 Triphibian
1960

Model of Monte-Copter Model 15 Triphibian Helicopter

Monte-Copter, Inc. was incorporated in June, 1953, to develop a light helicopter featuring the "cold-jet" type of rotor tip-drive.

The company's first prototype was the Monte-Copter Model 10, which began its test programme in 1955. It has since undergone considerable development and in its current form is known as the Model 12.

A brief description of the Model 12 is given below, together with full details of the production development, designated the Model 15 Triphibian, which was scheduled for completion late in 1959.

MONTE-COPTER MODEL 12

This aircraft began life in 1955 as the two-seat Monte Copter Model 10, powered by a 135hp Lycoming O-290-D2 engine, driving a two-blade rotor with servo-control surfaces mounted at 90 to the blades. At that time it had small fixed wings to off-load the rotor in forward flight and a tail-boom carrying twin fins.

After initial tests had been completed, this airframe was modified into the Model 10A by removal of the wings and cabin skin and replacement of the Lycoming piston-engine by two Continental Model 140 (Turbomeca Palouste) air compressors. These engines were mounted on each side of the fuselage and were used to supply compressed air to rotor-tip nozzles, from which the air was ejected without any form of combustion, to turn the rotor.

Further modification of the airframe has led to the present Model 12, with the fuselage skin replaced and a single rudder, working in the jet efflux, instead of the former tail-boom. In this form, it has been flying successfully since May, 1958.

No specification details are available except that the Model 12 has an empty weight of 454kg and a normal loaded weight of 635kg. Its rotor has a diameter of 32 ft. (9.75 m.)

MONTE-COPTER MODEL 15 TRIPHIBIAN

Developed from the Monte-Copter Model 12, the Model 15 Triphibian is a three-seat light helicopter with a "cold-jet" type of rotor drive, in which the rotor is turned by ejecting compressed air from nozzles at the blade-tips, without any form of combustion. The prototype was scheduled for completion late in 1959. The Model 15 is of very simple design, with a fiberglass boat-type hull to permit operation from water as well as land. It has small delta wings to offload the rotor in forward flight. Fuel tanks on the wing-tips serve also as stabilising floats during water operations.

TYPE: Three-seat amphibious helicopter.

WINGS: Small delta wings to offload rotor. Conventional ailerons.

ROTOR SYSTEM: Two-blade main rotor with fully-articulated semi-rigid all-metal blades, attached to hub by specially-designed serrated fittings. Spherical bearings at pitch and flapping hinge. Area of each main blade 1.11m2. Total disc area 94.76m2. No anti-torque rotor.

ROTOR DRIVE: Cold-jet type, in which compressed air is ejected from blade-tip nozzles. Rotor/engine r.p.m. ratio 340/ 35,000.

FUSELAGE: Aluminium and magnesium bulkhead and keel structure, with fiberglass skin.

LANDING GEAR: Non-retractable tricycle type. Torsion bar shock-absorbers. Goodyear wheels, size 5.00x5. Goodyear hydraulic brakes. Wheel track 3.05m. Wheelbase 2.13m.

POWER PLANTS: One Continental Model 141 air-compressor, rated at 200 gas h.p, mounted in rear fuselage. Fuel in wings and in wing-tip tanks, with total capacity of 136 litres. Oil capacity 4.5 litres.

ACCOMMODATION: Pilot and two passengers in enclosed cabin, with forward-sliding canopy. Baggage compartment with capacity of 0.79m3. Provision for carrying one stretcher and attendant.

Jane's All the World's Aircraft, 1959-60

Monte-Copter Inc. was established in 1953 in Seattle to design and build light helicopters. The first design was the Model 10, which was a two-seat machine with a large bubble canopy and a tailboom mounting a tailplane with large twin rudders. The two-blade rotor had control paddles similar to the Hiller system. It was driven by a 135hp Lycoming O-290 engine which generated cold airflow to the rotor tips. This piston engine was then replaced by two externally-mounted Turbomeca Palouste turbojets. The prototype, N68P, flew in 1955 and was later modified to become the Model 12, with a single tail fin. Monte-Copter then built the three-seat Model 15 Triphibian (N69P) which flew in 1960. This was a very streamlined machine with a boat-shaped fibreglass fuselage, forward-sliding canopy, small stub wings with sponsons to house the main wheels and a small full depth rudder. It was powered by a 200hp Continental gas generator housed in the rear fuselage feeding compressed air to the rotor tip nozzles.

R.Simpson "Airlife's Helicopter and Rotorcraft", 1998

Technical data for Model 15 Triphibian

Main rotor diameter: 10.97m, overall length: 4.65m, overall width: 3.35m, height to top of rotor pylon: 2.52m, weight empty: 545kg, weight loaded: 907kg, max speed: 158km/h, cruising speed: 120km/h, rate of climb at sea level: 335m/min, ceiling: 4570m, normal range: 160km, range with auxiliary tanks: 290km

Comments 
jack vander waal, jcav555=gmail.com, 09.02.2014

I use to work for the company back when we were actively testing the chopper The Model 15 is now located in a museum at the Ramona airport called Classic Rotors in Ramona California 92065 Their web site list the hours when open

Gayla Schroeder, Gayla.Schroeder=yahoo.com, 25.11.2012

All of the rights to the Monte-Copter were signed over to Boeing when the company folded. Mr. Ramme has passed away and his immediate family lives in the Seattle area. There are one or two of the Copters still around and as far as I know, at least one is still operable.

Tipjetheli, TIPJETHELI=gmail.com, 17.09.2012

Hi I am looking for this rotorcraft. In any condition. Please help me look for it. Also please help me find the rightful owner of the design and technology. My email TIPJETHELI@gmail.com or VTOLGYRO@gmail.com

Tipjetheli, TIPJETHELI=gmail.com, 17.09.2012

Hi I am looking for this rotorcraft. In any condition. Please help me look for it. Also please help me find the rightful owner of the design and technology. My email TIPJETHELI@gmail.com or VTOLGYRO@gmail.com

Gene Curry, gec1936=comcast.net, 15.11.2011

All of those holding stock in this no-longer-existing company are owners of zero. It went out of business, and therefore has no value.

polo, poloalobabab=gmail.com, 14.06.2011

Any ideas where i can find more info on this company.

Gene Curry, gec1936=comcast.net, 19.05.2011

Looking more closely, it's obvious the picture on this page is that of a model, not of the real aircraft.

Joe Dedera, cdedera=lycos.com, 29.09.2010

I also have stock in Monte-Copter, Inc. and have the same questions as these folks. Please let me know where I can find information about the value of these stocks. Thank you.

Karen, beanco2005=comcast.net, 05.09.2010

I have 200 shares bought on September 14th 1956. Are they
worth anything?

Maurice Holmes, maurice.holmes=ngc.com, 12.07.2010

I also have shares of stock in Monte-copter since the 50's and 60's (200+) Are they worth anything?

Teresa LeBeau, tree=ec.rr.com, 28.04.2010

I have 54 shares dated 1958. Would love to know anything about them.

tina stricklin, dusty97rose=yahoo.ca, 06.04.2010

My father also had stock in this company. What has happened to it?

Gary Murray, Ohiocowboy42=aol.com, 04.03.2010

After going through our late mother's papers, my sister and I found 40 shares of Monte-Copter stock. Are they of any value today?

Gene Curry, gec1936=comcast.net, 23.10.2009

I worked for Mr. Ramme and Monte-Copter for the summer of 1958. It was my first job out of college, before going on to graduate school. It was a small, but very interesting company. Lots of tension and doubt about its ability to raise money and keep going. I did some stress calculations on the body hoop frame and on the stub wings.

Norm Hower, mhower1=centurytel.net, 29.04.2009

Are Stocks in this company of any value.

Ron, ron_schaefer=msn.com, 26.03.2009

We have 20 shares dated 1st of June, 1965.. Any value to these shares? Was Monte copter sold to another company?

Patricia J Gallegos, patriciaj_gallegos=comcast.net, 23.08.2008

To all who have questions about their shares in Monte-Copter Inc. Mr. Ramme, the creator of the the craft and president of the company passed away in 1995. The company folded in 1998.

Mary Kikikis, marula4859=yahoo.com, 07.04.2008

I also have shares in Monte-Copter Inc, dated 1954, 1956, & 1965. Has anyone found any answers yet?

Clelia Stevens, emilouwho2=hotmail.com, 05.04.2008

i have shares of monte-copter.. can they be redeemed?

Edward Meier, afmeier=earthlink.net, 11.12.2007

I have 120 shares of stock bought in 1958 and 1965. Who do I talk with about them? Thank you.

john baker, jbaker3598=comcast.net, 24.11.2007

I have stocks dated back to 1955. Who do I talk with about them.

marv sims, sims1=canada.com, 22.11.2007

I have some old stock from Monte-copter inc.
dated 1957. Any ideas where i can find more info on this company

Do you have any comments concerning this aircraft ?

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