Back Brantly-Hynes Model 305

Brantly-Hynes Model 305

Basically a larger-scale version of the Model B-2B, the prototype of the original Brantly Model 305 was flown for the first time during January 1964. Apart from its increased dimensions, it differs from its predecessor externally by having a small variable-incidence tail-plane. Considerably more power is provided by an Avco Lycoming flat-six engine, and an enlarged cabin accommodates a total of five persons on two side-by-side forward seats, and an aft bench seat for three.

D.Donald "The Complete Encyclopedia of World Aircraft", 1997

Brantly-Hynes Model 305

The B-2 was a successful programme for Brantly but there was no denying that the aircraft was small and there was an opportunity for a larger version of the design. Brantly produced an enlarged B-2, named the Model 305 which had a longer forward fuselage providing a rear 3-passenger bench seat. The new five seater (N2200U) made its first flight in January 1964, powered by a 305hp Lycoming IVO-540-A1A engine and received its type certificate on 29 July 1965. Brantly immediately commenced production but the Model 305 suffered from persistent ground resonance problems and they only built 45 examples.

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

Original first flight January 1964; FAA type approval 29 July 1965; 44 built during mid-1960s. Another four built by Hynes Aviation in 1985 as the H-5. Improved prototype with redesigned rotor head and new blade aerofoil completed about 30 hours flying by mid-January 1990. New main rotor bearing fitted. Cabin streamlined. New production was to begin 1993, but none built.

DESIGN FEATURES: Rotor system and airframe as for B-2B, but enlarged.

FLYING CONTROLS: Conventional direct mechanical.


LANDING GEAR: Choice of skid, wheel or float gear. Skid type has four oleo struts, two on each side, and small retractable ground handling wheels. Wheel gear has single mainwheels and twin nosewheels, all with oleo-pneumatic shock-absorbers of Brantly manufacture. Goodyear mainwheels and tyres size 5.00-5, pressure 1.93 bars. Goodyear single-disc hydraulic brakes on mainwheels.

POWER PLANT: One 227.4kW Textron Lycoming IVO-540-B1A flat-six engine, mounted vertically, with dual cooling fans. One rubber fuel cell under engine, capacity 163 litres. Refuelling point in port side of fuselage. Oil capacity 9.5 litres.

ACCOMMODATION: Two individual seats side by side, with dual controls. Rear bench seat for three persons. Door on each side. Rear compartment for 113kg of baggage, with downward hinged door on starboard side.

AVIONICS: AlliedSignal or Narco radio, to customer's specification.

EQUIPMENT: Blind-flying instrumentation available, but helicopter not certified for instrument flight.

Jane's Helicopter Markets and Systems

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Technical data for Brantly-Hynes 305

Crew: 1, passengers: 4, engine: 1 x Avco Lycoming IVO-540-A1A pistone engine, rated at 227kW, main rotor diameter: 8.74m, fuselage length: 7.44m, height: 2.44m, take-off weight: 1315kg, empty weight: 816kg, max speed: 193km/h, cruising speed: 177km/h, ceiling: 3660m, range with max fuel: 1250km, range with max fuel and payload: 354km

Jim Gardner, e-mail, 29.07.2022reply

I toured the factory in Frederick Oklahoma sometime in 1979 while a medical student completing my rural medicine assignment. I recall that they were building a 5 seat model. I was also shown the R&D "department ", blueprints, modifications being built into the model that they were constructing. It was connected to a flight school which was either physically connected to a portion of the factory or in a very close by building. After taking the job in the local ER I was tempted to attend the flight school which gave both rotary and fixed wing license. That never happened for various reasons yet I fondly remember the hospitality.
I stopped in to see Frederick on an RV trip last fall. I left feeling so very sad. The city looks like it's on its way to become a ghost town. Homes that were pristine in 1980 are falling over. Streets are crumbling and pot holes galore. The hospital closed in 2016. I never made it out to the airport.
Anyway, fascinated by choppers since that tour and had wondered what became of the company.

Rebecca Tracer, e-mail, 17.12.2016reply

In early 1999 my dad worse for brantley down in Vernon Texas. I remember he told me about a problem with the tail motor and design in the 305. I believe his job was to design the changes and turn them to blueprints. It is only a bittersweet memory for me now.. He loved what he did at Brantley.

Reed S West, e-mail, 09.01.2021 Rebecca Tracer

Hello Rebecca
I owned a B2B in 1997, I went to the factory in Vernon for a visit and met with Maxim cheu the new Chinese owner about buying a new Brantley, currently I'm in the process of developing a B2B kit helicopter for the home built market, I'm contacting you to see if you have any of your dad's blueprints or design criteria for any of the Brantley models I could purchase? I'm also looking to contact other individuals in your area that worked for Brantley? And I'm a cash buyer looking for parts and non-flying brantley's, My email is,, cell. 360-827-2837 please feel free to contact me anytime, I live in Washington State. Regards Reed West


Don Hillberg, e-mail, 31.08.2010reply

Love the Brantly! Flew one across Alaska, Thanks Bob! It was fun!

B Schulte, e-mail, 20.12.2009reply

I learned to fly the Brantly B2-B under the Vietnam Vets GI bill. I logged 60+ hours at Michigan City Municipal Airport in Michigan City, Indiana. The B2-B was fun to fly but required much co-ordination to fly. L & R feet on rudder pedals, L Hand on throttle and main rotor pitch control, and R hand on cyclic stick 360 degree direction control. I needed 30 hours of dual to solo. At 29hrs I thought I would never get it, at 30 hours it seemed like I had always been able to do it. Like learning to ride a bicycle. Words cannot discribe the thrill of flying a helicopter.

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