fairey rotodyne
was gonna be used for mass transport
landing on one spot without need for a runway, but with the same speed, economics, and distance as a plane
helicopter
engine power to spin rotor, forcing air down and creating lift
tilting motor allows helicopters to move direction
rotodyne
main rotor not powered
air passes naturally through rotor blades, creating autorotation and therefore lift
lifting wind and turboprops like a plan, but in flight the rotor lifted half the weight
fastest helicopter
even though rotor not powered by a motor it could take off and land vertically so basically helicopter. cuz of tip jets
tip jets, during take off and landing fuel and compressed air supplied by turboprops ignite to spin the rotor. when in foreword motion they would turn off and rotor would spin freely
needed for travel between cities. by plane didnt take long but going to and from the airport would take rlly long in congested cities
one solution was to use helicopters, taking off from the tops of buildings in cities
1960s helicopter airlines used a lot but none of them actually made money cuz helicopters were too inefficient, spending 20 - 30 cents per seat mile. could only be used if government paid for operational costs
rotodyne costs to 4 cents per seat mile making helicopter flights profitable
rotoydne could also travel further meaning would change interstate travel
rotodyne idea went back to the 20s where spanish inventor jaun de la cierva wanted to make a safer plane so he put a free spinning rotor on the top so planes could fly slowly without stalling. with no forward motion it would glide down to earth slower than a parachute. called autogyrones and used in military and mail deliveries in the 30s
died out tho when helicopters became more advance
vertical take off and landing of helicopter, speed and effieciency of an airplane. fairey funded by british government and developed prototypes
1957 first rotodyne prototype flew . 40 passengers, 700 kms, over 300 kph so great success 350 successful test flights so safe so yay
biggest problem was the noise from the tip jets , 113 db at 180m which was bad for cities
fairey moved on to produce a production version that could carry up to 75 passengers. they spent years trying to develop a way to quite the tip jets. managed to get it 15% quieter
airlines interested, ordered a few
fairey needed about £10 mill more in funding to build a production ver from the british government but by 1960s there were too many aircraft producers making too little planes and all needed government funding, so govgernment merged a bunch of them and fairey got merged with westland aircraft lmt, saunders roe lmt, and bristol aeroplane company to form westland helicopters
other projects meant rotodyne stopped being worked on
also difficulties getting powerful engines and the need to reduce tip jet noise
airlines started pulling out of their rotodyne sales when they realised it wouldn’t be there in time and would also be way more expensive
1962 government had economic pressures to pulled funding for rotodyne so it just disappeard
only one ever built that was the 1 prototype
rotary wing aircraft first serious construction from da vinci’s notes
helicpoteres - lift and thrust through powered rotors
autogryos - more lift glider, pushing and pulling engines to spin unpowered motor and generate lift through forward momentum
1915 charles richard fairey founded fairey
charles wanted to join raf in ww1 but lots of pilots died and raf knew how talented he was as an aircraft designer so they rejected him, but gave him a contract to make seaplanes
iconic planes such as swordfish firefly and gannet
they were very famous
in 1940s inspired by single motor helicopter designs by igor sirkorski, fairey wanted to venture to make something that had speed of aircraft and efficiency of autogyro and manueverability of a helicopter
jet gyrodyne first time fairey made helicopters
didnt have a tail rotor but instead a single pull rotor on the sides under the main rotor as a stub wing. made it a ‘compound’ helicopter aka a hybrid
throttle and pitch in single control lever. in level flight yaw could be controlled using footpedals
alvis leonides 9 cylinder piston radial engine, 520 hp
triple bladed main rotor 15.62m. rotor stood out for its size. gyrodyne couldn’t carry as much (like 500 kg less) as other helicopters at the time fairey prioritised safety and stability to weight capacity, making passenger airlines take notice
dr j a j bennett known for helicotper design experience, recruited to work
first flight 1947 basil arkell near white waltham airfield
124 mph world speed record for helicopters
planes for jet powered gyrodyne after that. 1949 tragic rotorhead failure, broke apart and killed test pilot and a person watching so development postponed
doblhoff wnf 342 originally light weight reconnasance for nazis. after war american captured variant examined and showed potential after testing. fairey interested in tip jets so they got help from surviving members of the german team to research the technology
then they made the jet gyrodyne
2 rolls royce merlin compressers powered tip jets at the end of the blades
fins on stub wings enhanced control using propeller pitch
2 stub wing probs pusher configurigation
ultra light compound
tip jets burnt kerasine during vertical flight then would turn off in horizontal flight so blades could be free moving like in an autogyrone
1954 first flight in crown appointed programme testing jet powered helicopters
didnt make impression on government but showed the new direction fairey would take
transition from helicopter to autogyrone simple but other way round was difficult cuz unsafe elevation drops / forced landings
autogyros could do low speeed landings easily but for gyrodones cuz they were more technical was much more difficult
1955 - 1956, 190 trnasitions between forward flight and jet powered vtol proving gyrodyme could operate well
british military wanted helicopters after battle of imjin river in korean war gloucestershire regiment, 459 surrendered. this proved need for military operations as they couldve resupplied and evacuated the men like it was doing for other countries with military helicopters
2 years after battle air ministry ministry of supply wanted fairey to give ultralight helicopter for military observation
tip jet helictoper 817 kg when fully fueld and equiped, propulsion purely from tip jets with turbo gas turbine engine 250 hp directiont hrust - ultra-light helicotper 1955
showed rlly good versailty in movement but government pulled funding cuz there was more demand for larger helicopters
fairey wanted to sell design to america but they didnt buy so project stopped in 1959
after ww2 british aviation more focued on civilian and transporation
big demand for commuter planes and helicopters
challenge - communter flight service, waiting time, granting runway access, driving to airport. same problems we have today so ahead of its time
so fairey wanted to go in civilian market cuz they thought advantage cuz they could drive forward motion
tip jet for vertical landing, allowed to be used in city centres without need for aviation infrastructure
wanted to reduce wait times for lift offs and need to commute
market in america, city centres
150 mph theoretical cruising speed but was slower than others but had quicker takeoff and no delay runway clearance which set it aside from airplanes
1947 fairey proposed 20 passengers 2 rolls royce dart engine 4 blade tip jet rotor 3 blade driving motors on stub wings pull up position
british european airways interested demands increased so they worked on it. wanted 40 passenger 145 mph
rotodyne now 40 at theoretical 165 which made more airlines in europe city travel interestd
1952 first prototype made with 5 bladed design 2 dart engines forward propulsion 2 air compressing jets for tip jets
1953 british european airways accepted 4 bladed 2 larger napla eand engines for both forward propulsion and tip air compression. known as type y
£780,000 in funding from BEA and UK military
1957 final contruction started
27.4m circumference rotor with lift and steering
60 mph speed then vertical takeoff to forward movement
controls similar to gyrodyme used stick and pedals using both helicopter and plane elements
for civilians more luxury -
low altitudes meant no need for pressurisation meaning big windows, good head room 6ft, 4ft from the ground
air conditioning which wasn’t universally available, -10 to 35 degrees
similar in design to modern planes, fuel tanks in stub wings 727 gallons
pyramid shaped assembly supported rotor allowing compressor system powering tip jets to intake air and keep aerodynamic efficinecy and dampening vibrations
rotodyne very different to helicotper designs cuz no gear both
each 2800 hp napia elan turbo prop straight into auxiliary air compressors at each props rear, supplying tip jets through unique duct work in pylon assembly under rotor head
‘trouser leg’ 2 round ducts feeding tip jets through centre of each blade
scaffold for fuel and electrical lines that ignite jets during vertical motion
trouser leg meant a single engine could power them even if it was less efficient
retractable landing gear to increase cruising speed cuz no drag in case of hydraulic failure manually access landing gear so wheels drop from gravity and then lock into position - different to what else fairey did . really revolutionary as it would take decades for multiple hydraulic failures on passengers planes for the same thing to be implemented
tip jets very suitable and minimum pressure loss due to friction losses were comepnsated for by centrifugeal force generated by rotor
could survive forces as high as 350 G and core temps reaching 1800 celsius
no moving parts in blades cuz of the system of air, reduced cost and skills needed to maintain the jets
miaden flight 1957 big milestone simple maneouvers during testing like hovering or flying a short circuit
spring 1958 302 vertical takeoffs and landing tests had been done without incident
left tip jets on during early flight tests found out it made it much faster - new helicopter speed record 192 mph 1959, bea wanted max of 149 mph
june 1959 first transnational fight - britain, brussels, france
proof of concept flight and also advertising. completed 58 mins at 180 mph - very impressive, cutting helicopter times in half and would be faster than a plane
everyone in europe and america wanted it
454 flights 154 hours flight time during training
was planned for civilians and for military that they were testing
transporting bridge 5 miles and placing it above a river
up to 3600 kg without strain
1959 took centre stage society of british aircraft constructors in farmborough. fuselage remade for airline standards, carried 30 nurses
tip jets 113 db at 180 m during take off at landing. sound measurements tkaen at battersea heliport
bea concerned about noise
fairey focused on reducing noise, tip jet silences to 96 db
fairey argued sounds at take off and landing would be overshadowed by city sounds since towns near airports now day usually have 96 db per landing and takeoff
safety in emergency situations was huge selling point
and autogyro features made it safer for landings
1950s rotodyne funding ran out
shifts in uk industrial landscape - 1946 clement attlee nationalised industries which impacted aviation by 1960, by 1961 the multitude of aviation companies went down to 3 and fairey got merged with westland who were solely responsible for helicopters in uk
also napia taken over by rolls royce so no more ellen engines and rotodyne built heavily around ellen engine and they struggled to adjust to new engines and it took lots of time and money
engines meant to replaced ellen were discontinued also
westland kept the rotodyne project going and secured £4 mill for it from the uk government
bea pledged to order 6 of them if all requirments especially noise level
but as it went along backers backed out from uk, america, japan, etc
westland asked government if they could aquire the rights to the design and continue it as a private project, but government did not take them up and feb 1962 all government funding was taken cuz of the cost
westland reluctantly took steps to dismantle the development contract
then it went away
westland had so many contracts already for military helicopters that they couldn’t afford to spend money or time on an experimental venture, and company culture did not support unsupported private ventures
dismantled and scrapped
most of the bits left are in museums or private collectors
okay wiki for fairey jet gyrodyne
1 built
jan 1954 maiden flight
experimental compound gyroplane incorporating helicotper, gyrodyne, autogyro used to resaerch rotodyne
helicopter - motor power rotor
gyrodyne - rotor is powered for take off and landing but free moving in level flight
autogyro - unpowered free moving rotor
first prototype was fb 1 gyrodyne
jet built specificially to develop pressure-jet rotor drive system and operational procesdures used later on rotodyne
used fusealge undercarriage and engine of fb 1
alivs leonides nine cylinder raidla engine in the middle of fuselage, drove pushed propeller at tip of each stub wing and 2 rolls royce merlin engine superchargers
3 blade tilting hub rotor system replaced by 2 blade rotor controlled with swashplate actuated cyclic and collective pitch controls
empennage provides stabilisation about pitch and yaw
rotor driven by air delivered by superchargers and burnt with fuel in blae tip mounted pressure jets
zero torque rotor didn’t need anti-torque system
collective pitch of wingtip propellers controlled by rudder pedals for yaw
jet tips on for take off, landing, and low speed flight. used for hovering
when turned off, rotor autorotated while propellers provided thrust
underpowered could carry sufficient fuel for only 15 minutes of flight, sometimes external fuel tanks carried for increased endurance
tested with tethered flights at white waltham, first free flight jan 1954
retired when ground testing of rotoydyne commenced
jet is officially a compound gyroplane not a gyrodyne
General characteristics
Crew: 2
Length: 25 ft (7.6 m)
Height: 10 ft 2 in (3.10 m)
Empty weight: 3,600 lb (1,633 kg)
Gross weight: 4,800 lb (2,177 kg)
Powerplant: 1 × Alvis Leonides 9-cylinder air-cooled radial piston engine, 520 hp (390 kW)
Powerplant: 2 × Fairey fuel burning compressed air tip-jets
Main rotor diameter: 51 ft 9 in (15.77 m)
Main rotor area: 2,103.6 sq ft (195.43 m2)
Propellers: 3 (but see picture = 2 bladed ?)-bladed variable-pitch propeller (2 of)
Performance
Maximum speed: 140 mph (230 km/h, 120 kn)
wiki for rotodyne
commerial and military use
tip jet powered rotor burnt mix of fuel and compressed air, two wing mounted napier eland turboprops
fb 1 world airspeed record 1948 124.3 mph
fb 1 fatal accident 1949
bea requested passenger carrying rotorcraft to be called bealine bus / BEA bus. ministry of supply sponsered design studies and fairey submitted designs and got the contract in 1950. government funded
hard to find engines early on - rolls royce chairman argued against giving their engines saying he was part of too many contracts. initial dart engine selected was switched to mamba engine of rival firm armstrong siddeley. then armstrong sydney said they were also lacking resources so fairey thought of using de havilland goblin engine and rolls royce derwent turbojet for forward propellers, but fairey didn’t rlly have a good relationship with de havilland so instead they chose d napier and son and used their eland turboshaft in 1953
rotodyne design Y built around 2 eland N.EI.3 engines - with auxiliary compressors, large section four blade main rotor, projected weight 15000 kg. and also rotodyne z designed with 2 eland N.EI.7 engines and weight 18000kg
design y contraced by ministry of supply april 1953 just one to be built
would be largest transport helicopter of the time max 40 - 50 passengers cruise speed 150 mph range of 250 nautrical miles
final construction done in white waltham
when in construction there was army and raf interest as well as civilian interest
showed off feathered autogyro landings at fanborough and paris air shows
interest growing for intercity transport using heliports, as like a flying bus
jan 1969 bea wanted to buy 6 with maybe up to 20 and issues letter of intent state all demands must be met such as noise levels
raf ordered 12 military version versions
also interest in america and japan. also rumours us army wanted to buy 200
cancelled to cut costs
design of rotodyne
4 bladed rotor
2 napier eland n e l 3 turboprobs mounted under each wing
rotor blades symmetrical aerofoil around loud bearing spar, airfoil made of steel and light alloy cuz of CG concerns
compressed air channelled through 3 steel tubes within blade
air produced by compressors driven through a clutch off the main engines, fed through ducting in the leading edge of the wings and up to rotor head
each engine supplied air for a pair of opposite rotors and compressed air was mixed with fuel and burned
no anti torque correction system required cuz it was a torqueless rotor system
peopeller pitch controlled by rudder pedals for low speed yaw control
propellers provided thrust while rotor autorotated
cockpit controls included a cyclic and collective pitch lever as in a conventional helicopter
transition from helicotper and autogyro taken place at around 60 mph and accomplished by extinguishing tip jets. during autogyro flight, up to half aerodynamic lift provided by wings
General characteristics
Crew: two
Capacity: 40–48 passengers
Length: 58 ft 8 in (17.88 m) of fuselage
Wingspan: 46 ft 6 in (14.17 m) fixed wings
Height: 22 ft 2 in (6.76 m) to top of rotor pylon
Wing area: 475 sq ft (44.1 m2) [47]
Empty weight: 22,000 lb (9,979 kg)
Gross weight: 33,000 lb (14,969 kg)
Fuel capacity: 7,500 lb (3,402 kg)
Powerplant: 2 × Napier Eland N.El.7 turboprops, 2,800 shp (2,100 kW) each [49]
Powerplant: 4 × rotor tip jet , 1,000 lbf (4.4 kN) thrust each [50]
Main rotor diameter: 90 ft 0 in (27.43 m)
Main rotor area: 6,362 sq ft (591.0 m2) Rotor aerofoil: NACA 0015
Blade tip speed: 720 ft/s (220 m/s)
Disc loading: 6.14 lb/ft2 (30 kg/m2)
Propellers: 4-bladed, 13 ft (4.0 m) diameter Rotol propellers
Performance
Maximum speed: 190.9 mph (307.2 km/h, 165.9 kn) speed record [51]
Cruise speed: 185 mph (298 km/h, 161 kn)
Range: 450 mi (720 km, 390 nmi)
Service ceiling: 13,000 ft (4,000 m)