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AEROPLANES; HELICOPTERS (air-cushion vehicles B60V)
Special rules of classification within this subclass

The use of the available Indexing Codes under B64C 1/00- B64C 2230/00 is mandatory for classifying additional information.

Fuselages; Constructional features common to fuselages, wings, stabilising surfaces and the like (aerodynamical features common to fuselages, wings, stabilising surfaces, and the like B64C 23/00 ; flight-deck installations B64D)
Definition statement
This group covers:
  • Overall fuselage shapes and concepts (only documents relating thereto are attributed the symbol B64C 1/00, when the emphasis is on aerodynamic aspects the symbol B64C 1/0009 is attributed).
  • Structural features (including frames, stringers, longerons, bulkheads, skin panels and interior liners).
  • Windows and doors (including hatch covers, access panels, drain masts, canopies and windscreens).
  • Fuselage structures adapted for mounting power plants, floors, integral loading means (such as steps).
  • Attachment of wing or tail units or stabilising surfaces to the fuselage;
  • Relatively movable fuselage parts (for improving pilot's view or for reducing size for storage).
  • Severable/jettisonable parts for facilitating emergency escape.
  • Inflatable fuselage components.
  • Fuselage adaptations for receiving aerials or radomes.
  • Passive cooling of fuselage structures and sound/heat insulation (including isolation mats, and clips for mounting such mats and components such as pipes or cables).
References relevant to classification in this group
This group does not cover:

Aerodynamical features common to fuselages, wings, stabilising surfaces, and the like

Flight-deck installations

Structural features and concepts are attributed the relevant symbol(s) in

Special rules of classification within this group

Structures and components for helicopters falling within this main group and/or appended subgroups are additionally attributed the symbol B64C 27/04.

As an example, a helicopter fuselage with crash absorbing frames would be attributed the symbols B64C 1/062 and B64C 27/04

{Aerodynamic aspects}
Definition statement
This subgroup covers:

Complete fuselage shapes for obtaining aerodynamic effects, e.g. reduced drag.

Frames; Stringers; Longerons;{Fuselage sections}
Informative references
Attention is drawn to the following places, which may be of interest for search:

plastic composite structures, frames, stringers, spars, beams, longerons, stringers and skins (also filament-wounded fuselage shells) (working with plastics)

plastic composite structures, frames, stringers, spars, beams, longerons, stringers and skins (also filament-wounded fuselage shells) (laminates)

{Frames}
Relationship between large subject matter areas

Fuselage bulkheads: B64C 1/10

{Folding or collapsing to reduce overall dimensions, e.g. foldable tail booms (folding or collapsing wings B64C 3/56)}
Relationship between large subject matter areas

Parts of fuselage relatively moveable to reduce overall size for storage: B64C 1/30

References relevant to classification in this group
This subgroup does not cover:

Folding or collapsing wings

{Stringers; Longerons}
Relationship between large subject matter areas

Specifically for wings: B64C 3/182

Synonyms and Keywords

In patent documents the following expressions/words "stringer" is often also used in German.

{Spars}
Relationship between large subject matter areas

Specifically for wings: B64C 3/185

{Interior liners}
Definition statement
This subgroup covers:

Interior liners for aesthetic and/or protective purposes generally following the shape of the fuselage and visible from the inside in the completed fuselage.

References relevant to classification in this group
This subgroup does not cover:

Sound or heat insulating mat assemblies for being positioned adjacent the fuselage outer skin

{Fuselage sections}
Definition statement
This subgroup covers:

Complete fuselage structures (frames, stringers, skin) with the emphasis on structural features.

Relationship between large subject matter areas

Assembling (e.g. moving, positioning) fuselage components (e.g. barrels) into a complete fuselage: B64F 5/0009

Informative references
Attention is drawn to the following places, which may be of interest for search:

Working with plastics: documents describing plastic composite fuselage shells can also be attributed the symbols

Laminates only: when the emphasis is on manufacturing issues rather than the function in an aircraft context

Bulkheads
Definition statement
This subgroup covers:

Aircraft fuselage bulkheads such as pressure bulkheads.

Relationship between large subject matter areas

Fuselage frames: B64C 1/061

References relevant to classification in this group
This subgroup does not cover:

Cabin dividers for class separation

Construction or attachment of skin panels
Relationship between large subject matter areas

Skins specifically for wings: B64C 3/26

Special rules of classification within this group

Aircraft skin structures with integral lightning protection features are concurrently attributed the symbols B64C 1/12 and B64D 45/02 (aircraft lightning protectors).

Windows; Doors; Hatch covers or access panels; Surrounding frame structures; Canopies; Windscreens {accessories therefor, e.g. pressure sensors, water deflectors, hinges, seals, handles, latches, windscreen wipers}(fairings movable in conjunction with undercarriage elements B64C 25/16 ; bomb doors B64D 1/06)
References relevant to classification in this group
This subgroup does not cover:

Fairings movable in conjunction with undercarriage elements

Bomb doors

Informative references
Attention is drawn to the following places, which may be of interest for search:

Cleaning vehicle windows and windscreens

{Doors; surrounding frames}
Informative references
Attention is drawn to the following places, which may be of interest for search:

Door and window locks, handles and latches in general

Door and window operating mechanisms in general

Doors and windows in general

{Cargo doors, e.g. incorporating ramps}
Relationship between large subject matter areas

Other structures integral with the fuselage to facilitate loading (e.g. cargo bays, cranes): B64C 1/22

{Inspection hatches (for engine cowls B64D 29/08)}
References relevant to classification in this group
This subgroup does not cover:

Inspection hatches for engine cowls and nacelles

{Doors between cockpit and cabin}
Relationship between large subject matter areas

Anti-hijacking systems: B64D 45/0015

{Canopies; Windscreens or similar transparent elements}
Informative references
Attention is drawn to the following places, which may be of interest for search:

Windows in trains

Windows in vehicles

{Structure and mounting of the transparent elements in the window or windscreen}
References relevant to classification in this group
This subgroup does not cover:

Pyrotechnics for shattering canopies: B64C 1/32

specially adapted for mounting power plant
Relationship between large subject matter areas

Aircraft characterised by the power plant being within or attached to the fuselage (piston): B64D 27/08; (turboprop): B64D 27/14; (turbofan and turbojet): B64D 27/20

Aircraft characterised by the power plant mounting: B64D 27/26

Floors
Definition statement
This subgroup covers:
  • Construction of aircraft floors.
  • Decompression valves for mounting in the floor region.
specially adapted for freight
Definition statement
This subgroup covers:
  • Aircraft floors specially adapted to freight by virtue of location, strength and/or shape(s).
  • Aircraft floors with anchoring points or rails for freight;
  • Aircraft seat rails.
References relevant to classification in this group
This subgroup does not cover:

Roller trays, Power Drive Units (PDU), clamping devices and other device for moving and/or securing freight

Other structures integral with fuselages to facilitate loading {e.g. cargo bays, cranes(cargo door type ramps B64C 1/1415)}
Relationship between large subject matter areas

Equipment for handling freight in aircraft: B64D 9/00 - B64D 9/003

References relevant to classification in this group
This subgroup does not cover:

Cargo door type ramps

Steps mounted on, and retractable within, fuselages (readily removable B64D 9/00)
References relevant to classification in this group
This subgroup does not cover:

Readily removable steps or stairs

Parts of fuselage relatively movable to reduce overall size for storage
Relationship between large subject matter areas

Fuselage frames enabling folding or collapsing to reduce overall dimensions: B64C 1/062

References relevant to classification in this group
This subgroup does not cover:

Folding or collapsing wings

Severable or jettisonable parts of fuselage facilitating emergency escape (ejector seats B64D 25/10)
Definition statement
This subgroup covers:

Also includes pyrotechnics for shattering canopies.

References relevant to classification in this group
This subgroup does not cover:

Ejection seats

Ejectable capsules

comprising inflatable structural components (connection of valves to inflatable elastic bodies B60C 29/00)
References relevant to classification in this group
This subgroup does not cover:

Connection of valves to inflatable elastic bodies

Inflatable structural components for wings

Varying camber of complete wings or parts thereof by inflatable elements

adapted to receive aerials or radomes (aerials or radomes per se H01Q)
Definition statement
This subgroup covers:

Also covers details of the mounting of the aerial or radome to the fuselage, e.g. hinged connections for maintenance purposes

References relevant to classification in this group
This subgroup does not cover:

Aerials or radomes per se

Constructions adapted to reduce effects of aerodynamic or other external heating{(cooling structural parts of aircrafts with air flow B64D 13/006)}
Definition statement
This subgroup covers:

Cooling of the external fuselage skin

Relationship between large subject matter areas

Specifically for wings: B64C 3/36

References relevant to classification in this group
This subgroup does not cover:

Cooling structural parts of aircraft with air from an air-treatment apparatus (e.g. environmental control system) in the aircraft

Insulation mats or blankets adjacent the fuselage skin

Sound or heat insulation,{e.g. using insulation blankets(insulating elements for vehicles, in general B60R 13/08)}
References relevant to classification in this group
This subgroup does not cover:

Insulating elements for vehicles in general

Cooling of the external fuselage skin

{Arrangement of fasteners specially adapted therefor, e.g. of clips (in vehicles in general B60R 13/0206)}
References relevant to classification in this group
This subgroup does not cover:

Clips for sound or heat insulation in vehicles in general

Informative references
Attention is drawn to the following places, which may be of interest for search:

Fasteners in general

{in combination with supports for lines, e.g. for pipes or cables (arrangement of elements of electric or fluid circuits specially adapted for vehicles, in general B60R 16/00 ; supports for pipes, cables or protective tubing F16L 3/00 ; installations of electric cables or lines in vehicles H02G 3/00)}
References relevant to classification in this group
This subgroup does not cover:

Arrangement of elements of electric or fluid circuits specially adapted for vehicles in general

Supports for pipes, cables or protective tubing

Installations of electric cables or lines in vehicles

Wings (stabilising surfaces B64C 5/00 ; ornithopter wings B64C 33/02)
Definition statement
This group covers:
  • Wing shapes (planform, airfoil profile, frontal aspect).
  • Wing structures (spars, ribs, stringers, skin panels).
  • Wing adaptations for accommodating power plants.
  • Integral fuel tanks in the wings.
  • Passive cooling of wing structures.
  • Adjustment of complete wings or parts thereof (variable sweep, incidence, camber or area; warping, folding for storage purposes).
  • Wings with fixed fences or spoilers.
References relevant to classification in this group
This group does not cover:

Stabilising surfaces

Ornithopter wings

Hang-glider wings (delta-shaped)

Hang-glider wings (parafoil)

Disc- or ring-shaped wings

Flying wings

Informative references
Attention is drawn to the following places, which may be of interest for search:

Working with plastics: documents describing plastic composite fuselage shells can also be attributed the symbols

Laminates only: when the emphasis is on manufacturing issues rather than the function in an aircraft context

{Circulation Control Airfoils}
Definition statement
This subgroup covers:

Example (from US3756540):

media0.png

Frontal aspect
Definition statement
This subgroup covers:

Shape of wing(s) when viewed from the front, e.g. dihedral, anhedral, gull-wing.

Spars; Ribs; Stringers (attaching wing unit to fuselage B64C 1/26)
Relationship between large subject matter areas

For fuselages: B64C 1/06

References relevant to classification in this group
This subgroup does not cover:

Attaching wing unit to fuselage

{Stringers, longerons}
Relationship between large subject matter areas

For fuselages: B64C 1/064

Synonyms and Keywords

The expression "stringer" is often also used in German

{Spars}
Relationship between large subject matter areas

For fuselages: B64C 1/065

Integral or sandwich constructions (layered products or sandwich constructions in general B32B)
References relevant to classification in this group
This subgroup does not cover:

Layered products or sandwich constructions in general

Construction, shape, or attachment of separate skins, e.g. panels
Relationship between large subject matter areas

For fuselages: B64C 1/12

comprising inflatable structural components (connection of valves to inflatable elastic bodies B60C 29/00)
Relationship between large subject matter areas

Inflatable structural components for fuselages: B64C 1/34

References relevant to classification in this group
This subgroup does not cover:

Connection of valves to inflatable elastic bodies

For variation of shape, e.g. camber, for aerodynamical purposes

specially adapted for mounting power plant
Relationship between large subject matter areas

Aircraft characterised by the power plant being within or attached to the wing (piston): B64D 27/06; (turboprop): B64D 27/12; (turbofan and turbojet): B64D 27/18.

Aircraft characterised by the power plant mounting: B64D 27/26.

Integrally-constructed tanks, e.g. for fuel (other aircraft fuel tanks or fuel systems B64D)
References relevant to classification in this group
This subgroup does not cover:

Other aircraft fuel tanks or internal fuel systems

Structures adapted to reduce effects of aerodynamic or other external heating{(cooling structural parts of aircrafts with air flow B64D 13/006)}
Definition statement
This subgroup covers:

Cooling of the external wing skin

Relationship between large subject matter areas

For fuselages: B64C 1/38

References relevant to classification in this group
This subgroup does not cover:

Cooling structural parts of aircraft with air from an air-treatment apparatus (e.g. environmental control system) in the aircraft

by inflatable elements (connection of valves to inflatable elastic bodies B60C 29/00)
Definition statement
This subgroup covers:

Example of variation of camber by inflatable elements (WO0224525):

media1.png

This subgroup also includes documents where additionally wing skins are elastic (morphing; see also Glossary of Terms). Example (EP1442976):

media2.png

References relevant to classification in this group
This subgroup does not cover:

Connection of valves to elastic bodies

Inflatable elements for deicing only (e.g. inflatable leading edge boots)

Glossary of terms
In this subgroup, the following terms (or expressions) are used with the meaning indicated:

Morphing

modification of wing shape by deformation, e.g. elastic skin

by relatively-movable parts of wing structures
Definition statement
This subgroup covers:

Example of variation of camber by movable elements (EP2147856):

media3.jpg

This subgroup also includes documents where additionally wing skins are elastic (morphing; see also Glossary of Terms). Example (WO2009137143):

media4.png

media5.png

References relevant to classification in this group
This subgroup does not cover:

Connection of valves to elastic bodies

Movable wing elements for deicing only

Inflatable elements for deicing only (e.g. inflatable leading edge boots)

Glossary of terms
In this subgroup, the following terms (or expressions) are used with the meaning indicated:

Morphing

modification of wing shape by deformation, e.g. employing elastic skin

by leading or trailing edge flaps (ailerons B64C 9/00)
Definition statement
This subgroup covers:

Integral leading and/or trailing edge parts of wings forming flaps by being movable by (elastic) deformation.

Relationship between large subject matter areas

Bodily displaceable control surfaces: B64C 9/08

References relevant to classification in this group
This subgroup does not cover:

Ailerons

Rudders and hingedly connected flaps

Varying in area (flaps extendable to increase camber B64C 3/44)
References relevant to classification in this group
This subgroup does not cover:

Flaps extendable to increase camber

{by foldable elements}
Definition statement
This subgroup covers:

Folding wings or elements thereof to provide variable aerodynamic lift. Example (GB605075):

media6.jpg

References relevant to classification in this group
This subgroup does not cover:

Folding wings or elements for reducing dimensions for storage purposes

Folding or collapsing to reduce overall dimensions of aircraft
Definition statement
This subgroup covers:

Folding or collapsible wings or elements thereof to reduce overall aircraft size for storage, as typically used by aircraft on aircraft carriers or by trailerable aircraft.

Relationship between large subject matter areas

Relatively movable fuselage parts for reducing overall size for storage: B64C 1/32

References relevant to classification in this group
This subgroup does not cover:

Folding wings or elements thereof to provide variable, aerodynamic lift

provided with fences or spoilers (adjustable for control purposes B64C 9/00)
References relevant to classification in this group
This subgroup does not cover:

Adjustable for control purposes

Stabilising surfaces (attaching stabilising surfaces to fuselage B64C 1/26)
Definition statement
This group covers:

Substantially fixed stabilising structures such as tailplanes, noseplanes and fins. Adjustable stabilising structures only when adjustment is limited and not for primary control purposes, e.g. an adjustable tail plane)

References relevant to classification in this group
This group does not cover:

Attaching stabilising surfaces to fuselage

Tailplanes (fins B64C 5/06)
References relevant to classification in this group
This subgroup does not cover:

Fins

Movable parts

Noseplanes
Relationship between large subject matter areas

Canard-type aircraft: B64C 39/12

Fins (specially for wings B64C 5/08)
References relevant to classification in this group
This subgroup does not cover:

Specially for wings

mounted on or supported by wings
Definition statement
This subgroup covers:

Also some winglets

References relevant to classification in this group
This subgroup does not cover:

Winglets primarily for generating vortices

adjustable
Informative references
Attention is drawn to the following places, which may be of interest for search:

Adjustable to produce different aerodynamic forces for control purposes

for retraction against or within fuselage or nacelle
Informative references
Attention is drawn to the following places, which may be of interest for search:

Adjustable to produce different aerodynamic forces for control purposes

Varying angle of sweep
Relationship between large subject matter areas

Variable wing sweep: B64C 3/40

about spanwise axes
Definition statement
This subgroup covers:

For example horizontal stabilisers with limited movement about a spanwise axis for pitch trim.

in area (attaching stabilising surfaces to fuselage B64C 1/26)
Relationship between large subject matter areas

Varying wing area for variation in lift: B64C 3/54 - B64C 3/546

References relevant to classification in this group
This subgroup does not cover:

Attaching stabilising surfaces to fuselages

Structures or fairings not otherwise provided for
Definition statement
This group covers:
  • Any structure or fairing which is not provided for elsewhere in B64;
  • Sealing strips or fairings between fuselages and stabilising surfaces or wings;
  • Some gap seals for control surfaces (see also B64C 9/02);
  • Helicopter rotor hub fairings (see also the Special Rules of Classification below)
Relationship between large subject matter areas

Mounting control surfaces: B64C 9/02

Special rules of classification within this group

Helicopter rotor hub fairings are concurrently attributed the symbols B64C 7/00 and B64C 27/04

Nacelles
Informative references
Attention is drawn to the following places, which may be of interest for search:

Power plant nacelles

Adjustable control surfaces or members, e.g. rudders (trimming stabilising surfaces B64C 5/10)
Definition statement
This group covers:

Control surfaces such as rudders, ailerons, flaps, elevators, trim/servo tabs and air brakes, as well as their mounting and balancing.

References relevant to classification in this group
This group does not cover:

Trimming stabilising surfaces

Mounting or supporting thereof
Definition statement
This subgroup covers:

Mechanical (hinged, sliding) connections between control surfaces (e.g. aileron) and supporting part (wings).

Gap covers and seals.

Relationship between large subject matter areas

Structures and fairings not otherwise provided for: B64C 7/00

with compound dependent movements
Definition statement
This subgroup covers:

For example flaperons

bodily displaceable (varying camber of wings B64C 3/44)
References relevant to classification in this group
This subgroup does not cover:

Varying camber of wings

one surface adjusted by movement of another, e.g. servo tabs (B64C 9/04 takes precedence; adjusting surfaces of different type or function B64C 9/12)
References relevant to classification in this group
This subgroup does not cover:

Takes precedence

Adjusting surfaces of different type of function

forming slots (boundary-layer control B64C 21/00)
Relationship between large subject matter areas

Fixed leading or trailing edge slots: B64C 3/28

References relevant to classification in this group
This subgroup does not cover:

Boundary-layer control

{at an other wing location than the rear or the front (wings provided with fixed fences or spoilers B64C 3/58)}
References relevant to classification in this group
This subgroup does not cover:

Wings provided with fixed fences or spoilers

at the rear of the wing
Definition statement
This subgroup covers:

Mainly actuating connections and linkages in the region of the flap and the supporting structure (e.g. wing), as well as further details such as covers. Aerodynamic (airflow) aspects are attributed B64C 9/18 (single flaps) or B64C 9/20 (multiple flaps).

This and the associated subgroups also covers trailing edge flaps where no slot is formed (e.g. conventional split flaps)

by single flaps
Definition statement
This subgroup covers:
  • Aerodynamic (airflow) aspects.
  • Single flap in a given chordwise direction.
by multiple flaps
Definition statement
This subgroup covers:
  • Aerodynamic (airflow) aspects.
  • Multiple flaps in a given chordwise direction.
at the front of the wing
Definition statement
This subgroup covers:

Mainly actuating connections and linkages in the region of the flap and the supporting structure (e.g. wing), as well as further details such as covers. Aerodynamic (airflow) aspects are attributed B64C 9/24 (single flaps) or B64C 9/26 (multiple flaps).

This and the associated subgroups also covers leading edge flaps where no slot is formed (e.g. conventional Krüger flaps).

by single flap
Definition statement
This subgroup covers:
  • Aerodynamic (airflow) aspects.
  • Single flap in a given chordwise direction.
by multiple flaps
Definition statement
This subgroup covers:
  • Aerodynamic (airflow) aspects.
  • Multiple flaps in a given chordwise direction.
Air braking surfaces (braking by parachutes B64D 17/80)
Relationship between large subject matter areas

Stabilising surfaces for retraction against or within fuselage or nacelle: B64C 5/12

References relevant to classification in this group
This subgroup does not cover:

Braking by parachutes

collapsing or retracting against or within other surfaces or other members
Relationship between large subject matter areas

Stabilising surfaces for retraction against or within fuselage or nacelle: B64C 5/12

Jet flaps
Definition statement
This subgroup covers:

Example (US4674716):

media7.png

Example (US4398687):

media8.png

Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft (rotors specially adapted for rotorcraft B64C 27/32)
Definition statement
This group covers:
  • Propeller hubs, blades and pitch-changing mechanisms.
  • Propeller vibration absorbing or balancing means.- Arrangements of multiple propellers (e.g. coaxial propellers).
  • Active or passive propeller measures for noise reduction (only such disclosures are attributed the symbol B64C 11/00).
Relationship between large subject matter areas

Helicopter rotor blades with tips for noise reduction: B64C 27/463

References relevant to classification in this group
This group does not cover:

In marine propulsion

In rotors and blades for rotorcraft

In gas turbines (except for some documents relating to propellers of the "unducted fan" or "open rotor" type)

In wind motors/generators

In pumps

In (domestic) ventilation fans

Special rules of classification within this subclass/group

Propellers and associated components are only attributed B64C 11/00 and/or associated subgroup symbols when they are disclosed as being for use with aircraft, generally for producing longitudinal thrust.

{characterised by vibration absorbing or balancing means (for rotorcraft B64C 27/001)}
References relevant to classification in this group
This subgroup does not cover:

For rotorcraft

Solid blades
Definition statement
This subgroup covers:

Mainly wooden blades.

Hollow blades
Definition statement
This subgroup covers:

Mainly metal blades.

Fabricated blades
Definition statement
This subgroup covers:

Mainly composite blades.

Arrangements of or constructional features peculiar to multiple propellers{(B64C 11/306 takes precedence)}
Definition statement
This subgroup covers:

This and the associated subgroups B64C 11/48 and B64C 11/50 can also cover multiple propellers of the "unducted fan" or "open rotor" type.

References relevant to classification in this group
This subgroup does not cover:

Takes precedence

Control systems or transmitting systems for actuating flying-control surfaces, lift-increasing flaps, air brakes, or spoilers
Definition statement
This group covers:
  • Control sticks and yokes, stick shakers, tactile or force-feedback.
  • Mechanical, fluid or electric transmission means to the control surface(s), including use of autopilots, fly-by-wire and fly-by-light.
References relevant to classification in this group
This group does not cover:

Asymmetric flap detection

actuated personally
Definition statement
This subgroup covers:

Control sticks and yokes as well as associated components and details in the region thereof.

Relationship between large subject matter areas

Initiating means in rotorcraft: B64C 27/56

Informative references
Attention is drawn to the following places, which may be of interest for search:

Controlling members in general (e.g. joysticks, handles)

adjustable to suit individual persons
Definition statement
This subgroup covers:

For example longitudinal adjustment of rudder pedal assemblies.

comprising warning devices
Definition statement
This subgroup covers:
  • Vibrating control sticks or yokes ("stick shakers").
  • Tactile cueing
Relationship between large subject matter areas

Artificial feel (e.g. "force feedback") in the transmitting system: B64C 13/46

lockable (locking in position to suit individual persons B64C 13/06)
Definition statement
This subgroup covers:

For example locking a yoke against the dashboard to lock the control surfaces against wind gusts

References relevant to classification in this group
This subgroup does not cover:

Locking in position to suit individual persons

actuated automatically, e.g. responsive to gust detectors
Definition statement
This subgroup covers:

Also covers for example automatic rudder/aileron deflection to counter asymmetric thrust.

Relationship between large subject matter areas

Automatic or condition responsive initiating members in rotorcraft: B64C 27/57.

Fly-by-wire or fly-by-light: B64C 13/503.

Automatic or condition responsive initiating members in aircraft power plant control: B64D 31/06 - B64D 31/12.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Autopilots, stability augmentation systems, gust detection response and yaw dampers per se and with the emphasis on control technology

using automatic pilot
Definition statement
This subgroup covers:

Autopilots, stability augmentation systems, yaw dampers, mostly in the context of the whole or a major part of the transmitting system.

Relationship between large subject matter areas

Fly-by-wire or fly-by-light: B64C 13/503.

using radiated signals
Definition statement
This subgroup covers:

For example radio control

Relationship between large subject matter areas

Remote controlled aircraft (unmanned aerial vehicles): B64C 39/024.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Air traffic control

Remote controlled toy aircraft

readily revertible to personal control
Definition statement
This subgroup covers:

For example unmanned aerial vehicles, which can also be flown by a pilot (e.g. aircraft converted to "drones" or aerial targets).

Transmitting means
Definition statement
This subgroup covers:

Transmitting means between the initiating means (e.g. control stick) and the control surface (e.g. aileron).

Documents relating to power amplifying actuators (fluid, electric, mechanic) in aircraft control surfaces transmitting means are attributed this and the symbols of the associated subclasses when their use, mounting and/or function in the context of the transmitting means as a whole is described.

using toothed gearing
Definition statement
This subgroup covers:

Only intermeshing toothed gearing.

using fluid pressure
Definition statement
This subgroup covers:

Documents disclosing duplication or stand-by provisions (cf. B64C 13/42), overriding of personal controls (cf. B64C 13/44) or artificial feel (force feedback; cf. B64C 13/46) are attributed these symbols even if the power amplification is not by fluid pressure.

Also covers some hydraulic circuits.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Hydraulic circuits

overriding of personal controls; with automatic return to inoperative position
Relationship between large subject matter areas

Automatically activated personal initiating means: B64C 13/16 - B64C 13/22.

Automatic or condition responsive personal initiating members in rotorcraft: B64C 27/57.

Automatic or condition responsive initiating members in aircraft power plant control: B64D 31/06 - B64D 31/12.

with artificial feel
Relationship between large subject matter areas

Personally activated initiating means with warning devices (e.g. "stick shakers", tactile cueing): B64C 13/10.

{Fly-by-Wire}
Definition statement
This subgroup covers:

Also covers fly-by-light.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Fly-by-wire or fly-by-light technology with the emphasis on control technology

Attitude, flight direction, or altitude control by jet reaction
Definition statement
This group covers:

Control of aircraft by jet(s) generated by any means (including propellers).

References relevant to classification in this group
This group does not cover:

Vertical take-off and landing (VTOL) aircraft

the jets being propulsion jets
Definition statement
This subgroup covers:

Thrust vectoring.

Relationship between large subject matter areas

See also B64D 33/04 for arrangements of exhaust outlets or jet pipes.

the power plant being tiltable
Definition statement
This subgroup covers:

Thrust vectoring obtained by rotating the power unit as a whole.

the jets being other than main propulsion jets (jet flaps B64C 9/38)
Definition statement
This subgroup covers:

Aircraft control obtained by using dedicated jets.

References relevant to classification in this group
This subgroup does not cover:

Jet flaps

Boundary layer control

Aircraft stabilisation not otherwise provided for
Definition statement
This group covers:

This group contains documents concerning aircraft stabilisation which are not classified in e.g. B64C 5/00.

by gravity or inertia-actuated apparatus
Definition statement
This subgroup covers:

Stability control by e.g. shifting the CoG

by pendular bodies
Definition statement
This subgroup covers:

Pendulum stability is achieved when the centre of lift is above the CoG of the aircraft, or by using a dedicated pendulum.

by gyroscopic apparatus (automatic pilot control B64C 13/18)
Definition statement
This subgroup covers:

A gyro is used to directly stabilize the aircraft.

References relevant to classification in this group
This subgroup does not cover:

Automatic pilot control

by ballast supply or discharge (for lighter-than-air aircraft B64B)
Relationship between large subject matter areas

See B64B for lighter-than-air aircraft.

Transferring fuel to adjust trim
Definition statement
This subgroup covers:

Displacement of the CoG, aimed at reaching a desired trim condition, is achieved by fuel transfer between the internal tanks of the aircraft.

Aircraft control not otherwise provided for
Definition statement
This group covers:

Control of aircraft by using e.g. gyroscopic effects, vortex generators, moving aircraft parts and/or surfaces not provided for in B64C 9/00 or, in general, systems not provided for in B64C 13/00 or B64C 15/00.

Influencing air-flow over aircraft surfaces by affecting boundary-layer flow (boundary-layer control in general F15D)
Definition statement
This group covers:

Any device/method operating within the airfoil boundary layer to influence the air flow around the airfoil, especially in order to control boundary layer separation.

Relationship between large subject matter areas

Classify also in B64C 23/00 if necessary.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Boundary layer control in general

Hydrodynamic or hydrostatic features

by use of slot, ducts, porous areas, or the like
Definition statement
This subgroup covers:

Cavities, slots, holes along a structural surface whereby the net flow is null.

{for simultaneous blowing and sucking}
Definition statement
This subgroup covers:

Fluid is blown and sucked

References relevant to classification in this group
This subgroup does not cover:

Takes precedence

for blowing (B64C 21/08 takes precedence)
Definition statement
This subgroup covers:

Fluid is only blown.

References relevant to classification in this group
This subgroup does not cover:

Takes precedence

for sucking (B64C 21/08 takes precedence)
Definition statement
This subgroup covers:

Fluid is only sucked

References relevant to classification in this group
This subgroup does not cover:

Takes precedence

adjustable
Definition statement
This subgroup covers:

Fluid flow is explicitly adjustable by e.g. valves, variable aperture or slot area, variable pump action or fluid pressure.

References relevant to classification in this group
This subgroup does not cover:

Always classify, in the case or blown and/or sucked fluid, also in B64C 21/025 or B64C 21/04 or B64C 21/06.

using other surface properties, e.g. roughness
Special rules of classification within this group

The properties referred to are e.g. roughness or riblets.

Influencing air-flow over aircraft surfaces, not otherwise provided for
Definition statement
This group covers:

Air-flow over aircraft surfaces influenced e.g. by magnetic, electric or piezoelectric panels, by static charges, by ultrasound, by special shape, by rotating bodies.

Relationship between large subject matter areas

Influencing boundary layer: B64C 21/00.

References relevant to classification in this group
This group does not cover:

Attitude control by jet reaction

{by other means not covered by groups B64C 23/02 to B64C 23/08 , e.g. by electric charges, magnetic panels, piezoelectric elements, static charges or ultrasounds}
Relationship between large subject matter areas

Also B64C 21/00 if boundary layer explicitly involved.

by means of rotating members of cylindrical or similar form
Relationship between large subject matter areas

Circulation control airfoils: B64C 3/141

Using Magnus effect: B64C 23/08

References relevant to classification in this group
This subgroup does not cover:

The rotating body has exclusively a cylindrical form.

by generating shock waves
Definition statement
This subgroup covers:

Shock wave modification devices and methods. Reduction of shock drag as main searched technical effect.

Relationship between large subject matter areas

Supersonic type aircraft

Specific airfoil shape

by generating vortices
Relationship between large subject matter areas

Fins mounted on wings

{at the wing tip, e.g. winglets, splines}
Definition statement
This subgroup covers:

Devices of any type (winglets, fins, turbines, splines) arranged at the wing tip.

Relationship between large subject matter areas

Helicopter rotor blades tips: B64C 27/463

Fins on wings: B64C 5/08

using Magnus effect
Definition statement
This subgroup covers:

Devices having a cylindrical or spherical form which explicitly generate a force by using the Magnus effect.

Relationship between large subject matter areas

Circulation control airfoils: B64C 3/141

Alighting gear (air-cushion alighting gear B60V 3/08)
Definition statement
This group covers:
  • Any structure that supports/arrest the aircraft on a surface.
  • Wheels supported by shock absorbers, skis, floats, pontoons or combinations thereof.
  • Braking systems specific for aircraft.
  • Arrester hooks. Control/actuating systems thereof.
References relevant to classification in this group
This group does not cover:

Air-cushion alighting gear

Arrangement or disposition on aircraft
Definition statement
This subgroup covers:

Arrangement or disposition on aircraft with respect to the aircraft structure. Inter-relationship thereof.

Fairings movable in conjunction with undercarriage elements
Definition statement
This subgroup covers:

Systems for opening and closing undercarriage door bays. Fairings in general whose movement is performed in conjunction with the landing gear movement.

Operating mechanisms
Definition statement
This subgroup covers:

General methods and systems for operating unspecified aircraft landing gears.

mechanical
Definition statement
This subgroup covers:

Operating mechanisms comprising levers, pulleys, cables, gear wheels and/or characterised essentially by the kinematic aspects of the retracting/folding displacement.

Relationship between large subject matter areas

Locking mechanisms: B64C 25/26

fluid
Definition statement
This subgroup covers:

Operating mechanisms characterised by the control circuits/operating actuators being hydraulic or pneumatic.

electric
Definition statement
This subgroup covers:

Operating mechanisms characterised by using electrical or electromagnetic actuators.

Control or locking systems therefor
Definition statement
This subgroup covers:

Uplock assemblies for retaining and releasing landing gear systems, bracing locking devices, undercarriage locking and unlocking systems in general.

Relationship between large subject matter areas

Operating systems, mechanical aspects: B64C 25/20

with indicating or warning devices
Definition statement
This subgroup covers:

Ground lock detection devices, landing gear warning systems, landing gear verification systems.

Relationship between large subject matter areas

Devices specially adapted to indicate the position of a movable element of the aircraft, e.g. landing gear

emergency actuated
Definition statement
This subgroup covers:

Emergy release/actuation actuators and relevant control.

Relationship between large subject matter areas

Devices specially adapted to indicate the position of a movable element of the aircraft, e.g. landing gear

characterised by the ground or like engaging elements (arrester hooks B64C 25/68)
References relevant to classification in this group
This subgroup does not cover:

Arrester hooks: B64C 25/68

Arrangements or adaptations of wheels, tyres, or axles in general (construction of wheels or axles B60B ; construction of tyres in general B60C)
Informative references
Attention is drawn to the following places, which may be of interest for search:

Construction of wheels or axles

Construction of tyres

Endless-track type
Definition statement
This subgroup covers:

media9.png

the elements being rotated before touch-down
Definition statement
This subgroup covers:

Pre-landing acceleration devices for aircraft wheels, generally passive.

{Powered wheels, e.g. for taxing}
Definition statement
This subgroup covers:

Motorised wheels, any type of motor or installation thereof.

Arrangements or adaptations of brakes (the ground braking force being regulated, at least in part, by a speed condition, e.g. acceleration or deceleration of the ground engaging alighting gear, B60T 8/32)
References relevant to classification in this group
This subgroup does not cover:

The ground braking force being regulated, at least in part, by a speed condition, e.g. acceleration or deceleration of the ground engaging alighting gear

Informative references
Attention is drawn to the following places, which may be of interest for search:

Vehicle brake control systems or parts thereof

{Braking devices acting by reaction of gaseous medium (B64C 25/426 takes precedence; using rockets B64D 27/023)}
References relevant to classification in this group
This subgroup does not cover:

Takes precedence

Using rockets

Thrust reversers

Special rules of classification within this group

Originally meant for covering e.g. thrust reversers it is no longer used in this respect.

Thrust reversers shall not be classified in B64C 25/423.

{Braking devices providing an automatic sequence of braking}
Definition statement
This subgroup covers:

Braking methods/systems wherein the braking sequence is controlled by an electronic control unit and performed in accordance with predetermined steps, including controlling the brakes independently, to achieve a predetermined target, e.g. to achieve a predetermined deceleration rate or to optimize the braking force.

Actuating mechanisms
Definition statement
This subgroup covers:

Regulators, disks, valves.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Arrangements of brakes specially adapted for aircraft

Brake regulators for preventing skidding or aircraft somersaulting{(anti-skidding regulators; electric or electronic controllers therefor B60T 8/1703)}
Informative references
Attention is drawn to the following places, which may be of interest for search:

Anti-skidding regulators; electric or electronic controllers therefor

Steerable undercarriages; Shimmy damping (steering devices applicable to land vehicles B62D)
Definition statement
This subgroup covers:

Undercarriages whcih can be steered, relevant control systems and actuators, steering angle warning systems.

Relationship between large subject matter areas

When operated in combination with towing vehicles: B64F 1/22

{Shimmy damping}
Definition statement
This subgroup covers:

Wheel shimmy is a condition in which the landing gear wheel or wheels oscillate from side to side along a straight line parallel to the direction of travel of the aircraft. Documents concerning this problem are classified here.

Skis or runners
Definition statement
This subgroup covers:

Skis, skids, runners, various ground engaging structures, especially suitable for helicopters.

Relationship between large subject matter areas

Safety devices for helicopters: B64C 27/006

inflatable (connection of valves to inflatable elastic bodies B60C 29/00)
Definition statement
This subgroup covers:

media10.png

Arrangements or adaptations of shock-absorbers or springs (shimmy dampers B64C 25/50 ; vehicle suspension arrangements in general B60G ; shock absorber per se F16F)
Relationship between large subject matter areas

Shimmy dampers: B64C 25/505

Informative references
Attention is drawn to the following places, which may be of interest for search:

Suspensions in generals

Shock absorbers per se

Oleo legs
Definition statement
This subgroup covers:

Any shock absorber comprising hydraulic or pneumatic cylinders.

Convertible alighting gear; Combinations of different kinds of ground or like engaging elements
Definition statement
This subgroup covers:

The ground engaging elements can be converted from e.g. wheeled to floats or skis and vice-versa depending on the specific landing surface.

Arrester hooks (arresting gear, e.g. on aircraft carriers B64F)
Definition statement
This subgroup covers:

Comprises capturing/retrieving systems on aircraft.

Relationship between large subject matter areas

Arresting/launching/towing gears: B64F 1/02, B64F 1/04

Rotorcraft; Rotors peculiar thereto (alighting gear B64C 25/00)
Definition statement
This group covers:
  • Vibration damping, safety devices and rotor tracking/balancing devices for rotorcraft rotors.
  • Gyroplanes and autogyros, and rotors therefor.
  • Helicopters, flying platforms and compound rotorcraft/helicopters.
  • Rotors (including tail rotors), hubs, blades and rotor blade adjustment control (including flying controls, such as collective and pitch levers).
References relevant to classification in this group
This group does not cover:

Alighting gear for rotorcraft

{Vibration damping devices}
Definition statement
This subgroup covers:

Vibration or noise damping by means of isolators on the rotor head, suspended masses, actuators acting on the complete rotor assembly or active noise cancellation.

References relevant to classification in this group
This subgroup does not cover:

Noise or vibration damping by specifically shaped rotor blade tips

Noise or vibration damping by individual rotor blade control using flaps on the blades

Noise or vibration damping by individual control of rotor blades using individual actuators

{Safety devices}
Definition statement
This subgroup covers:

For example wire cutters or detectors, helicopter-specific use of airbags, distance sensors for tail booms, rotor blade crack detection, tail rotor guards, emergency tail rotor drives or emergency anti-torque means.

Relationship between large subject matter areas

Aircraft emergency devices: B64D 25/00

{Rotors tracking or balancing devices}
Definition statement
This subgroup covers:

For example rotor blade tip weights or rotor blade tracking apparatus and methods.

{Rotor or rotor head construction (for helicopters B64C 27/32)}
References relevant to classification in this group
This subgroup does not cover:

For helicopters

Helicopters
Special rules of classification within this group

The following helicopter components are not attributed any of the symbols in B64C 27/00 but only the symbol B64C 27/04 and one of the following associated, applicable symbols:

Fuselage structures and windows:B64C 1/00 - B64C 1/40

Rotor hub fairings:B64C 7/00

Underslung loads: B64D 1/22

Mounting cameras: B64D 47/08

Rotorcraft characterised by having shrouded rotors, e.g. flying platforms
Relationship between large subject matter areas

Shrouded propellers: B64C 11/001

Unmanned aerial vehicles: B64C 39/024

References relevant to classification in this group
This subgroup does not cover:

With wings

with forward-propulsion propellers pivotable to act as lifting rotors
Definition statement
This subgroup covers:

Mostly tiltrotor aircraft requiring an anti-torque tail rotor.

References relevant to classification in this group
This subgroup does not cover:

Takes preference

Rotors (features common to rotors and propellers B64C 11/00)
Definition statement
This subgroup covers:

Rotor hubs, special or unconventional rotors.

Relationship between large subject matter areas

Propeller hubs: B64C 11/02

References relevant to classification in this group
This subgroup does not cover:

Features common to rotors and propellers

having flexing arms
Definition statement
This subgroup covers:

Flexbeams for rigid rotors.

Relationship between large subject matter areas

Root attachment to rotor head: B64C 27/48

having elastomeric joints
Definition statement
This subgroup covers:

Elastomeric joints for articulated rotors

Informative references
Attention is drawn to the following places, which may be of interest for search:

Springs

having articulated joints (B64C 27/33 , B64C 27/35 take precedence)
References relevant to classification in this group
This subgroup does not cover:

Take preference

Aerodynamic features{(B64C 27/463 takes precedence)}
References relevant to classification in this group
This subgroup does not cover:

Takes preference

Constructional features{(B64C 27/463 takes precedence)}
Relationship between large subject matter areas

Constructional features for propeller blades: B64C 11/20 - B64C 11/26

References relevant to classification in this group
This subgroup does not cover:

Takes preference

Rotors for wind motors

Root attachment to rotor head
Relationship between large subject matter areas

Root attachment of propeller blades: B64C 11/04 - B64C 11/12

Blades foldable to facilitate stowage of aircraft
Relationship between large subject matter areas

Foldable propeller blades: B64C 11/28

For autogyros: B64C 27/022

{Damping of blade movements}
Relationship between large subject matter areas

Transmitting means for controlling lead-lag movement of rotor blades: B64C 27/635

Tilting of rotor bodily relative to fuselage (of see-saw type construction B64C 27/43)
References relevant to classification in this group
This subgroup does not cover:

See-saw type construction

Initiating means, e.g. actuated personally
Definition statement
This subgroup covers:

Cyclic sticks and collective levers as well as associated components and details in the region thereof.

Relationship between large subject matter areas

Personal control surface initiating means in aeroplanes: B64C 13/04

Informative references
Attention is drawn to the following places, which may be of interest for search:

Controlling members in general (e.g. joysticks, handles)

automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust
Definition statement
This subgroup covers:

Can also cover maintaining hover position or attitude.

Relationship between large subject matter areas

Automatic or condition responsive initiating members in aeroplanes: B64C 13/16 - B64C 13/22

Fly-by-wire or fly-by-light: B64C 13/503

Automatic or condition responsive initiating members in aircraft power plant control: B64D 31/06 - B64D 31/12

Informative references
Attention is drawn to the following places, which may be of interest for search:

With the emphasis on control technology

Transmitting means
Definition statement
This subgroup covers:

Transmitting means downstream of the cyclic stick and the collective lever.

Relationship between large subject matter areas

Transmitting means for aeroplanes: B64C 13/24 - B64C 13/503

Means acting on blades
Definition statement
This subgroup covers:

Individual blade control by acting directly on the blade, e.g. by a separate actuator for each blade.

References relevant to classification in this group
This subgroup does not cover:

Individual rotor blade control using flaps on the blades

Aircraft capable of landing or taking-off vertically (attitude, flight direction, or altitude control by jet reaction B64C 15/00 ; rotorcraft B64C 27/00 ; air-cushion vehicles B60V)
Definition statement
This group covers:

Vertical take-off and landing (VTOL) aircraft, e.g. of the BAe Harrier or Tiltrotor types.

References relevant to classification in this group
This group does not cover:

Attitude, flight direction or altitude control by jet reaction

Rotorcraft

Air-cushion vehicles

{the propellers being fixed relative to the fuselage}
References relevant to classification in this group
This subgroup does not cover:

Without wings

{the propellers being tiltable relative to the fuselage}
References relevant to classification in this group
This subgroup does not cover:

With anti-torque means (e.g. tail rotor)

{with horizontal jet and jet deflector}
Definition statement
This subgroup covers:

Also covers horizontal propeller/blower and airflow deflector.

Supersonic-type aircraft
Definition statement
This group covers:
  • Complete aircraft or structural features described as facilitating supersonic/hypersonic flight, including special shapes and planforms of complete aircraft.
  • Sonic boom alleviation means and methods.
References relevant to classification in this group
This group does not cover:

Airfoil profiles

Aircraft intended to be sustained without power plant; Powered hang-glider-type aircraft; Microlight-type aircraft
Definition statement
This group covers:
  • Gliders/sailplanes, accessories therefor when they cannot be classified elsewhere.- Microlight, ultralight and Light Sport Aircraft, and safety devices therefore (e.g. Ballistic Rescue Systems).
  • Hang-gliders (e.g. of the "Rogallo" type).
  • Man-powered (e.g. using pedals to drive a propeller) aircraft.
  • Kites.
Gliders, e.g. sailplanes (hang-gliders B64C 31/028)
Definition statement
This subgroup covers:

Also covers accessories for gliders (e.g. insect removal from leading edges) which cannot be adequately classified elsewhere.

Hang-glider-type aircraft; Microlight-type aircraft
Definition statement
This subgroup covers:

Mainly very simple and light, powered single or two-seat aircraft with an open frame fuselage, but also covers light, single or two-seat aircraft when the emphasis is on low weight and simplicity, and/or when described as an "ultralight", "microlight" or "light sport aircraft".

Example (US4548371)

media11.jpg

Example (WO2004094228):

media12.png

Example, "Trike" or weight-shift controlled microlight (DE3346860):

media13.png

Example; powered hang-glider (GB2164614):

media14.png

References relevant to classification in this group
This subgroup does not cover:

Unpowered hang-gliders with delta-shaped wings ("Rogallo"-type)

Informative references
Attention is drawn to the following places, which may be of interest for search:

Hang-glider-type aircraft with delta wings

Special rules of classification within this group

Attribute the symbol B64C 31/032 as well when details of a delta-shaped wing are also disclosed.

Glossary of terms
In this subgroup, the following terms (or expressions) are used with the meaning indicated:

Microlight or ultralight

Also covers the type of aircraft known in the USA as "Light Sport Aircraft"

Synonyms and Keywords

In patent documents the following abbreviations are often used:

ULM

Avion ultra-légèr motorisé

In patent documents the following expressions/words"ultralight aircraft", "light sport aircraft", "microlight aircraft" and "ultraleichtflugzeug"(german) are often used as synonym.

In patent documents the following expressions/words "trike"(english, german), "weight-shift control" and "gewichtskraftgesteuert" (german) are often used as synonym.

{Safety devices}
Definition statement
This subgroup covers:

For example (ballistic) parachute rescue systems specially adapted to microlight aircraft or hang-gliders.

Example:

media15.png

Relationship between large subject matter areas

Aircraft emergency apparatus comprising ejectable capsules or even whole aircraft with a rescue parachute: B64D 25/12

having delta shaped wing
Definition statement
This subgroup covers:

Mainly unpowered hang-gliders with rigid, delta-shaped wings of the "Rogallo"-type.

Example (FR2286055):

media16.png

Also covers powered, microlight aircraft when comprising details of such wings.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Powered microlight-type aircraft with such wings

having parachute-type wing (parachutes B64D 17/00)
Definition statement
This subgroup covers:

Microlight aircraft - mainly powered - with a parachute or parafoil type wing attached to a rigid/substantial structure (e.g. framework or rigid seat). Also covers backpack-type powerplants for paragliders.

Example (EP0278784):

media17.png

Example; backpack-powerplant (FR2606736):

media18.png

References relevant to classification in this group
This subgroup does not cover:

Parachutes

Paragliders

Man-powered aircraft (ornithopters B64C 33/00)
Definition statement
This subgroup covers:

Propulsive power produced by the pilot, e.g. pedals connected to a propeller.

References relevant to classification in this group
This subgroup does not cover:

Ornithopters

Kites (hang-gliders B64C 31/028 ; toy aspects A63H 27/08 ; towed targets F41J{ for propelling boats B63H 9/0685 ; for propelling wind driven boards, control means and harnesses therefor B63B 35/7976})
References relevant to classification in this group
This subgroup does not cover:

Toy aspects

Propelling wind driven boats, control means and harnesses therefor ("kite surfing")

Propelling boats

Hang-gliders

Towed targets

Advertising with kites

Ornithopters
Definition statement
This group covers:

All aircraft which fly by flapping the wings.

References relevant to classification in this group
This group does not cover:

Toy aircraft propelled by flapping of wings

Wings; Actuating mechanisms therefor
Definition statement
This subgroup covers:

Illustrative example of subject matter classified in this group.

media19.png

Flying-boats; Seaplanes (alighting gear B64C 25/00)
Definition statement
This group covers:

The word "seaplane" is used to describe two types of air/water vehicles: the floatplane and the flying boat. A floatplane has slender floats, mounted under the fuselage. Two floats are common, but other configurations are possible. Only the floats of a floatplane normally come into contact with water. The fuselage remains above water. In a flying boat, the main source of buoyancy is the fuselage, which acts like a ship's hull in the water. Most flying boats have small floats mounted on their wings to keep them stable.

Relationship between large subject matter areas

Floats: B64C 25/54

{with propellers, rudders or brakes acting in the water}
Definition statement
This subgroup covers:

Comprising devices acting in the water to generate thrust and/or slow down and/or steer the aircraft (e.g. propellers, jets, rudders).

{with lift generating devices}
Definition statement
This subgroup covers:

Comprising lift generating devices which are peculiar to the shape of a seaplane.

{Amphibious sea planes}
Definition statement
This subgroup covers:

Aircraft suitable for ground and water take-off and landing.

Convertible aircraft (vehicles capable of travelling in or on different media B60F)
Definition statement
This group covers:

Combined road (and/or water) /air vehicles usually provided with wheels (and/or e.g. pontoons) and in-air propelling/thrust means.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Vehicles convertible into aircraft

Flying units formed by separate aircraft (towing, air-refuelling, or aircraft-carrying aircraft B64D)
Definition statement
This subgroup covers:

Flying units wherein (possibly after an initial engagement phase) the multitude of (possibly different) flying vehicles (possibly including ground and/or water vehicles and/or dedicated units) are permanently connected.

Relationship between large subject matter areas

In-flight refuelling : B64D 39/00

Aircraft adaptations to facilitate towing or being towed: B64D 3/00

Aircraft transported by aircraft: B64D 5/00

Aircraft having multiple fuselages or tail booms: B64C 39/04

Aircraft not otherwise provided for
Definition statement
This group covers:

Essentially all the flying vehicles not classified in one of the previous groups, highly unconventional aircraft.

{Flying saucers}
Definition statement
This subgroup covers:

Flying vehicles characterised by sustainment without aerodynamic lift, often flying disks having a UFO-shape.

Relationship between large subject matter areas

Rotorcraft characterised by having shrouded rotors, e.g. flying platforms: B64C 27/20

References relevant to classification in this group
This subgroup does not cover:

Aircraft having annular wings with radial airflow

Informative references
Attention is drawn to the following places, which may be of interest for search:

Inertia motors

{with wings, paddle wheels, bladed wheels, moving or rotating in relation to the fuselage (rotorcraft B64C 27/00 , ornithopters B64C 33/00)}
Definition statement
This subgroup covers:

Example taken from GB2403460

media20.png

Relationship between large subject matter areas

Using Magnus effect:B64C 23/08

Paddle wheels: B64C 11/006

{Tethered aircraft}
References relevant to classification in this group
This subgroup does not cover:

Captive toy aircraft

{of the remote controlled vehicle type, i.e. RPV}
Definition statement
This subgroup covers:

UAVs, UCAVs, drones, remotely piloted flying vehicles in general

References relevant to classification in this group
This subgroup does not cover:

Controlling aircraft by using radiated signal

Model aircraft

Model helicopters

{for use as personal propulsion unit}
Definition statement
This subgroup covers:

Devices including rotors, wings, propellers, turbojets to be "worn" by a user.

Relationship between large subject matter areas

Parachutes: B64D 17/00

Ornithopters: B64C 33/00

Rotary wing parachutes: B64D 19/02

{Micro-sized aircraft}
Definition statement
This subgroup covers:

MAVs (micro aerial vehicles), usually for military purposes, any maximum dimension of which does not exceed 15 cm (6 inches).

having multiple fuselages or tail booms
Relationship between large subject matter areas

Flying units formed by separate aircraft: B64C 37/02

having disc- or ring-shaped wings{(B64C 39/001 takes precedence)}
Definition statement
This subgroup covers:

Illustrative example of subject matter classified in this group.

media21.png

Relationship between large subject matter areas

Aircraft capable of landing or taking-off vertically, having its flight directional axis vertical when landed: B64C 29/02

References relevant to classification in this group
This subgroup does not cover:

Takes precedence

{with radial airflow}
Definition statement
This subgroup covers:

An example taken from GB2471663

media22.png

Relationship between large subject matter areas

Flying saucers: B64C 39/001

Informative references
Attention is drawn to the following places, which may be of interest for search:

Coanda effect flying vehicles

--

{having channel wings}
Definition statement
This subgroup covers:

Illustrative example of subject matter classified in this group.

media23.png

Relationship between large subject matter areas

Frontal shape of wing: B64C 3/16

{having multiple wings joined at the tips}
Definition statement
This subgroup covers:

Illustrative example of subject matter classified in this group.

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Relationship between large subject matter areas

Frontal shape of wing: B64C 3/16

having multiple wings{(B64C 39/06 takes precedence)}
Relationship between large subject matter areas

Canard-type aircraft: B64C 39/12

References relevant to classification in this group
This subgroup does not cover:

Takes precedence

All-wing aircraft{(B64C 39/001 takes precedence)}
Definition statement
This subgroup covers:

This group includes e.g. the BWB (blended-wing-body)-type aircraft

References relevant to classification in this group
This subgroup does not cover:

Takes precedence

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Last Modified: 10/11/2013