| B | SK | PERFORMING OPERATIONS; TRANSPORTING |
| B64 | KL | AIRCRAFT; AVIATION; COSMONAUTICS |
| B64B | UKL | LIGHTER-THAN-AIR AIRCRAFT (ground installations for aircraft in general B64F) |
| B64B 1/00 | HGR | Lighter-than-air aircraft |
| B64B 1/02 | UGR1 | |
| B64B 1/04 | UGR2 | | . . | the profile being maintained by ties or cords connecting opposite surfaces |
|
| B64B 1/06 | UGR1 | | . | Rigid airships; Semi-rigid airships (B64B 1/58 takes precedence) |
|
| B64B 1/08 | UGR2 | | . . | Framework construction |
|
| B64B 1/10 | UGR2 | | . . | Tail unit construction (B64B 1/12 takes precedence) |
|
| B64B 1/12 | UGR2 | | . . | Movable control surfaces |
|
| B64B 1/14 | UGR2 | |
| B64B 1/16 | UGR3 | |
| B64B 1/18 | UGR3 | | . . . | Attachment to structure |
|
| B64B 1/20 | UGR2 | | . . | provided with wings or stabilising surfaces |
|
| B64B 1/22 | UGR2 | | . . | Arrangement of cabins or gondolas |
|
| B64B 1/24 | UGR2 | | . . | Arrangement of propulsion plant (B64B 1/34 takes precedence) |
|
| B64B 1/26 | UGR3 | |
| B64B 1/28 | UGR3 | |
| B64B 1/30 | UGR3 | | . . . | Arrangement of propellers |
|
| B64B 1/32 | UGR4 | |
| B64B 1/34 | UGR4 | | . . . . | of lifting propellers |
|
| B64B 1/36 | UGR2 | | . . | Arrangement of jet reaction apparatus for propulsion or directional control |
|
| B64B 1/38 | UGR2 | | . . | Controlling position of centre of gravity |
|
| B64B 1/40 | UGR1 | |
| B64B 1/42 | UGR2 | | . . | Construction or attachment of stabilising surfaces |
|
| B64B 1/44 | UGR2 | | . . | adapted to maintain predetermined altitude |
|
| B64B 1/46 | UGR2 | | . . | associated with apparatus to cause bursting |
|
| B64B 1/48 | UGR3 | | . . . | to enable load to be dropped by parachute |
|
| B64B 1/50 | UGR2 | |
| B64B 1/52 | UGR3 | | . . . | attaching trailing entanglements |
|
| B64B 1/54 | UGR3 | | . . . | connecting two or more balloons in superimposed relationship |
|
| B64B 1/56 | UGR3 | | . . . | stabilised by rotary motion |
|
| B64B 1/58 | UGR1 | | . | Arrangements or construction of gas-bags; Filling arrangements (connection of valves to inflatable elastic bodies B60C 29/00) |
|
| B64B 1/60 | UGR2 | | . . | Gas-bags surrounded by separate containers of inert gas |
|
| B64B 1/62 | UGR2 | | . . | Controlling gas pressure, heating, cooling, or discharging gas |
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| B64B 1/64 | UGR2 | | . . | Gas-valve operating mechanisms |
|
| B64B 1/66 | UGR1 | | . | Mooring attachments (mooring masts B64F 1/14) |
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| B64B 1/68 | UGR1 | |
| B64B 1/70 | UGR1 | |