aeroplane aeroplanes aviate aviation aviator aviators flight fly flying pilot pilots plane planes cockpit dial dials instrumentation instruments aid aircraft airfield airplane assist breeze bright climate communication conditions direction indicate indicator orange point pointer sock speed weather wind windsock anchored balloon cable checks circular colors colours control controlled duty-pilot engineers fabric filled flight-operation gondola height helium helium-balloon high inspected inspections large limited mesh metal-cable metal-line monitored monitoring motion movement net passengers piloted registered ride safe safety secure secured sights sightseeing Singapore tethered tourists views weather-limits wind-limits