Airliners are divided into three categories:
(i) Short range which operates at: distance of 1,000 km ≤ R ≤ 6,500 km, Cruise mach of 0.75 ≤ Mcr ≤ 0.80, and Flight height/Altitude [Hcr] = 10 km or 35,000 feet above the earth.
(ii) Medium range which operates at: distance of 6,500 km ≤ R ≤ 10,000 km, Cruise mach of 0.8 ≤ Mcr ≤ 0.86, and Flight height/Altitude [Hcr] = 12 km above the earth.
(iii) Long range which operates at: distance of 10,000 km ≤ R ≤ 17,000 km, Cruise mach of 0.8 ≤ Mcr ≤ 0.86, and Flight height/Altitude [Hcr] = 12 km above the earth.
Most airliners have similar features which include fuselage sizing, powerplant and wing configuration optimization.
Airliner design trends include families which entails stretching and shrinking an existing aircraft to produce new baseline airliners.
Commonalities in airliner trends could be achieved through design or operational modifications.
Key design considerations for future airliners include, Wings with large aspect ratio, Natural laminar flow and tradeoffs.
Solutions to consider for future airliners include, strut-based wing, blend wing body, and fuel burn.
The special features of a supersonic transport aircraft include:
(i) Slender ‘Ogive’ Delta wings (shape of wings).
(ii) CG (center of gravity) control by fuel transfer between various tanks
(iii) Drooping nose
(iv) Fly-by-wire flight control system (FCS).
Some airliner shapes to expect in the future includes the Maverics and Flying V concepts.
Maintaining Laminar Flow in an aircraft for a large fraction of the aircraft surface has been the holy grail of aeronautics.
Designs for Natural Laminar Flow (NLF) employ:
(i) A careful wing design process.
(ii) Altering the wing cross-section -> Charge pressure gradient.
Achieving SUPERSONIC Natural Laminar Flow will require wing designs with low sweep and sharp supersonic leading edge (L.E).
Cargo aircraft are also known as freighters could be:
(i) Ab-initio dedicated freighters.
(ii) Joint civil-military aircargo aircraft.
(iii) Products of passenger or military aircraft which are converted for cargo or logistics purposes towards the end of their lifespan.
(i) General Aviation Aircraft - For self usage, non-commercial flights.
(ii) Personal Aviation Aircraft - Relaxed certifications, mission specific designs.
Military Aircraft could be:
(i) Fighter Aircraft - sub-divided into Class I (interceptors) and Class II (long range) fighters.
(ii) Non-V/STOL Naval Fighters (iii) Bombers (iv) Attack/Strike Aircraft (v) Electronic Warfare Aircraft
(vi) Marine Patrol Aircraft (vii) Multirole Combat Aircraft (viii) Non-Combat Aircraft
Combi Aircraft: can transport both cargo and passengers.
Flying Cars: unique features include; (i) Distributed electrical system (ii) Twin electric motor pods (iii) Rechargeable batteries (iv) Propeller folds (v) Ducted fan for thrust (vi) etc.
Typical requirements of a combat aircraft include; aerodynamics, range, air superiority, stealth, maneuverability, powerplant, armament, maintainability and survivability.