Module 5 | Application of High-Speed Flight and its Limitations

Bell X-1 Rocket-powered research plane

• First aircraft to fly at supersonic speeds
• Piloted by Major Charles E. Yeager of US air Force
• Flown in October 14, 1947

XS-1

• Broke (local) sound barrier @ 1,066 km/hr speed
• Attained a top speed of 1,126 km/hr or Mach 1.06
• Dropped from the belly of a Boeing B-29 Mother ship

Soviet Tupolev Tu-144

• First Supersonic Transport
• First flight in June 1969
• Flying Mail between Moscow and Alma-Ata (Almaty) in 1975

Concorde

• First Supersonic Passenger-Carrying commercial airplane
• Built by aircraft manufacturers in Great Britain and France
• Made it first Transatlantic crossing on September 26, 1973
• Entered regular service in 1976
• 20 Concordes were built
• 14 Concordes were sold
    * 7 British Airways
    * 7 Air France
    * the rest were built as prototypes and flight test aircraft
• British Airways and Air France stopped flying it in 2003

Demise of Concorde

• Very Costly
    * Manufacturing Cost
    * Operating Cost
    * Maintenance Cost - Complexity
• Expensive to Operate (3 times as much fuel per passenger mile as a Subsonic aircraft) (Oil Cost)
    * 1970 - 1980
      * Golden Era for Oil Prices
• High Subsonic Noise Levels during Takeoffs and Landings (High Subsonic Noise near residential area complaints)
• Generally priced at about twice the regular first-class airfare (due to high cost expenses)
• Impractical for carrying cargo or mail due to limited space (too narrow thus, no space for cargo and mail)
• Fatal crash at the 1973 Paris Air Show (same year of debut)
• Need for Considerable federal funding (pioneer for supersonic air transportation)
• Lack of interest by the airlines (businessmen see this as not profitable)
• Major Challenges of addressing environmental concerns (Noise Pollution)

Disadvantages of High-Speed Flights

• Cost
• Noise
• Profitability

Advantage of High-Speed Flights

• Speed and Range

Main Source of income of Concorde

• Rich People specifically businessman and politicians who needs to be at a certain place at a certain time

High Speed Flight Limitations

• Circadian Dysrhythmia (Severe Jet Lag)
    * It is caused by the body regular asleep and awake cycle being out of sync with local time
    * Certain amount of time to rest is needed before they inboard another flight
• High Altitude
    * High Speed Flight is conducted much efficiently on high altitude due to less sonic boom effect
    * However, it compromises the pressurization system.
• Radiation
• Noise (Sonic Boom)

Sonic Boom

• It is a major problem which all supersonic aircrafts face
• it is used to refer to the shocks caused by the supersonic flight of an aircraft

Factors Affecting Sonic Boom Strength

• Aircraft Weight, Shape and Length
    * The Larger the Aircraft, More Air Molecules tends to push back
    * “The larger the Aircraft, the greater the effect of Sonic Boom”
• Aircraft Altitude
    * Supersonic flights are conducted at high altitudes to lessen the effect of sonic boom
    * “The higher the Altitude, the lesser the effect of Sonic Boom”
• Aircraft Maneuvers
    * More maneuvers made by the aircraft, more prone to Sonic Boom.
    * “More steady the aircraft, the lesser the effect of Sonic Boom”
• Location in Sonic Boom Carpet
    * Special topographic features in each area such as mountains, hills and valleys can create multiple reflections of shock waves thus affecting intensity.
• Attitude
    * orientation of the aircraft’s axes relative to its direction of motion.