Module 5 - Application of High-Speed Flight and its Limitations Flashcards
when and where did the first trans-oceanic supersonic passenger flight took off from?
1976, London Heathrow Airport
first successful commercial supersonic aircraft
the Concorde
which airlines commercially operated the Concorde?
- British Airways
- Air France
how many passengers did the Concorde service prior to its retirement?
2.5 million
when was the Concorde taken out of service?
2003
flight that is faster than the speed of sound
supersonic flight
value of the speed of sound near sea-level
about 760 mph
value of the speed of sound at cruising altitude of commercial aircraft
often less than 700 mph
the ratio of an aircraft’s speed divided by the speed of sound
Mach number
all current commercial aircraft are ____________, with Mach number _____________
subsonic, less than 1
the typical cruising speed of a Boeing 777 airliner is _________
Mach 0.84
flight near Mach 1 is called ____________
transonic
aircraft typically fly at _____________ speeds only briefly while they accelerate from subsonic to supersonic or vice versa
transonic
aircraft do not cruise near Mach 1 because they would experience _________
high drag
supersonic flight is faster than Mach _____
1
the Concorde cruised at about _________ when not over land
Mach 2.02
flight faster than Mach ____ is known as hypersonic
5
the space shuttle during reentry flew at about Mach _____
25
an aircraft in flight creates a series of ______________ that travel outward in all directions and are perceived as sound
pressure waves
the faster the aircraft move the more ____________ the pressure waves become
compressed
as the aircraft speed increases above Mach 1, eventually the pressure waves merge into a shock wave generating a ____________
sonic boom
although there has not been an accurate accounting of the costs, it was argued in 1976 that the official figure of ______________ had been a drastic underestimate, and that the program cost of Concorde was nearly ________________
£1.46 billion, £4.26 billion
Concorde aircraft were expensive to operate, reportedly using almost __________ as much fuel per passenger mile as subsonic aircraft
three times
of the ______ Concordes ever manufactured, _____ were sold to the state-owned carriers of Britain and France
20, 14
how many Concordes did the British Airways and Air France own?
seven each
Concorde tickets were generally priced at about _______ the regular first-class airfare on a comparable subsonic flight
twice
the first country to provide commercial supersonic flights
the Soviet Union
Soviet Union’s commercial supersonic aircraft
Tupolev TU-144
the Tupolev TU-144 was designed to fly Mach _____ and carry ______ passengers
2.2, 140
what ended the Soviet Union’s supersonic passenger jet ambition?
a fatal crash at the 1973 Paris Air Show
the first Concorde flight route
London Heathrow to Bahrain
when did the first Concorde flight take place?
January 1976
Concorde cruising altitude
65000 ft
disadvantages of high-speed flights
- need for considerable federal funding
- lack of interest by the airlines
- environmental concerns
- cost
- noise
- profitability
advantages of high-speed flights
- speed
- range
high-speed flight limitations or civil problems affecting both crew and passengers of high-speed aircraft
- Circadian dysrhythmia
- high altitude
- radiation
- noise (sonic boom)
Circadian dysrhythmia is colloquially called __________
jet lag
caused by the desynchronization of the normal sleep and wakefulness cycle of the body with local time
Circadian dysrhythmia
ways to minimize Circadian dysrhythmia
passengers should:
- be well rested
- be vaccinated
- minimize alcohol intake and smoking
- be allowed a day of rest to acclimate themselves to the local time, after flight
effect of a 4-in hole in an aircraft
- cabin altitude can rise up to 30,000 ft
- passengers can suffer from unconsciousness
effect of a 6-in hole in an aircraft
- cabin altitude can rise up to 42,000 ft
- passengers can suffer from unconsciousness and hypoxia (if oxygen was not administered immediately)
effect of a 8-in hole in an aircraft
- cabin altitude can rise up to 53,000 ft
- passengers can suffer from severe hypoxia (fatal)
at which altitude does radiation pose a risk to passengers and crew?
60,000 ft
average dose of radiation at 60,000 ft for transatlantic routes
1-5 mrem/hr
average dose of radiation at 60,000 ft for trans-Siberian routes
1-5.5 mrem/hr or 3.9 mrem/flight
exposure rates in excess of ___________ will alert the crew and _______________ will require descent to lower altitudes
10 mrem/hr, 50 mrem/hr
advisable limits of radiation
- 5 rem/year (for normal people)
- 3 rem in any 3 months (for radiation workers)
the principal regulatory concern surrounding supersonic aircraft is the ___________
sonic boom
a shock wave of pressure created by compression of sound waves as the air is displaced by the airframe traveling at or above Mach 1.0
sonic boom
aircraft noise standards
- stage 5 limits
- certification
stage 5 standards compared to stage 4 standards
7 dB quieter
stage 5 standards compared to stage 3 standards
17 dB quieter
stage 5 standards compared to stage 2 standards
1/4 of the sound intensity
noise certification standards pertain to the _________ itself
aircraft
factors affecting sonic boom strength
- aircraft weight, shape, and length
- aircraft altitude
- aircraft maneuvers
- location in sonic boom carpet
- attitude
which factor affecting sonic boom strength is the following:
the bigger the aircraft is, the more air molecules push aside; thus, a big aircraft will produce a stronger sonic boom
aircraft weight, shape, and length
the altitude of the aircraft and the strength of the sonic boom are _____________; as the altitude increases, the strength of the sonic boom _______________
reciprocal, decreases
maneuvers such as pushovers, S-turns and accelerating can __________ the intensity of the shock wave
amplify
a sonic boom hitting a concave topographic feature, will _____________ its intensity
increase
a sonic boom hitting a convex topographic feature, will _____________ its intensity
decrease
orientation of the aircraft’s axes relative to its direction of motion
attitude
