Misc Aerody. Flashcards
Best Endurance is achieved by flying at the A??
AOA which yields minimum fuel flow per hour.
Best Endurance occurs at a speed for Vimd and at an altitude where Vimd can be achieved using engine .. .. ..
design RPM
Wind has NO EFFECT on endurance because.. .. ..
fuel flow per hour is unaffected by wind!
As FOB is burnt, weight reduces, the drag curve moves down and left resulting in
LOWER maximum endurance speeds at LOWER Gross Weights!
The AOA for best endurance is
FIXED!
The speed for best endurance is dependant on w & a
Weight and Altitude!
(climbing)
Max AOC is achieved by flying at V?
Vimd
As weight reduces the curve moves down and left resulting in lower ….
Excess thrust speeds at lower gross weights!
AOA for max AOC is fixed but the speed depends on W & A
Weight and Altitude
Max ROC achieved using max
Power
Power available is developed by multiplying thrust by T….
TAS
Power available at Zero TAS is…
ZERO –> and increases as TAS increases.
Flaps increase lift and drag moving the curve up and….
LEFT
As flaps are lower Vimd
decreases!
Power available decrease with altitude. TAS or max ROC is higher with increased altitude but the IAS is….l
Lower!
It is common to climb at fixed IAS (increasing TAS) to about FL250 then at cons….
constant MACH which results in decreasing TAS and IAS (speed protection)
In a constant MACH climb the reduction of IAS compared to TAS
is much greater but ROC remains reasonable constant!
Approach attitude with leading edge devices only is h…
Higher
Approach attitude with trailing edge devices only is l…
Lower
Approach attitude with leading and trailing edge devices only is …
medium (just right)
Long Range Cruise tables publish speeds for lower gross weights to conserve
AOA!
Long Range Cruise speeds are typically 5% faster than Maximum Range Cruise speed and results in only a _ %
1% reduction in range!
LRC=99% of max range speed!
Max Thrust reduced with increases in
Altitude,
Temperature,
Humidity!
Thrust decreases until the aircraft approaches the speed of its exhaust, at high speeds some thrust is ‘recovered’ due to R.E>
Ram Effect - the increase of Mass Air Flow as a result of air being compressed at the intake at high speed.
Temperature rise due to the compression of air limits the benefit of Ram….rec…
Ram Recovery!
Flying at the speed of your exhaust achieves 100% propulsive efficiency but produces ZERO th…
Zero Thrust!
