What is induced drag?

What is induced drag?

Induced drag and its wing tip vortices are a direct consequence of the creation of lift by the wing.

Since the Coefficient of Lift is large when the Angle of Attack is large, induced drag is inversely proportional to the square of the speed whereas all other drag is directly proportional to the square of the speed.

The effect of this is that induced drag is relatively unimportant at high speed in the cruise and descent where it probably represents less than 10% of total drag. In the climb, it is more important representing at least 20% of total drag. At slow speeds just after take off and in the initial climb, it is of maximum importance and may produce as much as 70% of total drag.

Finally, when looking at the potential strength of wing tip vortices, all this theory on induced drag must be moderated by the effect of aircraft weight. Induced drag will always increase with aircraft weight.

What is a Rhumb Line?

What is a Rhumb Line?

A line across the surface of the earth that cuts all meridians at the same angle. i.e. a track of constant direction.

A straight line on a Mercator chart.

What is N1, N2, EGT and EPR?

What is N1, N2, EGT and EPR?

N1= Low pressure compressor spool or fan rotation speed. Usually expressed as a % of Max N1.

N2= High pressure compressor rotation speed.

EGT= Exhaust gas temperature, indicates the temperature at the first stage of the turbine, which is the most critical temperature in the engine.

EPR= Engine pressure ratio of the inlet to the jet pipe, displayed on the EPR gauge to use as a parameter for setting engine thrust

What does a bypass ratio of 11:1 mean?

What does a bypass ratio of 11:1 mean?

For every 1kg of air passing through the combustion chamber, 11kg of air pass bypass the combustion chamber.

On A high wing anhedral airplane, like a BAE146, and a high wing straight winged aircraft like a Fokker 50, why they don’t have dihedral wings if it has so many advantages?

On A high wing anhedral airplane, like a BAE146, and a high wing straight winged aircraft like a Fokker 50, why they don’t have dihedral wings if it has so many advantages?

A high wing location like the BAE and the Fokker give a natural stable contribution.

This is because the Center of Gravity is underneath the wing, therefore when disturbed the C.G. provides a positive momentum opposite to the distortion.

How does an altimeter work and which errors can an altimeter experience?

How does an altimeter work and which errors can an altimeter experience?

When an aircraft climbs, the static pressure in the instrument case decreases, which allows the enclosed capsule to expand.

This in turn moves the needle on the instrument to indicate a corresponding altitude.

During descent, the opposite function applies.

Altimeter errors can originate and vary from:

Instrument Pressure Time-lag Barometric Density Temperature Blocked static port

What errors would cause an altimeter to malfunction?

What errors would cause an altimeter to malfunction?

Altimeter errors:

Instrument error Pressure error Time-lag error Barometric error

How do you prevent an aircraft reaching Mcrit?

How do you prevent an aircraft reaching Mcrit?

Decreasing speed, by reducing engine power or pitching up.

What are wing tip vortices?

What are wing tip vortices?

Wingtip vortices are tubes of circulating air that are left behind a wing as it generates lift.

They are caused by the difference in pressure above and below the wing causing the air to 'escape' from the high pressure area below the wing to the low pressure area above the wing, by rolling around the tip of the wing. This creates a vortex that trails behind the wing.

At what speed does Mach tuck occur?

At what speed does Mach tuck occur?

Mcrit

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