M11.1 Flashcards
What are the three types of axis acting on a aircraft?
- lateral axis
- longitudinal axis
- vertical axis
What axis does pitch control?
The Lateral axis
What axis does roll control?
The longitudinal axis
What axis does yaw control?
Vertical axis
What is a primary flight control?
They’re flying controls that control the aircraft safely
What can be added to a larger aircraft to increase the efficiency of alieron flying control surfaces?
Roll spoilers
What is a secondary flight control?
They’re flying controls that help the performance characteristics or to relieve control loading
Which side will roll spoilers extend?
The side with upward aileron deflection
What is aileron lock out?
When the outboard ailerons remain locked down at high speeds
What is a stabiliser also known as?
An all-moving tail
What is a canard?
It is a fuselage mounted, horizontal surface that is located forward of the main wing to provide longitudinal stability and control
What are the two types of canard?
- lifting canard
- control canard
What is the job of a lifting canard?
To generate an upload or positive lift
What is the job of a control canard?
To help control pitch during manoeuvring
How far is the rudder allowed to move at speeds up to 150 knots?
30’
How far is the rudder allowed to move at speeds up to 150-200 knots?
15’
How far is the rudder allowed to move at speeds up to 200 knots?
5.7’
What is a ruddervator?
A combination between a rudder and a elevator
What is an elevon?
A combination of elevators and ailerons
Where can elevons be found?
On delta wing aircraft
What are the two types of lift devices?
Slats on the leading edge and flaps on the trailing edge
What are the two types of drag devices?
Speed brakes and spoilers
What is an flaperon?
A combination between flaps and ailerons that work symmetrically
What percentage does a fowler flap increase lift by?
95%
What percentage does a plain flap increase lift by?
55%
What percentage does split edge flap increase lift by?
65%
What percentage does slotted flaps increase lift by?
70%
What percentage does a slat increase lift by?
35%
Where are the air brakes located on an aircraft?
Anywhere the aircraft structure can take the heavy air-loads
What is span wise flow?
When boundary layers head towards the wing tips (especially at low speeds with a high angle of attack)
What is used to reduce span wise flow?
Wing fences
What has the same effect of wing fences?
Saw tooth leading edge
What is the job of a vortex generator?
To help increase lift by re-energising the boundary layer
What is a stall wedge?
A fixed device on the leading edge that modifies aerodynamics
What are stall wedges made out of?
Aluminium
How big are stall wedges?
6-12inches in a triangle cross section
What is the job of stall wedge?
At high angles of attack to stall at the root before the critical stall angle is reached
Why are trim systems used?
To keep the aircraft balanced
Which company uses side stick flying inputs?
Airbus
What is used to control the speed brakes?
The speed brake lever on the cockpit pedestal
What is used to control the slats and flaps
The flap lever on the cockpit pedestal
What is the job of a horn balance?
To go into the wind and help the turn of the flying control
Where is a balance tab located?
The trailing edge of a flap
Which direction will a balance tab go?
The opposite direction of the control surface
How does a balance panel work?
It separates the slot of the control surface into two and uses the change of static pressure to help balance
What is the purpose of a anti balance tab?
To increase the effectiveness of the flying control but takes more effort to deflect it
What is a trim tab?
It is a tab on the trailing edge of the flying control that automatically changes to help with balance
In dry air at 20C, how fast is the speed of sound?
343.2mps
How fast does speed travel through gases, liquids, solids?
- slowly in gases
- medium in liquids
- fast in solids
What are the three speed regions?
- subsonic
- transonic
- supersonic
How fast is subsonic?
Below the speed of sound
How fast is transonic?
Some speeds around the aircraft are below and some are above the speed of sound
How fast is supersonic?
Higher than the speed of sound
How does a pressure field affect the sound waves on a leading edge during flight?
If the aircraft is subsonic then the sound waves can move out the way. If the aircraft is supersonic they can’t move out the way
How is the Mach number figured out?
Aircraft speed divided by the speed of sound
What is the critical Mach number?
It is the highest Mach number we can have without supersonic flow (boundary layer between subsonic and transonic)
What is a shock wave?
A concentration of pressure waves
When does a normal shock wave take place?
At Mach 1.2
What does a normal shock wave create?
A large increase in static pressure behind the wave
When would a bow wave form?
When the flight speed of the leading edge exceeds the speed of sound
What is wave drag?
Total drag which is due to shock waves
What do shock waves turn useful energy into?
Heat energy
What affect does swept wings have on the time that air is on the wings?
The air is on the wing for longer
What angle are most modern aircraft swept back?
30 degrees
Why are wings swept back?
To reduce thickness but increase critical Mach number
What is the advantage of having a variable sweep angle?
You can get the best performance at high or low speeds
What type of profile do most aircraft use today?
Transonic profile
What is a transonic profile also known as?
Rear loaded wing (due to the high static energy at the lower back)
What is used to prevent the tuck under effect?
The horizontal stabiliser (also known as Mach trim system)
What happens to the elevators during transonic?
There operations have the opposite effect to normal
What do shockwaves do to energy?
They turn useful energy into wasted heat energy
What are the differenttypes of waves?
- normal shock waves
- oblique shock waves
- expansion waves
Where do normal shock waves form?
In front of the object
Where do oblique shock waves form?
Where supersonic air turns into a new flow direction
How fast must air be before it enters the compressor stage of an engine?
Subsonic velocity
What also increases with Mach number?
Friction temperature
What percentage of strength does aluminium alloy lose at 250C?
80%
