PRINCIPLES OF FLIGHT CHAPTER 4 CONTROLS

CONTROLS TO MAKE THE AIRCRAFT DO WHAT THE PILOT PRINCIPLES OF FLIGHT CONTROLS TO MAKE THE AIRCRAFT DO WHAT THE PILOT REQUIRES, THE PILOT MUST HAVE A MEANS OF CONTROL OF THE AIRCRAFT. THREE MAIN CONTROLS ARE PROVIDED :- ELEVATORS AILERONS RUDDER THEIR FUNCTION IS TO MOVE THE AIRCRAFT ABOUT IT’S 3 AXIS.

PRINCIPLES OF FLIGHT Elevators Rudder Ailerons

THE PILOT USES THESE CONTROLS TO MAKE THE AIRCRAFT MOVE IN : - PRINCIPLES OF FLIGHT THE PILOT USES THESE CONTROLS TO MAKE THE AIRCRAFT MOVE IN : - PITCH – WHERE THE NOSE OF THE AIRCRAFT RISES (PITCHING UP) OR FALLS (PITCHING DOWN). CONTROL USED - ELEVATORS ROLL - WHEN ONE WING RISES THE OTHER WING FALLS. RIGHT WING DOWN IS ROLLING RIGHT. CONTROL USED - AILERONS YAW - WHEN THE NOSE OF THE AIRCRAFT MOVES LEFT (LEFT YAW) OR RIGHT (RIGHT YAW). CONTROL USED - RUDDER

PITCHING, ROLLING AND YAWING IS ALWAYS DESCRIBED RELATIVE TO THE PRINCIPLES OF FLIGHT MOVEMENT PITCHING, ROLLING AND YAWING IS ALWAYS DESCRIBED RELATIVE TO THE PILOT RATHER THAN THE HORIZON. PILOT RATHER THAN THE HORIZON. THE PITCHING PLANE PILOT USES ELEVATORS ELEVATORS ARE USUALLY TWO MOVEABLE PARTS HINGED TO THE TRAILING EDGE OF THE TAILPLANE. THEY ARE LINKED TO THE PILOT’S CONTROL COLUMN.

MOVING THE CONTOL COLUMN FORWARD MOVES THE ELEVATORS DOWN, INCREASING PRINCIPLES OF FLIGHT MOVING THE CONTOL COLUMN FORWARD MOVES THE ELEVATORS DOWN, INCREASING THE ANGLE OF ATTACK AND PRODUCING MORE LIFT. PRODUCING MORE LIFT MOVES THE AIRCRAFT AROUND IT’S LATERAL AXIS AND PITCHES THE NOSE DOWN. THE AIRCRAFT DESCENDS AND THE SPEED INCREASES.

THE AIRCRAFT WILL CONTINUE TO PITCH OVER PRINCIPLES OF FLIGHT CONTROL COLUMN ELEVATOR FORCE LATERAL AXIS AIRCRAFT DESCENDS AND SPEED INCREASES LATERAL AXIS CONTROL COLUMN TO NUETRAL ELEVATOR FORCE NUETRAL THE AIRCRAFT WILL CONTINUE TO PITCH OVER UNTIL THE CONTROL COLUMN IS PUT BACK IN THE NUETRAL POSITION.

WHATEVER THE ATTITUDE OF THE AIRCRAFT PRINCIPLES OF FLIGHT WHATEVER THE ATTITUDE OF THE AIRCRAFT THE REACTION TO MOVING THE CONTROL COLUMN IS THE SAME.

PRINCIPLES OF FLIGHT C130 ELEVATORS

MOVING THE CONTROL COLUMN BACK HAS THE OPPOSITE EFFECT. PRINCIPLES OF FLIGHT MOVING THE CONTROL COLUMN BACK HAS THE OPPOSITE EFFECT.

PRINCIPLES OF FLIGHT VC10 ELEVATORS

THE PILOT USES AILERONS. PRINCIPLES OF FLIGHT THE ROLLING PLANE THE PILOT USES AILERONS. AILERONS ARE USUALLY TWO MOVEABLE PARTS HINGED TO THE TRAILING EDGE OF THE WINGS AND PLACED CLOSE TO THE WINGTIPS TO GIVE MAXIMUM LEVERAGE ABOUT THE C of G. THEY ARE LINKED TO THE PILOT’S CONTROL COLUMN.

BY MOVING THE CONTROL COLUMN TO THE LEFT, THE LEFT AILERON RISES AND PRINCIPLES OF FLIGHT BY MOVING THE CONTROL COLUMN TO THE LEFT, THE LEFT AILERON RISES AND THE RIGHT LOWERS. LEFT WING RIGHT WING AILERON AND WING CHORD LINE CHANGE IN ANGLE OF ATTACK WING CHORD LINE WING CHORD LINE AILERON AND WING CHORD LINE RAISING THE LEFT AILERON REDUCES IT’S ANGLE OF ATTACK AND THEREFORE PRODUCES LESS LIFT. THIS CAUSES THE WING TO DROP. THE OPPOSITE OCCURS ON THE RIGHT WING.

STRAIGHT AND LEVEL FLIGHT PRINCIPLES OF FLIGHT THE ROLLING PLANE STRAIGHT AND LEVEL FLIGHT CONTROL COLUMN RIGHT LEFT AILERON DOWN, RIGHT AILERON UP AIRCRAFT ROLLS RIGHT

WHEN THE AIRCRAFT ACHIEVES THE REQUIRED PRINCIPLES OF FLIGHT WHEN THE AIRCRAFT ACHIEVES THE REQUIRED BANK ANGLE THE CONTROL COLUMN IS PLACED CENTRAL. AILERONS NOW FLARE WITH THE WING AND THE AIRCRAFT MAINTAINS THE PRESENT BANK ANGLE.

THE EFFECT ON EACH WING IS DIFFERENT PRINCIPLES OF FLIGHT ON LARGE AIRCRAFT THE EFFECT ON EACH WING IS DIFFERENT AS THE LIFT CHANGE IS MORE PRONOUNCED ON THE DOWN MOVING AILERON. THEREFORE THE DOWN MOVING AILERON IS DEFLECTED LESS THAN THE UP MOVING. LEFT WING RIGHT WING UP IS USUALLY 2 TIMES THE MOVEMENT OF DOWN THIS IS KNOWN AS DIFFERENTIAL AILERON.

PRINCIPLES OF FLIGHT C130 AILERONS

THE YAWING PLANE THE PILOT USES THE RUDDER. PRINCIPLES OF FLIGHT THE YAWING PLANE THE PILOT USES THE RUDDER. ON MOST AIRCRAFT THE RUDDER IS A SINGLE CONTROL SURFACE HINGED TO THE TRAILING EDGE OF THE FIN WHERE IT HAS MOST EFFECT. THE PILOT USES THE RUDDER. FIN RUDDER

TO YAW TO THE LEFT, THE PILOT PUSHES THE PRINCIPLES OF FLIGHT TO YAW TO THE LEFT, THE PILOT PUSHES THE LEFT RUDDER PEDAL WHICH DEFLECTS THE RUDDER LEFT. FIN RUDDER CHORD LINE FORCE THIS CAUSES AN ANGLE OF ATTACK ON THE FIN AND CAUSES A FORCE TO PUSH THE FIN RIGHT AND THEREFORE THE NOSE OF THE AIRCRAFT MOVES LEFT.

THE YAWING PLANE FLYING STRAIGHT LEFT RUDDER PEDAL PUSHED FORWARD, PRINCIPLES OF FLIGHT THE YAWING PLANE FLYING STRAIGHT LEFT RUDDER PEDAL PUSHED FORWARD, RIGHT PEDAL WILL MOVE BACK, RUDDER MOVES LEFT

THE YAWING PLANE FORCE APPLIED TO FIN AND AIRCRAFT NOSE PRINCIPLES OF FLIGHT THE YAWING PLANE FORCE APPLIED TO FIN AND AIRCRAFT NOSE MOVES LEFT ABOUT THE NORMAL AXIS. i.e. LEFT YAW. NORMAL AXIS BRINGING THE RUDDER PEDALS BACK TO THE NUETRAL POSITION, CENTRALISES THE RUDDER AND THE AIRCRAFT NOSE STOPS MOVING AND MAINTAINS THE PRESENT HEADING.

PRINCIPLES OF FLIGHT C130 RUDDER

TRIM TABS THE WEIGHT AND POSITION OF THE C of G PRINCIPLES OF FLIGHT TRIM TABS THE WEIGHT AND POSITION OF THE C of G CAN CHANGE IN FLIGHT DUE TO:- BURNING FUEL DROPPING BOMBS FIRING AMMUNITION DROPPING STORES OR MEN BY PARACHUTE THE CENTRE OF PRESSURE WILL ALSO CHANGE DUE TO CHANGES IN:- ENGINE POWER THE WEIGHT AND POSITION OF THE C of G CAN CHANGE IN FLIGHT DUE TO:- BURNING FUEL DROPPING BOMBS FIRING AMMUNITION DROPPING STORES OR MEN BY PARACHUTE THE CENTRE OF PRESSURE WILL ALSO CHANGE DUE TO CHANGES IN:- ENGINE POWER ALTITUDE SPEED THE WEIGHT AND POSITION OF THE C of G CAN CHANGE IN FLIGHT DUE TO:- BURNING FUEL DROPPING BOMBS FIRING AMMUNITION DROPPING STORES OR MEN BY PARACHUTE THE CENTRE OF PRESSURE WILL ALSO CHANGE DUE TO CHANGES IN:- THE WEIGHT AND POSITION OF THE C of G CAN CHANGE IN FLIGHT DUE TO:- BURNING FUEL DROPPING BOMBS FIRING AMMUNITION DROPPING STORES OR MEN BY PARACHUTE THE CENTRE OF PRESSURE WILL ALSO CHANGE DUE TO CHANGES IN:- ENGINE POWER ALTITUDE THE WEIGHT AND POSITION OF THE C of G CAN CHANGE IN FLIGHT DUE TO:- BURNING FUEL DROPPING BOMBS FIRING AMMUNITION THE WEIGHT AND POSITION OF THE C of G CAN CHANGE IN FLIGHT DUE TO:- THE WEIGHT AND POSITION OF THE C of G CAN CHANGE IN FLIGHT DUE TO:- BURNING FUEL THE WEIGHT AND POSITION OF THE C of G CAN CHANGE IN FLIGHT DUE TO:- BURNING FUEL DROPPING BOMBS THE WEIGHT AND POSITION OF THE C of G CAN CHANGE IN FLIGHT DUE TO:- BURNING FUEL DROPPING BOMBS FIRING AMMUNITION DROPPING STORES OR MEN BY PARACHUTE

TRIM TABS AN ENGINE FAILURE ON A MULTI ENGINE PRINCIPLES OF FLIGHT TRIM TABS AN ENGINE FAILURE ON A MULTI ENGINE AIRCRAFT WOULD CAUSE ASYMETRIC POWER WHICH THE PILOT WOULD HAVE TO OPPOSE BY USING RUDDER. PILOT APPLIES RIGHT RUDDER. X THRUST ASYMETRIC THRUST CAUSES YAW LEFT. COUNTERS ASYMETRIC THRUST. TURNING FORCE

TRIM TABS TRIMMING TABS A LATERAL UNBALANCE (POSIBLY UNEVEN PRINCIPLES OF FLIGHT TRIM TABS A LATERAL UNBALANCE (POSIBLY UNEVEN FUEL DISTRIBUTION) WOULD HAVE TO BE CORRECTED BY THE PILOT USING AILERON. LEFT WING HEAVIER THAN RIGHT WING. IN ALL THESE CONDITIONS A PILOT COULD NOT FLY FOR LONG HOLDING THESE FORCES WITHOUT SOME HELP. THIS HELP COMES IN THE FORM OF:- TRIMMING TABS

TRIM TABS THESE ARE USUALLY SMALL CONTROL PRINCIPLES OF FLIGHT TRIM TABS THESE ARE USUALLY SMALL CONTROL SURFACES ATTACHED TO THE TRAILING EDGE OF THE AILERONS, ELEVATORS AND RUDDER WHICH BY APPLYING SMALL MOVEMENTS CAN REMOVE THE LOAD FROM THE PILOT. EXAMPLE: ELEVATORS TRIM TAB TAILPLANE ELEVATOR

PRINCIPLES OF FLIGHT IF THE PILOT HAS TO MAINTAIN A BACKWARDS PRESSURE ON THE CONTROL COLUMN TO MAINTAIN LEVEL FLIGHT. DOWNWARD FORCE TO KEEP AIRCRAFT NOSE UP BY MOVING THE TRIM TAB DOWN, THE INCREASE IN ANGLE OF ATTACK WILL CAUSE THE ELEVATOR FORCE TO BE COUNTERACTED. DOWNWARD FORCE TO KEEP AIRCRAFT NOSE UP SMALLER FORCE TO BALANCE ELEVATOR FORCE DIFFERENT LEVERAGE ARMS SO TAKING THE LOAD OFF THE PILOT.

TRIM TABS AILERON AND RUDDER TRIM TABS WORK ON THE SAME PRINCIPLE. PRINCIPLES OF FLIGHT TRIM TABS AILERON AND RUDDER TRIM TABS WORK ON THE SAME PRINCIPLE. TRIM TABS

TRIM TABS ON SOME AIRCRAFT THERE ARE NO ELEVATOR TRIM TABS. PRINCIPLES OF FLIGHT TRIM TABS ON SOME AIRCRAFT THERE ARE NO ELEVATOR TRIM TABS. INSTEAD THE WHOLE TAILPLANE MOVES TO TAKE OUT ANY LOADS FROM THE PILOT. THIS CAN BE ACHIEVED BY A MECHANICAL LINKAGE OR BY HYDRAULIC CONTROL.

PRINCIPLES OF FLIGHT MOVING TAILPLANE TRIM TABS

PRINCIPLES OF FLIGHT TRIM TABS MOVING TAILPLANE

HIGH LIFT DEVICES THESE DEVICES IMPROVE THE LIFT PRINCIPLES OF FLIGHT HIGH LIFT DEVICES THESE DEVICES IMPROVE THE LIFT CAPABILITIES OF THE WING AND IMPROVE TAKE-OFF AND LANDING PERFORMANCE. TYPES:- FLAPS SLATS SLOTS KRUGER FLAPS DROOP SNOOT FLAPS

FLAPS - LANDING FOR A SAFE LANDING THE AIRCRAFT MUST BE PRINCIPLES OF FLIGHT FLAPS - LANDING FOR A SAFE LANDING THE AIRCRAFT MUST BE ABLE TO FLY SLOW ENOUGH TO BE ABLE TO STOP ON THE RUNWAY AND HAVE A STEEP APPROACH ANGLE TO LET THE PILOT SEE THE RUNWAY. AN AIRCRAFT WING IS DESIGNED FOR A SPECIFIC ROLE, NOT USUALLY FOR LANDING. THEREFORE TO ACHIEVE A SAFE LANDING THE WING HAS TO BE MODIFIED. THIS IS ACHIEVED BY USING: - FLAPS. FLAPS ARE ATTACHED TO THE TRAILING EDGE OF THE WING AND ARE EXTENDED TO INCREASE THE WING AREA AND CHORD LENGTH.

PRINCIPLES OF FLIGHT LANDING FLAP

FLAPS - TAKE-OFF A SMALL AMOUNT OF FLAP WILL PRODUCE PRINCIPLES OF FLIGHT FLAPS - TAKE-OFF A SMALL AMOUNT OF FLAP WILL PRODUCE EXTRA LIFT BUT LITTLE DRAG AND SO ALLOW A SHORTER TAKE-OFF DISTANCE. TAKE-OFF FLAP

FLAPS PRINCIPLES OF FLIGHT TYPES OF FLAP GENERAL WING SECTION SIMPLE OR PLAIN FLAP SPLIT FLAP FOWLER FLAP

FLAPS WHEN THE FLAPS ARE “UP” THEY ARE FLUSH PRINCIPLES OF FLIGHT FLAPS WHEN THE FLAPS ARE “UP” THEY ARE FLUSH WITH THE WING AND WHEN “DOWN” THEY CAN BE UP TO 90° TO THE WING. WHEN THE FLAPS ARE “UP” THEY ARE FLUSH WITH THE WING AND WHEN “DOWN” THEY CAN BE UP TO 90° TO THE WING. WHEN THE FLAPS ARE “UP” THEY ARE FLUSH WITH THE WING AND WHEN “DOWN” THEY CAN BE UP TO 90° TO THE WING. UP TO 60° THE INCREASE IN LIFT IS LARGE AND THE INCREASE IN DRAG SMALL. FROM 60° TO 90° THE INCREASE IN LIFT IS SMALL AND THE INCREASE IN DRAG IS LARGE.

FLAPS A SMALL AMOUNT OF FLAP WILL ALLOW A PRINCIPLES OF FLIGHT FLAPS A SMALL AMOUNT OF FLAP WILL ALLOW A SLOWER STALLING SPEED BUT NOT GIVE AN INCREASE IN APPROACH ANGLE. A LARGE AMOUNT OF FLAP WILL GIVE A STEEPER APPROACH ANGLE AND WILL ALLOW A SLOWER STALLING SPEED.

FLAPS PRINCIPLES OF FLIGHT 15° LARGE INCREASE IN LIFT. VERY SMALL 60° SOME INCREASE IN LIFT. LARGE INCREASE IN DRAG 15° LARGE INCREASE IN LIFT. VERY SMALL INCREASE IN DRAG. 90° VERY SMALL INCREASE IN LIFT. HUGE INCREASE IN DRAG.

FLAPS PRINCIPLES OF FLIGHT FULL FLAP – GOOD VIEW OF LANDING AREA AND REDUCED STALLING SPEED NO FLAP-POOR FORWARD VIEW

PRINCIPLES OF FLIGHT FLAPS GROB TUTOR – PLAIN FLAP

PRINCIPLES OF FLIGHT FLAPS SPITFIRE – SPLIT FLAP

PRINCIPLES OF FLIGHT FLAPS VC10 – FOWLER FLAP

FLAPS PRINCIPLES OF FLIGHT BOEING 747 – DOUBLE SLOTTED FOWLER FLAP

SLATS SLATS ARE ANOTHER DEVICE WHICH CAN PRINCIPLES OF FLIGHT SLATS SLATS ARE ANOTHER DEVICE WHICH CAN IMPROVE LOW SPEED HANDLING AND STALL SPEED. THEY ARE SMALL AEROFOIL SECTIONS ON THE LEADING EDGE OF WINGS, WHICH WHEN EXTENDED INCREASE LIFT AND AIRFLOW CONTROL. SLATS

SLATS THE DIAGRAM SHOWS AN AUTOMATIC SLAT PRINCIPLES OF FLIGHT SLATS THE DIAGRAM SHOWS AN AUTOMATIC SLAT WHICH IS HELD IN THE CLOSED POSITION BY SPRINGS.

PRINCIPLES OF FLIGHT SLATS - AUTOMATIC SLAT WHEN THE WING REACHES A HIGH ANGLE OF ATTACK, THE LIFT FORCES ON THE SLAT OVERCOME THE SPRINGS AND THE SLATS EXTEND. THE AIR CAN NOW FLOW BETWEEN THE SLAT AND THE WING, CAUSING THE AIR TO ACCELERATE OVER THE WING SO IMPROVING THE AIRFLOW OVER THE WING.

SLATS USUALLY THE WING CRITICAL ANGLE IS 15°, PRINCIPLES OF FLIGHT SLATS USUALLY THE WING CRITICAL ANGLE IS 15°, BUT WITH SLATS THIS CAN INCREASE TO 25°. THIS CAN BE A DIFFERENCE OF 20-25 KTS IN THE STALLING SPEED.

PRINCIPLES OF FLIGHT SLATS ON MOST LARGE AIRCRAFT THE SLATS ARE NOT AUTOMATIC BUT OPERATED FROM THE FLIGHT DECK IN CONJUNCTION WITH THE FLAPS FOR TAKE-OFF AND LANDING.

PRINCIPLES OF FLIGHT LOCKHEED TRISTAR SLATS

SLOTS AS THE ANGLE OF ATTACK OF THE WING PRINCIPLES OF FLIGHT SLOTS AS THE ANGLE OF ATTACK OF THE WING INCREASES THE EFFECT OF THE AIRFLOW THROUGH THE SLOT INCREASES AND SMOOTHS THE AIRFLOW OVER THE TOP SURFACE OF THE WING, SO REDUCING TURBULENCE. SLOT A SLOT CAN INCREASE THE CRITICAL ANGLE TO ABOUT 20°.

KRUGER FLAPS THESE ARE SIMILAR TO SLATS AND HAVE THE PRINCIPLES OF FLIGHT KRUGER FLAPS THESE ARE SIMILAR TO SLATS AND HAVE THE SAME EFFECT, BUT ARE HINGED TO THE LEADING EDGE OF THE WING AND EXTEND FORWARD. INCREASES THE CRITICAL ANGLE TO 25o

PRINCIPLES OF FLIGHT KRUGER FLAPS

DROOP SNOOT FLAP INCREASES THE CRITICAL ANGLE TO 20o PRINCIPLES OF FLIGHT DROOP SNOOT FLAP INCREASES THE CRITICAL ANGLE TO 20o