PRINCIPLES OF FLIGHT Lift & Weight CHAPTER 1

PRINCIPLES OF FLIGHT CENTRE OF GRAVITY THE POINT ON A BODY WHERE THE TOTAL WEIGHT OF THAT BODY IS SAID TO ACT. WEIGHT CENTRE OF GRAVITY

PRINCIPLES OF FLIGHT MOMENT OR LEVERAGE 1TON 1 TON TON 2 METRES THE LEFT WEIGHT IS BALANCED WITH THE RIGHT WEIGHT ABOUT THE FULCRUM. EACH WEIGHT HAS MOMENT OF IT’S WEIGHT TIMES IT’S DISTANCE FROM THE FULCRUM. FULCRUM 1 TON X 2 METRES = 2 TONMETRES

PRINCIPLES OF FLIGHT 1 METRE3 METRES MOMENT OR LEVERAGE 1/3 1/3 TON TON 1 FULCRUM WILL THE BEAM BE BALANCED ?YES. 1 TON X 1 METRE = 1 TONMETRE 1/3 TON X 3 METRES = 1 TONMETRE THEREFORE IT CAN BE SEEN THAT A SMALL WEIGHT CAN BALANCE A LARGE WEIGHT IF IT HAS ENOUGH LEVERAGE OR MOMENT.

PRINCIPLES OF FLIGHT VECTORS WHEN A FORCE ACTS AT AN ANGLE AWAY FROM THE HORIZONTAL OR VERTICAL IT CAN BE BROKEN DOWN INTO HORIZONTAL AND VERTICAL VECTORS. FORCE VERTICAL COMPONENT HORIZONTAL COMPONENT THIS FORCE IS KNOWN AS THE RESULTANT FORCE OF THE HORIZONTAL AND VERTICAL COMPONENTS RESULTANT

PRINCIPLES OF FLIGHT NEWTON’S 3 RD LAW PRINCIPLES OF FLIGHT THE BORING BITS NEWTON’S 3 RD LAW PRINCIPLES OF FLIGHT THE BORING BITS TO EVERY ACTION THERE IS AN EQUAL AND OPPOSITE REACTION NEWTON’S 3 RD LAW PRINCIPLES OF FLIGHT THE BORING BITS TO EVERY ACTION THERE IS AN EQUAL AND OPPOSITE REACTION A CAR SITS ON THE ROAD AND IS SUPPORTED BY IT

PRINCIPLES OF FLIGHT NEWTON’S 3 RD LAW PRINCIPLES OF FLIGHT THE BORING BITS TO EVERY ACTION THERE IS AN EQUAL AND OPPOSITE REACTION A BOAT SITS ON WATER AND IS SUPPORTED BY IT

PRINCIPLES OF FLIGHT NEWTON’S 3 RD LAW THE BORING BITS TO EVERY ACTION THERE IS AN EQUAL AND OPPOSITE REACTION AN AIRCRAFT WHEN FLYING IS IN THE AIR AIR AIR IS A SUBSTANCE JUST LIKE THE ROAD AND WATER WHAT SUPPORTS IT ?

PRINCIPLES OF FLIGHT IF AIRSPEED INCREASES THEN AIR PRESSURE DECREASES AIRSPEED INCEASES TO GET SAME MASS OF AIR THROUGH RESTRICTION WHAT HAPPENS AT B ? AIRSPEED AND PRESSURE AT A AND C ARE THE SAME ABC

PRINCIPLES OF FLIGHT NOW APPLY THIS TO AN AIRCRAFT WING BERNOULLI’S PRINCIPLES THE BORING BITS WHEN AIR IS MOVING IN A STREAMLINED FLOW IF THE AIRSPEED INCREASES THE AIR PRESSURE DECREASES AND IF THE AIRSPEED DECREASES THE AIR PRESSURE INCREASES. PAPER DEMOS THIS IS KNOWN AS LIFT

PRINCIPLES OF FLIGHT AIRCRAFT WING UNDISTURBED AIRFLOW AIRFLOW BETWEEN THE UNDISTURBED AIR AND THE TOP SURFACE OF THE WING IS JUST LIKE A RESTRICTION. THEREFORE THE AIRFLOW ABOVE THE WING INCREASES IN SPEED AND THE AIR PRESSURE DROPS, CAUSING THE WING TO RISE.

PRINCIPLES OF FLIGHT IN REALITY THE WING IS NOT USUALLY HORIZONTAL TO THE AIRFLOW. THIS CAUSES A DOWNWASH WHICH ADDS TO THE LIFT OF THE WING, BUT NOT AS MUCH AS THE UPPER SURFACE OF THE WING. UNDISTURBED AIRFLOW DOWNWASH

PRINCIPLES OF FLIGHT LIFT FORCES ON A TYPICAL WING IN FLIGHT ONCOMING AIR THE LENGTH OF THE ARROW INDICATES THE AMOUNT OF LIFT BEING PRODUCED. MOST LIFT IS PRODUCED ABOUT 1/3 FROM THE LEADING EDGE OF THE WING.

PRINCIPLES OF FLIGHT RATHER THAN WORK WITH LOTS OF SMALL FORCES, THE TOTAL LIFT ON A WING IS DEEMED TO WORK THROUGH A SINGLE POINT. RATHER THAN WORK WITH LOTS OF SMALL FORCES, THE TOTAL LIFT ON A WING IS DEEMED TO WORK THROUGH A SINGLE POINT. THIS POINT IS CALLED :- THE CENTRE OF PRESURE

PRINCIPLES OF FLIGHT CHORD LINE ONCOMING AIRFLOW DEFINITIONS CHORD LINE IS A LINE JOINING THE LEADING EDGE TO THE TRAILING EDGE OF THE WING. MEAN CAMBER LINE ONCOMING AIRFLOW THE MEAN CAMBER LINE IS A LINE EQUI-DISTANT FROM THE TOP AND BOTTOM OF THE WING.

PRINCIPLES OF FLIGHT SEVERAL FACTORS AFFECT THE AMOUNT OF LIFT PRODUCED BY A WING. AIRSPEED. INCREASE IN AIRSPEED WILL CAUSE AN INCREASE IN LIFT. LIFT INCREASES BY THE SQAURE OF THE SPEED. 2 x SPEED = 4 x LIFT 3 X SPEED = 9 x LIFT

PRINCIPLES OF FLIGHT ANGLE OF ATTACK CHORD LINE ONCOMING AIRFLOW ANGLE OF ATTACK ANGLE OF ATTACK IS THE ANGLE BETWEEN THE CHORD LINE AND THE ONCOMING AIRFLOW. IF THE ANGLE OF ATTACK INCREASES THE LIFT INCREASES UP TO AN ANGLE OF 15°. AFTER THIS THE LIFT RAPIDLY DECREASES LEADING TO A STALL (TO BE COVERED LATER).

PRINCIPLES OF FLIGHT AIR DENSITY IF THE AIR BECOMES “THINNER” OR LESS DENSE, THE LIFT WILL DECREASE. i.e. INCREASE IN ALTITUDE.

0° + _ + - LIFT = A LITTLE PRESSURE ENVELOPE AT O° PRINCIPLES OF FLIGHT TOTAL REACTION EQUALS LIFT

PRESSURE ENVELOPE AT 5° LIFT = MORE PRINCIPLES OF FLIGHT + + _ - 5° TOTAL REACTION LIFT DRAG

10° + _ + PRESSURE ENVELOPE AT 1O° LIFT = MORE PRINCIPLES OF FLIGHT TOTAL REACTION LIFT DRAG

+ + __ 15° PRESSURE ENVELOPE AT 15° PRINCIPLES OF FLIGHT LIFT = MORE TOTAL REACTION LIFT DRAG

PRINCIPLES OF FLIGHT WING SHAPE AND AREA THE SHAPE AND WING SIZE (AREA) WILL AFFECT THE AMOUNT OF LIFT. THESE ARE DECIDED AT THE AIRCRAFT DESIGN STAGE, DEPENDING ON THE ROLE OF THE AIRCRAFT EXAMPLES

PRINCIPLES OF FLIGHT HERCULES C Mk 1 – GENERAL PURPOSE WING

PRINCIPLES OF FLIGHT VIKING GLIDER – HIGH LIFT WING

PRINCIPLES OF FLIGHT TYPHOON – HIGH SPEED WING

PRINCIPLES OF FLIGHT F117A NIGHTHAWK – HIGH SPEED WING

PRINCIPLES OF FLIGHT LIFT ON OCCASIONS AIRCRAFT NEED TO SLOW DOWN, BUT STILL REQUIRE LIFT. HOW CAN THIS BE DONE ? IF THE CAMBER OR AREA OF THE WING INCREASES, THEN LIFT INCREASES. THIS CAN BE ACHIEVED BY USING FLAPS.

PRINCIPLES OF FLIGHT GROB TUTOR – PLAIN FLAP

PRINCIPLES OF FLIGHT VC10 - FOWLER FLAP

PRINCIPLES OF FLIGHT LIFT AND WEIGHT IN STRAIGHT AND LEVEL FLIGHT IN STEADY STRAIGHT AND LEVEL FLIGHT, THE LIFT FORCE EQUALS THE FORCE OF GRAVITY WORKING ON THE AIRCRAFT (IT’S WEIGHT). LIFT equals WEIGHT WEIGHT equals LIFT IF THE LIFT IS GREATER THAN THE WEIGHT THEN THE AIRCRAFT WILL CLIMB. LIFT greater than WEIGHT IF THE WEIGHT IS GREATER THAN THE LIFT THEN THE AIRCRAFT WILL DESCEND. WEIGHT greater than LIFT