LECTURE 6 OTHER POTENTIAL THREATS AVIATION SAFETY AND SECURITY

INTRODUCTION List of potential threats: 1) Terrorism 2) Hijacking [done] 3) Bombing [done] 4) Bird Striking 5) Mechanical Failure 6) Metal Fatigue 7) Accident 8) Fuel Spilling 9) Lightning 10) Ice and Snow 11) Ground Damage

Foreign Object Damage (FOD) FOD is any damage that is caused by foreign object. In aviation, FOD is usually refer to the damage done to aircraft by foreign objects. Example of FOD: a. Bird Striking b. Icing c. Ash Cloud (Volcanic Ash) INTRODUCTION

BIRD STRIKING Is a collision between airborne animal such as bird, bat or insects and man made vehicle such as aircraft. Bird strikes are a significant threat to flight safety. There are many incidents and accidents happen due to bird striking. VS

Bird strikes have caused a number of accidents with human casualties. Although accidents involving civil aircraft is quite low (compared to other incidents), records show that there is an accident resulting in death of man. Even though bird strikes cause little damage to aircraft, still the damage provide great danger to aviation. BIRD STRIKING

Figure : Bird striking on an aircraft

BASED ON THE PICTURE: WHAT IS YOUR OPINION? WHAT IS THE EFFECT OF THE BIRD STRIKING TO AIRCRAFT? BIRD STRIKING

BIRD STRIKING DISCUSSION Imagine a bird as a stone while the aircraft as a car. If the car does not move, what would happen if we throw stones at the car? However, if a train moving fast and at the same time a stone was thrown into the car, what effect would happen? NOW IMAGINE WHAT WOULD HAPPEN TO AIRCRAFT IF THE BIRD STRIKE TO THE AIRCRAFT?

BIRD STRIKING EFFECT Figure: Birds strike on a/c fan Figure: Birds strike on a/c screen If a bird strike into an engine, it may cause engine failure.

BIRD STRIKING EFFECT Figure: Birds strike on a/c wing Can a/c fly in this condition? Predict what will happen?

BIRD STRIKING EFFECT Figure: Birds strike on a/c fuselage

ENGINE FAILURE They are 2 ways on how aircraft engine can fail: Foreign Object Damage (Bird Striking, Volcanic ashes)  Any object hit into aircraft engine.  The object may damage the structure of the engine.  The object cause change in engine operation properties. Mechanical Failure  Unscheduled engine maintenance.  Unexpected system failure.

ENGINE FAILURE Figure: MAS aircraft with engine failure

ENGINE FAILURE Figure: Aircraft with engine failure

Bird Striking Video Show See the YouTube Video - Thomson Fly 757 bird strike _ flames captured on video. Upon take-off, a bird strike into an aircraft engine. As a result, the engine fail. The aircraft immediate need to do landing.

ICING AND SNOWING Occurs when water droplets in the atmosphere on objects they contact. This cause great danger to aircraft. Why??  The built-up ice changes the aerodynamics of the flight surfaces.  In other words, the design of the wing shape has been changed.

ICING AND SNOWING Figure : Effect of Ice and snow to aircraft

ICING AND SNOWING Figure: Icing on the aircraft wing during flight

TIME TO THINK! Group Discussion Based on the figure shown, why icing produce great danger to aircraft? What will happen if an aircraft keep flying under this condition? How does aviation world overcome this problem?

Bernoulli Principle Faster moving air Produce less pressure Slower moving air Produce more pressure Top surfaceBottom surface Reason of Design Basic principle of physics This pressure difference create lift and enable the aircraft to fly !!

Bernoulli Principle However, to create lift the surface of the wing must be ensured to have a smooth surface. The present of ice on the wing surface cause distraction to the air flow at the wing.

Overcome Icing Problem Use anti-icing or de- icing system. An aircraft is equipped with the anti-icing instrument in case of icing happen during flight. Before flight, the authorities will spray anti-icing liquid on the fuselage and wing surface to avoid icing.

LIGHTNING Lightning is the natural high-voltage electrical discharge between a cloud and the ground. Lightning affect the aircraft by build up the static electricity in the airframe. Risks of lightning are:  Lead to the loss of radio communications  Damage the aircraft’s structure  Making instrument reading impossible  Affect the crew's vision  Explosion of aircraft fuel system

The outer skin of most airplanes is primarily aluminum which is good conductor of electricity; The engineer built an aircraft body from composite structure to prevent lightning problem. There are also prevention made by the manufacturers to avoid lightning effect. HOWEVER AVOIDING THUNDERSTORMS AND LIGHTNING IS THE BEST POLICY! LIGHTNING

The secret to safe lightning hits is:  Allow the current to flow through the skin from the point of impact to some other point without interruption or diversion to the interior of the aircraft.  skin around the fuel tanks must be thick enough to withstand a burn through.  All of the structural joints and fasteners must be tightly designed to prevent sparks, because lightning current passes from one section to another. LIGHTNING

Figure: Aircraft hit by lightning LIGHTNING

Figure: Aircraft skin acts as electricity conductor

ANY QUESTION? THANK YOU!