Foreign Object Damage
Foreign Object Damage (FOD) (engl .: foreign object damage ), the damage to an aircraft (except other aircraft) foreign object called. This includes foreign objects coming from the runway (in particular the sucking in of parts in aircraft engines, even in parking positions when the engines are started), bird strikes and hail . Damage caused by guided missiles , icing on wings and engine failure as a result of sucked in sand do not count as foreign object damage .
Causes of Foreign Object Damage
The main causes of foreign object damage today are high speeds, the size of modern engines and the air masses they move. In jet engines that are used to propel jet planes, very large amounts of air are sucked in to generate forward thrust before take-off . The suction effect of the engine that occurs in this context harbors the risk that even very large foreign parts can get into the engine with the airflow and cause damage there. For this reason, careful and regular rail control by the airport operator is important at airports or aircraft carriers . B. the apron control this task.
A special case is the bird strike , i.e. the collision of a bird with the aircraft (e.g. the glass of the cockpit window ) or its engines, which can result in considerable damage and thus endanger people.
Measures against Foreign Object Damage
Since the problem is omnipresent in air traffic, a variety of measures are taken against foreign object damage:
- regular control of the runways for foreign objects during flight operations
- Checking the parking position before the aircraft lands by the handling staff (especially ramp agent )
- Creation of a zone around runways that is not attractive to birds
- Weather radar with hail detection
- Checking the completeness of tools and personal items before and after work in a sensitive area
- technical measures, e.g. B. Arrangement of the engines above the wing (as in the VFW 614 and Fairchild-Republic A-10 ), and engine shapes that make it difficult to suck in foreign objects
Foreign Object Debris
The abbreviation FOD is used, especially in the naval armed forces, for the foreign objects lying around, whereby the "D" in this case stands for debris (English: fragment, rubble, foreign body) : Foreign Object Debris .
Examples
When designing the Airbus A380 , the risk of FOD was taken into account: only the inner engines are equipped with a thrust reverser function. Due to the large wingspan, there would otherwise be a risk of dirt being whirled up and sucked in on relatively narrow runways.
A tragic example of FOD is the crash of a Concorde on July 25, 2000 shortly after take-off from Paris ( Air France flight 4590 ), which was triggered by a metal part of a DC-10 that was on the runway .
