Last week, I managed to handle one interesting case about Boeing 747. As far as I remember, this maybe the first incident happened for at least the last 3 years. Given that we have total about 160 aircrafts in our fleet, I would say that this incident is rarely happen.
One of the Boeing 747 aircraft has encountered nacelle/pod strike during landing. The damage was not really serious, just minor scracthes on the nacelle components external skin (i.e Thrust Reverser and Fan Cowl). In fact, the pilot did not realize that the engine nacelle has touched the ground during landing. They only found it when the engineers did the walk around check when the aircraft arrived at the gate.
For those who does not know what is the “nacelle”, a nacelle is a housing, separate from the fuselage, that holds engines, fuel, or equipment on an aircraft. Since the shape is like a “pod”, that is the reason why we call it “pod strike” if it touches the ground while take off or landing. You can see below illustration for further understanding.
One of the most common cause for the nacelle/pod strike is due to crosswind landing. Unexpected gusts of wind may cause an aircraft to roll to one side or the other during landing, whether they are performing a crosswind landing or not. However, crosswind landings have a much more complex dynamic relationship between the wind and the aircraft attitude. Because the wind is blowing across the runway, the aircraft has to either roll or yaw into the wind to be able to approach down the runway’s centerline. Due to the complication, sometime the aircraft wing or engine nacelle can touch the ground while landing and caused some damage.
Below is the some video that I took from youtube about nacelle/pod strike. This incident maybe more worse than the one that I had last week. Just imagine how difficult for pilot to land the aircraft in the crosswind condition.
Ir. Edie Fendie
13 Jan 2014