A Cyclone was approaching a remote island in the Indian Ocean. The national telecommunications operators invoked the emergency preparedness plans developed after the last cyclone had hit the island 12 years ago. One of the measures taken was, to position parabolic antenna for satellite communication links into a horizontal position, minimizing the wind load on this structure. The operator informed the counterpart ground station relaying all traffic from and to the island, that the link would now be disconnected for the time being until the cyclone had passed the island.

Meanwhile, relief organizations abroad were watching the progress of the storm. The eye of the storm narrowly missed the island, but the impact of the wind and the rain could have been disastrous nevertheless. Given the very limited resources available on a small island, international assistance might well be required urgently. But even 24 hours after the storm had again moved out to the open sea, all attempts establish contact with the island failed.

How could that be?  When the cyclone approached, the preparedness plans had been taken out of the drawer where they had been kept since the cyclone of 12 years ago.   However: In all this time, it had not been verified if they still corresponded to the requirements; they had never been tested. The antenna survived the storm without apparent damage, but when it was manoeuvred back to its operating position, communication with the satellite could not be established.

Closer examination showed, that the "feed horn", the central element of the satellite dish, was bent, so that the parabolic antenna no longer pointed to the direction its control panel indicated.  The larger such an antenna is, the more narrow is its aperture, and the more critical is the positioning. The cause of the damage was quickly identified: Several nearby palm trees had grown to considerable height over the past 12 years, and the wind threw branches and coconuts on the feed horn, bending its structure out of shape. The dish no longer "saw" the satellite, when it was moved to the known position. Re-alignment required the intervention of experts not residing on the island - and which could, without any communications link working, not be reached.

With the modernization of the telecommunications infrastructure on the island, the outside links of all public networks had been centralized and used the broadband capacity of that single satellite station. The damage to its one antenna disrupted all of them simultaneously.

Lessons learned: Make sure your preparedness plans are reviewed in regular intervals, and never "put all your eggs in one basket. The palm trees presented no danger when the plans were drawn up, but over time they became a hazard for the vulnerable antenna. Abandoning all other links in favour of the one broadband connection was certainly the most economic solution, but did not consider the possible loss of this one facility in an emergency situation.