21.   On Tuesday, aides had to whisk Arafat to an underground shelter as they heard Israeli helicopters approaching his headquarters in the West Bank town of Ramallah.

22.   Russian helicopters could be heard overhead for the first time.

23.   The base received calls from witnesses reporting that they heard two helicopters crashing into each other and saw them fall into a nearby mountain, Goshima said.

24.   Two helicopters were heard in the air moments before three explosions were heard, witnesses said.

25.   Two helicopters were heard in the air moments before three explosions were heard.

26.   In a separate report, a Belgian national in Goma said friends staying in the Zairean town of Kisangani had heard helicopters flying over the region overnight.

27.   The reporter also heard helicopters clattering over the devastated city.

28.   Israeli helicopters could be heard over the city.

29.   On Wednesday night at least two helicopters were heard in a possible indication that US or British special forces might have been flown into the area.

30.   She told BOC officials in a radio call to race headquarters in Sydney that she had heard the helicopter coming to rescue her at sunrise.