It's nothing to worry about. Probably some kind of aerial salute for the President while he signs the armistice.
7 seconds sound clip from the Battlestar Galactica (1978) movie soundboard.
You can hear this line at 00:16:28 in the Blu-ray version of the movie.
Quote context
[...]
- Get that pilot up here as soon as he lands.
- Sure ruined a good card game.
- Mr. President, a wall of unidentified craft is closing in on the fleet.
- Possibly a Cylon welcoming committee.
- Sir, may I suggest we launch a welcoming committee of our own?
[...]