Ellipitical / cylindrical with a size at least double of a 747 Jet airliner...
"Following my departure from Denpasar Bali airport by commercial airlines, Air Asia, to Singapore. Approximately thirty minutes out, I saw, looking south with a westerly direction of my flight, down to the first cloud level (as we were probably 20,000 feet in elevation), I witnessed an elliptical / cylindrical air craft UFO, flying eastward along the coast. Camera failure was the distraction at this time and when I looked back the object (slow flight) continued on and changed direction and was now flying south into the island, away from the coast. This region has no occupation of anything more than remote villages as no city was anywhere in view along the coast region of the island of Madura. As the Air Asia airlines continued it's course west towards Singapore, I saw the craft continue on it's course south until it went out of sight. Semi cloudly day of cumulus formations with clear views at the twenty thousand foot elevation."