Large field of view airborne down-looking synthetic aperture imaging ladar with sine phase modulation is reported. The high resolution and high quality synthetic aperture imaging is realized at target distance of 3.8 km outdoors. Then the airborne down-looking synthetic aperture imaging ladar is used for flight demonstration. The height of the flight is 3 km. High quality and large field of view is achieved. The field of view is enhanced by over an order of magnitude, which is up to 4.8 mrad.