A preliminary investigation into the emergency revealed that the Beechcraft Musketeer's engine started running roughly during flight exercises at Palo Alto Airport, prompting the forced landing about two miles west of the airport at 9:47 a.m., FAA spokesman Ian Gregor said.
Neither the instructor nor the student was injured, Gregor said.
The plane's left wing struck a tree after the landing, causing substantial damage.
The incident remains under investigation by the FAA.
