(Credit:John Palminteri/KEYT Santa Barbara)

Air Force Two, a modified Boeing 757 government airplane carrying Vice President Joe Biden, struck birds Thursday night as it was on approach to Santa Barbara Airport in California, an administration official told ABC News.

Sources familiar with the incident said to the passengers, the landing didn't feel any different than normal, no one could tell the plane hit a bird.  But the pilots of the plane noticed the bird strike when it happened.

The plane touched down safely between 10 and 10:30 pm PT without further incident, allowing Biden to continue on his itinerary, officials said.  Biden was in Santa Barbara for a campaign fundraiser Friday morning.

"When there is a bird strike our safety procedure is to land safely as quickly as possible to get an assessment of what happened and review the  extent of damage if there is damage," said Lt. Gregg Johnson of the 89 th Airlift Wing at Joint Base Andrews, which maintains the presidential fleet.

It's not clear as of now whether there was any damage to the plane; mechanics today began the process of conducting normal checks on the plane just make sure everything was OK.  It's engines were seen under inspection by mechanics on the airport tarmac.

"The Vice President left Santa Barbara this afternoon as scheduled, aboard an alternate U.S. Air Force aircraft," a spokesperson for the vice president said.

The alternate plane - the military version of a Gulf Stream 3 - assumed the designation "Air Force Two" when the Vice President boarded for the return trip, according to military policy.

Sources familiar with the incident said to the passengers, the landing didn't feel any different than normal, no one could tell the plane hit a bird.

This post has been updated.