Alaska Airlines cabin crew used a beverage cart to stop a passenger trying to enter the cockpit, prosecutors say

• An Alaska Airlines passenger tried three times to access the cockpit, an affidavit says.
• Flight attendants blocked the door with a beverage cart, the affidavit adds.

An Alaska Airlines cabin crew blocked the cockpit with a beverage cart to stop a passenger from accessing the cockpit, an affidavit states.

Nathan Jones was flying from San Diego to Washington, DC, on March 3 when he made three attempts to open the cockpit door, the court document says.

The affidavit, seen by Business Insider, is based on an investigation from an FBI officer who's also a federal air marshal with the Transportation Security Administration.

Off-duty law-enforcement officers "restrained Jones in flex cuffs and sat on either side of him" for the rest of the flight, the affidavit says.

It adds that when a flight attendant asked why he was trying to get into the cockpit, Jones replied that he "was testing them."

The cockpit was locked down for the rest of the flight, and flight attendants barricaded the cockpit door with a beverage cart, the affidavit says.

When the plane landed, law-enforcement officers searched Jones' luggage and found his student pilot's license and notebooks describing how to operate an aircraft, the court document says.

Jones was charged with one count of interference with a flight crew the day after the incident.

On Wednesday, his lawyer submitted a motion for a mental-competency evaluation.

A letter from the senior therapist at the jail where Jones is detained said Jones was displaying "symptoms indicative of a serious mental illness."

Alaska Airlines did not immediately respond to a request for comment from BI sent outside normal working hours.