The Best Prophet of the Future is the Past, Part II: Cockpit Doors

This post was written by Chris Naylor, Director of the Textual Records Division.

The devastating Germanwings plane crash on March 24, 2015 has reinvigorated the dialogue surrounding airplane cockpit doors, an issue of paramount concern both in 1970 as well as in the wake of the 9/11 attacks. I recently wrote a blog post about President Nixon’s announcement of a program to deal with airplane hijackings on September 11, 1970. During this same period, members of Congress and concerned citizens were writing to the White House and federal agencies to express their views on the issue of hijacking as well as to offer suggestions on various means of dealing with this issue in the future. For one, the Airline Pilots Association (ALPA) was very concerned for the safety of crew and passengers aboard airplanes.

By 1970, there had been several incidents that revealed the vulnerability of access to the cockpit from the passenger cabin. On May 5, 1964, a deranged passenger shot both pilots aboard Pacific Air Lines Flight 773 resulting in the death of all forty-four people aboard. This was not the first attempted murder-suicide aboard a commercial airplane, nor would it be the last. In recognition of this threat, the Federal Aviation Administration (FAA) began requiring the locking of the door separating passenger and flight crew compartments on large commercial airplanes in August 1964. However, the FAA understood the limitations of this rule due to the fact that the flight crew required access to the passenger cabin several times during flight which provides opportunities for an unauthorized person to enter the cockpit as well as the potential to gain access through threat of violence to passengers or crew.

During another incident on March 17, 1970 an armed passenger entered the cockpit of Eastern Airlines Flight 1302 en route from Newark, New Jersey to Boston,Massachusetts and ordered the pilot to fly the plane out to sea. When the captain attempted to turn the flight back to the mainland, the hijacker, John J. Divivo, shot the pilot and copilot. Although mortally wounded, the copilot disarmed Divivo and shot him twice. The pilot, who had been shot in both arms, fought off another attack by Divivo, then landed the plane at the original destination. Had it not been for the heroism of the pilot, Captain Robert Wilbur Jr., and the copilot, James Hartley, this flight would have ended in disaster.

Following the Eastern Airlines incident, the ALPA began a concerted effort to push for a secure cockpit concept with the FAA. The FAA files from 1970 contain numerous documents relating to ALPA inquiries relating to the strengthening of cockpit doors.

On September 5, 1970, Dr. Constantin Paul Lent wrote a letter to Vice President Spiro Agnew regarding how to prevent hijackings. Dr. Lent was a mechanical engineer who can be viewed as a visionary and “outside the box” thinker for his prolific writing on rocketry and space travel beginning as early as the 1930s as well as his filing of numerous patents relating to these subjects. Dr. Lent offered the following proposal: “A simple way to prevent highjackers for passing their orders to the aviator is to build a solid wall across the entry door leading from the passenger cabin to the cockpit so as to separate the two and not permit passage.” He included an article he had written for the Summer 1970 issue of his journal Rocket-Jet Flying, which explained how hijackings could be discouraged by using this approach. The article provided the following solution: Provide the pilot’s cabin with its own lavatory facilities and a food compartment. In this manner, there would be no need for physical contact between the flight crew and passenger cabin during the flight, which would eliminate the possibility of hijackers gaining access to the cockpit.

Dr. Lent concluded his letter to the Vice President with the following:

Please communicate this plan to the heads of the various aviation firms and airlines to take effect immediately so as to prevent future highjacking of aircraft. This practice of highjacking could cause huge financial defisits [sic] and may also become in time the cause for another World War.

Sohmer Letter-res

Letter from Arthur Sohmer to Dr. Constantin Lent, Sept 25, 1970


Dr. Lent’s letter was forwarded to the FAA for their consideration and was docketed as comments for the FAA advance notice of proposed rule making (Notice 70-28, 23 July 1970, Docket #10460) which solicited comments concerning bulletproof bulkheads and other cockpit arrangements to enhance security on large passenger carrying airplanes.

On October 21, 1970, the acting FAA administrator provided the Secretary of Transportation with a requested summary of the comments received for the FAA advance notice of proposed rule making.  In general, the airline industry comments were against the proposals.  On the other hand, non-professional comments were overwhelmingly in support of bulletproofing the cockpit, with particular mention of the argument for complete isolation between the flight deck and passenger cabin. It was noted, however, that the responses did not appear to be very helpful.

The implementation of mandatory passenger screening in 1973 lessened the sense of urgency regarding cockpit security.  In time the aviation industry adopted the FAA-approved Common Strategy approach to accommodate the demands of hijackers aboard a plane in order to try to get the plane to land safely, rather than any strategy to counter hijackings mid-flight.  The Common Strategy was based on decades of experience that hijackings could best be resolved once the plane had landed, but would be ineffective in any situation where the hijackers had no intention to land the plane.

Thirty-one years after the ALPA demanded immediate action and Dr. Lent provided his proposal on securing the cockpit to thwart hijacking attempts, access to the flight deck continued to remain a vulnerability on commercial airplanes.  Following the September 11, 2001 attacks, the security of flight deck doors became a major concern as a result of the relative ease with which the hijackers on the four planes were able to enter the cockpits and take control of the planes.  In fact, the Aviation and Transportation Security Act of 2001 passed shortly following the 9/11 attacks included requirements for the strengthening of flight deck doors as well as the locking of the doors while the aircraft is in flight except when necessary to permit access and egress by authorized persons.

To this day, aviation security experts continue to assess options for improving cockpit security.  Dr. Lent may not have realized it at the time, but his vision of a secure cockpit with a lavatory and food compartment would not only protect from hijackers in the passenger cabin, but would also avoid the necessity of a pilot leaving the cockpit, as occurred on the Germanwings flight as well as other known instances of pilot murder-suicide aboard commercial airplanes.