OKLAHOMA CITY - The mysterious boom that shook much of northeastern Oklahoma Saturday happened just a week short of the 50th anniversary of a huge U.S. government sonic boom research project that was centered in the Sooner State.

Thousands of people from Sapulpa to Claremore and Inola reported hearing and feeling a powerful boom at about 8 p.m. on Saturday, January 25, 2014. No one in an official capacity has offered an explanation for what caused it, but the most likely cause seems to be a sonic boom.

Turns out sonic booms and Oklahoma have a long history.

On February 3, 1964, the Federal Aviation Administration began Operation Bongo II. It was a major study aimed at discovering if the general public would object to hearing and feeling repeated sonic booms for extended periods. There had been other sonic boom studies in the U.S. before, but nothing on this scale.

For six months, the U.S. Air Force subjected Oklahoma City to 1,253 sonic booms, then researchers from the National Opinion Research Center at the University of Chicago surveyed public opinion about them.

The result is a 422-page report detailing how the operation was conducted and how the researchers scientifically gathered responses from the public without telling them the real purpose of the survey.

Picking Oklahoma City

The Federal Aviation Administration wanted to test the public's response to repeated sonic booms because it was directing research into the Supersonic Transport, or SST. The SST would be a civilian jet liner that would break the sound barrier on every flight. Before the skies over the U.S. would be filled with SSTs and their sonic booms, the FAA decided to learn what kind of backlash, if any, they'd generate.

The FAA settled on Oklahoma City for many reasons. The city had "previous sonic boom experience," it was relatively flat, had buildings of different types and ages and a population that was used to seeing propeller and jet aircraft.

Flight Schedule

The U.S. Air Force used primarily Lockheed F-104 Starfighters and Convair B-58 Hustler bombers to create the sonic booms. In a schedule designed to simulate the flight schedule of the SST, the planes created eight sonic booms over Oklahoma City every day. The booms happened at the following times:

7:00 a.m.           11 a.m.
7:30 a.m.           11:20 a.m.
9:00 a.m.           1 p.m.
9:20 a.m.           1:20 p.m.

The booms were so regular, a film crew commissioned by the FAA was surprised to see construction workers use one of them as a signal to break for lunch.

The flight track was 100 nautical miles long, from the southwest to the northeast, stretching from Minco to Arcadia. That took the airplanes over densely populated areas, both in the city and in the country, over both new neighborhoods and older communities.

The Interviews

Once the flights were over, researchers conducted interviews of more than 3,000 people both in person and over the phone.

The researchers never told the subjects the real purpose of the interviews, asking them questions about all kinds of local problems, as well as specific questions about sonic booms. The FAA had widely publicized the boom study, so people usually mentioned sonic booms before the researchers ever asked about them.

The Results

The FAA actually set up a message center to handle complaints about the study. It received 12,389 calls and letters during the project.

The researchers reported "complainers about sonic booms were not chronic gripers." They said the complainers were more likely to be older women with fewer children at home.

The researchers found that more than 90 percent of the people they talked to felt they could get used to repeated sonic booms. They said Oklahoma City residents "generally have a low general complaint potential," but concluded that "widespread feelings of futility in complaining" probably had something to do with that.

The researchers were careful to note that the project did not cover sonic booms at night and recommended further research into whether the public would object to them. That research never happened.

The FAA claimed the study was a success, demonstrating widespread support for the SST, however, the large number of complaints received, including lawsuits against the FAA and the federal government, would suggest otherwise.

Eventually the FAA would prohibit sonic booms by civilian aircraft over land in the U.S. and the federal government would scrap plans for the SST.