Full FAA Chronology at this link.
19470404: The Convention on International Civil Aviation came into force after being ratified by 26 countries. (Among these was the United States, which had ratified the Convention on August 9, 1946.) The Convention had been drawn up at a conference in Chicago over two years before (see November 1-December 7, 1944). The fact that it was now in force officially created the International Civil Aviation Organization (ICAO) to succeed its temporary predecessor, PICAO (see June 6, 1945). The first General Assembly of ICAO was held in Montreal during May 6-28.
19470404: CAB certificated Piedmont Airlines as a local service carrier. The airline, whose original routes ran along the Piedmont-Appalachia area, began operations on February 20, 1948. Piedmont expanded steadily during the succeeding decades, then grew rapidly after airline deregulation was introduced in the late 1970s. (See October 30, 1987.)
19490404: The North Atlantic Treaty was signed by the U.S. Secretary of State and the Foreign Ministers of Britain, Belgium, Canada, Denmark, France, Holland, Iceland, Italy, Luxembourg, Norway, and Portugal. Article 5 of the treaty specified that “an armed attack against any one or more of them in Europe or North America shall be considered an attack against them all.”
19600404: FAA placed in effect the first of a series of regulations designed to minimize aircraft noise at major airports by procedural methods while retaining safety as the primary objective. This Special Civil Air Regulation No. 438 set up rules for both civil and military aircraft operating at Los Angeles International Airport, including minimum altitudes, preferential runways, and approach and departure routes over the least populated areas. Similar special regulations covering operations at New York International (Idlewild) and at Washington National Airport were issued October 15 and November 29, 1960 respectively. (See July 18, 1960, and December 4, 1967.)
19630404: Under the air route traffic control center consolidation program, FAA completed a phaseout of the Spokane center and transferred its responsibilities to the Seattle center. The agency completed two similar phase-outs on June 22 (El Paso, with responsibilities transferred to the Albuquerque center) and June 30 (Norfolk, with responsibilities transferred to the Washington center).
19750404: A regulation governing the installation and safe operation of X-ray devices for screening carry-on luggage at airports became effective this date. The rule had been proposed on June 21, 1974, after a U.S. District Court judge declared that FAA acted illegally by allowing the X-ray machines to be installed without certifying as to their safety. The new regulation required testing to ensure that the devices complied fully with radiation level standards set by the Food and Drug Administration, and also provided for the training and protection of operators of this equipment.
19770404: A Southern Airways DC-9 crashed near New Hope, Ga. The pilot attempted an emergency landing on a highway, but the aircraft broke apart and caught fire. The accident killed 62 of the 85 persons aboard, as well as 8 persons on the ground. In addition, one passenger and one person injured on the ground died about a month later. The National Transportation Safety Board cited the probable cause of the crash as the total and unique loss of thrust after the engines ingested massive amounts of water and hail as the aircraft penetrated an area of severe thunderstorms. As contributory causes, the NTSB listed: failure of the airline’s dispatch system to provide up-to-date severe weather data; the captain’s reliance on airborne weather radar to enter a thunderstorm area; and FAA’s lack of a system for disseminating real-time hazardous weather warnings. (See May 19, 1977.)
19790404: A Trans World Airlines 727 flying at 39,000 feet over Michigan entered an uncontrolled spiral dive and descended to about 5,000 feet in about 63 seconds before the flight crew regained control. Eight passengers received minor injuries. The crew denied that they had caused the dive or erased the Cockpit Voice Recorder tape, most of which was found to be blank. In a June 1981 report, however, the National Transportation Safety Board described the probable cause of the mishap as the crew’s manipulation of the flap/slat controls.
19910404: FAA completed transfer of more than 600,000 square miles of oceanic airspace from the Miami and Boston en route centers to the New York center. The action completed the last phase of a larger restructuring begun in September 1989, with transfer of airspace from the San Juan center to the New York center.
19910404: FAA issued a rule increasing protection against cabin fires by upgrading requirements for lavatory fire detectors, lavatory trash receptacles, and hand fire extinguishers. (See March 29, 1985.)
20120404: FAA announced release of its seventh annual update to the controller workforce plan, which outlined the agency’s strategies to maintain controller staffing levels at air traffic control facilities across the country for the next decade. According to the plan, FAA had hired more than 7,500 new air traffic controllers in the past five years, and currently employed more controllers than in 2000, even though air traffic had declined 23 percent in the past decade. FAA planned to hire 6,200 more controllers over the next five years to keep pace with forecast retirements and traffic growth. In the previous five years, 3,151 controllers had retired. (See March 7, 2007; February 10, 2014.)
20130404: US Airways announced it had received FAA certification, the first airline to receive such approval, to use SafeRoute on its wide-body Airbus A330. The SafeRoute suite of four applications used automatic dependent surveillance-broadcast (ADS-B) technology to provide pilots with more precise position information of the operating aircraft and other airplane traffic. It also included interval management (IM), in-trail procedures (ITP), cockpit display of traffic information to assist in visual separation (CAVS), and surface area movement management (SAMM). IM made use of onboard aircraft surveillance to provide flight deck spacing commands that enable aircraft to follow one another at the safest, most efficient interval possible, from cruise altitude to the runway. ITP improved situational awareness and enabled flight crews to perform desired altitude changes on a more frequent basis in oceanic or non-radar airspace. CAVS allowed the flight crew to continue visual approach procedures using the electronic display to maintain separation if they lost visual contact with traffic-to-follow due to hazy or night conditions. It also assisted the flight crew in properly timing the deceleration to final approach speed, configuring the aircraft for landing and properly spacing aircraft on the final approach segment just prior to landing. SAMM provided a moving map display of the airport surface in the cockpit that showed other traffic operating in the terminal, taxi, and runway areas. (See January 2, 2013; June 9, 2013.)