In aviation, blue ice is frozen sewage material that has leaked mid-flight from commercial aircraft lavatory waste systems. It is a mixture of human biowaste and liquid disinfectant that freezes at high altitude. The name comes from the blue color of the disinfectant. Airlines are not allowed to dump their waste tanks mid-flight, and pilots have no mechanism by which to do so; [1] however, leaks sometimes do occur from a plane's septic tank.
There were at least 27 documented incidents of blue ice impacts in the United States between 1979 and 2003. [2] These incidents typically happen under airport landing paths as the mass warms sufficiently to detach from the plane during its descent. A rare incident of falling blue ice causing damage to the roof of a home was reported on October 20, 2006 in Chino, California. [3] A similar incident was reported in Leicester, UK, in 2007. [4]
Other documented incidents include:
Blue ice can also be dangerous to the aircraft itself — the National Transportation Safety Board has recorded three very similar incidents where waste from lavatories caused damage to the leaking aircraft, [11] [12] [13] all involving Boeing 727s. In all three cases, waste from a leaking lavatory hit one of the three engines the 727 has mounted in the rear, causing a power loss. [11] [12] [13] The flights made safe emergency landings with the two remaining functioning engines; nobody was injured. Only one report specifically mentions ice, [12] while another mentions "soft body FOD" (foreign object damage), [13] indicating that the damage was caused by a relatively soft object like a bird, or even ice, as opposed to (for example) a stone or an object made of metal.
The National Transportation Safety Board (NTSB) is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine accidents, pipeline incidents, bridge failures, and railroad accidents. The NTSB is also in charge of investigating cases of hazardous materials releases that occur during transportation. The agency is based in Washington, D.C. It has four regional offices, located in Anchorage, Alaska; Denver, Colorado; Ashburn, Virginia; and Seattle, Washington. The agency also operates a national training center at its Ashburn facility.
Northwest Airlink was the brand name of Northwest Airlines' regional airline service, which flew turboprop and regional jet aircraft from Northwest's domestic hubs in Minneapolis, Detroit, and Memphis. Service was primarily to small-to-medium-sized cities and towns where larger aircraft might not be economical to operate and also to larger markets to either provide additional capacity or more frequent flights than could be justified using mainline aircraft. Beginning in July 2009, the Northwest Airlink trade name was phased out, and replaced by the Delta Connection trade name for Delta Air Lines as part of the Delta/Northwest merger.
Aloha Airlines Flight 243 was a scheduled Aloha Airlines flight between Hilo and Honolulu in Hawaii. On April 28, 1988, a Boeing 737-297 serving the flight suffered extensive damage after an explosive decompression in flight, caused by part of the fuselage breaking due to poor maintenance and metal fatigue. The plane was able to land safely at Kahului Airport on Maui. The one fatality, flight attendant Clarabelle "C.B." Lansing, was ejected from the airplane. Another 65 passengers and crew were injured. The substantial damage inflicted by the decompression, the loss of one cabin crew member, and the safe landing of the aircraft established the incident as a significant event in the history of aviation, with far-reaching effects on aviation safety policies and procedures.
Air Canada Flight 797 was an international passenger flight operating from Dallas/Fort Worth International Airport to Montréal–Dorval International Airport, with an intermediate stop at Toronto Pearson International Airport.
United Airlines Flight 811 was a regularly scheduled international flight from Los Angeles to Sydney, with intermediate stops at Honolulu and Auckland. On February 24, 1989, the Boeing 747-122 serving the flight experienced a cargo-door failure in flight shortly after leaving Honolulu. The resulting explosive decompression blew out several rows of seats, killing nine passengers. The aircraft returned to Honolulu and landed without further incident.
JetBlue Flight 292 was a scheduled flight from Bob Hope Airport in Burbank, California, to John F. Kennedy International Airport in New York City. On September 21, 2005, Captain Scott Burke executed an emergency landing in the Airbus A320-232 at Los Angeles International Airport after the nose gear jammed in an abnormal position. No one was injured.
Chalk's Ocean Airways Flight 101 was an aircraft crash that occurred off Miami Beach, Florida, in the United States on December 19, 2005. All 18 passengers and both of the crew members on board the 1947 Grumman G-73T Turbine Mallard died in the crash, which was attributed to metal fatigue on the starboard wing resulting in separation of the wing from the fuselage.
The 2007 San Francisco International Airport runway incursion occurred around 1:36 p.m. PDT on May 26, 2007, when SkyWest Airlines Flight 5741, an Embraer EMB 120 Brasilia turboprop aircraft, nearly collided with Republic Airways Flight 4912, an Embraer 170 Regional Jet, at the intersection of Runways 1L and 28R at San Francisco International Airport (SFO).
An aircraft lavatory or plane toilet is a small unisex room on an aircraft with a toilet and sink. They are commonplace on passenger flights except some short-haul flights. Aircraft toilets were historically chemical toilets, but many now use a vacuum flush system instead.
British Airways Flight 38 was a scheduled international passenger flight from Beijing Capital International Airport in Beijing, China, to London Heathrow Airport in London, United Kingdom, an 8,100-kilometre trip. On 17 January 2008, the Boeing 777-200ER aircraft operating the flight crashed just short of the runway while landing at Heathrow. No fatalities occurred; of the 152 people on board, 47 sustained injuries, one serious. It was the first time in the aircraft type's history that a Boeing 777 was declared a hull loss, and subsequently written off.
During the 1990s, a series of issues affecting the rudder of Boeing 737 passenger aircraft resulted in multiple incidents. In two separate accidents, pilots lost control of their aircraft due to a sudden and unexpected rudder movement, and the resulting crashes killed everyone on board, 157 people in total. Similar rudder issues led to a temporary loss of control on at least one other Boeing 737 flight before the cause of the problem was ultimately identified.
Continental Airlines Flight 1404 was a Continental Airlines domestic flight from Denver International Airport in Denver, Colorado, to George Bush Intercontinental Airport in Houston, Texas. On the evening of December 20, 2008, the flight crashed while taking off from Denver, resulting in two critical injuries, 36 noncritical injuries, and a hull loss of the Boeing 737-524 aircraft.
Southwest Airlines Flight 2294 (WN2294/SWA2294) was a scheduled US passenger aircraft flight which suffered a rapid depressurization of the passenger cabin on July 13, 2009. The aircraft made an emergency landing at Yeager Airport in Charleston, West Virginia, with no fatalities or major injuries to passengers and crew. An NTSB investigation found that the incident was caused by a failure in the fuselage skin due to metal fatigue.
Northwest Airlines Flight 5 was a flight from Miami International Airport to Minneapolis−Saint Paul International Airport, which, on January 4, 1990, suffered the loss of the number three (starboard) engine at 35,000 feet (11,000 m) in mid-flight over Madison, Florida.
Southwest Airlines Flight 812 was a Boeing 737-300 passenger jet that on April 1, 2011, suffered rapid depressurization while cruising at 34,000 ft (10,000 m) near Yuma, Arizona, leading to an emergency landing at Yuma International Airport. Two of the 123 people on board suffered minor injuries. The aircraft was operating Southwest Airlines' domestic scheduled service from Phoenix, Arizona, to Sacramento, California.
American Eagle is a brand name for the regional branch of American Airlines, under which six individual regional airlines operate short- and medium-haul feeder flights. Three of these airlines, Envoy Air, Piedmont Airlines, and PSA Airlines, are wholly owned subsidiaries of the American Airlines Group. American Eagle's largest hub is Charlotte Douglas International's Concourse E, which operates over 340 flights per day, making it the largest express flight operation in the world.
British Airways Flight 2276 was a scheduled international passenger service from Las Vegas to London. On 8 September 2015, the Boeing 777-200ER operating the flight suffered an uncontained engine failure and fire in the left (#1) GE90 engine during take-off from Las Vegas-McCarran International Airport, prompting an aborted take-off and the evacuation of all passengers and crew. All 170 people on board survived, but 20 were injured.
Southwest Airlines Flight 3472 was a regularly scheduled passenger flight operating from New Orleans International Airport in New Orleans, Louisiana to Orlando International Airport in Orlando, Florida. On August 27, 2016, the Boeing 737-7H4, with 99 passengers and five crew, 12 minutes after departure from New Orleans, was climbing through 31,000 feet and heading east over the Gulf of Mexico when the aircraft's number one CFM International CFM56-7 engine suffered an engine failure. A fan blade in the engine broke due to a fatigue crack. The separated portion of the blade rotated within the engine, moving forward, striking the engine inlet. Debris from the damaged engine inlet punctured the left side of the fuselage causing a loss of cabin pressure and damaged the wing and empennage. Oxygen masks were deployed to passengers while the crew initiated an emergency descent to 10,000 feet. The aircraft then diverted to Pensacola International Airport for a safe landing about 20 minutes later without further incident. While the aircraft sustained substantial damage, there were no injuries.
On February 20, 2021, United Airlines Flight 328 (UA328/UAL328), a scheduled U.S. domestic passenger flight from Denver to Honolulu, suffered what was technically ruled a contained engine failure despite shedding large pieces of debris, approximately four minutes after takeoff from Denver International Airport (DEN). Parts departing from the engine cowling of the Boeing 777-222 aircraft resulted in a debris field at least 1 mile (1.6 km) long over suburban residential areas of Broomfield, Colorado. Falling debris was recorded by eyewitnesses using smartphone cameras and a dash cam. Debris fell through the roof of a private home and significantly damaged a parked vehicle.
In aviation safety, parts departing aircraft or parts detached from aeroplanes (PDA), also known as objects falling off airplanes (OFA), things falling off aircraft (TFOA), and other analogous variations, can range from small fasteners like screws and rivets up to major sub-assemblies like hatch covers and doors. PDA are a safety concern because they may be critical parts needed to continue safe flight, may damage other critical parts of the aircraft as they depart, may cause foreign object damage to other aircraft, or may cause serious injuries or damage to people and property on the ground. These occurrences are a longstanding worldwide problem in aviation.
The Living in Everyday Earth Web site reports there have been at least 27 documented blue-ice incidents nationally in the past 24 years.