Tag Archives: United Airlines

24 February 1989

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United Air Lines' Boeing 747 N4713U, photographed at Los Angeles International Airport, 14 April 1982. (Ted Quackenbush via Wikipedia)
United Airlines’ Boeing 747-122 s/n 19875, N4713U, photographed at Los Angeles International Airport, 14 April 1982. (Ted Quackenbush via Wikipedia)

24 February 1989: At 01:52:49 HST, United Airlines Flight 811 was cleared for takeoff from Honolulu International Airport (HNL), enroute to Auckland International Airport (AKL) and onward to Sydney, Australia (SYD). On board were 337 passengers and 18 crew members. The airliner was under the command of Captain David Cronin, with First Officer Gregory Slader and Second Officer Randal Thomas. The airliner was a Boeing 747-122, serial number 19875, registered N4713U.

16 minutes after takeoff, about 60 miles (97 kilometers) south of Honolulu, the 747 was climbing through an altitude of 22,000 feet (6,705 meters) at 300 knots (345 miles per hour/556 kilometers per hour) when, at 02:09:09 HST, the cargo door on the lower right side of the fuselage, just forward of the wing, failed, blowing outward. Explosive decompression blew a huge hole in the fuselage. Ten passenger seats were carried away along with nine passengers. A flight attendant was nearly lost, but was dragged back inside by passengers and crew.

The damaaged fuselage of United Airlines Flight 811. (BBC)

Debris damaged the two engines on the right wing, causing them to lose power. Flames were visible. Both engines had to be shut down. Flight 811 declared an emergency, began descending and dumping fuel to reduce the airliner’s weight for an emergency landing. The 747 turned back toward Honolulu.

Because the wing had also been damaged, the flaps could not be fully extended and this required a much higher than normal approach speed. The 747 touched down at approximately 200 knots (230 miles per hour/370 kilometers per hour). After coming to a stop, Flight 811 was completely evacuated within 45 seconds. Every flight attendant suffered some injury.

Damaged forward fuselage of N4713U. (Paul Sakuma/AP)

The cause of the cargo door failure was determined to be a faulty design, combined with a short in the 747’s electrical system. The door was recovered by a U.S. Navy deep sea submersible from a depth of 14,100 feet (4,298 meters).

United Airlines’ Boeing 747 N4713U was repaired and returned to service. It was re-registered N4724U. チャーリーマイクさん

N4713U made its first flight 20 October 1970 and had accumulated 58,814:24 flight hours  and 15,027 cycles prior to takeoff from Honolulu. It was repaired at a cost of $14,000,000 and then returned to service, re-registered N4724U. In 1997, 19875 was sold to Air Dabia and assigned registration C5-FBS. It has since been scrapped.

Air Dabia Boeing 747-100 C5-FBS, photographed January 1998. (Aero Icarus)

The 747-100 series was the first version of the Boeing 747 to be built. It was operated by a flight crew of three and was designed to carry 366 to 452 passengers. It is 231 feet, 10.2 inches (70.668 meters) long with a wingspan of 195 feet, 8 inches (59.639 meters) and overall height of 63 feet, 5 inches (19.329 meters). The interior cabin width is 20 feet (6.096 meters), giving it the name “wide body.” Its empty weight is 370,816 pounds (168,199 kilograms) and the Maximum Takeoff Weight (MTOW) is 735,000 pounds (333,390 kilograms).

The 747-100 is powered by four Pratt & Whitney JT9D-7A high-bypass ratio turbofan engines. The JT9D is a two-spool, axial-flow turbofan engine with a single-stage fan section, 14-stage compressor (11 high- and 3 low-pressure stages) and 6-stage turbine (2 high- and 4 low-pressure stages). The engine is rated at 46,950 pounds of thrust (208.844 kilonewtons), or 48,570 pounds (216.050 kilonewtons) with water injection (2½-minute limit). This engine has a maximum diameter of 7 feet, 11.6 inches (2.428 meters), is 12 feet, 10.2 inches (3.917 meters) long and weighs 8,850 pounds (4,014 kilograms).

The 747-100 has a cruise speed of 0.84 Mach (555 miles per hour, 893 kilometers per hour) at 35,000 feet (10,668 meters). The maximum certificated operating speed is 0.92 Mach. The airliner’s maximum range is 6,100 miles (9,817 kilometers).

The Boeing 747 has been in production for 48 years. More than 1,520 have been delivered to date. 205 of these were the 747-100 series. The U.S. Air Force has selected the Boeing 747-8 as the next presidential transport aircraft.

Captain David M. Cronin died 6 October 2010 at the age of 81 years.

A surprisingly poor quality image showing teh damage to Boeing 747 N4713U resulting from the failure of the cargo door. (Unattributed)
A surprisingly poor quality image showing the damage to Boeing 747 N4713U resulting from the failure of the cargo door. (Unattributed)

© 2019, Bryan R. Swopes

23 November 1959

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Boeing 720-022 c/n 17907, N7201U. (Boeing)
Boeing 720-022 c/n 17907, N7201U, parked on the taxiway at the south shore of Lake Washington. (Boeing)

23 November 1959: The first Boeing 720 airliner, a 720-022, registered as N7201U, made its first flight at Renton, Washington. The 720 was a development of the 707 and no prototype was built. N7201U was used by Boeing for flight testing and was then delivered to United Airlines, 1 October 1960. The airline named the new 720 Jet Mainliner Capt. F. M. Crismore. Over the next two years, United acquired 29 Boeing 720s.

N7201U was sold to Contemporary Entertainment, owned by singer Bobby Sherman and his manager, Ward Sylvester, in January 1973. It was repainted in a gold and black livery and christened The Starship. As a VIP transport, it was used by such rock bands as Led Zeppelin, Deep Purple, The Rolling Stones, Alice Cooper and Elton John. It was last chartered by Peter Frampton.

N7201U was withdrawn from service in 1977 and after being stored for several years, was broken up at Luton Airport near London, England, in 1982.

The Boeing 720 was a variant of the Model 707, intended for short to medium range flights. It had 100 inches (2.54 meters) removed from the fuselage length and improvements to the wing, decreasing aerodynamic drag.

Boeing built 154 720 and 720B airliners from 1959 to 1967.

The Boeing 720 was operated by a flight crew of four and could carry up to 149 passengers. It was 136 feet, 2 inches (41.25 meters) long with a wingspan of 130 feet, 10 inches (39.90 meters) and overall height of 41 feet, 7 inches (12.65 meters). The airplane had an empty weight of 103,145 pounds (46,785 kilograms) and Maximum Takeoff Weight of 220,000 pounds (100,800 kilograms).

The Boeing 720 was powered by four Pratt & Whitney Turbo Wasp JT3C-7 turbojet engines, a civil variant of the military J57 series. The 720B was equipped with the more efficient P&W JT3D-1 turbofan engines. The JT3C-7 was a “two-spool” axial-flow engine with a 16-stage compressor (9 low- and 7 high-pressure stages), 8 combustion tubes, and a 3-stage turbine (1 high- and 2 low-pressure stages). It was rated at 12,030 pounds of thrust (53.512 kilonewtons) for takeoff.

The JT3D-1 was a dual axial-flow turbofan engine, with a 2-stage fan section 13-stage compressor (6 low- and 7 high pressure stages), 8 combustion chambers and a 4-stage turbine (1 high- and 3 low-pressure stages). This engine was rated at 14,500 pounds of static thrust (64.499 kilonewtons) at Sea Level, and 17,000 pounds (75.620 kilonewtons), with water injection, for takeoff (2½ minute limit). Almost half of the engine’s thrust was produced by the fans. Maximum engine speed was 6,800 r.p.m. (N1) and 10,200 r.p.m. (N2). It was 11 feet, 4.64 inches (3.471 meters) long, 4 feet, 5.00 inches (1.346 meters) wide and 4 feet, 10.00 inches (1.422 meters) high. It weighed 4,165 pounds (1,889 kilograms). The JT3C could be converted to the JT3D configuration during overhaul.

The maximum cruise speed was 611 miles per hour (983 kilometers per hour) and maximum speed was 620 miles per hour (1,009 kilometers per hour). Range at at maximum payload was 4,370 miles (7,033 kilometers).

The last flight of a Boeing 720 was on 9 May 2012, when a 720B aircraft used by Pratt and Whitney Canada as a test aircraft was placed in the National Air Force Museum of Canada at Trenton, Ontario.

United Airlines' Boeing 720-022, N7201U. (Unattributed)
United Airlines’ Boeing 720-022, N7201U. The airliner’s name, “Jet Mainliner Capt. F. M. Crismore,” is visible under the cockpit windows. (Bill Larkins via Wikipedia)

© 2018, Bryan R. Swopes

19 July 1989

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United Airlines’ DC-10 N1819U, Flight 232, on final approach to Sioux City Gateway Airport, 19 July 1989. In this image, damage to the right horizontal stabilizer is visible, and the aircraft tail cone is missing. (Wikipedia)

19 July 1989: United Airlines Flight 232 was a McDonnell Douglas DC-10-10, registration N1819U, enroute from Stapleton International Airport, Denver, Colorado to O’Hare International Airport, Chicago, Illinois. There were 296 persons aboard the airliner: 285 passengers and 11 crew members. The flight crew consisted of Captain Alfred C. Haynes, First Officer William Record, and Second Officer Dudley Dvorak. Also aboard, riding in the passenger cabin, was an off-duty United Airlines DC-10 Check Airman, Captain Dennis E. Fitch.

At 3:16:10 p.m., the fan disk of the airliner’s tail-mounted General Electric CF6-6 turbofan engine (Number Two) failed catastrophically. Shrapnel from the exploding engine chopped through the DC-10’s tail section and severed the three independent hydraulic systems that powered the flight control surfaces. The crew immediately lost their ability to control the airliner with rudder, elevators and ailerons. Flaps and wing leading edge slats were inoperative. Controls to the damaged engine also failed and only by cutting off fuel flow were they able to shut if down and prevention further damage or a fire. Landing gear could only be lowered by use of an emergency procedure.

The uncontrolled airliner immediately started to roll and dive. The pilots’ cockpit flight controls were completely useless to stop the roll. Only by varying the thrust on the two remaining wing mounted engines could some degree of control be maintained. Realizing there was a problem with the DC-10, Captain Fitch told a flight attendant to inform Captain Haynes that he was aboard and ask if he could assist. Haynes immediately asked Fitch to come forward, and once there to take over the throttle controls while the crew dealt with all the other problems that were occurring.

Flight 232 radar  track. (NTSB)

The simultaneous loss of all three hydraulic systems was considered to be “impossible” and there were no emergency procedures to deal with the problem. The crew did the best they could by varying power on the two remaining engines to turn the airplane and to descend. They were heading for an emergency landing at Sioux City Gateway Airport, Iowa (SUX).

United Airlines Flight 232 on final approach to Sioux Gateway Airport, 19 July 1989. (Gary Anderson/Sioux City Journal)

At 4:00:16 p.m., the DC-10 touched down on Runway 22 at an estimated at 215 knots (247.4 miles per hour, 398.2 kilometers per hour) and a rate of descent of 1,620 feet per minute (8.23 meters per second). At about 100 feet (30.5 meters) above the ground, the airliner’s nose began to pitch downward and the airliner started to roll to the right. Touchdown was at the runway threshold, just left of the centerline.

The DC-10 touched down at teh threshold of Runway 22, just left of the centerline.
The DC-10 touched down at the threshold of Runway 22, just left of the centerline.
Captain Alfred C. Haynes

The force of the impact caused the airframe break apart and the wreck rolled over to the right side of the runway. Fuel exploded and fire spread. 110 passengers and 1 flight attendant were killed in the crash and fire. There were 185 survivors of the crash, including the four pilots who were trapped in the crushed nose section of the airplane which had broken away from the main wreckage.

The National Transportation Safety Board (NTSB) investigation determined that the the center engine fan disk failed due to a crack which had formed when the original titanium ingot from which it was made had been cast 18 years before.

The official report said that a landing under these conditions was stated to be “a highly random event“. The NTSB further noted that “. . . under the circumstances the UAL flight crew performance was highly commendable and greatly exceeded reasonable expectations.”

This was one of the finest displays of airmanship during an inflight emergency since the beginning of aviation.

An iowa National Guard UH-1 medevac helicopter hovers over the wreckage of the United DC-10.
An Iowa National Guard UH-1 medevac helicopter hovers over the wreckage of the United Airlines DC-10, 19 July 1989.

© 2018, Bryan R. Swopes