On 25 October 1999, a rented Learjet 35 was scheduled to fly from Orlando, Florida, to Dallas, Texas. At the start of the flight, the plane, which climbs to a height determined by autopilot, quickly loses cabin pressure and all passengers are incapacitated due to hypoxia - lack of oxygen. The plane continued to climb over a specified altitude, then failed to turn west toward Dallas in northern Florida and continued its journey northwest, flying over South America and the middle west for nearly four hours and 1,500 miles (2,400 km). The plane ran out of fuel in South Dakota and crashed into a field near Aberdeen after it went down uncontrollably. Four passengers on board were PGA golfer Payne Stewart, his agent, Van Ardan and Robert Fraley, and Bruce Borland, a golf architect with Jack Nicklaus golf course design company.
Video 1999 South Dakota Learjet crash
Chronology of flight
- Note: all times are presented in 24-hour, military format. As the flight takes place in both Eastern time zones - Eastern Daytime (EDT) - and Middle Time zone - Daylight Time (CDT) - over time given in this article in Coordinated Universal Time (indicated by the time followed by the letter Z)
Departure
On October 25, 1999, Learjet 35, registration N47BA, operated by Sunjet Aviation of Sanford, Florida, departed Orlando International Airport (IATA: MCO , ICAO: KMCO ) at 1319Z (0919 EDT) on two days, five flights. Before departure, the aircraft has been pumped with 5,300 pounds (2,400 kg) of Jet A, enough for 4 hours and 45 minutes of flight. On the ship there are two pilots and four passengers.
In 1327: 13Z, the controller of the ARTCC Jacksonville instructed the pilot to climb and maintain the flight level (FL) 390 (39,000 ft (11,900 m) above sea level). At 1327: 18Z (0927: 18 EDT), the pilot admitted permission by stating, "three nine zero bravo alpha." This is the last known radio transmission from the plane, and occurs when the plane is passing 23,000 feet (7,000 m). The next attempt to contact the plane took place six minutes, 20 seconds later (14 minutes after departure), by plane at 36,500 feet (11,100 m), and the control message was not recognized. The controller tried to contact N47BA five more times in 4 1 / 2 the next minute, again without answering.
First interception
Around 1454Z (now 0954 CDT as the flight crossed into the Central Time zone), the F-16 US Air Force test pilot from the 40th Fly Test Squadron at Eglin AFB in west Florida, which happens to be airborne nearby, is directed by a controller to intercept the N47BA. When the fighter was about 2,000 feet (600 m) from Learjet, at an altitude of about 46,400 feet (14,100 m), the test pilot made two radio calls to the N47BA but received no response. F-16 pilot made a visual inspection of Lear, did not find any damage seen on the plane. Both machines are running, and the anti-collision flare turns red lit (standard operation for aircraft). Fighter pilots could not see the passenger side of the plane because the windows were dark. Furthermore, it states that the entire windshield of the cockpit is completely opaque, as if condensation or ice covered the inside. He also pointed out that the left cockpit windshield is opaque, although some parts of the center of the windshield are only covered thinly by condensation or ice; the small rectangular sections of the windshield are clear, with only a small part of the glare shield seen through this area. He did not see the movement of flight controls. Around 1512Z, the F-16 pilot concluded his examination of the N47BA and the bankrupt formation, progressing to Scott AFB in southwest Illinois.
Second interrupt
At 1613Z, nearly three hours on an unresponsive Learjet flight, two F-16s from the 138 Fighter Wing of the Oklahoma National Air Guard (ANG), flew under the "TULSA 13 flight call" sign, directed by Minneapolis ARTCC to intercept. The TULSA 13 team pilot reported that he could not see any movement in the cockpit, that the windshield was dark and he did not know if the windshield was ice. A few minutes later, a TULSA 13 pilot reported, "We do not see anything inside, it could be just a dark cockpit... he does not react, move or anything like that he should be able to see us now." In 1639Z, TULSA 13 went to meet with a tanker to refuel.
The plane reaches a maximum height of 48,900 feet (9.3 miles; 14.9 km).
The third interruption and escort
Around 1650Z, two F-16s from the 119 North Dakota ANG wing with identification of "NODAK 32 flights" directed to intercept the N47BA. Flight TULSA 13 also returned from refueling, and all four fighters maneuvered near Lear. The TULSA 13 team pilot reported, "We have two visuals on it.This looks like an ice cockpit window and there is no displacement on one of the control surfaces as far as ailerons or trim." Around 1701Z, the TULSA 13 flight returns to the tanker again, while the NODAK 32 stays with the N47BA.
There has been some speculation in the media that military jets are set to shoot down Lear if threatened to fall in densely populated areas. Officials at the Pentagon strongly denied the possibility. Shooting down on the plane "there is never an option," Air Force spokesman Captain Joe Della Vedova said, "I do not know where it came from."
Crash
The Learjet cockpit voice recorder (CVR), which is found from the wreck, contains an audio recording of the last 30 minutes of flight (it is an old model that only records 30 minutes of audio; the aircraft is not equipped with flight data recorders). In 1710: 41Z, the Learjet engine could be heard to subside, indicating that the plane's fuel had run out. In addition, the sound of the beat and the autopilot termination can be heard. With the engine turned off, the autopilot will try to maintain the altitude, causing the plane's speed to fall to near the kiosk's speed, at which point the shaker stick will automatically engage to alert the pilot and the pilot will automatically shut itself out.
In 1711: 01Z, Lear began to turn right and down. The NODAK 32 aircraft remained in the west, while the TULSA 13 aircraft broke away from the tanker and followed the N47BA down. At 1211: 26 CDT, the NODAK 32 lead pilot reported, "The target is down and he's doing some aileron scrolls, it looks like he's out of control... in a bad state, asking for an emergency landing to follow the targets." Pilot TULSA 13 reported, "Soon it will affect the soil; he is in a downward spiral." The fighter planes were forced to stop their pursuit at this point and had to land at the local airport, having reached their endurance limits.
The impact occurred around 1713Z, or 1213 local, after a total flight time of 3 hours, 54 minutes, with the plane crashing into the ground at almost supersonic speed and extreme angle. Learjet falls in South Dakota, just outside Mina in Edmunds County, on relatively flat ground and leaves a 42-foot (13 m) crater long, 21 feet wide, and 8 feet (2.4 m). None of its components remain intact.
Maps 1999 South Dakota Learjet crash
Passenger and crew
In addition to Payne Stewart and three others, there are two pilots on board:
The 42-year-old captain, Michael Kling, holds airline transport pilot certificates and type ratings for Boeing 707, Boeing 737, and Learjet 35. He also has Air Force experience flying KC-135 and Boeing E-3 Sentry. Kling was also an instructor pilot at KC-135E at the Maine Air National Guard. According to Sunjet Aviation records, the captain has collected a total of 4,280 hours of flight time (military and commercial) and has flown a total of 60 hours with Sunjet, 38 as a Learjet-in-command pilot and 22 as Learjet second- in command.
The first officer, Stephanie Bellegarrigue, 27 years old, holds a commercial pilot certificate and grade assessment for Learjet and Cessna Citation 500. She is also a certified flight instructor. He has accumulated a total of 1,751 hours of flight time, of which 251 hours with Sunjet Aviation as the second command and 99 as a second-in-command Learjet.
Investigation
The National Transportation Safety Agency (NTSB) has several levels of investigation, of which the highest is a "major" investigation. Due to the extraordinary circumstances in this accident, a major investigation was conducted.
NTSB menetapkan bahwa:
The probable cause of this crash is the inability of the flight crew as a result of their failure to receive supplemental oxygen after the loss of cabin pressure, for unspecified reasons.
The council added comments on possible reasons why the crew did not get supplemental oxygen:
After depressurization, the pilot does not receive supplemental oxygen in sufficient time and/or sufficient concentration to avoid hypoxia and disability. The wreckage of the aircraft indicates that the oxygen bottle pressure regulator opens on an accident flight. Furthermore, although one connector of aircraft crew hose masks is found in debris dislodged from its valve container (other connectors not found), damage to recovered connectors and both containers are consistent with both flight crew masks that have been connected to aircraft oxygen. supply lines in the event of a collision. In addition, both microphones of the flight crew mask were found plugged into the microphone jack of each crew. Therefore, assuming the oxygen bottle contains sufficient oxygen supply, supplemental oxygen should be available for both pilot oxygen masks.
[A] a possible explanation for a pilot's failure to receive emergency oxygen is that their ability to think and act decisively is disturbed due to hypoxia before they can wear their oxygen mask. There is no definite evidence to indicate the degree to which the flight of accidents loses its cabin pressure; Therefore, the Safety Board evaluates the conditions of depression both rapidly and gradually.
If there are violations on the fuselage (even small ones that can not be detected visually by observers on the plane) or seal failure, the cabin may experience gradual, rapid, or even explosive pressure drops. Studies have shown that a period of as little as 8 seconds without additional oxygen after rapid depressurization of up to about 30,000 feet (9,100 m) may lead to a decrease in oxygen saturation that can significantly impair cognitive function and increase the amount of time required to complete the complex. task.
More gradual decompression may result from other possible causes, such as smaller leaks in pressure vessels or closed flow control valves. The Security Council test specifies that the closed flow control valve will cause complete depressurization to the aircraft's flying height for several minutes. However, without supplemental oxygen, substantial detrimental effects on cognitive and motor skills will be expected soon after the first clear indication of decompression, when the cabin height reaches 10,000 feet (3,000 m) (which can occur in about 30 seconds).
Investigations from other accidents in which flight crews attempt to diagnose pressure problems or initiate emergency pressures instead of immediately wearing oxygen masks after cabin-level warnings have revealed that, even with relatively gradual depressurization rates, pilots quickly lose cognitive or motor skills. to solve problems effectively or provide their masks immediately afterwards. In this accident, the failure of the flight crew to obtain supplemental oxygen in time to avoid disability can be explained by the delay in wearing an oxygen mask; just a few seconds in the case of explosive or rapid decompression, or a slightly longer delay in the case of decompression gradually.
In short, the Safety Board can not determine why the crew can not, or not, receive enough oxygen in sufficient time and/or enough concentration to avoid hypoxia and disability.
The NTSB report shows that the aircraft has several examples of maintenance work linked to cabin pressure in the months leading up to the crash. NTSB can not determine whether they are from common issues - replacements and improvements are documented, but not pilot pilot reports that drive them or the frequency of those reports. The report criticized Sunjet Aviation for the possibility that this would make the problem more difficult to identify, track and resolve, as well as the fact that at least one instance of the aircraft was flown with unauthorized maintenance delays for cabin pressure problems.
Aftermath
Stewart eventually headed to Houston for the 1999 Tour Championship, but plans to stop in Dallas to discuss with his alma mater athlete department, Southern Methodist University, about building a new home course for a school golf program. Stewart is immortalized in the Tour Championship with a single bagpipe player playing in the first hole at Champions Golf Club before the start of the first day of play. The owner of the fall site, after consulting with the wives of Stewart and several other victims, made a warning at about 1 acre (4,000m 2 ) from the site. At its center is a stone drawn from a site that reads the names of the victims and the passage of Scripture.
The 2000 U.S. The Open, held at Pebble Beach Golf Links, begins with a golfing version of the 21-gun salute when 21 of Stewart's fellow colleagues simultaneously hit the ball into the Pacific Ocean.
In 2001, Stewart was posthumously appointed to the World Golf Hall of Fame.
On June 8, 2005, a Florida Florida court jury found that Learjet was not responsible for the deaths of Stewart and his agents Robert Fraley and Van Ardan, who had also boarded the plane.
See also
- Bo Rein
- 2000 Australia Beechcraft King Air crash
- Helios Airways 522 flights
Documentary
The documentary series Mayday , (also known as Air Crash Investigation) featured this event in the first episode of the 16th season. The episode titled "Deadly Silence" was broadcast on June 7, 2016.
References
This article incorporates public domain material from websites or documents from the National Transportation Safety Agency.
External links
- Brief Aircraft Accident of National Transport Safety
- Presentation slide show of NTSB Board on collision
- List of NTSB resources at a standstill
- Flights of ghost planes to disaster, " BBC News , 1999-10-25
Source of the article : Wikipedia
0 Comments