Boeing 707 crash on Santa Maria

Aircraft

The crashed plane in 1980 (during the period of work in Trans World Airlines )

The crashed Boeing 707-331B with a serial number of 19572 and a factory number of 687 was released in 1968 and had the original tail number N28727, as it was intended for Trans World Airlines (TWA). Its four jet engines were the Pratt & Whitney JT3D-3B (HK) models . On March 22 of the same [1968], the TWA leased the aircraft to Saudi Aramco . On June 30, 1980, the airliner returned to TWA. By August 26, 1983, he had bought itIAL Air Services Inc., after which it leased Atlanta Skylarks, and on September 8, the tail number changed to N7231T. Atlanta Skylarks itself was transformed into Independent Air in December 1984 . It was a small airline with only 2 Boeing 707 (N7231T and N7232X) in its fleet and charter flights for various tour operators and the US Army . At the time of the crash, the N7231T had 44 755 flight hours and 12 589 landings, including 186 hours 54 minutes and 48 landings since the last check ^{[1] [2] [3]} .

Crew

• The aircraft commander (FAC) is 41-year-old Leon Daugherty. In 1971, he received an amateur pilot license and later became a helicopter pilot in the US Army , in 1975 he got a job as a civil aviation air traffic controller, while he also worked as a helicopter pilot in the National Guard of the Tennessee Army. In October 1981, he was qualified for flight engineer Boeing 727, and in May 1986 - for the commander. In Independent Air, from April 1987, as a co-pilot of a Boeing 707, in July 1988, he qualified for the Boeing 707 commander. The total flight time at the time of the crash was 7,766 hours, of which 766 were on the Boeing 707 (including 488 hours as commander) and 2259 hours on the Boeing 727 (including 1912 hours in the post of the FAC), a raid for the previous 30 days - 22 hours 36 minutes. Colleagues, the commander was characterized as a fan of aviation, who in his spare time loved to fly his own private plane ^{[4] [5]} . In December 1988, he underwent surgery on one of his legs in order to correct the consequences of an injury sustained in his youth. Recovery after the operation required about 6 weeks, but did not require additional treatment, because on January 25, 1989 the commander returned to flying. One of his friends later said that a week before the crash, when they were flying in a private plane, the commander felt uncomfortable in his leg and could not press the pedals to control the rudder ^[5] .
• The co - pilot is 36-year-old Sammy Adcock . In 1980, received a license as an amateur pilot. From 1983 to October 1988, he worked as an instructor pilot, co-pilot and commander and senior pilot at several small Tennessee airlines, in particular, at his last job (before joining Independent Air), he worked as a senior pilot for a 6-8-seat Piper PA- for 20 months 31 . He settled in Independent Air in October 1988, where he was sent to beginner courses in flying the B-707, which he completed on November 23 . After theoretical training, there were also three lessons on a simulator lasting 5 hours, 6 hours as an observer, and on November 26 a control flight was conducted. The total duration of training was 194 hours by November 29, 1988. On November 28, he was admitted to the internship, which began on December 15 and included 8 flights, 9 take-offs and 9 landings with a total duration of 34 hours. January 23, 1989 was qualified for the second pilot. In total, at the time of the disaster, he had a total of 3764 hours of flying, including 64 hours on the B-707, flying time for the previous 30 days - about 37 hours 42 minutes ^[5] . During the investigation, it was found that shortly before being assigned to the airline, the mother died from the co-pilot, and he experienced financial difficulties, and therefore got a job at Independent Air. At the same time, the friend of the co-pilot said that he managed to recover from the loss of his mother and solve the problem with money, and was also pleased with the new job. It also turned out that the co-pilot often suffered from exacerbations of allergies and self-medicated with antihistamines ^[5] .
• Flight Engineer - 34-year-old Jorge Gonzalez ( born Jorge Gonzalez ). At the time of the crash, he had a total of 6756 hours of flying, including 1056 hours on B-707, 2888 hours on B-727 and 2823 hours on Lockheed C-5A , flying time for the previous 30 days - about 95 hours 48 minutes. His colleagues characterized him as a professional in his work, who had his own set of navigation charts, could control the approach and bring the necessary information to the pilots ^[5] . During the investigation, it was found that the flight engineer was being treated by a psychiatrist for aggression, since it led to serious problems in the family. But it was also noted that he was making serious progress in treatment and even the day before the disaster called his wife to discuss reconciliation. It also turned out that since April 1988, the flight engineer received weekly treatment in connection with chronic allergies, and the last exacerbation occurred 6 days before the disaster ^[6] .

Prior Circumstances

On February 3, a flight crew with this crew made a flight to Montego Bay ( Jamaica ), on February 4, flew to Fort Worth ( Texas ), then to Denver ( Colorado ). On February 5, the crew returned to Montego Bay, where they received a mission for IDN 1851 flight from Milan ( Italy ) to Punta Cana ( Dominican Republic ) with an intermediate landing on Santa Maria ( Azores , Portugal ). On February 7, after a flight lasting 10 hours and 40 minutes, the crew arrived in Genoa (Italy). According to the plan, the landing was supposed to be made at Milan Malpensa airport , but bad weather made adjustments. Then in 3 hours the crew arrived in Bergamo , which was located near the planned departure airport . The next 46 hours the crew was in the hotel is unknown, but in the early morning of February 9 , according to witnesses, everyone left the hotel in a good mood ^[6] .

Departure according to the plan was supposed to be at 08:00 (hereinafter referred to as GMT ), but due to fog, the N7231T board delayed in Genoa and was able to land at Bergamo airport only at 07:20. According to the flight plan, the duration of the first part of the flight was supposed to be 4 hours 10 minutes with landing on lane 33. It should also be noted that in the flight plan the airport coordinates were indicated as N36756 (latitude) and W025096 (longitude), the elevation of the strip is 0 feet. But the indicated coordinates did not correspond to either Santa Maria airport or any of its navigation equipment, and the actual level of the airfield is 305 feet (93 meters). Also, during the investigation, it was noted that the aeronautical charts for this airport were dated February 1, 1962 and were not adjusted over the past 27 years ^[6] .

At 10:04, flight IDN 1851 with 7 crew members and 137 passengers on board flew from Bergamo Airport ^[6] .

Holocaust

During the flight, it turned out that during a radio exchange between flight 1851 and high-frequency (HF) air traffic controllers, communication often disappeared, although it worked without failures on the ground. At 12:46:33 the crew got in touch with the Santa Maria control center and reported on the passage of The duties of the dispatcher at that time were performed by the intern ^[7] . As investigators later noted, radio communications were conducted with violations of phraseology. Also, the dispatcher practically avoided the word Decimal , meaning a decimal point. Radio communication with the ground was conducted mainly by the second pilot, only at 13:43:57 the flight engineer requested a weather report ^[8] . To this, at 13:44:20, the dispatcher transmitted: One eight five wind [course] two six zero ... Fourteen, yes fourteen knots, gusts up to two four knots, visibility more than ten kilometers, [cloudiness] one octant per one two zero zero feet , three octants per three thousand feet, temperature one seven, QNH [reduced pressure ^[9] ] one zero one nine . In transmitting the weather report, the dispatcher used the non-standard expression at in the sentence, one octant per one two zero zero . Due to interference on the air, on an airplane they heard it as one octant two two zero zero , from which the crew made a false conclusion that there are no clouds below 2 thousand feet ^[10] .

At 13:56:47, when flight 1851 performed a descent to the airfield and passed level 220 (6705 meters), the dispatcher transmitted: Independent one eight five one, Roger , come down ... three thousand feet QNH one zero two seven, the strip will be one nine . And in this broadcast, the intern made a gross mistake, because he reported to the crew about the reduced pressure of 1027 hPa, while the actual one was 1018.7, or rounded up to 1018, that is, 9 hPa lower. The mentor noticed this and wanted to send the corrected information to the plane, but he was distracted by a phone call. Also, the crew did not notice the transmission of increased pressure, which 12 minutes earlier was much lower. This could be facilitated by the presence in the cockpit of a woman, presumably a flight attendant, whose voice was recorded by the recorder at 13:48:30 and at 14:04:09 ^[10] .

At 13:56:59, the second pilot told the dispatcher: We were going down to two thousand feet , after which at 13:57:02 I paused, and at that time (probably the commander) sounded in the background - He said three [thousand] . Then 13:57:07 the second pilot continued: one zero two seven . This was the last broadcast from flight 1851, but the dispatcher did not hear its first part, as he continued to say that the landing would be on lane 19, and therefore did not know that the plane continued to fall below a safe altitude of 3000 feet to 2000 feet and was flying directly onto the mountain Pico Alto ^[11] .

At 2:02 p.m. at a speed of 260 knots, the plane passed an altitude of 6,500 feet (1981 meters) and fell into the zone of light turbulence . To this, at 14:03, the second pilot noted: And after two thousand we will be below these clouds . At 14:06 at a speed of 250 knots, the aircraft took an altitude of 2000 feet (610 meters). At 14:07 flying in the clouds, flight 1851 went to Santa Barbara at an actual altitude of about 700 feet (213 meters) above the ground, when at a speed of 223 knots it fell into a zone of strong turbulence. At 14:07:52, the commander said: I can’t hold it, the son of a bitch is jumping up and down . The co-pilot offered help, but the commander gave a negative answer. Then at 2:08 p.m. due to turbulence, the height jumped sharply from 1,751 feet (534 meters) to 1,869 feet (570 meters). Next, the radio altimeter gave a warning signal, and in the climb due to turbulence, the GPWS alarm about the proximity of the earth also lasted, which lasted about 5-odd seconds. But the crew did not react to this in any way ^[11] .

At 14:08:12 at an actual altitude of 1795 feet above sea level, an airliner flying in the clouds crashed into a wall by the road running along the crest of the top of Puerto Plata, and then, rushing through trees with trunks about 30-40 centimeters in diameter, completely collapsed. The impact occurred on the eastern side and is so close to the peak that part of the wreckage was on the western slope ^[11] . All 144 people (7 crew members and 137 passengers) on board died. In terms of the scale of the present (2013), this aviation accident takes the 1st place in Portugal and the 4th with the participation of the Boeing 707 ^[3] .

The altimeters found at the crash site had an set pressure of 1028 and 1026 hPa, and their altitude was 2,000 feet. An increase in pressure by 9 hPa led to an overstatement of readings by 240 feet (73 meters), but taking into account the distance to the top and the height of trees growing on the mountain, it was concluded that this difference did not have a significant role in the disaster, unlike the decision crew descend below a safe height of 3000 feet, which is indicated on the navigation charts ^{[11] [12]} .

According to the conclusion of the Portuguese commission, 10 factors contributed to the disaster ^{[12] [13] [14]} :

1. The Santa Maria Airport Tower dispatcher indicated a QNH value of 9 hPa above the actual value, resulting in altimeters reading 240 feet above the actual height;
2. Violation of the rules of radio communication by the co-pilot, who began to repeat the command to reduce to 2,000 feet before the dispatcher completed the transmission;
3. The tower dispatcher, in violation of the rules, did not demand from the crew a complete repetition of the information received;
4. Failure by the crew to comply with the principles of the “ Sterile Cabin ” published in the relevant company manuals, including violation of discipline in the cockpit and negotiating when it is necessary to repeat the descent altitude aloud, as well as unofficial conversations in the cockpit when descending below 10 thousand feet (3050 meters);
5. Indifference of the flight crew to the violation of the minimum established height, which was known to at least one crew member, as well as neglect of warnings about dangerous altitude;
6. Violation of the phraseology of radio exchange by the crew and the dispatcher during negotiations;
7. Little experience of the crew, especially the co-pilot, performing international flights;
8. Inadequate crew training on actions when the GPWS warning is triggered, including the execution of an evasion maneuver;
9. Use of a route that did not comply with the guidelines of the Aeronautical Information Collection of the National Aviation Institute of Portugal (AIP Portugal);
10. A flight plan whose final destination was not a beacon SMA was compiled without using information from the Aeronautical Information Collection.

• The crash of the Boeing 727 in Funchal ( Madeira ) is the previous largest plane crash in Portugal.

• Aircraft Descended Below Minimum Sector Altitude and Crew Failed to Respond to GPWS as Chartered Boeing 707 Flew into Mountain in Azores . FLIGHT SAFETY FOUNDATION (February 1995). Date of treatment November 30, 2013.