From Routine To DISASTER | The Mystery of Turkish Airlines Flight 1951

imagine you're on a routine flight everything seems to be going smoothly and you're looking forward to landing at your destination but suddenly things take a dark turn without warning the plane starts to lose altitude rapidly and the crew is struggling to keep it under control Panic sets in as you realize that something is terribly wrong in this video we'll dive into the details of Turkish Airlines flights 1951 and explore the mystery behind its fateful Landing join me as we unravel the events that led to this catastrophic event and shed light on the importance of AirSpeed and altitude monitoring during Landing are you ready to uncover the truth behind this tragedy let's get started on the 25th of February 2009 Turkish Airlines flights of 1951 are Boeing 737-800 was flying a routine flight from Istanbul airport in Turkey to skip whole airport in the Netherlands there were 128 passengers on the flight and seven crew members the cockpit crew of the flight consisted of three individuals the captain the first officer under supervision and the safety pilot the captain who was 54 years old had over 17 000 total flying hours he was occupying the left-hand Copic seats and acting as the instructor for this flight the first officer under supervision was 42 years old with approximately 4 146 hours with 44 hours on the Boeing 737 he would be occupying the right-hand seat and was the pilot flying for this flight lastly the safety pilot who was also a first officer was 28 years old with approximately 2 126 hours of Total flying experience he had 720 hours on the Boeing 737 and the safety pilot was there to provide additional assistance and support and to help monitor the situation in the cockpit the crew and passengers boarded the aircraft it was started up taxied and took off at 0-823 local time they then climbed to their cruising level a flat level 360 or 36 000 feet and so far everything had run smoothly for the first officer under supervision before preparing for their descent it's a skep whole airport they listened to the 80s this stands for automatic terminal information service and it is a system that allows Crews to hear up-to-date information on the Airfield through a continuous broadcast the information will have a letter assigned to it such as Alpha and when it is updated it will be given another identifying letter such as Bravo this means that when the crews check in with air traffic control if the code given is correct Air Traffic Control knows that the crew have the most up-to-date information and if not they will inform them that the code has changed and then we'll update them on the information that has been changed so when the crew listened to the atis it informed them that the main Landing Runway was one eight right the wind direction was two zero zero degrees at seven knots the visibility was 3 500 meters with mist and the cloud cover consists of few clouds at 600 feet broken clouds at 1 100 feet and overcast at 1 300 feet the temperature is also 4 degrees Celsius after collecting the information from the atis the crew were happy to continue to skepo airport and the first officer conducted an approach briefing at zero eight fifty three hours while the aircraft was flying over Germany during the briefing he informed the crew that they would fly the ILS category 1 approach and the decision height would be 200 feet so the decision height is the height above the ground where the crew will have to decide to land or to go around the aircraft could not continue the approach without this decision being made if they were to get to that height and a knots visual of the runway they must go around and simply cannot continue hoping that they become visual closer to the ground the time was now zero nine zero four flights 1951 entered Dutch airspace and contacted Amsterdam area control the crew were given instructions to descend and head towards the landing Runway the instruction was to descend to flight level 280 and head toward three one zero shortly after this instruction they received a further instruction to descend to flight level 150 on Runway one eight right and maintain the speed of 300 knots or greater the reason for their speed instruction was to deconflict the aircraft with other approaching traffic Turkish Airlines flight 1951 then continued on their approach and as they arrived closer to the Airfield they are cleared to descend to flight level 7-0 during that Ascent as they passed flight level 84 an audio warning regarding the landing gear can be heard this lasts for approximately one minute and a half the caption States radio altimeter the captain's radio altimeter was reading -8 feet on his primary flight display whilst the first officers on the right hand side was working correctly so the way in which this system works is the radio altimeter computer will continuously transmit signals to the ground those reflective signals are used by the computer to calculate the height of the aircraft above the ground the height values originating from these systems are displayed on their respective primary flight displays if the values are between -20 and 2500 feet for it to be showing -8 feet whilst the aircraft was approximately 8 000 feet above showed that the left system was not working correctly and this appeared to be the reason for the unusual landing gear audio warning a few moments after the first landing gear warning was received they then received another one this time the captain stated landing gear the first officer was aware of the issue and responded okay instructor following this at 10 19 flight 1951 were instructed to descend to 2000 feet on head in 265. the captain now contacts the ground handling company of Turkish Airlines at Skip Hall airport to specify the number of passengers and to request a parking position he is told to expect parking Stand golf too the first officer now starts to configure the aircraft for landing the first officer asked for flaps one and the crew then set the speed of 195 knots using the mode control panel the first officer then responds speed 195 instructor the mode of the auto throttle was mode control panel speed air traffic control then instructs flight from 1951 on a further left turn to intercept the localizer this means that the localizer signal of the instrument Landing system is received by the aircraft and that the autopilot can use it for the ILS approach 210 degrees was set by the first officer and as they were still at 2000 feet they expected to intercept the localizer at 6.2 nautical miles as this is when they will begin their descent on the ILS to maintain the appropriate Glide path the first officer selected approach mode then he attempted to engage the second autopilot for a dual Channel approach the right autopilot and the auto throttle have been activated from their departure in turkey and he now attempted to engage the left autopilot as well this attempt resulted in the right autopilot disconnecting and the left autopilot did not engage the first officer then re-engaged the right autopilot and no new attempt was made to engage the left Auto violet before we continue I have some exciting news to share with you all today I've received several requests asking for merchandise for this Channel and as of today I've opened a store so that this is possible as you know creating content for this channel takes days of work and this will be a way to support the channel but also to get some really cool items too all the designs were created by me and inspired by this Channel and the best part by purchasing from my store you'll be supporting this Channel and helping me continue to create even more content for you I've also decided to give away some hats patches and coins that I've collected in the past and each month I'll pick someone who has purchased from the store or supported the channel through a Super Chat and send you one of these items thank you for your continued support I'm so grateful to have such an amazing community of viewers check out the link in description to head over to the store and to see what there is to offer just remember to do this at the end of the video as this one is not to be missed thank you the first officer then stated flaps five a speed of 170 knots was also selected however soon after an aura warning regarding the landing gear configuration Was Heard again for five seconds the captain told the first officer to lower the landing gear flaps 15 and reduce the aircraft speed to 160 knots the first officer then quickly followed up with flaps 15 call and he set 160 knots the gear was lowered and the speed was starting to reduce when the aircraft intercepted the localizer and turned left to join the ILS as they were about to start their descent to land the first officer set 140 knots the speed was still reducing on the aircraft but was now just below 175 knots due to The Heading they had been given to approach the Airfield they were now 5.5 nautical miles away from the runway and 170 feet above the Glide path this meant that they needed to descend at a higher rate to rejoin the appropriate Glide path the first officer then changed The Descent mode and selected vertical speed mode on the autopilot he then sets The Descent rate initially of 1 400 feet per minute to re-establish the aircraft on the correct Glide path the aircraft now started to descend at the initial speed of 168 knots the crew were now informed by air traffic control but they were cleared to land on Runway one eight right winds 210 at 9 Knox the captive responded with clear to land thank you the safety pilot now pointed out that the radio altimeter had failed the captain confirmed that they were aware of this issue and at this time the aircraft had rejoined the Glide path at 1 300 feet during this increased rate of descent the speed initially reduced to 158 knots before increasing to 169 knots now that the aircraft had rejoined the Glide path speed started to reduce the captain now announced that they were passing 1000 feet flaps 40 was selected and the speed of 144 knots was set the captain now finished off the landing checklist during the final checks the crew tried to arm the speed brakes they were moved in and out of the arm position three times with both the green speed brake armed and the Amber speed brake do not arm lights Illuminating this was likely occurring as there was a difference in the left and right radio outmeters but was concluded with the statements speed brake armed green light whilst the crew were distracted with the speed brake the autopilot was trimming the aircraft pitch to ensure it was following the correct Glide path the safety pilot now reported to the captain that he had received the call from the cabin it was ready for landing as the aircraft passed 750 feet the speed dropped below the set speed of 144 knots the final parts of the land and checklist were carried out with the land and lights being switched on and the cabin crew being worn to take their seats and put their safety belts on the captain then called out 500 feet as the aircraft passed 460 feet the stick Shaker was activated the safety pilot then warned too low speed and as the crew checked their speed they were flying at 107 knots and the nose was 12 degrees above the Horizon the captain immediately took control and began to push the nose down the safety pilot continued to report that the speed was too low the auto throttle and autopilot were disconnected and the aircraft nose was now 8 degrees below the Horizon the stick Shaker stopped but was then activated again two seconds later frantically looking around the cockpit they noticed the thrust levers were in the idle position the captain then pushed the thrust levers forward for maximum thrust this ball up time was about four seconds and during this time various ground proximity warning system warnings were generated trying to increase the aircraft's height the captain pitched up but it was too late the aircraft impacted the ground 1.5 kilometers from the threshold of Runway one eight right in a testament to the crew's final actions and the aircraft's structural strength 126 passengers and crew survived the crash unfortunately four crew members including the three pilots and five passengers were killed so how did this happen during the investigation they looked at several possibilities including turbulence aircraft issues the Pilot's actions and other outside factors they quickly dismissed turbulence as a Cause there was a Boeing 757 that was going to land before Turkish Airlines flight 1951. according to the international and National regulations the minimum distance between the two aircraft should be five nautical miles this is to prevent the aircraft wake turbulence when Flight 1951 was given permission to start the approach the distance between both aircraft was approximately 6.5 nautical miles and during the approach the distance between both aircraft dropped to approximately 5.5 nautical miles the minimum distance requirement was therefore met during the approach data from the flat data recorder showed that there was no corrective steering movements that were made during the approach in response to any turbulence so turbulence was ruled out as a cause as we know the aircraft was suffering from a malfunctioning left radio outmeter this was identified during the investigation to have started recording erroneous readings just as the aircraft climbed to 400 feet although the crew were unaware of any current issues with the radio altimeter there were reports of radio altimeter problems occurring within the Boeing 737 Fleet for many years Communications from Turkish Airlines and Boeing between 2001 and 2003 contained complaints of fluctuating and negative Heights recorded from the systems among other things following these complaints the airline attempted to resolve these problems with Boeing and the radio altimeter system antenna manufacturers and the suspected moisture and corrosion damage was dealt with in a temporary manner by installing gaskets and moisture proof wraps there was no attempt to replace the antennas even though this genuinely resolved the problems with no permanent solution on the aircraft the pilots were not informed of this potential problem as Turkish Airlines considered it to be a technical issue and not a safety concern so how did this affect the flight the crew were flying on the right-hand autopilot and the right-hand radio altimeter was working correctly the comment made by the captain about the landing gear configuration warning during The Descent seems to indicate that the crew were aware of the problem and were happy to continue what wasn't known to the crew at the time was that the signal from the left radio altimeter system was the one used primarily by the auto throttle there is only a switch to the right hand system if that left hand system is no longer working so although the autopilot was getting its inputs from the right-hand instruments and systems the auto throttle was being fed by the left this meant that the auto throttle believed the aircraft was at -8 feet and when the first officer activated the vertical speed mode this caused the auto throttle to enter a Mode called flare this is because the aircraft believed it was about to land so the thrust levers were being closed to take the position for minimum engine thrust based on this input and the system logics the only indication to the crew that this mode had been activated was an indication on their primary flight displays further adding to the masking of this issue was their late feeding to the ILS this was caused due to the actual winds at 2000 feet pushing the aircraft towards the runway it was flying a heading of 210 which would have intercepted the Glide path at 6.2 nautical miles but the actual ground track of the aircraft was 202 which meant they'd joined the Glide path at 5.5 nautical miles and they were above the Glide path because they started their descent above the Glide path the fact that the thrust levers were in the idle position was not abnormal because the aircraft had to decrease speed due to the higher rate of descent further to this due to the high rates of descent their speed increased and when they joined the correct Glide path they still needed the speed to wash off this further masks the fact that the thrust levers are idle as they were expecting and wanting the speed to reduce this increased workload further distracted the crew other issues such as the speed brake not Armin due to the radio altimeter miscompare also added to this overall distraction preventing them from monitoring their instruments as well as they should have one final point was during the stall recovery when the stick Shaker was activated it was discovered that the immediate actions of the first officer was to pitch the nose down and to start to increase the thrust the correct action for the saw was immediate thrust the thrust levers were moved forward about halfway when the captain took control the aircraft then reverted back to the flare mode and the thrust lever returned to the idle position this meant that the aircraft was still without thrust for nine seconds after the stick Shaker was activated this is not meant to point any blame at the captain but more at the awareness that the aircraft was acting in a way that the crew was not expecting so what was changed due to this incident Boeing implemented several measures following the Turkish Airlines accident the measures included informing users about the identified radio altameter system problems and the response to the auto throttle advising flight Crews to carefully monitor primary flight instruments and the flight mode Annunciation releasing a maintenance tip about damage radio altimeter antennas adding a procedure to the master minimum equipment list which stated that using Auto thrustle during an approach is forbidden when the radio altimeter or outer meters do not function prior to Landing releasing an update to The Fault isolation manual with additional troubleshooting advice and emphasize an additional training scenarios for erroneous radio altitude values Turkish Airlines also implemented several measures to improve flight safety including issuing caution bulletins and revising faster seat belt sign operation they also establish an online reporting system and monthly safety meetings expedited a study on Associated risks and added simulator sessions for store recovery procedures Turkish Technic Incorporated also implemented an aircraft reliability report and a maintenance operational quality assurance program changes were made to swapping procedures and Technical bulletins were also issued for maintenance purposes Boeing issued maintenance tips relating to radio altimeter systems on the Boeing 737 Fleet and Turkish Airlines plan to issue a technical information bulletin and hold training sessions to inform technical Personnel about the recommendations and warnings if you find these videos interesting I have a playlist full of several other fascinated incidents here also if you're looking for some new Aviation related products designed by me and want to support the channel check out the merchandise shop in the link in the description thank you for watching and as always I'll see you in the next one

Channel: Curious Pilot

Views: 88,570

Keywords: air crash investigation, turkish airlines, turkish airlines flight 1951, air disasters, curious pilot, aviation

Id: yKbvB80OY1s

Length: 20min 26sec (1226 seconds)

Published: Sun Apr 30 2023