Air India Runway Excursion
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Re position of the throttles - anything is possible here as to why pedestal controls are in the position they are - it is possible that the separate of fuselage sections pulled the cables sufficiently to change throttle positions...
It is possible that the g-forces of impact could have moved the throttles (not to mention flying debris). However if the T/R piggyback levers are lifted, it mechanically locks the throttle levers at idle so it suggests the reversers were not deployed.
Or that if they were deployed, they were cancelled? Having recently done several rejected landings (in the sim I hasten to add), you are not far off flying speed and it doesn’t take that much time and distance to become airborne again. If you had touched down, autobrakes kicked in, selected reverse then realised it wasn’t working and tried to unravel all that you are in a whole different ballgame.
I think it's reasonable to assume that if an overrun was looking likely and you were still trying to stop, you would be bending the TRs backwards all the way to the end of the runway and beyond. As pointed out above, thrust levers out of idle means no reverse.
I think it's reasonable to assume that if an overrun was looking likely and you were still trying to stop, you would be bending the TRs backwards all the way to the end of the runway and beyond. As pointed out above, thrust levers out of idle means no reverse.
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I read an Indian newspaper article where it says that a ground personnel saw the aircraft bounce twice before it went off the runway.
Some of the above posts mention flaps 1 setting, the flap lever is at 40. Looks like they did not move the flap lever if they were indeed trying to go around or they simply didn’t have the time before it went off the runway.
Some of the above posts mention flaps 1 setting, the flap lever is at 40. Looks like they did not move the flap lever if they were indeed trying to go around or they simply didn’t have the time before it went off the runway.
Some good speculation here and some bad. In defence of the pilot I wonder about the elephant in the room and that is aquaplaning. 9 x the square root of the tyre pressure. I have only flown the 200/300/400. On the 400 we ran the tyres around 220psi. This gets very close to a common Vref. Add water and no grooving and a little tail-wind for good measure. I have flown four different Boeings and the 737 is the only one I have experienced aquaplaning and it very nearly was my undoing once. A strange sensation and a horrible feeling of accelerating.
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FullWings
The FCTM tells us to continue with normal go around procedures after a baulked landing. That’s assuming they didn’t select reverse thrust after touchdown. Another member has very kindly uploaded a screenshot of the FCTM page where Boeing says in no uncertain terms that safe flight is NOT possible if a go around is initiated after you select reverse thrust.
Since the FR24 data shows them coming in hot, and (eyewitness reports?) then bouncing twice, they may have finally touched down with very little runway remaining to stop. However the spoilers would be raised for the duration of their ground roll (assuming they were armed for landing) until the moment they advanced the thrust levers for the go around. The DFDR will reveal the actual facts. Also worth noting is the wet muddy patch of the area past the paved surface of the runway may have slowed them down sufficiently to prevent reaching Vmcu /airborne.
It’s worth noting that whenever I use Autobrake 3 on both the B737CL or B737NG, the braking provided in combination with max reverse is fantastic on both dry & wet runways. I can’t comment on contaminated runways because my operation manual prohibits taking off or landing from contaminated runways/whenever braking action is reported as poor. So they may have slowed to ~ 100kts before realising that they were running out of runway. Again, these are just my 2 cents.
The FCTM tells us to continue with normal go around procedures after a baulked landing. That’s assuming they didn’t select reverse thrust after touchdown. Another member has very kindly uploaded a screenshot of the FCTM page where Boeing says in no uncertain terms that safe flight is NOT possible if a go around is initiated after you select reverse thrust.
Since the FR24 data shows them coming in hot, and (eyewitness reports?) then bouncing twice, they may have finally touched down with very little runway remaining to stop. However the spoilers would be raised for the duration of their ground roll (assuming they were armed for landing) until the moment they advanced the thrust levers for the go around. The DFDR will reveal the actual facts. Also worth noting is the wet muddy patch of the area past the paved surface of the runway may have slowed them down sufficiently to prevent reaching Vmcu /airborne.
It’s worth noting that whenever I use Autobrake 3 on both the B737CL or B737NG, the braking provided in combination with max reverse is fantastic on both dry & wet runways. I can’t comment on contaminated runways because my operation manual prohibits taking off or landing from contaminated runways/whenever braking action is reported as poor. So they may have slowed to ~ 100kts before realising that they were running out of runway. Again, these are just my 2 cents.
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An update on the investigation from the Hindustan Times.
https://www.hindustantimes.com/india...7kWYRbwyJ.html
Weather dismissed as factor in deadly Air India crash The Boeing Co. 737 appeared to touch down near the middle of the 9,000-foot-long (2,743-meter-long) runway at Kozhikode, the person said, before skidding off the end and careening down a slope, breaking into three parts.INDIA Updated: Aug 10, 2020 18:38 IST
Bloomberg | Posted by Arpan Rai
Weather conditions were within safe ranges and pilots were briefed about them by controllers just before the Air India Express jet they were flying crashed at a southern Indian airport Friday, killing at least 18 people and injuring more than 100, according to a person with direct knowledge of the matter.
The Boeing Co. 737 appeared to touch down near the middle of the 9,000-foot-long (2,743-meter-long) runway at Kozhikode, the person said, before skidding off the end and careening down a slope, breaking into three parts. The captain was experienced, with 11,000 flying hours, while the co-pilot had 2,000 hours. Neither one made a distress call, and both died in the crash. Visibility, precipitation and tailwinds were within acceptable guidelines for landing, the person said, asking not to be identified because the investigation is ongoing.
A playback on the FlightRadar24 website shows a first attempt to land the plane was aborted before another effort was made from the opposite direction. The flight-tracking site shows visibility at the airport was 1,500-to-2,000 meters, and winds were blowing at 12-13 knots, which is a moderate breeze on the Beaufort scale. Indian officials say 800 meters is sufficient visibility for landing.
Bloomberg | Posted by Arpan Rai
Weather conditions were within safe ranges and pilots were briefed about them by controllers just before the Air India Express jet they were flying crashed at a southern Indian airport Friday, killing at least 18 people and injuring more than 100, according to a person with direct knowledge of the matter.
The Boeing Co. 737 appeared to touch down near the middle of the 9,000-foot-long (2,743-meter-long) runway at Kozhikode, the person said, before skidding off the end and careening down a slope, breaking into three parts. The captain was experienced, with 11,000 flying hours, while the co-pilot had 2,000 hours. Neither one made a distress call, and both died in the crash. Visibility, precipitation and tailwinds were within acceptable guidelines for landing, the person said, asking not to be identified because the investigation is ongoing.
A playback on the FlightRadar24 website shows a first attempt to land the plane was aborted before another effort was made from the opposite direction. The flight-tracking site shows visibility at the airport was 1,500-to-2,000 meters, and winds were blowing at 12-13 knots, which is a moderate breeze on the Beaufort scale. Indian officials say 800 meters is sufficient visibility for landing.
Last edited by Airbubba; 11th Aug 2020 at 16:06.
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From the New India Express.
https://www.newindianexpress.com/sta...l-2181339.html
Kozhikode plane crash: Did Air India flight land at speed higher than normal?It is suspected that the reverse thrust mode used to reduce the speed after landing probably didn’t work, which could indicate a technical fault.
Published: 10th August 2020 09:31 AM | Last Updated: 10th August 2020 09:31 AM
By Dhinesh Kallungal
Express News Service THIRUVANANTHAPURAM: The Air India Express plane involved in the accident at the Kozhikode airport on Friday night that claimed 18 lives approached the runway at a speed higher than what is ideal for a safe touchdown, sources at the airport revealed.
Also, it is learnt that the aircraft touched down on the runway well beyond the threshold mark, making it a risky landing.
Besides, it is suspected that the reverse thrust mode used to reduce the speed after landing probably didn’t work, which could indicate a technical fault.
“Normally, aircraft approach the runway at a speed range of 220-240kmph (120-130 knots). But this plane descended on the runway at over 300kmph,” said a reliable source in the Airport Authority of India.
Further, the aircraft touched down on the 2,860-metre runway (which includes the 240-metre Runway End Safety Area) at the 1,300-metre point.
The Boeing 737 with 190 on board skidded and fell off the edge of the table-top runway while landing in bad weather.
The Aircraft Accident Investigation Bureau and the Directorate General of Civil Aviation have launched an investigation into the accident.
An inspection of the accident site also raised suspicion whether the aircraft engine had really worked in reverse thrust — a process of temporarily diverting the engine’s thrust against the forward travel to provide deceleration. According to experts, even aircraft that touchdown beyond the threshold mark can be effectively stopped if the engine is in the reverse thrust mode.After landing, the plane crossed Runway End Safety Area and broke the instrument landing system lights.
The officials who inspected the site told Express the splinters of the landing system lights were strewn on the tarmac.
“If the aircraft was in the reverse thrust mode, the splinters would have been lying on the front side,” one of them said.
“Further, around 90 metres of the sand-filled portion ahead of the runway remained almost intact, showing no signs of reverse thrust,” said an official.
The official, however, said it’s hard to believe that a senior pilot in command, who used to train Air India Express pilots, did not put the plane in reverse thrust mode in a distress condition.
“Maybe something beyond one’s judgment or imagination would have happened. We have to wait till data from the cockpit voice recorder (CVR) and flight data recorder (black box) are decoded, which can give a clear idea about what happened in the last minutes,” the official said.
Meanwhile, airport sources told Express that the runway surface tailwind during the time of landing was 8 knots, while a Boeing 737 can withstand a tailwind of up to 15 knots. The sources also confirmed that when the pilot aborted the first attempt to land on Runway 28, he cited heavy wind as the reason.
Later, he approached Runway 10 after the takeoff of a Delhi aircraft from the same runway. No distress signal was sent to the air traffic control unit of the airport from the cockpit even after landing, sources said.
Published: 10th August 2020 09:31 AM | Last Updated: 10th August 2020 09:31 AM
By Dhinesh Kallungal
Express News Service THIRUVANANTHAPURAM: The Air India Express plane involved in the accident at the Kozhikode airport on Friday night that claimed 18 lives approached the runway at a speed higher than what is ideal for a safe touchdown, sources at the airport revealed.
Also, it is learnt that the aircraft touched down on the runway well beyond the threshold mark, making it a risky landing.
Besides, it is suspected that the reverse thrust mode used to reduce the speed after landing probably didn’t work, which could indicate a technical fault.
“Normally, aircraft approach the runway at a speed range of 220-240kmph (120-130 knots). But this plane descended on the runway at over 300kmph,” said a reliable source in the Airport Authority of India.
Further, the aircraft touched down on the 2,860-metre runway (which includes the 240-metre Runway End Safety Area) at the 1,300-metre point.
The Boeing 737 with 190 on board skidded and fell off the edge of the table-top runway while landing in bad weather.
The Aircraft Accident Investigation Bureau and the Directorate General of Civil Aviation have launched an investigation into the accident.
An inspection of the accident site also raised suspicion whether the aircraft engine had really worked in reverse thrust — a process of temporarily diverting the engine’s thrust against the forward travel to provide deceleration. According to experts, even aircraft that touchdown beyond the threshold mark can be effectively stopped if the engine is in the reverse thrust mode.After landing, the plane crossed Runway End Safety Area and broke the instrument landing system lights.
The officials who inspected the site told Express the splinters of the landing system lights were strewn on the tarmac.
“If the aircraft was in the reverse thrust mode, the splinters would have been lying on the front side,” one of them said.
“Further, around 90 metres of the sand-filled portion ahead of the runway remained almost intact, showing no signs of reverse thrust,” said an official.
The official, however, said it’s hard to believe that a senior pilot in command, who used to train Air India Express pilots, did not put the plane in reverse thrust mode in a distress condition.
“Maybe something beyond one’s judgment or imagination would have happened. We have to wait till data from the cockpit voice recorder (CVR) and flight data recorder (black box) are decoded, which can give a clear idea about what happened in the last minutes,” the official said.
Meanwhile, airport sources told Express that the runway surface tailwind during the time of landing was 8 knots, while a Boeing 737 can withstand a tailwind of up to 15 knots. The sources also confirmed that when the pilot aborted the first attempt to land on Runway 28, he cited heavy wind as the reason.
Later, he approached Runway 10 after the takeoff of a Delhi aircraft from the same runway. No distress signal was sent to the air traffic control unit of the airport from the cockpit even after landing, sources said.
https://www.newindianexpress.com/sta...l-2181339.html
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masalama
But why so many reversals?? Even when there was not flight scheduled for departure during that period? If someone looks at historical data, there are fewer 'reversals' when attempting landing of RWY28 as compared to RWY10. The only edge RWY10 has is that there is no obstacle upto 10 kms from RWY10 whereas RWY28 has a mast ELEV 621 ft. DIST. 7017m from beginning of RWY28 Bearing 104o 15' (M)
But why so many reversals?? Even when there was not flight scheduled for departure during that period? If someone looks at historical data, there are fewer 'reversals' when attempting landing of RWY28 as compared to RWY10. The only edge RWY10 has is that there is no obstacle upto 10 kms from RWY10 whereas RWY28 has a mast ELEV 621 ft. DIST. 7017m from beginning of RWY28 Bearing 104o 15' (M)
de minimus non curat lex
How are ‘reversals’ relevant to the tragic crash?
1. Concentrate on landing deep into the runway with a tailwind.
2. Runway contamination / braking action.
3. The inadequate RESA and the steep slope / airfield boundary wall.
4. CRM / decision making by the crew. Was Command gradient a factor?
5. G/S “u/s” RW 28.
These so far are some of the relevant factors, from a non exhaustive list.
Item 3 caused the fatality
1. Concentrate on landing deep into the runway with a tailwind.
2. Runway contamination / braking action.
3. The inadequate RESA and the steep slope / airfield boundary wall.
4. CRM / decision making by the crew. Was Command gradient a factor?
5. G/S “u/s” RW 28.
These so far are some of the relevant factors, from a non exhaustive list.
Item 3 caused the fatality
Last edited by parkfell; 11th Aug 2020 at 08:42. Reason: syntax
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1. Cannot compare approach and landing performance of an ATR with a B737-8.
2. What about the wind component at the moment of landing?
3. Runway contamination?
4. Where did they made contact with the runway? (how deep into it)?
2. What about the wind component at the moment of landing?
3. Runway contamination?
4. Where did they made contact with the runway? (how deep into it)?
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If it was a very long landing, - Reports say the aircraft touched down near the center of the runway- at any phase of the final approach, the aircraft should have not been calibrated with the glideslope parameter. It should have flown way too high. Then it is obvious that the pilot must have attempted to increase the descent rate. But here the transponder data from various sources indicate that the descent rate of the aircraft was within normal limit! The last known position of the aircraft was at 945 ft Calibrated altitude, 175 kts Groundspeed, and descending at a rate of 896 ft/mint. Normal except the ground speed. (It seems way too a high speed at that point even if the 12 kts tailwind is considered) .... Then the Pictures of the broken cockpit shows a fully advanced thrust liver, a disengaged reverse thrust, a completely up Spoilers Arm, and a flap setting of 40... !! Strange and Extremely confusing.
Last edited by Physel Poilil; 11th Aug 2020 at 07:53.
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CRM
I have to wonder who was the PF on this flight. If it was the FO, why didn’t the PIC assume control or call for a go around earlier? If it was the PIC, I’m curious to know if the FO spoke up (was assertive enough) to call for a go around earlier? Surely he couldn’t have just sat there & done nothing, watching his PIC mishandle the aircraft.
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Vref F40 is 141kias at 65ton, min add +5 (if gusty wind maybe they used +15??) gives 157kias on the MCP, correct for pressure/temp results in 162ktas and with 14kts tailwing gives the 176kts groundspeed