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Why did this 737 not take off on first attempt?
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This video shows a 737 'near miss' takeoff. I'm curious as to why the aircraft did not take off as expected, i.e. is there anything obvious from the video?
I'm assuming the speed and payload would have been within the expected limits, so wondering if someone can explain what happened.
safety takeoff boeing-737 stall
asked 3 hours ago
Cloud
2,24311238
add a comment |Â
up vote
3
down vote
favorite
This video shows a 737 'near miss' takeoff. I'm curious as to why the aircraft did not take off as expected, i.e. is there anything obvious from the video?
I'm assuming the speed and payload would have been within the expected limits, so wondering if someone can explain what happened.
safety takeoff boeing-737 stall
asked 3 hours ago
Cloud
2,24311238
1
Either they didn't set the power levers correctly or they rotated way too early (I'm guessing the latter). Unless there is an incident report on this anything we say here is going to be opinions, armchair piloting, and pure conjecture.
– Ron Beyer
2 hours ago
1
@RonBeyer While the actual reason cannot be guessed indeed, a short list of most likely causes is all the OP is looking for. No need for armchair piloting, no need for making a phd thesis out of it.
– bogl
2 hours ago
Note that in spite of what the title says the aircraft didn't seem to actually stall, it just was too slow to climb out of ground effect. It can't stall at this point, because it is “geometrically limitedâ€Â, which means the pitch angle for tail strike is lower than the angle of attack for stall and it is moving horizontally, so you can meaningfully compare those two angles in this specific situation.
– Jan Hudec
1 hour ago
add a comment |Â
up vote
3
down vote
favorite
up vote
3
down vote
favorite
This video shows a 737 'near miss' takeoff. I'm curious as to why the aircraft did not take off as expected, i.e. is there anything obvious from the video?
I'm assuming the speed and payload would have been within the expected limits, so wondering if someone can explain what happened.
safety takeoff boeing-737 stall
asked 3 hours ago
Cloud
2,24311238
This video shows a 737 'near miss' takeoff. I'm curious as to why the aircraft did not take off as expected, i.e. is there anything obvious from the video?
I'm assuming the speed and payload would have been within the expected limits, so wondering if someone can explain what happened.
safety takeoff boeing-737 stall
safety takeoff boeing-737 stall
asked 3 hours ago
Cloud
2,24311238
asked 3 hours ago
Cloud
2,24311238
asked 3 hours ago
Cloud
2,24311238
asked 3 hours ago
Cloud
2,24311238
asked 3 hours ago
Cloud
2,24311238
2,24311238
1
Either they didn't set the power levers correctly or they rotated way too early (I'm guessing the latter). Unless there is an incident report on this anything we say here is going to be opinions, armchair piloting, and pure conjecture.
– Ron Beyer
2 hours ago
1
@RonBeyer While the actual reason cannot be guessed indeed, a short list of most likely causes is all the OP is looking for. No need for armchair piloting, no need for making a phd thesis out of it.
– bogl
2 hours ago
Note that in spite of what the title says the aircraft didn't seem to actually stall, it just was too slow to climb out of ground effect. It can't stall at this point, because it is “geometrically limitedâ€Â, which means the pitch angle for tail strike is lower than the angle of attack for stall and it is moving horizontally, so you can meaningfully compare those two angles in this specific situation.
– Jan Hudec
1 hour ago
add a comment |Â
1
Either they didn't set the power levers correctly or they rotated way too early (I'm guessing the latter). Unless there is an incident report on this anything we say here is going to be opinions, armchair piloting, and pure conjecture.
– Ron Beyer
2 hours ago
1
@RonBeyer While the actual reason cannot be guessed indeed, a short list of most likely causes is all the OP is looking for. No need for armchair piloting, no need for making a phd thesis out of it.
– bogl
2 hours ago
Note that in spite of what the title says the aircraft didn't seem to actually stall, it just was too slow to climb out of ground effect. It can't stall at this point, because it is “geometrically limitedâ€Â, which means the pitch angle for tail strike is lower than the angle of attack for stall and it is moving horizontally, so you can meaningfully compare those two angles in this specific situation.
– Jan Hudec
1 hour ago
1
1
Either they didn't set the power levers correctly or they rotated way too early (I'm guessing the latter). Unless there is an incident report on this anything we say here is going to be opinions, armchair piloting, and pure conjecture.
– Ron Beyer
2 hours ago
Either they didn't set the power levers correctly or they rotated way too early (I'm guessing the latter). Unless there is an incident report on this anything we say here is going to be opinions, armchair piloting, and pure conjecture.
– Ron Beyer
2 hours ago
1
1
@RonBeyer While the actual reason cannot be guessed indeed, a short list of most likely causes is all the OP is looking for. No need for armchair piloting, no need for making a phd thesis out of it.
– bogl
2 hours ago
@RonBeyer While the actual reason cannot be guessed indeed, a short list of most likely causes is all the OP is looking for. No need for armchair piloting, no need for making a phd thesis out of it.
– bogl
2 hours ago
Note that in spite of what the title says the aircraft didn't seem to actually stall, it just was too slow to climb out of ground effect. It can't stall at this point, because it is “geometrically limitedâ€Â, which means the pitch angle for tail strike is lower than the angle of attack for stall and it is moving horizontally, so you can meaningfully compare those two angles in this specific situation.
– Jan Hudec
1 hour ago
Note that in spite of what the title says the aircraft didn't seem to actually stall, it just was too slow to climb out of ground effect. It can't stall at this point, because it is “geometrically limitedâ€Â, which means the pitch angle for tail strike is lower than the angle of attack for stall and it is moving horizontally, so you can meaningfully compare those two angles in this specific situation.
– Jan Hudec
1 hour ago
add a comment |Â
2 Answers
2
active
oldest
votes
up vote
5
down vote
It looks to me like a too-early rotation (lifting the nose off of the runway). This may have happened as a result of a miscalculation of the rotation speed (known as Vr speed). A miscalculation of the Vr speed, for example, can happen if you derive this speed using a lower than actual aircraft takeoff weight in your performance calculation. This would lead to a calculated Vr speed that was less than was required.
If this was the case, as the pilot rotated the aircraft into the liftoff attitude there would not enough speed to allow the aircraft to climb out. Instead the aircraft would stay on the ground (or in ground effect) until it accelerated to the proper lift off speed.
The crew could also have miscalculated the power setting necessary for takeoff by using an incorrect temperature, or physically failing to advance the thrust levers to the correct position. Since the B737 in the video was a later model it likely had a Flight Management System (FMS) that would have calculated the takeoff thrust setting based on keyboard entries made by the crew.
Also, it's common for the takeoff thrust to be set, based on the FMS calculated values, using the auto-throttle function (sometimes takeoff thrust is set by the crew using the calculation provided by the FMS[or similar]). In other words, after initially moving the thrust levers forward a bit, the pilot would just push a button on the mode control panel and the throttles would automatically move to the proper takeoff setting. Again, this would depend on the proper information being loaded into the FMS so that proper calculations for Vr speed, thrust setting, etc. would be utilized.
There are many variables depending on what procedures the crew used and the pilot technique, but the video shows the airplane rotating and not lifting off, and just my opinion, but this was likely because the rotation was started at a lower speed than was appropriate.
Here is a link to a incident involving a B737 that appears to have some similar circumstances.
B737 tail strike
answered 2 hours ago
757toga
5,6631132
add a comment |Â
up vote
1
down vote
With the help of the clearly visible livery (Royal Air Maroc), registration (CN-RNV) and approximate time (before August 2016, probably not by too much), I managed to find the specific Incident: Royal Maroc B737 at Frankfurt on Jul 23rd 2016, three takeoffs for the price of one on The Aviation Herald. It even links to the very same video that you do.
Unfortunately:
On Aug 30th 2016 the BFU responded to an inquiry by The Aviation Herald of Aug 25th 2016 stating, the BFU had neither received any notification by the crew, airline or airport involved nor by the person taking the video (see below) and became aware of the occurrence only through the release of the video into the public more than a months after the occurrence. The BFU argued that as result it will not be possible to establish sufficient facts and evidence needed for a detailed investigation, hence the BFU decided to refrain from initiating an investigation.
So we won't have anything better than guesses anyway.
answered 21 mins ago
Jan Hudec
37.3k395180
add a comment |Â
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
5
down vote
It looks to me like a too-early rotation (lifting the nose off of the runway). This may have happened as a result of a miscalculation of the rotation speed (known as Vr speed). A miscalculation of the Vr speed, for example, can happen if you derive this speed using a lower than actual aircraft takeoff weight in your performance calculation. This would lead to a calculated Vr speed that was less than was required.
If this was the case, as the pilot rotated the aircraft into the liftoff attitude there would not enough speed to allow the aircraft to climb out. Instead the aircraft would stay on the ground (or in ground effect) until it accelerated to the proper lift off speed.
The crew could also have miscalculated the power setting necessary for takeoff by using an incorrect temperature, or physically failing to advance the thrust levers to the correct position. Since the B737 in the video was a later model it likely had a Flight Management System (FMS) that would have calculated the takeoff thrust setting based on keyboard entries made by the crew.
Also, it's common for the takeoff thrust to be set, based on the FMS calculated values, using the auto-throttle function (sometimes takeoff thrust is set by the crew using the calculation provided by the FMS[or similar]). In other words, after initially moving the thrust levers forward a bit, the pilot would just push a button on the mode control panel and the throttles would automatically move to the proper takeoff setting. Again, this would depend on the proper information being loaded into the FMS so that proper calculations for Vr speed, thrust setting, etc. would be utilized.
There are many variables depending on what procedures the crew used and the pilot technique, but the video shows the airplane rotating and not lifting off, and just my opinion, but this was likely because the rotation was started at a lower speed than was appropriate.
Here is a link to a incident involving a B737 that appears to have some similar circumstances.
B737 tail strike
answered 2 hours ago
757toga
5,6631132
add a comment |Â
up vote
5
down vote
It looks to me like a too-early rotation (lifting the nose off of the runway). This may have happened as a result of a miscalculation of the rotation speed (known as Vr speed). A miscalculation of the Vr speed, for example, can happen if you derive this speed using a lower than actual aircraft takeoff weight in your performance calculation. This would lead to a calculated Vr speed that was less than was required.
If this was the case, as the pilot rotated the aircraft into the liftoff attitude there would not enough speed to allow the aircraft to climb out. Instead the aircraft would stay on the ground (or in ground effect) until it accelerated to the proper lift off speed.
The crew could also have miscalculated the power setting necessary for takeoff by using an incorrect temperature, or physically failing to advance the thrust levers to the correct position. Since the B737 in the video was a later model it likely had a Flight Management System (FMS) that would have calculated the takeoff thrust setting based on keyboard entries made by the crew.
Also, it's common for the takeoff thrust to be set, based on the FMS calculated values, using the auto-throttle function (sometimes takeoff thrust is set by the crew using the calculation provided by the FMS[or similar]). In other words, after initially moving the thrust levers forward a bit, the pilot would just push a button on the mode control panel and the throttles would automatically move to the proper takeoff setting. Again, this would depend on the proper information being loaded into the FMS so that proper calculations for Vr speed, thrust setting, etc. would be utilized.
There are many variables depending on what procedures the crew used and the pilot technique, but the video shows the airplane rotating and not lifting off, and just my opinion, but this was likely because the rotation was started at a lower speed than was appropriate.
Here is a link to a incident involving a B737 that appears to have some similar circumstances.
B737 tail strike
answered 2 hours ago
757toga
5,6631132
add a comment |Â
up vote
5
down vote
up vote
5
down vote
It looks to me like a too-early rotation (lifting the nose off of the runway). This may have happened as a result of a miscalculation of the rotation speed (known as Vr speed). A miscalculation of the Vr speed, for example, can happen if you derive this speed using a lower than actual aircraft takeoff weight in your performance calculation. This would lead to a calculated Vr speed that was less than was required.
If this was the case, as the pilot rotated the aircraft into the liftoff attitude there would not enough speed to allow the aircraft to climb out. Instead the aircraft would stay on the ground (or in ground effect) until it accelerated to the proper lift off speed.
The crew could also have miscalculated the power setting necessary for takeoff by using an incorrect temperature, or physically failing to advance the thrust levers to the correct position. Since the B737 in the video was a later model it likely had a Flight Management System (FMS) that would have calculated the takeoff thrust setting based on keyboard entries made by the crew.
Also, it's common for the takeoff thrust to be set, based on the FMS calculated values, using the auto-throttle function (sometimes takeoff thrust is set by the crew using the calculation provided by the FMS[or similar]). In other words, after initially moving the thrust levers forward a bit, the pilot would just push a button on the mode control panel and the throttles would automatically move to the proper takeoff setting. Again, this would depend on the proper information being loaded into the FMS so that proper calculations for Vr speed, thrust setting, etc. would be utilized.
There are many variables depending on what procedures the crew used and the pilot technique, but the video shows the airplane rotating and not lifting off, and just my opinion, but this was likely because the rotation was started at a lower speed than was appropriate.
Here is a link to a incident involving a B737 that appears to have some similar circumstances.
B737 tail strike
answered 2 hours ago
757toga
5,6631132
It looks to me like a too-early rotation (lifting the nose off of the runway). This may have happened as a result of a miscalculation of the rotation speed (known as Vr speed). A miscalculation of the Vr speed, for example, can happen if you derive this speed using a lower than actual aircraft takeoff weight in your performance calculation. This would lead to a calculated Vr speed that was less than was required.
If this was the case, as the pilot rotated the aircraft into the liftoff attitude there would not enough speed to allow the aircraft to climb out. Instead the aircraft would stay on the ground (or in ground effect) until it accelerated to the proper lift off speed.
The crew could also have miscalculated the power setting necessary for takeoff by using an incorrect temperature, or physically failing to advance the thrust levers to the correct position. Since the B737 in the video was a later model it likely had a Flight Management System (FMS) that would have calculated the takeoff thrust setting based on keyboard entries made by the crew.
Also, it's common for the takeoff thrust to be set, based on the FMS calculated values, using the auto-throttle function (sometimes takeoff thrust is set by the crew using the calculation provided by the FMS[or similar]). In other words, after initially moving the thrust levers forward a bit, the pilot would just push a button on the mode control panel and the throttles would automatically move to the proper takeoff setting. Again, this would depend on the proper information being loaded into the FMS so that proper calculations for Vr speed, thrust setting, etc. would be utilized.
There are many variables depending on what procedures the crew used and the pilot technique, but the video shows the airplane rotating and not lifting off, and just my opinion, but this was likely because the rotation was started at a lower speed than was appropriate.
Here is a link to a incident involving a B737 that appears to have some similar circumstances.
B737 tail strike
answered 2 hours ago
757toga
5,6631132
edited 1 hour ago
answered 2 hours ago
757toga
5,6631132
answered 2 hours ago
757toga
5,6631132
answered 2 hours ago
757toga
5,6631132
5,6631132
add a comment |Â
add a comment |Â
up vote
1
down vote
With the help of the clearly visible livery (Royal Air Maroc), registration (CN-RNV) and approximate time (before August 2016, probably not by too much), I managed to find the specific Incident: Royal Maroc B737 at Frankfurt on Jul 23rd 2016, three takeoffs for the price of one on The Aviation Herald. It even links to the very same video that you do.
Unfortunately:
On Aug 30th 2016 the BFU responded to an inquiry by The Aviation Herald of Aug 25th 2016 stating, the BFU had neither received any notification by the crew, airline or airport involved nor by the person taking the video (see below) and became aware of the occurrence only through the release of the video into the public more than a months after the occurrence. The BFU argued that as result it will not be possible to establish sufficient facts and evidence needed for a detailed investigation, hence the BFU decided to refrain from initiating an investigation.
So we won't have anything better than guesses anyway.
answered 21 mins ago
Jan Hudec
37.3k395180
add a comment |Â
up vote
1
down vote
With the help of the clearly visible livery (Royal Air Maroc), registration (CN-RNV) and approximate time (before August 2016, probably not by too much), I managed to find the specific Incident: Royal Maroc B737 at Frankfurt on Jul 23rd 2016, three takeoffs for the price of one on The Aviation Herald. It even links to the very same video that you do.
Unfortunately:
On Aug 30th 2016 the BFU responded to an inquiry by The Aviation Herald of Aug 25th 2016 stating, the BFU had neither received any notification by the crew, airline or airport involved nor by the person taking the video (see below) and became aware of the occurrence only through the release of the video into the public more than a months after the occurrence. The BFU argued that as result it will not be possible to establish sufficient facts and evidence needed for a detailed investigation, hence the BFU decided to refrain from initiating an investigation.
So we won't have anything better than guesses anyway.
answered 21 mins ago
Jan Hudec
37.3k395180
add a comment |Â
up vote
1
down vote
up vote
1
down vote
With the help of the clearly visible livery (Royal Air Maroc), registration (CN-RNV) and approximate time (before August 2016, probably not by too much), I managed to find the specific Incident: Royal Maroc B737 at Frankfurt on Jul 23rd 2016, three takeoffs for the price of one on The Aviation Herald. It even links to the very same video that you do.
Unfortunately:
On Aug 30th 2016 the BFU responded to an inquiry by The Aviation Herald of Aug 25th 2016 stating, the BFU had neither received any notification by the crew, airline or airport involved nor by the person taking the video (see below) and became aware of the occurrence only through the release of the video into the public more than a months after the occurrence. The BFU argued that as result it will not be possible to establish sufficient facts and evidence needed for a detailed investigation, hence the BFU decided to refrain from initiating an investigation.
So we won't have anything better than guesses anyway.
answered 21 mins ago
Jan Hudec
37.3k395180
With the help of the clearly visible livery (Royal Air Maroc), registration (CN-RNV) and approximate time (before August 2016, probably not by too much), I managed to find the specific Incident: Royal Maroc B737 at Frankfurt on Jul 23rd 2016, three takeoffs for the price of one on The Aviation Herald. It even links to the very same video that you do.
Unfortunately:
On Aug 30th 2016 the BFU responded to an inquiry by The Aviation Herald of Aug 25th 2016 stating, the BFU had neither received any notification by the crew, airline or airport involved nor by the person taking the video (see below) and became aware of the occurrence only through the release of the video into the public more than a months after the occurrence. The BFU argued that as result it will not be possible to establish sufficient facts and evidence needed for a detailed investigation, hence the BFU decided to refrain from initiating an investigation.
So we won't have anything better than guesses anyway.
answered 21 mins ago
Jan Hudec
37.3k395180
answered 21 mins ago
Jan Hudec
37.3k395180
answered 21 mins ago
Jan Hudec
37.3k395180
answered 21 mins ago
Jan Hudec
37.3k395180
37.3k395180
add a comment |Â
add a comment |Â
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1
Either they didn't set the power levers correctly or they rotated way too early (I'm guessing the latter). Unless there is an incident report on this anything we say here is going to be opinions, armchair piloting, and pure conjecture.
– Ron Beyer
2 hours ago
1
@RonBeyer While the actual reason cannot be guessed indeed, a short list of most likely causes is all the OP is looking for. No need for armchair piloting, no need for making a phd thesis out of it.
– bogl
2 hours ago
Note that in spite of what the title says the aircraft didn't seem to actually stall, it just was too slow to climb out of ground effect. It can't stall at this point, because it is “geometrically limitedâ€Â, which means the pitch angle for tail strike is lower than the angle of attack for stall and it is moving horizontally, so you can meaningfully compare those two angles in this specific situation.
– Jan Hudec
1 hour ago