https://twitter.com/NTSB_Newsroom/status/986396859785760768?s=20
Missing Fan Blad at around 8 o'clock
Missing Fan Blad at around 8 o'clock
Southwest engine failure
- Thread starter CincyDavid
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Originally Posted By: nthach
Originally Posted By: JLTD
"Uncontained failure" is the industry term. It's supposed to stay inside the engine's titanium (or other metals) shroud.
Sounds like the crew handled things well, landed quickly and safely. There will be an investigation into the engine and why it became uncontained...
I was about to say that as well - it looks like there is an uncontained failure, the fan case did let go. We can't speculate but the CFM56-7B engine used on the 737NG does use a titanium fan(the new LEAP engine on the MAX is carbon fiber like the GE90/NX). I wonder if one of the fan blades broke loose from the hub and had enough inertia to be hurled through the window? 2nd engine failure for WN in the last year too, there has to be root cause - either shoddy maintenance practice or something isn't caught at a shop visit.
And in an modern airliner, should the inner window pane be enough to hold together in the event of a outer window failure or the rapid decompression event that happened is enough to rip the Lexan inner pane from the fuselage as well?
There’s no inner and outer pane; at least, not on the Embraer airliners I work on. Just a piece of lexan around .75” thick. The “inner pane” is only a thin piece of non-structural plastic, for cosmetic purposes only. Doesn’t hold pressure or provide any protection in the event the window is compromised.
Interesting tidbit for ya - those windows are held in place by little “c-clamps”. The nuts that hold those C-clamps are only torqued to 8-10 lb/in. Only to hold it in place against the rubber seal, really. Being a plug-type design, its strength comes from cabin pressure. Very strong, but obviously can’t withstand what is effectively a cannon shot (a chunk of steel or Ti alloy hurled off the engine spool with tremendous force).
Originally Posted By: JLTD
"Uncontained failure" is the industry term. It's supposed to stay inside the engine's titanium (or other metals) shroud.
Sounds like the crew handled things well, landed quickly and safely. There will be an investigation into the engine and why it became uncontained...
I was about to say that as well - it looks like there is an uncontained failure, the fan case did let go. We can't speculate but the CFM56-7B engine used on the 737NG does use a titanium fan(the new LEAP engine on the MAX is carbon fiber like the GE90/NX). I wonder if one of the fan blades broke loose from the hub and had enough inertia to be hurled through the window? 2nd engine failure for WN in the last year too, there has to be root cause - either shoddy maintenance practice or something isn't caught at a shop visit.
And in an modern airliner, should the inner window pane be enough to hold together in the event of a outer window failure or the rapid decompression event that happened is enough to rip the Lexan inner pane from the fuselage as well?
There’s no inner and outer pane; at least, not on the Embraer airliners I work on. Just a piece of lexan around .75” thick. The “inner pane” is only a thin piece of non-structural plastic, for cosmetic purposes only. Doesn’t hold pressure or provide any protection in the event the window is compromised.
Interesting tidbit for ya - those windows are held in place by little “c-clamps”. The nuts that hold those C-clamps are only torqued to 8-10 lb/in. Only to hold it in place against the rubber seal, really. Being a plug-type design, its strength comes from cabin pressure. Very strong, but obviously can’t withstand what is effectively a cannon shot (a chunk of steel or Ti alloy hurled off the engine spool with tremendous force).
NTSB says #13 blade is missing at the hub and metal fatigue is suspect !!!
Wonder if this is a maintenance issue or new defect with the GE CFM engines like what happened in FL back in 2016 ??
Wouldn't be surprised if we see a fleet grounding soon like the 787's a few years ago !!!
I fly allot on SW, Now kinda worried
RIP to the victim, Mother of 2 from New Mexico
Dave
Wonder if this is a maintenance issue or new defect with the GE CFM engines like what happened in FL back in 2016 ??
Wouldn't be surprised if we see a fleet grounding soon like the 787's a few years ago !!!
I fly allot on SW, Now kinda worried
RIP to the victim, Mother of 2 from New Mexico
Dave
Originally Posted By: bubbatime
Her head probably popped with all that pressure differential(600-700PSI ish) behind it.
People said blood was everywhere.
Lady has died.
Are you referring to pressure from the airspeed outside being 600-700psi? Because the pressure differential frmo inside the cabin to outside of the cabin at altitude isn't more than about 8-10psi.
Her head probably popped with all that pressure differential(600-700PSI ish) behind it.
People said blood was everywhere.
Lady has died.
Are you referring to pressure from the airspeed outside being 600-700psi? Because the pressure differential frmo inside the cabin to outside of the cabin at altitude isn't more than about 8-10psi.
Originally Posted By: Lethal1ty17
Originally Posted By: bubbatime
Her head probably popped with all that pressure differential(600-700PSI ish) behind it.
People said blood was everywhere.
Lady has died.
Are you referring to pressure from the airspeed outside being 600-700psi? Because the pressure differential frmo inside the cabin to outside of the cabin at altitude isn't more than about 8-10psi.
Just one figure I saw somewhere.
A small window opens up. ALL the air in the plane tries to escape that small hole at once. The persons head gets sucked out. ALL the air in the plane continues to rush around the head. A HUGE volume of air. It may only be an 8-10 PSI difference, but with the head in the hole, the pressure acting on the head is even more pronounced. You can see a blood spray on the exterior windows behind the popped window. Her head likely exploded from the pressure.
Originally Posted By: bubbatime
Her head probably popped with all that pressure differential(600-700PSI ish) behind it.
People said blood was everywhere.
Lady has died.
Are you referring to pressure from the airspeed outside being 600-700psi? Because the pressure differential frmo inside the cabin to outside of the cabin at altitude isn't more than about 8-10psi.
Just one figure I saw somewhere.
A small window opens up. ALL the air in the plane tries to escape that small hole at once. The persons head gets sucked out. ALL the air in the plane continues to rush around the head. A HUGE volume of air. It may only be an 8-10 PSI difference, but with the head in the hole, the pressure acting on the head is even more pronounced. You can see a blood spray on the exterior windows behind the popped window. Her head likely exploded from the pressure.
"Head exploded" is very unlikely.
Trauma from impact with engine parts, perhaps, or slammed against the frame/bulkhead by the rushing air.
A lot of what you read about airplanes, or see in movies, is complete fabrication.
The pressure differential is a maximum of 8PSI between inside and outside. That's an airplane structural limit. However, with a hole in the structure, the outflow valve will try to regulate/maintain that pressure differential by closing, so there will continue to be air forced into the cabin by the bleed air system, using the remaining engine as a source.
The masks DO fit over your nose and mouth, and that's how you're supposed to wear them, but 98% of passengers talk, sleep, read, or remain immersed in the smart phones during the safety demo/video. Blissfully ignorant of their responsibilities in an emergency...utterly clueless on how the emergency equipment works.
So it comes as no surprise that this group donned the masks incorrectly. You should see them try to get a life vest on...one buckle, and 75% of them can't figure it out...just ask Sully...
There is one extra mask in every service unit (a group of 3 to 5 seats, depending on cabin layout) intended for lap infants, or even flight attendants who might be nearby when cabin pressure is lost.
Trauma from impact with engine parts, perhaps, or slammed against the frame/bulkhead by the rushing air.
A lot of what you read about airplanes, or see in movies, is complete fabrication.
The pressure differential is a maximum of 8PSI between inside and outside. That's an airplane structural limit. However, with a hole in the structure, the outflow valve will try to regulate/maintain that pressure differential by closing, so there will continue to be air forced into the cabin by the bleed air system, using the remaining engine as a source.
The masks DO fit over your nose and mouth, and that's how you're supposed to wear them, but 98% of passengers talk, sleep, read, or remain immersed in the smart phones during the safety demo/video. Blissfully ignorant of their responsibilities in an emergency...utterly clueless on how the emergency equipment works.
So it comes as no surprise that this group donned the masks incorrectly. You should see them try to get a life vest on...one buckle, and 75% of them can't figure it out...just ask Sully...
There is one extra mask in every service unit (a group of 3 to 5 seats, depending on cabin layout) intended for lap infants, or even flight attendants who might be nearby when cabin pressure is lost.
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Originally Posted By: Astro14
"Head exploded" is very unlikely.
Trauma from impact with engine parts, perhaps, or slammed against the frame/bulkhead by the rushing air.
A lot of what you read about airplanes, or see in movies, is complete fabrication.
The pressure differential is a maximum of 8PSI between inside and outside. That's an airplane structural limit. However, with a hole in the structure, the outflow valve will try to regulate/maintain that pressure differential by closing, so there will continue to be air forced into the cabin by the bleed air system, using the remaining engine as a source.
The masks DO fit over your nose and mouth, and that's how you're supposed to wear them, but 98% of passengers talk, sleep, read, or remain immersed in the smart phones during the safety demo/video. Blissfully ignorant of their responsibilities in an emergency...utterly clueless on how the emergency equipment works.
So it comes as no surprise that this group donned the masks incorrectly. You should see them try to get a life vest on...one buckle, and 75% of them can't figure it out...just ask Sully...
There is one extra mask in every service unit (a group of 3 to 5 seats, depending on cabin layout) intended for lap infants, or even flight attendants who might be nearby when cabin pressure is lost.
He summed it up quite nicely.
"Head exploded" is very unlikely.
Trauma from impact with engine parts, perhaps, or slammed against the frame/bulkhead by the rushing air.
A lot of what you read about airplanes, or see in movies, is complete fabrication.
The pressure differential is a maximum of 8PSI between inside and outside. That's an airplane structural limit. However, with a hole in the structure, the outflow valve will try to regulate/maintain that pressure differential by closing, so there will continue to be air forced into the cabin by the bleed air system, using the remaining engine as a source.
The masks DO fit over your nose and mouth, and that's how you're supposed to wear them, but 98% of passengers talk, sleep, read, or remain immersed in the smart phones during the safety demo/video. Blissfully ignorant of their responsibilities in an emergency...utterly clueless on how the emergency equipment works.
So it comes as no surprise that this group donned the masks incorrectly. You should see them try to get a life vest on...one buckle, and 75% of them can't figure it out...just ask Sully...
There is one extra mask in every service unit (a group of 3 to 5 seats, depending on cabin layout) intended for lap infants, or even flight attendants who might be nearby when cabin pressure is lost.
He summed it up quite nicely.
Originally Posted By: billt460
Didn't this happen to a A-380 a few years ago?
I think that was compressor or HP/LP turbine failure Qantas had happen on their A380s with Rolls-Royce Trent 900s. They happened on flights from LAX or Dallas/Houston where those planes are at or near MTOW.
From what I've read, Rolls-Royce wanted an engine derate. And there was a lawsuit between Qantas and RR.
Didn't this happen to a A-380 a few years ago?
I think that was compressor or HP/LP turbine failure Qantas had happen on their A380s with Rolls-Royce Trent 900s. They happened on flights from LAX or Dallas/Houston where those planes are at or near MTOW.
From what I've read, Rolls-Royce wanted an engine derate. And there was a lawsuit between Qantas and RR.
Originally Posted By: FowVay
Generally speaking, blade removal and relubrication of the root is done as routine maintenance. During this time the blades are removed from the disk, visually inspected, relubricated with dry film lubricant and reinstalled.
On component overhaul the blades will get a dimensional inspection and a fluorescent penetrant inspection also. We may see this heavy maintenance procedure begin to include some sort of ultrasonic or eddy current inspection in the future. Note that this is a CFM56-7 engine which uses the large twisted blade sets. They're different from the less powerful versions and this type of failure is specific to this engine nomenclature (that I've noticed).
Nicks on the leading edge of a blade can lead to stress risers and ultimately blade failure if it goes undetected for too long. As a rule any nicks need to be blended out. There is a critical area at the blade root that does not allow for any damage and it's always possible that this was a problem here.
Planes get a walk-around visual inspection prior to flight but this is never detailed to the level of spotting blade root damage. The inlet cowls stick out three feet making it difficult to see much if anything in the engine inlet.
I thought engine thrust in many cases was controlled via the ROM/EEPROM module in the FADEC and/or what the FMC has loaded in case a plane has to depart from certain airports and a rerate is needed. Or at least what I've read in some cases like Delta wanting a bit more thrust at TOGA for departing SNA.
In the case of a fan blade that is nicked or cracked, is SOP to have it sent back to a workshop to get it repaired and re-checked for damage via NDT? Or is it scrapped for a new OEM blade? Is there a different procedure for a composite blade like what the GE90/GENX/LEAP uses?
And what lubricant is used to lube the fan blade roots and hub?
Generally speaking, blade removal and relubrication of the root is done as routine maintenance. During this time the blades are removed from the disk, visually inspected, relubricated with dry film lubricant and reinstalled.
On component overhaul the blades will get a dimensional inspection and a fluorescent penetrant inspection also. We may see this heavy maintenance procedure begin to include some sort of ultrasonic or eddy current inspection in the future. Note that this is a CFM56-7 engine which uses the large twisted blade sets. They're different from the less powerful versions and this type of failure is specific to this engine nomenclature (that I've noticed).
Nicks on the leading edge of a blade can lead to stress risers and ultimately blade failure if it goes undetected for too long. As a rule any nicks need to be blended out. There is a critical area at the blade root that does not allow for any damage and it's always possible that this was a problem here.
Planes get a walk-around visual inspection prior to flight but this is never detailed to the level of spotting blade root damage. The inlet cowls stick out three feet making it difficult to see much if anything in the engine inlet.
I thought engine thrust in many cases was controlled via the ROM/EEPROM module in the FADEC and/or what the FMC has loaded in case a plane has to depart from certain airports and a rerate is needed. Or at least what I've read in some cases like Delta wanting a bit more thrust at TOGA for departing SNA.
In the case of a fan blade that is nicked or cracked, is SOP to have it sent back to a workshop to get it repaired and re-checked for damage via NDT? Or is it scrapped for a new OEM blade? Is there a different procedure for a composite blade like what the GE90/GENX/LEAP uses?
And what lubricant is used to lube the fan blade roots and hub?
Originally Posted By: nthach
And what lubricant is used to lube the fan blade roots and hub?
Bug guts... actually I think the USAF employed a baked on graphite coating... however the most wear was noted when the C5A fan blades windmilled in the breeze... someone invented a fan stop which was a 2x4 painted red and wrapped in rubber...
And what lubricant is used to lube the fan blade roots and hub?
Bug guts... actually I think the USAF employed a baked on graphite coating... however the most wear was noted when the C5A fan blades windmilled in the breeze... someone invented a fan stop which was a 2x4 painted red and wrapped in rubber...
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Originally Posted By: Astro14
There is one extra mask in every service unit (a group of 3 to 5 seats, depending on cabin layout) intended for lap infants, or even flight attendants who might be nearby when cabin pressure is lost.
Thanks!
There is one extra mask in every service unit (a group of 3 to 5 seats, depending on cabin layout) intended for lap infants, or even flight attendants who might be nearby when cabin pressure is lost.
Thanks!
Originally Posted By: nthach
FowVay said:
Originally Posted By: BusyLittleShop
however the most wear was noted when the C5A fan blades windmilled in the breeze... someone invented a fan stop which was a 2x4 painted red and wrapped in rubber...
It's a fairly common problem in high speed rotating machinery.
Power Station Generators suffer a phenomenon called "copper dusting" when the conductor bars rub on each other when the machine is on low speed barring for cooldown (4 days), or warmup during a start. On low speed barring, they flop around in their attachments, while at speed, they are held through centripetal force in the right place.
however the most wear was noted when the C5A fan blades windmilled in the breeze... someone invented a fan stop which was a 2x4 painted red and wrapped in rubber...
It's a fairly common problem in high speed rotating machinery.
Power Station Generators suffer a phenomenon called "copper dusting" when the conductor bars rub on each other when the machine is on low speed barring for cooldown (4 days), or warmup during a start. On low speed barring, they flop around in their attachments, while at speed, they are held through centripetal force in the right place.
Using that fan stop may be enforceable in military aircraft ops, but it's not going to happen in the civy world. The accountability and discipline is not there. The people using and maintaining the aircraft don't give a [censored] enough to ensure sticking to a program like that.
Originally Posted By: FowVay
The CFM specifies MolyDag 254 as the blade root dry film lubricant.
http://na.henkel-adhesives.com/adhesives/product-search-1554.htm?nodeid=8798046126081
Sounds like a MoS2 and graphite-filled epoxy matrix, while the Molykote G-n paste specified on the CF34 does sound a lot like Honda's Moly 60 Paste(and Honda also says G-n is an acceptable substitute for their stuff).
I presume with the MolyDag that when the epoxy carrier sets, the constant expansion/contraction of the blade root will expose a fresh moly film?
The CFM specifies MolyDag 254 as the blade root dry film lubricant.
http://na.henkel-adhesives.com/adhesives/product-search-1554.htm?nodeid=8798046126081
Sounds like a MoS2 and graphite-filled epoxy matrix, while the Molykote G-n paste specified on the CF34 does sound a lot like Honda's Moly 60 Paste(and Honda also says G-n is an acceptable substitute for their stuff).
I presume with the MolyDag that when the epoxy carrier sets, the constant expansion/contraction of the blade root will expose a fresh moly film?
Originally Posted By: john_pifer
Using that fan stop may be enforceable in military aircraft ops, but it's not going to happen in the civy world. The accountability and discipline is not there. The people using and maintaining the aircraft don't give a [censored] enough to ensure sticking to a program like that.
You are referring to Spartan grads, right?
Using that fan stop may be enforceable in military aircraft ops, but it's not going to happen in the civy world. The accountability and discipline is not there. The people using and maintaining the aircraft don't give a [censored] enough to ensure sticking to a program like that.
You are referring to Spartan grads, right?
Originally Posted By: Yah-Tah-Hey
Originally Posted By: john_pifer
Using that fan stop may be enforceable in military aircraft ops, but it's not going to happen in the civy world. The accountability and discipline is not there. The people using and maintaining the aircraft don't give a [censored] enough to ensure sticking to a program like that.
You are referring to Spartan grads, right?
Bahaha!
Yeah.
Originally Posted By: john_pifer
Using that fan stop may be enforceable in military aircraft ops, but it's not going to happen in the civy world. The accountability and discipline is not there. The people using and maintaining the aircraft don't give a [censored] enough to ensure sticking to a program like that.
You are referring to Spartan grads, right?
Bahaha!
Yeah.
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