How Does This Keep Happening?!

[Teken]

In the last six months there has been no less than three planes which have declared an emergency due to a wheel coming off?!? I am at a complete loss as to how this could happen just once!

 

But no less than three different airlines from Air Canada, West Jet, to Delta. This has occurred and you just have to shake your head in disbelief in wondering how many pot heads do they have working in this industry?

 

This is right up there where a planes emergency sliding chutes was found deployed mid air and on the ground.

 

Toronto-bound Air Canada flight declares emergency after wheel falls off during take-off

https://toronto.ctvnews.ca/toronto-bound-air-canada-plane-lands-after-declaring-mid-air-emergency-1.4817379

 

 

 

 

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[larryllix]

Oh well! There was many, many more wheels to land with.  I thought you were going to say it was returning from China...  

Add wheels to the checklist, Captain Sully. Where it went is pretty scary!

[TrojanHorse]

Oh well! There was many, many more wheels to land with.  I thought you were going to say it was returning from China...  

Add wheels to the checklist, Captain Sully. Where it went is pretty scary!

 

I was thinking the same thing. Plenty of wheels - for this exact reason?!?

 

And yeah, where TF is the wheel?

 

Actually just watched a Captain Sully NAt Geo special the other day. Maybe add another thing to the captain’s pre-flight checklist - tighten lugnuts??

 

 

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[larryllix]

5 minutes ago, TrojanHorse said:

 

I was thinking the same thing. Plenty of wheels - for this exact reason?!?

 

And yeah, where TF is the wheel?

 

Actually just watched a Captain Sully NAt Geo special the other day. Maybe add another thing to the captain’s pre-flight checklist - tighten lugnuts??

 

 

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Ask Firestone how to do it.  

[TrojanHorse]

Gotta ask - Is this happening only in Canada?


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[oberkc]

9 hours ago, Teken said:

I am at a complete loss as to how this could happen just once!

Anything can happen once.  But...multiple times in a short period....very surprising, strange, suspicious, etc.

[Teken]

8 hours ago, TrojanHorse said:

Gotta ask - Is this happening only in Canada?


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Two of the incidents happen to Canadian air line carriers whether they were in home ports I can't say. The other was an American airline named Delta again don't know if this happen in their home port. I believe that's important to know as lots of follow up and safety checks are done at various points of the planes journey. 

[Teken]

1 hour ago, oberkc said:

Anything can happen once.  But...multiple times in a short period....very surprising, strange, suspicious, etc.

At first blush one would just chalk it up to incompetence but given the short period of time and the exact same failure??? I have to lean toward this is work related matter either a method to get back at the company or is a reaction to union negotiations. Temperatures flair quite often when peoples jobs and benefits are on the line so this is a possibility. I guess without seeing and knowing how the wheel was affixed.

How the hell did the plane even roll out to the gate, stage, and begin the take off without the wheel coming off? One lug nut left on? 

[oberkc]

2 hours ago, Teken said:

Temperatures flair quite often when peoples jobs and benefits are on the line so this is a possibility. I guess without seeing and knowing how the wheel was affixed.

It is hard to me to believe that this would be a form of sabotage in retaliation for contract negotiations.  It appears to be across multiple airlines, so that makes it also hard for me to believe that this is a process or cultural issue.  On the other hand, sometimes maintenance is contracted out and perhaps there is a common maintenance shop involved here.

I don't believe the wheels of aircraft of this type are held on by lug nuts.  I expect these wheels to be split-rim type and I also believe that there is a single axle nut holding the wheel/tire assembly on to the axle.  Torque on these nuts are critical.  Too loose and the wheel comes off.  Too tight and there is damage to bearings and axle.

It also appears from the pictures that the brake assembly is still in place, which makes me suspect the axle is still there.

[Teken]

15 minutes ago, oberkc said:

It is hard to me to believe that this would be a form of sabotage in retaliation for contract negotiations.  It appears to be across multiple airlines, so that makes it also hard for me to believe that this is a process or cultural issue.  On the other hand, sometimes maintenance is contracted out and perhaps there is a common maintenance shop involved here.

I don't believe the wheels of aircraft of this type are held on by lug nuts.  I expect these wheels to be split-rim type and I also believe that there is a single axle nut holding the wheel/tire assembly on to the axle.  Torque on these nuts are critical.  Too loose and the wheel comes off.  Too tight and there is damage to bearings and axle.

It also appears from the pictures that the brake assembly is still in place, which makes me suspect the axle is still there.

Is this similar to F1 racing cars where there is simply a center hub ring to hold the tire on? I also agree it could be a common shop their aircraft's happen to be docked with? With respect to sabotage I can sadly state in my time dealing with corporate restructuring people do crazy things.

It can be the whole blue flu, slow roll, to out right sabotage.

I never underestimate a persons ability to do something so out of scope or the norm when peoples health or livelihood is on the line. 

[oberkc]

40 minutes ago, Teken said:

I never underestimate a persons ability to do something so out of scope or the norm when peoples health or livelihood is on the line. 

I see that you are a realist.

 

40 minutes ago, Teken said:

s this similar to F1 racing cars where there is simply a center hub ring to hold the tire on?

I am less familiar with racing cars, but I believe this to be true.  I think, also, that one of the reasons that race cars are done this way is that is can be quicker in the pit stop for tire changes.  I doubt that this is a factor with aircraft.

[TomL]

 I would look at the manufacturer of the product, companies are always trying to save a dime or 2 on the mfg. process or the material used.  They may be rated for a certain number of hours (or however they rate airplane tires)  and the mfg. has life tested it to the bare bone minimum.  Then again the airlines may just be pushing the limits of the rating instead of replacing at required interval.  Though some engineers may want you to believe it is, it is not always the technicians fault.

[Teken]

10 minutes ago, oberkc said:

I see that you are a realist.

 

I am less familiar with racing cars, but I believe this to be true.  I think, also, that one of the reasons that race cars are done this way is that is can be quicker in the pit stop for tire changes.  I doubt that this is a factor with aircraft.

I guess seeing how the wheel is held on would give me more insight as to how this could allow an aircraft to roll around and not have visual queue? Maybe the shear weight of the aircraft is holding the tire in place as they aren't racing around when they are in taxi mode. Gather upon take off once the wheels are in the air that's when the tire spins off?? I wonder how they knew the wheel came off maybe there is a sensor that tells them said wheel is missing??

I know they can see from the lights the gear is fully engaged and up / down. Not sure if they are informed a tire came off - Anyone?

[oberkc]

I am not aware of any "missing wheel" sensor.  Perhaps, from a combination of speed, temp, and ABS system sensors they can extrapolate.

I doubt that axle nut torque gives a visual clue.

I would imagine that the forces on the axle nut are relatively light at low speed taxi.  Perhaps only at the high RPM of takeoff runs does the wheel attempt to spin itself off the axle.

[IndyMike]

Interesting that this has happened on different model aircraft, as well as different carries.  The wheels are part of a wheel and brake assembly.  Each is purpose built for each model aircraft.  We have different brake manufacturers, different maintenance crews, and different aircraft manufacturers.  No a lot of commonality.

The Air Canada article mention two different Airbus aircraft.  The A319 is similar to the A320 in this video : https://www.youtube.com/watch?v=RSrTX1Oi2hc.

The wheel and brake manufacturer may be different, but the approach is similar.

There is no "missing wheel" sensor.  There is a Tire pressure sensor in the wheel "hub cap" that is used by the anti-skid system.  The hub cap would have left the aircraft along with the wheel.  The loss of the tire pressure would have been detected - not sure how it is communicated to the cockpit (it is rather serious). 

The Wheel departure would also have damaged brake components (temp sensors, possibly hydraulics) which may also be communicated.

One of our sister divisions manufactures wheel/brake assemblies for Airbus/Boeing aircraft.  I'll ask if there has been a rash of wheel losses.  I'm retired now, but having refreshments with the guys tonight.

My other though would be TAKEOFF???.  That sounds like a maintenance problem.  Not much stress on the wheel/brake during takeoff unless you abort (the worst), or the brake is dragging (not supposed to happen).  I'll ask about failure modes as well.

Keep your heads down,

IM

Edit - there are locking nuts, locking features, lockwire, etc on everything.  Anything that is critical, or could cause damage, requires secondary retenion.

[Teken]

10 minutes ago, IndyMike said:

Interesting that this has happened on different model aircraft, as well as different carries.  The wheels are part of a wheel and brake assembly.  Each is purpose built for each model aircraft.  We have different brake manufacturers, different maintenance crews, and different aircraft manufacturers.  No a lot of commonality.

The Air Canada article mention two different Airbus aircraft.  The A319 is similar to the A320 in this video : https://www.youtube.com/watch?v=RSrTX1Oi2hc.

The wheel and brake manufacturer may be different, but the approach is similar.

There is no "missing wheel" sensor.  There is a Tire pressure sensor in the wheel "hub cap" that is used by the anti-skid system.  The hub cap would have left the aircraft along with the wheel.  The loss of the tire pressure would have been detected - not sure how it is communicated to the cockpit (it is rather serious). 

The Wheel departure would also have damaged brake components (temp sensors, possibly hydraulics) which may also be communicated.

One of our sister divisions manufactures wheel/brake assemblies for Airbus/Boeing aircraft.  I'll ask if there has been a rash of wheel losses.  I'm retired now, but having refreshments with the guys tonight.

My other though would be TAKEOFF???.  That sounds like a maintenance problem.  Not much stress on the wheel/brake during takeoff unless you abort (the worst), or the brake is dragging (not supposed to happen).  I'll ask about failure modes as well.

Keep your heads down,

IM

Edit - there are locking nuts, locking features, lockwire, etc on everything.  Anything that is critical, or could cause damage, requires secondary retenion.

So looking forward to some facts and insight! Kick back a few cold ones for some of us still on duty! 

[IndyMike]

After some quick reading...  It seems far more likely that the lading gear hub itself failed (stress cracking) causing the entire wheel/brake assembly to leave.  Aircraft is much heavier at takeoff due to the fuel load.  While we make landing gear, most of our experience is with navy aircraft.  I'll still ask.

[Teken]

This is not related to this story but as noted seems to be an issue: https://www.latimes.com/archives/la-xpm-2000-mar-15-mn-9152-story.html 

Quote

It bounced across Firestone, which is 80 feet wide, into the parking lot of St. Helen’s Roman Catholic Church.

The Rev. John Provenza said the wheel landed next to a woman who was entering the church to pray.

“Maybe she prayed a little harder,” Provenza said. “By the grace of God, it could have really been bad.”

He said the wheel was traveling so fast it would have destroyed anything it hit.

[DrLumen]

29 minutes ago, IndyMike said:

After some quick reading...  It seems far more likely that the lading gear hub itself failed (stress cracking) causing the entire wheel/brake assembly to leave.  Aircraft is much heavier at takeoff due to the fuel load.  While we make landing gear, most of our experience is with navy aircraft.  I'll still ask.

That was what I was thinking is that the manufacturers had a bad batch of _____ causing failures.

[chrishick]

It reminds me of this skit.?

 

[Teken]

It reminds me of this skit.
 

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[apostolakisl]

love that British humor