Landing with a flat tire?

[Wildhorsesracing]

Taxiing today to take off and 1/2 down the taxiway the rudder pedals started shaking violently.   We got out and found a flat tire on the nose wheel.  The discussion became how lucky we were to have it happen before take off and not on a landing.  Has anyone landed with a flat tire?  Is it even possible to safely land with minimal damage on a flat tire?

 

 

[Yooper Rocketman]

Yep.  Have done it twice, with my Rocket, which is really interesting.  Have to pull full elevator and just stop, even if still on the runway.  

[carusoam]

Return question...

how did you get your ship back to the maintenance shop?

Best regards,

-a-

[Wildhorsesracing]

The airport had a sweet "trolley" that lifted the front tire and towed it all the way back to the maintenance shop with a tug.

[gsxrpilot]

I've landed with a flat nose tire as well. Hold it off as long as possible, then hard on the brakes to get it stopped. Don't try to turn off the runway.  If it's a small airport and a suitable tug doesn't exist, it's not that hard to lift the front by pushing down on the tail. Then set the front wheel on a dolly/cart of some sort to allow you to pull it off the runway.

[MooneyMitch]

I've not had the experience with landing with a flat tire.  

I've had the experience of having a main flat tire after touchdown.  My experience was initially frightening, as I had no idea what was transpiring.

The process happens very fast.  The vibration increased rapidly and became semi-violent. The Mooney pulled hard to one side and stopped quickly.  

I did learn quickly, one cannot taxi, at least in the Ovation.  And with that, I believed trying to do so would very possibly have cause damage.

My FBO friends were monitoring ATC and quickly came to my rescue.

We raised the wing, supported, removed blown tire/wheel, installed a spare tire/wheel and towed the plane to their shop.

An experience I hope to not repeat.

I am curious of what might happen with a nose tire collapse upon landing or takeoff roll.

[201er]

19 minutes ago, gsxrpilot said:

I've landed with a flat nose tire as well. Hold it off as long as possible, then hard on the brakes to get it stopped. Don't try to turn off the runway.  If it's a small airport and a suitable tug doesn't exist, it's not that hard to lift the front by pushing down on the tail. Then set the front wheel on a dolly/cart of some sort to allow you to pull it off the runway.

When you say push down on the tail, do you mean pushing on the empennage or on the horizontal stabilizer?

[201er]

1 hour ago, Wildhorsesracing said:

Taxiing today to take off and 1/2 down the taxiway the rudder pedals started shaking violently.   We got out and found a flat tire on the nose wheel.  The discussion became how lucky we were to have it happen before take off and not on a landing.  Has anyone landed with a flat tire?  Is it even possible to safely land with minimal damage on a flat tire?

Just curious, how high was your prop from the ground (when vertical)?

[gsxrpilot]

5 minutes ago, 201er said:

When you say push down on the tail, do you mean pushing on the empennage or on the horizontal stabilizer?

Push down on the horizontal stab. One guy on each side, right at the root/leading edge, easily lifted the nose wheel off the ground. We actually held it up this way while the wheel was changed out. The local A&P swapped a loaner wheel on the the axel, and then took my wheel away to replace tube/tire. Then brought it back and we lifted the nose again to reinstall.  The whole thing took about 30 minutes from stopping on the runway, pulling it off the runway, repairing the tire, and ready to take off.

[201er]

Just now, gsxrpilot said:

Push down on the horizontal stab. One guy on each side, right at the root/leading edge, easily lifted the nose wheel off the ground. We actually held it up this way while the wheel was changed out. The local A&P swapped a loaner wheel on the the axel, and then took my wheel away to replace tube/tire. Then brought it back and we lifted the nose again to reinstall.  The whole thing took about 30 minutes from stopping on the runway, pulling it off the runway, repairing the tire, and ready to take off.

I'm no engineer but that seems like a lot of stress on the pivoting tail trim system. Does anyone have a guess as to how much downward force the tail makes during normal flight?

[gsxrpilot]

4 minutes ago, 201er said:

I'm no engineer but that seems like a lot of stress on the pivoting tail trim system. Does anyone have a guess as to how much downward force the tail makes during normal flight?

I was concerned initially, but noticed that it really didn't take much force at all to raise the nose wheel and push the tail all the way down to the skid.

I should add, this was a short body Mooney.

[DonMuncy]

Haven't you heard Bill Wheat's story of some FAA guys questioning the strength of the pivot point on the Mooney tail. He replaced the pivot bolt with a 1/4 inch bolt and took it up. The FAA guys refused to fly with him. He said it was a little sloppy with the play in the mechanism, but otherwise OK. (This is from memory, and I may have messed up some detail, but basically true).

[takair]

Landed twice with a flat nose tire, same runway, same airport.  The shimmy is quite violent in the pedals.  In both cases I made it partially off the runway due to a convenient taxi way, but could not make it all the way off.  Tower shut that runway down.  There was plenty of prop clearance, but I was afraid of breaking something in the steering.  FBO had a Lectro type tug that lifted the nose gear.  Main tire would likely require more work.  I keep saying I will throw a can of fix a flat in the plane simply to clear a runway if this happens again.  It could be a disaster at an uncontrolled field at night.  This thread is a reminder for me to do just that.  In both cases it was a pinhole leak....tire was fine at takeoff and flat upon touch-down.  Oh, I started to become superstitious, both events took place near the graves in runway 10 at Savannah/Hilton Head International.  Yes, graves.  They are marked and visible if you know where to look.

[201er]

2 minutes ago, takair said:

I keep saying I will throw a can of fix a flat in the plane simply to clear a runway if this happens again.

Would that really work on a tubed tire?

[MooneyMitch]

17 minutes ago, DonMuncy said:

Haven't you heard Bill Wheat's story of some FAA guys questioning the strength of the pivot point on the Mooney tail. He replaced the pivot bolt with a 1/4 inch bolt and took it up. The FAA guys refused to fly with him. He said it was a little sloppy with the play in the mechanism, but otherwise OK. (This is from memory, and I may have messed up some detail, but basically true).

You can watch and hear Bill Wheat's actual story on his flights with different sized empennage bolts, which were progressively installed in smaller increments and then test flown, by watching Boots On The Ground DVD.  That particular segment of the video is worth the price of the DVD alone!

During filming of the Boots Mooney documentary, many questions were asked of Bill, and others, regarding specific Mooney points of interest.  

These questions were asked with the specific purpose of getting accurate answers on film, directly from the horses mouth, so to speak.

I apologize as this is not meant to derail this thread.  It's only inserted to add information to Don Muncy's post.

[takair]

14 minutes ago, 201er said:

Would that really work on a tubed tire?

Not sure.  I always wondered...might be why I haven't actually added it as ballast to the airplane.  Perhaps someone here has actually tried it?  

[carusoam]

Realistically the force needed to raise the nose by pushing down on the tail will be similar to the The forces in flight.

The basic difference will be the The fulcrum will be the main landing gear in place of the center of lift.

Where we see this in real life...  A Cessna with snow on the tail (horizontal stabilizer) will point to the sky.

the placement of the MLG of the Mooney requires a tad more weight on the tail than Cessna.

In engineering these calculations come from a class called statics.  The same way we do weight and balance calculations!

All the forces X distances will balance out.  Cg, total weight, axle distance to the cg, and the weight on the tail, and distance to the axles...  that kind of thing....  pick a plane/point of reference, then do the math...

repeat doing the math using the center of lift as the fulcrum to see how much additional force is required to raise the nose.

While doing this math you may quickly find how important it is to tie the tail down or jack the nose up while on jacks for annual maintenance.... a few 50# bags of sand are often used around the maintenance shop.  The long Bodies use a jack point on the engine mount. No sand bags on my tail...

PP advice only, not a mechanic, but I did take statics, several decades ago...

Best regards,

-a-

Edited March 6, 2017 by carusoam

[MooneyMitch]

"take statics, several decades ago..."

And you still remember all that?  Impressive I say! 

[carusoam]

Old memories are still good.  What I had for lunch today is more of a challenge... 

Best regards,

-a-

[201er]

3 minutes ago, carusoam said:

Old memories are still good.  What I had for lunch today is more of a challenge... 

Best regards,

-a-

Hmm, I'd say chicken sandwich. And you weren't even at the fly-in.

[carusoam]

I already used all my likes, Mike.  So take this instead...   

Ran into a slight challenge that I couldn't overcome all the way. The below freezing temperature didn't go away until it was lunch time already....

Its supposed to be warmer this week.

Best regards,

-a-

[MooneyMitch]

And another attempt at not derailing this very "HOT" thread......one of their very awesome aspects of living on the left coast is the fact that we get the last opportunity to post at night while all you other mid-westerners and eastcoasters are snoring!

[Shadrach]

1 hour ago, 201er said:

I'm no engineer but that seems like a lot of stress on the pivoting tail trim system. Does anyone have a guess as to how much downward force the tail makes during normal flight?

How far forward or aft of the main gear do you think the center of pressure is? The tail sees the similar loads in flight but they are distributed evenly across the  stabalizer. The  method Paul describes is SOP for moving rental Cessnas around the ramp at some airports. It can be done, but be careful.

[carusoam]

Mitch, I would have thrown you a like too!   

Apparently the east coast is staying up tonight!

Compare the Mooney during soft field activities to Brand C doing the same...

Brand C can be taxied with the nose off the ground by a skilled pilot... both landing and taking off.

201er does a nice job of landing on the mains before slowly lowering the nose.

Me in the LB, there are micro seconds before the nose hits the pavement...

 

1 part center of lift, with the flaps down (during landing)

1 part location of the MLG

3 parts skill

 

it is definely in the neighborhood of a hundred pounds or so.  best to be spread out over a wide surface area, definitely don't want to use hard tools with minimal surface area to push down on the sheet metal.  Stress and strain strengths of the aluminum sheet will become important if exceeded.  Deformation occurs when the limits are exceeded...

Just think how strong violent turbulence can be.  The bolts need to withstand some pretty well known forces.  That is why the maneuvering speed is published as a safety mechanism.  Stall before breaking.

Fortunately, the stall occurs prior to breaking parts.  Pretty much a design criterium...

for the wing loading, they always quote how many gs can be supported. Expect the tail to be doing a similar job, only inverted...  if it didn't, controlled flight would no longer be maintained...  

Late night PP thoughts, not an aeronautical engineer...

Best regards,

-a-

Edited March 6, 2017 by carusoam

[carusoam]

Depends on what caused the leak...

if the stem has departed the tube the glue won't be able to hold the bits together...

if it is a small hole like a puncture, probably will...

In the case of a folded and leaky tube, 50/50...

The can of fix-a-flat might work, but it was designed to work for punctures. Best to leave the screw or nail in place while letting the glue find its way around the hole.

If the leak is very slow, The can of air may fill the tire long enough to move somewhere better...

I have used a few cans for the road...

Best regards,

-a-