tire ply rating on nose gear

[AJ88V]

Apologies for old topic, but, IIRC,......

M20(-,A,B,C,D,E)  all have 4-ply rating tires on the nose gear.

M20F has 6-ply rating tires on the nose gear.

The nose gear system is identical on these airplanes (including wheel well, gear assembly, actuations, doors, etc.)

Vaguely recall discussions on failing ramp checks for having the wrong tire ply rating.  Would certainly understand a problem having 4-ply rating on the F model, but what's the problem with a 6-ply rating on the real short bodied Mooneys.

Thanks! (and let the fireworks fly! )

[PT20J]

Use what’s specified in the TCDS and you will be fine.

[Brandt]

I suspect failing a ramp check on a ply rating is an old wives tale. 

[Hank]

7 minutes ago, Brandt said:

I suspect failing a ramp check on a ply rating is an old wives tale. 

Does the FAA have time and people to ramp check light, noncommercial GA?

[DXB]

21 minutes ago, Brandt said:

I suspect failing a ramp check on a ply rating is an old wives tale. 

 

15 minutes ago, Hank said:

Does the FAA have time and people to ramp check light, noncommercial GA?

Dunno about ply rating specifically, but I have direct knowledge of a similarly absurd ramp check in Buffalo on my friend's G model.  They said his data plate, which was riveted in one of the front air inlets, was not acceptable and had to be moved to the factory location in the tail immediately.   In reality, planes came from the factory with the plate in either location.  He tried contesting with the FSDO initially but decided it wasn't worth the fight and just moved the plate.  The whole affair was Kafka-esque. 

[EricJ]

A stickler will say it needs to be exactly what's on the TCDS, but others would likely be fine with using more plies than the TCDS specifies, as you are suggesting.

When I was a teenage lineboy in Europe our American flying club got tires from the Army, somehow, we weren't supposed to ask.   They were something like 10-ply, and somebody skidded a tire down the runway once and we verified that there were way more plies than the stock tires.   They worked fine, though.

I don't know about ramp checks, although I doubt it'd be an issue to find a tire with more plies than the TCDS requires.   A more likely concern would be a stickler IA having a problem with it.

I have, however, seen some FAA reps say that "...at least equal to..." means it has to be equal, it can't be better.   So there are definitely some oddball interpretation that happens.

[M20F]

1 hour ago, Hank said:

Does the FAA have time and people to ramp check light, noncommercial GA?

Flying since 1988 never seen an inspector let alone been ramp checked.  I always wonder who all these folks getting ramp checked are. 

[EricJ]

1 hour ago, M20F said:

Flying since 1988 never seen an inspector let alone been ramp checked.  I always wonder who all these folks getting ramp checked are. 

I think it's usually targeted to an area where there are known problems, or trying to catch someone specific.   At a Wings meeting several years ago about "How to survive a ramp check", the FSDO guy pointed out that if you're even reasonably in good shape they're not looking for you and don't want to have to spend time on the paperwork a violation would create.   They're looking for the guy without a license or medical flying an airplane that hasn't had an annual for ten years, and apparently there are enough of those that those cases alone keep them busy.

The only other real take-away I got from that meeting was to keep your seat belts in good shape.   They can't go in the airplane, but they can have you tug on the back seat belts (which apparently many people don't maintain), and sometimes they get violations from that when the belt or latch fails.

[N201MKTurbo]

I have had two encounters with FAA folks on the ramp. I wouldn’t call either one a ramp check. 
 

The first was about 1985 in the dead of winter in Casper WY. I had to fix some equipment for the airline at the terminal. The FSS was right next to the terminal and had two parking spots, so I would park there and walk over to the terminal to work. When I was done I went back to the Mooney to leave and the starter wouldn’t engage. It did that sometimes when it was cold. This day it was -20 F without the windchill and the wind was blowing. When the starter did this I could go out and manually engage the bendix with my pen. I was doing this and the FAA guy comes out and tells my how stupid I am for moving the prop like I was. I was moving it a few degrees back and forth. I personally thought it would be a miracle if I could get it started at all. 
 

The second was about 15 years ago. I was working on the turbo and was done and was taxiing to the gas pumps for a test flight. When I got there there was an FAA inspector waiting at the pumps for someone he was going to give a checkride to. When I got out he came walking over and said my plane was smoking really bad. I looked and there was oil dripping out of the exhaust. I said oh crap, I was working on the turbo. I know what the problem is, I put the suction check valve in backwards. He asked if I was a mechanic, I said yes and he asked for my license. I handed it to him, he looked at it and handed it back and said “you should fix that” I said that is my plan. That was the end of that.

[M20F]

59 minutes ago, EricJ said:

but they can have you tug on

I got something they can watch me tug on and it ain’t a seatbelt. 

[A64Pilot]

3 hours ago, Hank said:

Does the FAA have time and people to ramp check light, noncommercial GA?

Yes and they even have a quota of some number per month per inspector, or so I have been told by a Senior Inspector.

Where I used to live they ramp checked often at the end of the month at Falcon Field near Atl, where AC Spruce is. I think it’s real close to the FSDO hence it got more than its share of “business”. I got ramp checked once and told the inspector who wanted to see the Airworthiness Cert. that I was sorry but as it was I was late for a meeting, jumped in put my belt on and called clear, he backed up and I left. He was looking hard at the prop though I suspect with the plan of red tagging the airplane. I have been told, but do not know that they cannot detain you without some kind of probable cause maybe? Just like I have been told to not turn loose of your Certificate too, doing so could be considered you surrendering it? Maybe both are BS, I’m no Lawyer.

But where I did most of my flying I never saw one, but they do often conduct surveillance on shops and I’m told will check out things that they observe that just don’t look right when they are there. Many have their pet things like the data plate or maybe a chromed spinner or whatever that they always look for.

Ref the nose wheel ply rating, very often as in most always what’s in the TCDS is what they tested with drop test wise, if a 4-ply passed why check a 6 or 8? More testing than min you don’t do, nothing to gain and it’s expensive. Hopefully they are smart enough to test what’s most commonly available and or least expensive first. Ply ratings and surprisingly even tire pressure can make a big difference in passing the drop test. I suspicion that’s why my J models nose wheel tire pressure is so high. it shouldn’t be for prop strike because you have to have a min distance with a flat tire.

Doesn't matter why really, just my suspicion is all.

[AJ88V]

The genesis of starting this thread was that a very close friend was reading MS and there was a discussion on the ply rating, and admonitions about having a 6-ply tire on a plane where the TCDS specifies 4-ply.  "Good friend" was thinking about running a 6 ply tire and higher pressure (per the M20F) and found, upon checking his front wheel that it was already a 6-ply tire installed recently at last annual.

Before posting, I found this article from AOPA:  https://www.aopa.org/news-and-media/all-news/2013/april/15/whats-so-special-about-aircraft-tires

• I’ve often been asked if it makes sense to purchase a stronger tire than that specified by the manufacturer (i.e. purchase a 6-ply tire when a 4-ply is specified). The answer is definitely no. More plies are not necessarily better. Each aircraft is designed for a specific tire, and tires with higher ply ratings than specified may not be suitable for a variety of reasons. More plies don’t make a tire last longer, and since those extra plies need to go somewhere, they wind up decreasing the interior diameter of the tire. In addition, more plies make a tire run hotter. This, along with the difference in stiffness, can affect the way a tire performs.

That's consistent with the advice from many online articles.

To me, putting a 6-ply tire on a short-bodied Mooney doesn't rise to even a minor mod based on installation on the F model, but thought I'd ask.  thanks!

[A64Pilot]

2 hours ago, EricJ said:

A stickler will say it needs to be exactly what's on the TCDS, but others would likely be fine with using more plies than the TCDS specifies, as you are suggesting.

When I was a teenage lineboy in Europe our American flying club got tires from the Army, somehow, we weren't supposed to ask.   They were something like 10-ply, and somebody skidded a tire down the runway once and we verified that there were way more plies than the stock tires.   They worked fine, though.

I don't know about ramp checks, although I doubt it'd be an issue to find a tire with more plies than the TCDS requires.   A more likely concern would be a stickler IA having a problem with it.

I have, however, seen some FAA reps say that "...at least equal to..." means it has to be equal, it can't be better.   So there are definitely some oddball interpretation that happens.

I have 8 ply’s on both my Mooney and my C-140, reason is the Thrush S2R-T660 uses a 10 ply 6.00-6 tailwheel tire, we ordered 8 plies once by mistake and couldn’t use them or send them back I guess. This is my last sets of “free”tires though as I Retired 9 yrs ago.

[philiplane]

A four ply tire will be lighter, and that will reduce vibration and shimmy, and it will be more flexible, to isolate the airframe from the pavement. Which is all better for the airplane. Don't go heavier than needed, but still buy the highest quality tire that meets the spec. 

[Utah20Gflyer]

8 hours ago, DXB said:

 

Dunno about ply rating specifically, but I have direct knowledge of a similarly absurd ramp check in Buffalo on my friend's G model.  They said his data plate, which was riveted in one of the front air inlets, was not acceptable and had to be moved to the factory location in the tail immediately.   In reality, planes came from the factory with the plate in either location.  He tried contesting with the FSDO initially but decided it wasn't worth the fight and just moved the plate.  The whole affair was Kafka-esque. 

The data plate on my G is in the front air inlet as well.   Never even considered that it could be an issue.  

[PT20J]

The point is that airplanes are supposed to comply with the type design or an STC or some other data acceptable to the administrator. Otherwise, some FAA inspector or IA may quibble. I know an IA that used to refuse to sign off an annual if the airplane had the wrong ply nose wheel tire. If you stick with approved data, you will never have a problem.

Regarding the data plate, Mooney would have some documentation showing the location and an email from Frank Crawford would settle the issue.

[Pinecone]

There is a recent thread somewhere about tires that stated that they really don't make 4 ply tires now, they just mark them as 4 ply to make people happy.  

[Pinecone]

I have been ramped checked once.

I was at KFDK airshow with my friend's T-34.  FAA guy was wandering around.

He wanted to see the logs to see that the, then recent, AD regarding wing spars was completed.  I told him they were in CT.  But I pointed out the added new markings on the airspeed indicator that was part of AD.  He mumbled something. 

When he checked my docs, he noted my medical has expired.  I pointed out that it was a Class 2, so it had not expired, but downgraded to a Class 3.   He them mumbled something about me not accepting free fuel and wandered off.

[Hank]

2 minutes ago, Pinecone said:

I have been ramped checked once.

I was at KFDK airshow . . .

FAA types are specifically instructed to not conduct ramp.checks at air shows. Nevertheless, I was once asked for my registration as I parked at one, it was the first of the three-year issuance. I saw him ask a couple of others, too, but that's all he wanted.

[Pinecone]

This was about 1999, so rules may have changed.

And he was only doing show planes, not the GA parking area.

[philiplane]

Check the differences in Goodyear tires here. Oddly though, they don't have the weights in this chart. You can see a 2 lb variation between otherwise similar 600x6 tires.

[PT20J]

1 hour ago, Pinecone said:

There is a recent thread somewhere about tires that stated that they really don't make 4 ply tires now, they just mark them as 4 ply to make people happy.  

It used to be that the number of plies was specified. But nowadays, tire manufactures use "ply rating" to describe the tire strength and load carrying capacity of tires. The rating and the actual number of cord plies may or may not be the same.

[MB65E]

10 hours ago, M20F said:

Flying since 1988 never seen an inspector let alone been ramp checked.  I always wonder who all these folks getting ramp checked are. 

Was ramped checked at 7:45 AM on a Saturday while standing infront of our Citation last week. Inspector wanted to see the maintenance aircraft records. He thought they were supposed to be on the airplane. 
I then went back to my office and grabbed 15y worth of totes full of binders. Handed it to him while I gathered passengers and catering. 
No issues.

-Matt

 

[kortopates]

There is a recent thread somewhere about tires that stated that they really don't make 4 ply tires now, they just mark them as 4 ply to make people happy.  

Quite the conspiracy theorist! lol
Only partially true, it’s a “Ply Rating” - not a ply count. it’s been since before my time that the rating actually matched the count. With modern materials they make 4 and 6 ply “rated” tires with fewer than that many physical plies and have been doing this for decades. Think of it as a standard rather than a count.


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[kortopates]

We had inspectors from a neighboring FSDO conduct ramp checks at one our local fields over the course of several days. We all
wondered why they were doing so outside of there own jurisdiction.
If i recall correctly it was part of a new inspectors training.


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