Wireless Tire Pressure Monitoring System (TPMS): Anyone have it?

[tigers2007]

For a few years I've seen the Schrader valve stem air caps that have built-in transmitters that send pressure info to a cabin mounted receiver. Has anyone tried to use one of these in their aircraft? I think they tx in the 315Mhz and 433Mhz ranges. Scouring Amazon I see a zillion choices.

[jaylw314]

13 minutes ago, tigers2007 said:

For a few years I've seen the Schrader valve stem air caps that have built-in transmitters that send pressure info to a cabin mounted receiver. Has anyone tried to use one of these in their aircraft? I think they tx in the 315Mhz and 433Mhz ranges. Scouring Amazon I see a zillion choices.

how much do they weigh?  On a car tire and wheel which might weigh 30-40 lbs, it may not throw off the balance much, but on a small aircraft wheel, you'd need some serious rebalancing...

Also, they'd probably have alarms going off all the time with the pressure changing as you change altitudes.

A simpler idea might be those valve caps with a visible color flag when the pressure drops below a set PSI

[1964-M20E]

Year ago I thought I saw where somebody had this for a plane even came as a set of 3 but I couldn't tell you when or where I saw it.

 

[MB65E]

There were some available that I was going to put on a CJ. STC’d and everything. They wanted $1500 or so. 

Spruce sells a little kit too. 

-Matt

[Boilermonkey]

52 minutes ago, jaylw314 said:

how much do they weigh?  On a car tire and wheel which might weigh 30-40 lbs, it may not throw off the balance much, but on a small aircraft wheel, you'd need some serious rebalancing...

Also, they'd probably have alarms going off all the time with the pressure changing as you change altitudes.

A simpler idea might be those valve caps with a visible color flag when the pressure drops below a set PSI

The risk-reward might not be balanced.  I'd imagine the valve caps would actually need to depress the stem to get a reading...so if the cap becomes loose you might lose your pressure.  If it's a slow leak in a car, you just pull over.   In an airplane, you've got a bigger problem.  I'd imagine the only viable method would be a system that goes around the wheel like on cars....but that's with a tubeless tire.  

[Guest]

A client of mine has an autometive set on his Cirrus SR22 with no issues.

Clarence

[jaylw314]

Is the valve on the nose tube a non-standard size?  I've noticed when I try to use a normal tire pressure gauge, I have to press down really hard to reach the pin in the valve.  When I use my compressor, there's almost always a little leakage when I hook it up, no matter how hard I press it on.

This has happened with two separate tubes, and doesn't happen with the main gear

[ArtVandelay]

how much do they weigh?  On a car tire and wheel which might weigh 30-40 lbs, it may not throw off the balance much, but on a small aircraft wheel, you'd need some serious rebalancing...

One of them said 9 grams.
It would be nice if you lost air pressure during a flight for some reason to know it before landing. How often does this happen?


Tom

[Hank]

6 minutes ago, ArtVandelay said:

One of them said 9 grams.
It would be nice if you lost air pressure during a flight for some reason to know it before landing. How often does this happen?

That depends on how often you run over stuff while taxiing and taking off . . . . .

[tigers2007]

32 minutes ago, ArtVandelay said:

One of them said 9 grams.
It would be nice if you lost air pressure during a flight for some reason to know it before landing. How often does this happen?


Tom

I suppose you could email Falcon while in the air and bump up the insurance coverage with the fresh intel that you have no more air in the tires

[RLCarter]

if you get a low pressure alarm, there might be a service though 

[1964-M20E]

Cute exhibition.  Although it would be a little more difficult on our planes hanging under the wing.  Besides those old planes had all those wires to hang on to while you are out there walking on the wings.

Oh she didn't have a parachute either. 

@M20Doc Do you offer in flight maintenance services?  Might be a new  business opportunity.

[peevee]

5 hours ago, MB65E said:

There were some available that I was going to put on a CJ. STC’d and everything. They wanted $1500 or so. 

Spruce sells a little kit too. 

-Matt

the cirrus guys would easily pay that, you'd make a mint if you stc'd it for them. The access holes in the pants are really small and hard to access the stems. Not sure I'd trust the caps not to leak though.

Edited April 29, 2019 by peevee

[MB65E]

https://www.craneae.com/Products/Sensing/SmartStemBizJets.aspx

 

Go for it! I’d rather not deal with them! 

Lol.

-Matt

[jaylw314]

These were the ones I was talking about

[Ragsf15e]

5 hours ago, M20Doc said:

A client of mine has an autometive set on his Cirrus SR22 with no issues.

Clarence

Heck on a Cirrus they are just about required equipment!  Who designed their tiny access for checking/filling air??

[peevee]

11 minutes ago, Ragsf15e said:

Heck on a Cirrus they are just about required equipment!  Who designed their tiny access for checking/filling air??

there's a guy that sells bigger doors, for like $5,000. They'd be lined up to buy smart stem for $1.5k

Seriously, if I had the slightest clue how to get an stc I'd be on it.

Edited April 29, 2019 by peevee

[Ragsf15e]

1 minute ago, peevee said:

there's a guy that sells bigger doors, for like $5,000.

That’s sounds about right for the Cirrus crowd.

[rbridges]

1 hour ago, peevee said:

the cirrus guys would easily pay that, you'd make a mint if you stc'd it for them. The access holes in the pants are really small and hard to access the stems. Not sure I'd trust the caps not to leak though.

Then you develop the self inflating tires like they have on Hummers.  Mo money, Mo money!

[Browncbr1]

1 hour ago, jaylw314 said:

These were the ones I was talking about

I was looking at the garmin caps that transmit pressure and I read one review that after 6 months, one cap sprung a leak and the tire went flat overnight.   That’s when I quit looking at any of those things.  

[Boilermonkey]

I was looking at the garmin caps that transmit pressure and I read one review that after 6 months, one cap sprung a leak and the tire went flat overnight.   That’s when I quit looking at any of those things.  

Not worth it.

Sent from my SM-G960U using Tapatalk

[BDPetersen]

Apparently all NFL footballs now contain a chip developed by a 26 year old whiz kid on our field. A smart phone app ( I think) reads the ball internal pressure. Tomorrow as he works on his long eze I will find out if that has an aeronautical tire pressure application. Something tells me he has already considered that. (That’s a lotta footballs)

[tigers2007]

On 4/29/2019 at 8:52 PM, BDPetersen said:

Apparently all NFL footballs now contain a chip developed by a 26 year old whiz kid on our field. A smart phone app ( I think) reads the ball internal pressure. Tomorrow as he works on his long eze I will find out if that has an aeronautical tire pressure application. Something tells me he has already considered that. (That’s a lotta footballs)

That would be nice if it was tiny and could be inserted into the innertube like a long pill.

[carusoam]

On 4/29/2019 at 6:05 PM, peevee said:

there's a guy that sells bigger doors, for like $5,000. They'd be lined up to buy smart stem for $1.5k

Seriously, if I had the slightest clue how to get an stc I'd be on it.

We have at least two MSers that write STCs... (part of their business skill set) David and Rob.

 

Follow-up question... how high does a Mooney’s tire pressure get on wam days at altitude?

That little schreder valve has proven to keep the pressure in the tube... a cap that allows air pressure past the schreder valve has to keep the air pressure in using the external threads...   

Keep in mind the threads are only designed to keep the dust cap on, and keep the schreder valve clean...

PP thinking out loud... not a mechanic...

I like the idea, just wouldn’t want to be the first to try it on a Mooney...

Best regards,

-a-

[jaylw314]

51 minutes ago, carusoam said:

We have at least two MSers that write STCs... (part of their business skill set) David and Rob.

 

Follow-up question... how high does a Mooney’s tire pressure get on wam days at altitude?

It stays the same --  it's the outside pressure that changes