Tire Pressures?
JDupre5762
aircraft?
Take the two most common tires, the 5.00x5 and 6.00x6. On some aircraft I have
seen pressures as high as 40 psi and on others as low as 25 psi. In general it
seems that tire pressures are related to weight of the aircraft with the
heavier aircraft getting the higher pressures. If a lighter aircraft has had a
lot of additional equipment added is that a cause to raise the tire pressures?
I have seen on some aircraft that the nose tire gets a higher pressure than the
mains and then vice versa. Is this related to the weight distribution over the
landing gear?
What are the consequences of running a higher than specified pressure in the
tires? With the lower rated pressures i.e. in the 20's the tires will take a
set and then be difficult to maneuver in ground operations with the tow bar.
Will bumping the pressure up by 5 or 8 psi really be detrimental?
Thanks for your input.
John Dupre'
Rich S.
news:20011114075904...@mb-ma.aol.com...
> Can anyone explain for me the relationship between tire pressures in light
> aircraft?
Looking forward to learning something, here.
Rich S.
David Levy
"Rich S." <n7...@nospamharbornet.com> wrote in message
news:hIwI7.875$573....@newsfeed.slurp.net...
jerry wass
dispense a few oysters of Wisdom??
Dptate
Manufacturers of aircraft tires list the max load rating and max speed of each
type of tire. Any given size tire may have a different max load rating
depending on the number of plies.
The amount of air pressure to use depends on the actual load that you plan to
have on the tire and is listed in the manufacturers data sheet. So determine
the weight of the airplane on that tire and look up the correct air pressure
from the data sheet.
You want to have a certain amount of deflection of the tread in normal
operation.
If there is too much air pressure for the load, there will be insufficient
deflection to cushion the landing. If there is not enough air pressure for the
load, there will be too much deflection leading to excessive heat buildup and
possibility of failure. So when in doubt, use a tad higher air pressure.
Shimmy is an entirely different matter.
Dave "Firestone retiree, so what do I know" Tate ..... PS. If you want to
know what happens when you have low tire pressure just ask about the Ford
Explorer
Rich S.
news:20011114201925...@mb-fq.aol.com...
> The amount of air pressure to use depends on the actual load that you plan
to
> have on the tire and is listed in the manufacturers data sheet. So
determine
> the weight of the airplane on that tire and look up the correct air
pressure
> from the data sheet.
So I call Desser (Dresser?) Tire and ax them for a data sheet?
Rich
assa9
assa9
Rich S. <n7...@nospamharbornet.com> wrote in message
news:9TEI7.197$q4.4...@newsfeed.slurp.net...
assa9
You know, the one that comes with the aircraft, that is required by the FAA
to be in the airplane to make it airworthy.
The one you will be required to show when you are ramp checked.
assa9
JDupre5762 <jdupr...@aol.com> wrote in message
news:20011114075904...@mb-ma.aol.com...
Dptate
>So I call Desser (Dresser?) Tire and ax them for a data sheet?
>
>Rich
>
Yep, you got it. If the pilot operating handbook has it, its because they
copied it from the manufacturers data sheet.
Dave
assa9
recommended.
But they don't exceed the manufacturers max.
Just like cars.
The writing on the side of the tires is max.
You don't automatically use that figure for every vehicle that tire is on
assa9
Dptate <dpt...@aol.com> wrote in message
news:20011114215941...@mb-fq.aol.com...
Rich S.
news:tv7gdes...@corp.supernews.com...
> I believe different airplanes use the same tire with different pressures
> recommended.
> But they don't exceed the manufacturers max.
> Just like cars.
> The writing on the side of the tires is max.
> You don't automatically use that figure for every vehicle that tire is on
Would you care to point out the specific FAR which requires a POH containing
tire pressure recommendations, in an experimental homebuilt aircraft?
Didn't Dave say that air pressure is dependent on the weight applied to that
tire, not that they should be inflated to the max pressure molded on the
side of the tire?
Rich S.
assa9
assa9
Rich S. <n7...@nospamharbornet.com> wrote in message
news:_WQI7.1599$fL.7...@newsfeed.slurp.net...
JDupre5762
>that
>> tire, not that they should be inflated to the max pressure molded on the
>> side of the tire?
He may have said that but in any event I have never seen a tire pressure molded
into the side of an aircraft tire. I have never seen any published data from
the aircraft manufacturers regarding variations in tire pressure other than a 2
to 5 psi variation allowed when checking tire pressure on some models. Most
every model aircraft has only one pressure listed for each size tire used.
I started this thread and maybe I was not clear about what I want to know.
What I want to know is why does the same size tire used on two different weight
aircraft have two different tire pressures? I suspect it is related to weight
in that a heavier aircraft will take more air in the tire to establish the
correct size "contact patch" between the tire and the surface.
I also want to know if the variation in lower or higher pressures in nose tires
versus main tires is related to the weight distribution of the aircraft over
the landing gear. In other words is an aircraft that is more nose heavy going
to have a higher tire pressure on the nose wheel than one that is not so nose
heavy?
John Dupre'
Dan Thomas
> Can anyone explain for me the relationship between tire pressures in light
> aircraft?
>
> Take the two most common tires, the 5.00x5 and 6.00x6. On some aircraft I have
> seen pressures as high as 40 psi and on others as low as 25 psi. In general it
> seems that tire pressures are related to weight of the aircraft with the
> heavier aircraft getting the higher pressures. If a lighter aircraft has had a
> lot of additional equipment added is that a cause to raise the tire pressures?
>
> I have seen on some aircraft that the nose tire gets a higher pressure than the
> mains and then vice versa. Is this related to the weight distribution over the
> landing gear?
Raising tire pressures beyond the manufacturer's recommendations
will result in wearing off the centre of the tread long before the
edges, and underinflation will result in edge wear. Either way, the
life of the tire is shortened. Nosewheel tire pressures might be
higher because of the extra weight they put up with during heavy
braking, and higher pressure might make the airplane easier to steer
on the ground. And it might reduce nosehweel shimmy.
We had a long discussion on tailwheel shimmy here about four or
five months ago. Lots of conflicting opinions. We run a fleet of
Cessna singles that all love to shimmy, and we have to watch several
things to prevent it:
1. Balance that nosewheel dynamically. If it wants to wobble at speed
it will wear the nosegear stuff and create slack in the linkages and
shimmy will result.
2. Keep all the play in the scissors to minimum. Cessna sells shims
and bushings and so on for this but there's only so much you can do
before replacing some expensive parts.
On second thought, there are no inexpensive parts.
3. Keep the shimmy dampener mounts free of play and keep it absolutely
full of MIL-5606.
4. Don't abuse your nosegear. Use full up elevator when braking hard
and when maneuvering tight turns during taxi (saves the prop, too, by
keeping it just a bit higher off the pavement), and don't try to turn
so tight that the inside tire isn't rolling much. This puts extra side
force on the nosegear, and it tries to caster past the stops and
stresses the scissor links and loosens them up so the shimmy returns.
Dan
Dptate
>weight
>aircraft have two different tire pressures? I suspect it is related to
>weight
>in that a heavier aircraft will take more air in the tire to establish the
>correct size "contact patch" between the tire and the surface.
>
A factor to keep in mind is that any given size tire can be designed to carry
different loads. For instance a 6 ply tire will will carry a heavier load and
accomodate higher inflation pressure than a 4 ply tire of the same size (Some
of this info may be molded into the sidewall but it doesn't hurt to check the
mfgs data sheet).
Dave Tate
assa9
shimmy.
Of course, an out-of-round and/or out-of-balance tire/wheel assembly
will shake any set up apart.
There are shims to take out the UP AND DOWN play out of the rotatable part
of the nosewheel.
Lot of work and a BIG snap ring involved
There should be a small amount of pre-load on this adjustment.
Most people don't know about and have never done it.
assa9
Dan Thomas <dan.t...@pbi.ab.ca> wrote in message
news:1a291bd5.01111...@posting.google.com...
Dan Thomas
> There is another adjustment on the cessna nosewheels that will minimize
> shimmy.
> Of course, an out-of-round and/or out-of-balance tire/wheel assembly
> will shake any set up apart.
> There are shims to take out the UP AND DOWN play out of the rotatable part
> of the nosewheel.
> Lot of work and a BIG snap ring involved
> There should be a small amount of pre-load on this adjustment.
> Most people don't know about and have never done it.
>
> assa9
Yeah. I didn't mention that specific part, but if it gets loose
the steering yoke will rock sideways and add to the overall slop. It's
actually not that big a job to pull the whole leg off the airplane and
fix it, but you need that big set of snapring pliers to get it apart.
If not, then it's lots of work.
Some of these oleos are held in by a clamp at the bottom and a
big spring pin at the top. Make a long punch rod that will fit your
rivet gun and use that affair to drive the pin out and back in. Saves
many minutes and bashed knuckles.
Dan
Wayne Sweet
run 42 - 45 for 10 years with no unusual wire problems. One aspect to
consider is that tire pressure is a factor in the equation for hydroplaning:
then higher the tire pressure the higher the speed for hydroplaning. And the
equations are different for a tire spun up, such as on TO or one not, such
as on landing.
Wayne
"JDupre5762" <jdupr...@aol.com> wrote in message
news:20011114075904...@mb-ma.aol.com...
Stealth Pilot
trike undercarriages you can probably overinflate a little with
impunity.
on a taildragger over inflation may make it the devils own to land
smoothly.
The tailwind has wittman tapered spring gear which has no rebound
dampening. pumping the 5.00x5's to 40 psi will see a bounce that
excites and excites while taxying until you are positively bounding
sideways down camber on the taxiway. once it starts you need to brake
to a halt to stop it. ...an amazing experience.
With austers, the bungees, and tailwinds the spring gear will just
bounce you back into the air if you land with any vertical component
..very humbling.
on the tailwind (o-200 powered) the tyre pressure has a magic spot at
25 psi. below that and direction is difficult to maintain while tail
up in the takeoff and landing roll. above that and it will bounce
forever on touchdown. (full stick back and ride it out in that
situation or you will bang the prop).
just on 25psi and you can land sweetly all the time and tail up
direction is easy to maintain.
if you ever find that the tyre pressures are high and the touchdown is
difficult just flare and put one of the mains on first. as it takes
the weight the bounce energy will be absorbed by rolling the aircraft
level and a good landing will usually eventuate.
in any sort of wind put the upwind wheel on first.
so trike gear, low tyres will make the landings sweeter.
taildragger gear, there is a sweet spot pressure that will absorb the
spring energy and will help you, while making taxying easier.
with low tyre pressures, never stand on the brakes! the tyre creep on
the rim may cause the tyre valve stem to be sheared off.
just some observations.
stealth pilot
On Mon, 24 Dec 2001 02:18:35 GMT, "Wayne Sweet" <swee...@pacbell.net>
wrote:
Jim Vandervort
Mine was a little problem to land easily, but after I put on cuffs, it is
super easy.
Easier than my T'craft, by a lot.
assa9
Stealth Pilot <tail...@ieyenetdotnetdotau.spurious> wrote in message
news:3c270a47...@news.m.iinet.net.au...
Stealth Pilot
<dpi...@yahoo.com> wrote:
>Do you have cuffs on your tapered part of your gear?
>Mine was a little problem to land easily, but after I put on cuffs, it is
>super easy.
>Easier than my T'craft, by a lot.
>
>assa9
>
define what you mean by cuffs jim.
the fibreglass stiffeners - no
streamline fairings - yes.
Jim Vandervort
I just can't imagine you having any sort of problem landing a Tailwind.
I have a Pietenpol and a T'craft also, and the Tailwind is the easiest to
land of the three.
In fact, a hangar fell on my Tailwind, and when i repaired it, I didn't even
bother to straighten the left gear leg.
It remains bent so that the left wing is closer to the ground by 6 inches
than the right wing.
It lands straight ahead and no "bouncy" in spite of me!!
assa9
Stealth Pilot <tail...@ieyenetdotnetdotau.spurious> wrote in message
news:3c272867...@news.m.iinet.net.au...
BOb U
>In fact, a hangar fell on my Tailwind, and when i repaired it, I didn't even
>bother to straighten the left gear leg.
>It remains bent so that the left wing is closer to the ground by 6 inches
>than the right wing.
>It lands straight ahead and no "bouncy" in spite of me!!
>
>assa9
>> >> if you ever find that the tyre pressures are high and the touchdown is
>> >> difficult just flare and put one of the mains on first. as it takes
. ^^^^^^^^^^^^^^^^^^^^^^
>> >> the weight the bounce energy will be absorbed by rolling the aircraft
>> >> level and a good landing will usually eventuate.
>> >> in any sort of wind put the upwind wheel on first.
+++++++++++++++++++++++++++++++++++++++++++++++
Why is it....
Some folks are compelled to fix what ain't broken,
While other's dwell in the opposite camp.
Oddball antics lead oddball folks into oddball accidents....
Sooner or later.
BOb U
Ron Wanttaja
> I'll top post since I'm adding an observation.
> trike undercarriages you can probably overinflate a little with
> impunity.
> on a taildragger over inflation may make it the devils own to land
> smoothly.
> The tailwind has wittman tapered spring gear which has no rebound
> dampening. pumping the 5.00x5's to 40 psi will see a bounce that
> excites and excites while taxying until you are positively bounding
> sideways down camber on the taxiway. once it starts you need to brake
> to a halt to stop it. ...an amazing experience.
> With austers, the bungees, and tailwinds the spring gear will just
> bounce you back into the air if you land with any vertical component
> ..very humbling.
Fly Babies, of course, don't have either springs or damping in their
landing gear...the gear is rigid, and only "give" is in the tires
themselves. On the good side, they don't add energy to a bounce; on the
negative side, they don't absorb much of it, either.
I haven't really noticed any difference in the way the things land with
the tires at high pressure vs. low, but I don't run a real wide range of
pressures in them.
Where tire pressure does make a difference is in the "dribble." If the
tires are too hard, you get some sort of harmonic effect while taxiing,
making the plane jiggle up and down. I'm sure the amplitude is just an
inch or so, but it's not only a bit uncomfortable, it probably looks
goofy as hell from the outside. I've heard the same story from several
Fly Baby jockeys on the Fly Baby mail list.
Ron Wanttaja
r...@wanttaja.com
Stealth Pilot
huh????
the guy was asking for comments on the effects of different tyre
pressures.
try to keep up :-)
Jim Vandervort
Stealth Pilot <tail...@ieyenetdotnetdotau.spurious> wrote in message
impending death.
Besides, one would think my death would have occured sometime in the last
500 hours in that particular death-trap.
assa9
BOb U
Try to look past the obvious, grasshopper. ;+)
BOb U
>> >>In fact, a hangar fell on my Tailwind, and when i repaired it, I didn't
>even
>> >>bother to straighten the left gear leg.
>> >>It remains bent so that the left wing is closer to the ground by 6
>inches
>> >>than the right wing.
>> >>It lands straight ahead and no "bouncy" in spite of me!!
>> >>
>> >>assa9
>> >+++++++++++++++++++++++++++++++++++++++++++++++
>> >
>> >Why is it....
>> >Some folks are compelled to fix what ain't broken,
>> >While other's dwell in the opposite camp.
>> >
>> >Oddball antics lead oddball folks into oddball accidents....
>> >Sooner or later.
>> >
>> >
>> >BOb U
>At least my off topic post was about aviation, no veiled threats of
>impending death.
>Besides, one would think my death would have occured sometime in the last
>500 hours in that particular death-trap.
>
>assa9
+++++++++++++++++++++++++++++++++++++++++++++
Ooooooo.
What high drama!!!!
Ya' know....
There is no time limit on luck.
You have had 500 hours of good fortune in spite of yourself, then.
I've exceeded 7200 accident free hours in taildraggers, but so what????
We are just that much closer to that first accident.
Familiarity absolutely breeds contempt.
There are far too many taildragger accidents with PROPER attitudes
and properly rigged planes without ASSININE remarks that promote
absurd behavior to the contrary.
Advising newbies that frequent here to ignore a bent landing gear
is irresponsible and MOST UNWISE in any safety minded circle.
Especially, when you care to brag about being a high time pilot
that beats the odds and they could well follow in your footsteps.
Wrong message, bubba.
I'm attempting to move the line of good judgement back to where it outta' be.
I have flown with bent landing gear, broken main spars, no rudders , flattened
leading edges, chunks of missing fabric, bent props and a host of other wild and
wooly shit, but this forum should promote MAXIMUM SAFETY.....
not anyone's particular brand of recklessness, good fortune or whatever.
With that out of the way....
Have a SAFE and Merry Christmas, ya' all.
BOb - don't do as I did - U
Roger Halstead
"BOb U" <N86...@hotmail.net> wrote in message
news:823h2us3srv0ujjjn...@4ax.com...
Which gets me to wondering...If I were in the UK, could I still use my Tire
gauge on Tyres, or would I have to get a new one?
--
Roger (K8RI - EN73)
WWW.RogerHalstead.com
N833R World's oldest Debonair? (S#CD-2)
Stealth Pilot
>On Tue, 25 Dec 2001 08:25:20 -0500, "Jim Vandervort" <dpi...@yahoo.com> wrote:
>
>>> >>In fact, a hangar fell on my Tailwind, and when i repaired it, I didn't
>>even
>>> >>bother to straighten the left gear leg.
>>> >>It remains bent so that the left wing is closer to the ground by 6
>>inches
>>> >>than the right wing.
>>> >>It lands straight ahead and no "bouncy" in spite of me!!
>>> >>
you realise that you probably ARE landing one wheel first all the
time?
>
>Advising newbies that frequent here to ignore a bent landing gear
>is irresponsible and MOST UNWISE in any safety minded circle.
>Especially, when you care to brag about being a high time pilot
>that beats the odds and they could well follow in your footsteps.
>Wrong message, bubba.
>
It took me 6 months of research and work to repair a similar problem.
his bend isnt probably that bad.
I straightened out 6 bends on the left leg (wasnt aware of them) and 9
bends on the right leg (8 of them I wasnt aware of) and had it
retempered.
I flew it across Australia to get back home but it was immediately out
of the air for repairs.
Admittedly I only test flew for an hour before setting off across
australia again :-)
(it is all in the engineering confidence Bob)
Stealth Pilot
Jim Vandervort
the constant carping of the need of BOb to soothe the ravages of his
psyco-ceramic illness. (cracked pot)
His body is racked with a disease called "little man syndrome".
He has a felt need to be overly correct and overly good in his every post,
thus proving every one else is wrong and bad.
It is not serious to the general public or us as long as we ignor it and
him.
He is entertaining.
Fun to watch.
assa9
Stealth Pilot <tail...@ieyenetdotnetdotau.spurious> wrote in message
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