How Long Can An Airplane Sit?

[Bill Denton]

A pilot owns an airplane.

He isn't able to fly the plane very often, but when he does it's usually two
hours out for a $100 hamburger, then two hours back.

The airplane is always hangered; all inspections and maintenance are done by
the book.

How long could the airplane sit between flights before it begins to
deteriorate?

[Steven Barnes]

"Bill Denton" > wrote in message
...
> A pilot owns an airplane.
>
> He isn't able to fly the plane very often, but when he does it's usually
two
> hours out for a $100 hamburger, then two hours back.
>
> The airplane is always hangered; all inspections and maintenance are done
by
> the book.
>
> How long could the airplane sit between flights before it begins to
> deteriorate?
>

Approx 2 days. At least that what *my* plane needs. ;-)
Of course my wife thinks it can sit for weeks...

[tony roberts]

One week

If you can 't fly it every week, pickle the engine.

Sorry - but that's how it really is.

Tony

In article >,
"Bill Denton" > wrote:

> A pilot owns an airplane.
>
> He isn't able to fly the plane very often, but when he does it's usually two
> hours out for a $100 hamburger, then two hours back.
>
> The airplane is always hangered; all inspections and maintenance are done by
> the book.
>
> How long could the airplane sit between flights before it begins to
> deteriorate?




--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H

[Peter Duniho]

"tony roberts" > wrote in message
news:nospam-5887C9.22294723102004@shawnews...
> One week
>
> If you can 't fly it every week, pickle the engine.

That's just silly.

Yes, a week is short enough for corrosion to occur. A few hours is, for
that matter (and that's the literal answer to the original question), and of
course every day you go without flying incurs additional damage.

But honestly, you obviously don't own an airplane. No owner would seriously
consider pickling the engine for a mere week of downtime. Most owners
wouldn't go to that much trouble for less than a couple of months or more of
downtime. It's just not practical.

Anyway, to the original poster: as I said, as you asked "before it *begins*
to deteriorate" (emphasis mine), the answer is a few hours after shutdown.
Corrosion is a constant process, and the longer you go, the worse it is.

It would be best for an airplane to be flown at least once a day, if not
multiple times a day. A week's not bad, nor are two. Beyond that, you are
likely going to see noticeable long-term effects on maintenance and engine
life.

You may be able to minimize the effects by using certain oils (Exxon claims
to have an oil that nearly eliminates corrosion even after long periods of
time), or that might just be marketing hype. I'm not aware of any unbiased
tests that would indicate one way or the other.

Pete

[Brien K. Meehan]

Mine complains if I don't fly it about once a week.

[Ben Jackson]

In article . com>,
Brien K. Meehan > wrote:
>
>Mine complains if I don't fly it about once a week.

You have a voice annunciator for corrosion?

--
Ben Jackson
>
http://www.ben.com/

[Cub Driver]

>One week
>
>If you can 't fly it every week, pickle the engine.
>
>Sorry - but that's how it really is.

The same is true of the pilot, of course.

all the best -- Dan Ford
email: (put Cubdriver in subject line)

Warbird's Forum www.warbirdforum.com
Piper Cub Forum www.pipercubforum.com
the blog www.danford.net

[g n p]

"Brien K. Meehan" > wrote in message
oups.com...
> Mine complains if I don't fly it about once a week.
>

Same here!!
SX-ADE, Socata TB-9 Tampico Club

[Geoffrey Barnes]

> You have a voice annunciator for corrosion?

I've never heard of one of those. However, I have found a very effective
voice annunciator for flying too *often*. It's very sensitive, and it
adjusts the stridency of its warnings in direct proportion to both the last
3-6 weeks of flying history and the amount of the previous month's flying
club bill. If not much flying has been going on, it stays quiet. If you
have flown only a little bit, it merely emits frustrated sighs as you leave
for the airport. If you have been flying as much as you probably should to
maintain currency, it begins speaking aloud, usually asking questions like,
"Again?", and "So when are you going to get <insert some non-flying task
here> done?". And finally, if you have been flying as much as you wanted,
you will see the volume increase to ear-splitting levels, the voice
frequency reach into the soprano range, the questions turn into both
declarative statements and dire predictions, and the language evolve into
something that would make most sailors blush. As an added option, it can
also start throwing dishes, frying pans, and rolling pins at you.

My annunciator is called a "wife". If you want to buy mine, let me know!

<Really honey, if you happen to catch this on Google, it was all a big joke,
OK. No, no! Look, it was just a little joke. I thought the guys would all
get a big laugh over it! I'll get the lawn cut as soon as the weather
clears up, I promise. What? Yes, dear. I'll get those shelves up right
now, dear. Yes, dear.>


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.778 / Virus Database: 525 - Release Date: 10/15/2004

[Stealth Pilot]

On Sat, 23 Oct 2004 23:18:55 -0700, "Peter Duniho"
> wrote:

>
>Yes, a week is short enough for corrosion to occur. A few hours is, for
>that matter (and that's the literal answer to the original question), and of
>course every day you go without flying incurs additional damage.
>
lets blow away the mystery here. yes corrosion can start in a few
hours ....but why????

>But honestly, you obviously don't own an airplane. No owner would seriously
>consider pickling the engine for a mere week of downtime. Most owners
>wouldn't go to that much trouble for less than a couple of months or more of
>downtime. It's just not practical.
>
my aircraft with an O-200 in it has sat for a year at a time unused on
two occasions. on the first occasion the accessory drive at the back
of the engine disintegrated requiring some major work. on the second
occasion it has now flown 2 years subsequently incident free. why??

>Corrosion is a constant process, and the longer you go, the worse it is.
>
bull**** (and I mean that in the nicest way :-) )

>It would be best for an airplane to be flown at least once a day, if not
>multiple times a day. A week's not bad, nor are two. Beyond that, you are
>likely going to see noticeable long-term effects on maintenance and engine
>life.
>
ok why??? what is the actual process going on here that makes the
running better?

>You may be able to minimize the effects
what effects???
> by using certain oils (Exxon claims
>to have an oil that nearly eliminates corrosion even after long periods of
>time), or that might just be marketing hype. I'm not aware of any unbiased
>tests that would indicate one way or the other.
>
of course there are. you just havent read of them. :-) :-)

ok let me answer the questions I posed in tickling peter in the ribs.

moisture in the engine is primarily the bad guy here.
it condenses in the oil as the engine cools after use and will
actually emulsify (well that it what it looks like to me) through the
oil on to the steel surfaces and set off corrosion.
it is worse in winter than in summer and this is probably the one
thing that a hangar offers no protection against.

in my aircraft the first time it sat for a period unloved (the last
owner was sick and grounded for the year) there must have been
moisture/water in the oil. the bearing surfaces in the gear train
within the accessory case all corroded on to the gears. of course as
well as gluing the bits together the corrosion roughens the bearing
surfaces.
crud in the gallery obstructing the oil flow and roughened bearing
faces saw the gear train sieze and part company about half an hour
into the first subsequent flight.
the second time I took precautions to minimise water in the oil and
had no identifiable damage.

there are two methods of making sure the oil and the inside of your
engine is moisture free.
always fly the engine for a minimum of an hour after it has warmed up.
this will assist considerably in boiling off the moisture in the oil
(so thats what the breather tube is for on the engine :-) )
the other technique if you can only make short flghts is to change the
oil regularly. fresh oil is moisture free.
a third technique is to drop the oil into a container. boil it dry on
a stove then put it back into the engine. oil fires are horrific
though and nowhere as much fun as just flying it dry.

if you know that the aircraft is to sit for a long period put fresh
oil into it and run it for a minute or two to get fresh oil in all the
galleries and bearing surfaces then shut it down.
worked for me.

Stealth (there you go a mystery evaporated) Pilot
australia.

btw this matter has been subject of safety advisories in this country.

[dave]

Bill,
The citabria I bought last year had been serviced regularly with exxon
elite semi-synthetic oil. I've continued using this product. According
to exxon, I'm a very smart guy:) Whether it really works or not remains
to be seen but even exxon recommends changing the oil before extended
periods of downtime and having a sample tested for water content every
60 days. I haven't had that done but I think I will. Check out their
admittedly biased website, exxonelite.com.
Dave
68 7ECA

Bill Denton wrote:
> A pilot owns an airplane.
>
> He isn't able to fly the plane very often, but when he does it's usually two
> hours out for a $100 hamburger, then two hours back.
>
> The airplane is always hangered; all inspections and maintenance are done by
> the book.
>
> How long could the airplane sit between flights before it begins to
> deteriorate?
>
>

[Rutger]

"Bill Denton" > wrote in message >...
>
> How long could the airplane sit between flights before it begins to
> deteriorate?

At least every two weeks you need to fly it for at minimum 30 to 40
minutes. And if you're gonna fly it that very little much, then you
need to make those short flights at or above 75% power setting to make
sure the oil gets fully up to temperature to cook out any moisture.

[Bill Denton]

Thanks to all who've posted so far. Unfortunately it appears I might not
have been very clear in what I was looking for. Please allow me to
clarify...

Our pilot wants to own his own airplane, and he doesn't want others to fly
it. Therefore he doesn't want to put it on leaseback or some other situation
that would increase the "flight frequency". The plane would only be flown
when he could fly it himself. Because his flying time is limited, whenever
he does have time to fly he would like to go to the airport, do a thorough
preflight, get in and go, while not sacrificing safety.

As several pointed out, corrosion begins as soon as you shut the engine
down. Let's assume our pilot has plenty of money and really enjoys flying,
so he is willing to accept even a 20% reduction in TBO in order to own his
own plane.

I noticed that engines were about the only things mentioned. We al so want
to consider all of the airplane, including tires, landing gear, lights,
instruments, avionics, and whatever else.

So let's look at it this way: how long could the airplane sit without
incurring extremely excessive wear or situations that would make the
airplane even slightly unsafe to fly?





"Bill Denton" > wrote in message
...
> A pilot owns an airplane.
>
> He isn't able to fly the plane very often, but when he does it's usually
two
> hours out for a $100 hamburger, then two hours back.
>
> The airplane is always hangered; all inspections and maintenance are done
by
> the book.
>
> How long could the airplane sit between flights before it begins to
> deteriorate?
>
>

[C J Campbell]

"Bill Denton" > wrote in message
...
>
> So let's look at it this way: how long could the airplane sit without
> incurring extremely excessive wear or situations that would make the
> airplane even slightly unsafe to fly?

Quite honestly, if you are willing to accept the maintenance cost, it can
sit for a month or more. Many airplanes do not fly all winter. It helps if
the hangar is dry, etc.

I have seen airplanes, literally covered with moss, which have been sitting
outside in the grass for over a year in the moisture laden Puget Sound
region. Pump up the tires, check the battery, oil, and gas and get three
strong men to pull the plane out of the holes the landing gear made, and it
starts up and flies just fine. Granted, the plane needed an annual, but
there was nothing particularly unsafe about it. The cylinders showed no
corrosion.

[Peter Duniho]

"Stealth Pilot" > wrote in message
...
> lets blow away the mystery here. yes corrosion can start in a few
> hours ....but why????

Because moisture is always present. No mystery...not sure why you say there
is.

>>Corrosion is a constant process, and the longer you go, the worse it is.
>>
> bull**** (and I mean that in the nicest way :-) )

Doesn't matter how nice you mean it...you're still wrong.

> ok why??? what is the actual process going on here that makes the
> running better?

Mostly it's the recurrent coating of corrosion-susceptible surfaces with
oil, protecting them from moisture. Again, no great mystery.

>> [...] I'm not aware of any unbiased
>>tests that would indicate one way or the other.
>>
> of course there are. you just havent read of them. :-) :-)

I'm all ears. Show me an unbiased report that compares efficacy of the
corrosion-preventative oils. I would love to be proved wrong, as such a
report would be very useful to aircraft owners.

> moisture in the engine is primarily the bad guy here.
> it condenses in the oil as the engine cools after use

It is also present in the air, and the engine not being a sealed
environment, humidity will get into the engine as it sits, regardless of how
much moisture got into the oil as a result of operating the engine.

> [...]
> the second time I took precautions to minimise water in the oil and
> had no identifiable damage.

How did you attempt to identify the damage? Did you disassemble the engine
and inspect it for corrosion? Where was the airplane stored? Was it in a
desert (extremely low humidity) or in a coastal environment (high humidity)?

Regardless of the answers to the above questions, two years in service is
not enough time for you to notice the effects of corrosion. If you think
that corrosion did not occur in your engine during the second year it sat
unattended and unoperated, you are fooling yourself. The degree of
corrosion is highly variable, but to say that corrosion did not occur is
just stupid.

Pete

[Peter Duniho]

"Bill Denton" > wrote in message
...
> Thanks to all who've posted so far. Unfortunately it appears I might not
> have been very clear in what I was looking for. Please allow me to
> clarify...

Thank you. :) It's very hard to answer very vague questions.

> I noticed that engines were about the only things mentioned. We al so want
> to consider all of the airplane, including tires, landing gear, lights,
> instruments, avionics, and whatever else.
>
> So let's look at it this way: how long could the airplane sit without
> incurring extremely excessive wear or situations that would make the
> airplane even slightly unsafe to fly?

What CJ said. Most of the airplane is relatively immune to long-term
corrosion; aluminum winds up with a thin layer of oxidation that prevents
any further corrosion, and that's what most of the airplane is made of. In
a humid, salty environment (coastal) you may still get more significant
corrosion, but even so you can go months and months without anything serious
happening to most of the airplane.

The reason everyone's talking about the engine is that the engine is what's
most susceptible to sitting there. As far as the rest of the airplane goes,
the main things that will be affected are the battery and the tires. The
battery will gradually lose its charge, and discharging a lead acid battery
will shorten the battery's life. The tires will gradually lose pressure,
and even after relatively short periods of time (weeks) will develop a flat
spot (even if the pressure hasn't noticeably been lost during that time)
that you'll notice taxiing around and during takeoff; it will probably
return to its round shape by the time you land.

You can minimize the problem with the battery by charging it periodically
when the airplane's not going to fly. If the airplane's hangared, I
wouldn't sweat the tires too much, other than maybe checking the pressure
occasionally and adding air if necessary (at the extreme, if they get
completely deflated the weight of the airplane will be resting on the
rubber, squeezing it between the ground and the wheel hub, which isn't all
that good for the tire...but if it doesn't take an extraordinarily long time
for the tire to lose all its pressure, there's something wrong with it, like
a leaky valve stem, a puncture, or something).

Other stuff you mentioned, like landing gear, lights, instruments, and
avionics are all going to be basically unaffected, especially in a hangared
airplane (outside, in hot sun, some things like avionics and o-rings in
gas/oleo landing gear struts can bake and deteriorate).

One of your biggest concerns is probably the local wildlife finding the
airplane to be a desirable home. This is mostly a problem if the airplane
is kept outside, but even in a hangar, sometimes birds can find their way
in.

The bottom line here is that, while letting an airplane sit isn't exactly
good for it, it's not going to destroy it either. Most of the issues
associated with letting it sit will be economic, not safety-related. It's
not possible to economically justify owning an airplane if you don't fly it
often, and your annual inspections will, at a minimum, cost you much more
per flying hour than if you flew regularly, and there may be additional
costs due to the lack of use. The per-hour costs of an airplane that isn't
used regularly are likely to exceed the cost of a rental by a significant
amount, perhaps a factor of two or three or more.

So, for someone considering buying an airplane and not being able to fly it
regularly, personally I think the greater issue is the cost issue. By
taking appropriate steps, you can ensure that the airplane is safe, but
there's nothing you can do about the much greater cost that will be
incurred.

Pete

[Steven Barnes]

"Geoffrey Barnes" > wrote in message
ink.net...
> > You have a voice annunciator for corrosion?
>
> I've never heard of one of those. However, I have found a very effective
> voice annunciator for flying too *often*. It's very sensitive, and it
> adjusts the stridency of its warnings in direct proportion to both the
last
> 3-6 weeks of flying history and the amount of the previous month's flying
> club bill. If not much flying has been going on, it stays quiet. If you
> have flown only a little bit, it merely emits frustrated sighs as you
leave
> for the airport. If you have been flying as much as you probably should
to
> maintain currency, it begins speaking aloud, usually asking questions
like,
> "Again?", and "So when are you going to get <insert some non-flying task
> here> done?". And finally, if you have been flying as much as you wanted,
> you will see the volume increase to ear-splitting levels, the voice
> frequency reach into the soprano range, the questions turn into both
> declarative statements and dire predictions, and the language evolve into
> something that would make most sailors blush. As an added option, it can
> also start throwing dishes, frying pans, and rolling pins at you.
>
> My annunciator is called a "wife". If you want to buy mine, let me know!
>
> <Really honey, if you happen to catch this on Google, it was all a big
joke,
> OK. No, no! Look, it was just a little joke. I thought the guys would
all
> get a big laugh over it! I'll get the lawn cut as soon as the weather
> clears up, I promise. What? Yes, dear. I'll get those shelves up right
> now, dear. Yes, dear.>

You been peeking in my windows?

[G.R. Patterson III]

Cub Driver wrote:
>
> >One week
> >
> >If you can 't fly it every week, pickle the engine.
> >
> >Sorry - but that's how it really is.
>
> The same is true of the pilot, of course.

If you can't fly every week, pickle the pilot? I'll drink to that!

George Patterson
If a man gets into a fight 3,000 miles away from home, he *had* to have
been looking for it.

[Judah]

Geoffrey,
The good news is that this device can be removed.

The bad news is that it will cost you half of everything you own, except,
perhaps, the plane itself.


The good news is that it will be worth every penny!



"Geoffrey Barnes" > wrote in
ink.net:

>> You have a voice annunciator for corrosion?
>
> I've never heard of one of those. However, I have found a very
> effective voice annunciator for flying too *often*. It's very
> sensitive, and it adjusts the stridency of its warnings in direct
> proportion to both the last 3-6 weeks of flying history and the amount
> of the previous month's flying club bill. If not much flying has been
> going on, it stays quiet. If you have flown only a little bit, it
> merely emits frustrated sighs as you leave for the airport. If you
> have been flying as much as you probably should to maintain currency,
> it begins speaking aloud, usually asking questions like, "Again?", and
> "So when are you going to get <insert some non-flying task here>
> done?". And finally, if you have been flying as much as you wanted,
> you will see the volume increase to ear-splitting levels, the voice
> frequency reach into the soprano range, the questions turn into both
> declarative statements and dire predictions, and the language evolve
> into something that would make most sailors blush. As an added option,
> it can also start throwing dishes, frying pans, and rolling pins at
> you.
>
> My annunciator is called a "wife". If you want to buy mine, let me
> know!
>
> <Really honey, if you happen to catch this on Google, it was all a big
> joke, OK. No, no! Look, it was just a little joke. I thought the
> guys would all get a big laugh over it! I'll get the lawn cut as soon
> as the weather clears up, I promise. What? Yes, dear. I'll get those
> shelves up right now, dear. Yes, dear.>
>
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.778 / Virus Database: 525 - Release Date: 10/15/2004
>
>

[Dan Thomas]

"Peter Duniho" > wrote in message >...
> "Bill Denton" > wrote in message
> ...
> > Thanks to all who've posted so far. Unfortunately it appears I might not
> > have been very clear in what I was looking for. Please allow me to
> > clarify...
>
> Thank you. :) It's very hard to answer very vague questions.
>
> > I noticed that engines were about the only things mentioned. We al so want
> > to consider all of the airplane, including tires, landing gear, lights,
> > instruments, avionics, and whatever else.
> >
> > So let's look at it this way: how long could the airplane sit without
> > incurring extremely excessive wear or situations that would make the
> > airplane even slightly unsafe to fly?
>
> What CJ said. Most of the airplane is relatively immune to long-term
> corrosion; aluminum winds up with a thin layer of oxidation that prevents
> any further corrosion, and that's what most of the airplane is made of. In
> a humid, salty environment (coastal) you may still get more significant
> corrosion, but even so you can go months and months without anything serious
> happening to most of the airplane.
>
> The reason everyone's talking about the engine is that the engine is what's
> most susceptible to sitting there. As far as the rest of the airplane goes,
> the main things that will be affected are the battery and the tires. The
> battery will gradually lose its charge, and discharging a lead acid battery
> will shorten the battery's life. The tires will gradually lose pressure,
> and even after relatively short periods of time (weeks) will develop a flat
> spot (even if the pressure hasn't noticeably been lost during that time)
> that you'll notice taxiing around and during takeoff; it will probably
> return to its round shape by the time you land.
>
> You can minimize the problem with the battery by charging it periodically
> when the airplane's not going to fly. If the airplane's hangared, I
> wouldn't sweat the tires too much, other than maybe checking the pressure
> occasionally and adding air if necessary (at the extreme, if they get
> completely deflated the weight of the airplane will be resting on the
> rubber, squeezing it between the ground and the wheel hub, which isn't all
> that good for the tire...but if it doesn't take an extraordinarily long time
> for the tire to lose all its pressure, there's something wrong with it, like
> a leaky valve stem, a puncture, or something).

The trace of ozone in the air will attack the rubber and make
it brittle, and it cracks and the moisture can get into the cords and
weaken them. Covering the tires helps, and keeping them out of the sun
also reduces the reaction.

> Other stuff you mentioned, like landing gear, lights, instruments, and
> avionics are all going to be basically unaffected, especially in a hangared
> airplane (outside, in hot sun, some things like avionics and o-rings in
> gas/oleo landing gear struts can bake and deteriorate).

The bearing in the tach tends to dry out and seize up over time,
breaking the cable. Cockpit heat really kills the radios, and also
cooks the upholstery. Both take considerable time, but it's a shame to
see a 500-hour airplane in need of a complete refurbishing.

>
> One of your biggest concerns is probably the local wildlife finding the
> airplane to be a desirable home. This is mostly a problem if the airplane
> is kept outside, but even in a hangar, sometimes birds can find their way
> in.

Amen to that. Mice love our hangars here, as they afford protection
from the
cold winds in winter, and there is almost no way of keeping them out
except to use mothballs or something really objectionable like that.


Dan

[David Herman]

Bill, I think you need to stopy worrying about the details so much.

Look, if you want your own airplane and can afford it, go buy one.

Here is the rule of thumb to follow: Fly it as often as you can.

If you can fly it every day (you lucky bastid...), great. If you can fly it
every week, you're doing better than most of us. If you can generally fly
once every 10 days to two weeks, you're still doing fine. But if three or
four weeks regularly go by without you having a chance to fly, you need to
look at making some changes to your life so you can get out to the airport
more often.

Once you own the plane, it will break your heart if a month goes by without
you flying it. Trust me, if that happens, you'll know what to do. It's not
really any more complicated than that.

Come on in, the water's fine....

David Herman
N6170T 1965 Cessna 150E
Boeing Field (BFI), Seattle, WA
- - - - - - - - - - - - - - - - - - - - - - - - - -
Visit the Pacific Northwest Flying Forum:
http://www.pacificnorthwestflying.com/



"Bill Denton" > wrote in message
...
> Thanks to all who've posted so far. Unfortunately it appears I might not
> have been very clear in what I was looking for. Please allow me to
> clarify...
>
> Our pilot wants to own his own airplane, and he doesn't want others to fly
> it. Therefore he doesn't want to put it on leaseback or some other
> situation
> that would increase the "flight frequency". The plane would only be flown
> when he could fly it himself. Because his flying time is limited, whenever
> he does have time to fly he would like to go to the airport, do a thorough
> preflight, get in and go, while not sacrificing safety.
>
> As several pointed out, corrosion begins as soon as you shut the engine
> down. Let's assume our pilot has plenty of money and really enjoys flying,
> so he is willing to accept even a 20% reduction in TBO in order to own his
> own plane.
>
> I noticed that engines were about the only things mentioned. We al so want
> to consider all of the airplane, including tires, landing gear, lights,
> instruments, avionics, and whatever else.
>
> So let's look at it this way: how long could the airplane sit without
> incurring extremely excessive wear or situations that would make the
> airplane even slightly unsafe to fly?
>
>
>
>
>
> "Bill Denton" > wrote in message
> ...
>> A pilot owns an airplane.
>>
>> He isn't able to fly the plane very often, but when he does it's usually
> two
>> hours out for a $100 hamburger, then two hours back.
>>
>> The airplane is always hangered; all inspections and maintenance are done
> by
>> the book.
>>
>> How long could the airplane sit between flights before it begins to
>> deteriorate?
>>
>>
>
>

[C J Campbell]

"Dan Thomas" > wrote in message
om...
>
> The trace of ozone in the air will attack the rubber and make
> it brittle, and it cracks and the moisture can get into the cords and
> weaken them. Covering the tires helps, and keeping them out of the sun
> also reduces the reaction.
>
> The bearing in the tach tends to dry out and seize up over time,
> breaking the cable. Cockpit heat really kills the radios, and also
> cooks the upholstery. Both take considerable time, but it's a shame to
> see a 500-hour airplane in need of a complete refurbishing.
>

These things all happen to an airplane whether it flies or not, don't they?
They are not a consequence of letting the plane sit, but just consequences
of age?

[Dan Thomas]

"C J Campbell" > wrote in message >...
> "Dan Thomas" > wrote in message
> om...
> >
> > The trace of ozone in the air will attack the rubber and make
> > it brittle, and it cracks and the moisture can get into the cords and
> > weaken them. Covering the tires helps, and keeping them out of the sun
> > also reduces the reaction.
> >
> > The bearing in the tach tends to dry out and seize up over time,
> > breaking the cable. Cockpit heat really kills the radios, and also
> > cooks the upholstery. Both take considerable time, but it's a shame to
> > see a 500-hour airplane in need of a complete refurbishing.
> >
>
> These things all happen to an airplane whether it flies or not, don't they?
> They are not a consequence of letting the plane sit, but just consequences
> of age?

Yes. But too many owners/buyers look only at flight time, and get
fooled into believing that it must be a good airplane if the time is
so low. Some parts can dry out and crack or fail when they're not used
(some seals and gaskets), and engines that are flown little can have a
short life both in hours and years. I have seen tires that have rotted
on the side against the ground where they've sat for too long. Seen
damage caused by pests that had time to start a whole extended family
in the airplane; regular flight would have prevented their getting so
comfortable. Seen fuel systems with crud formed from old gasoline.

Dan