airplane construction

[Mike[_11_]]

Hi,

I'm interested in learning more about airplane construction, say maybe a
Cessna 172. I know the basics of airframes and power plants, but what
I'm having a hard time finding is actual diagrams and depictions of the
actual assembly. For example, wing root connections, engine mounts,
supporting structures, etc. I imagine this might be available in a
mechanics manual, but I don't know where else to look. I've scoured the
Internet with no success.

Thanks for your time.

--
Mike

[Stubby]

Mike wrote:
> Hi,
>
> I'm interested in learning more about airplane construction, say maybe a
> Cessna 172. I know the basics of airframes and power plants, but what
> I'm having a hard time finding is actual diagrams and depictions of the
> actual assembly. For example, wing root connections, engine mounts,
> supporting structures, etc. I imagine this might be available in a
> mechanics manual, but I don't know where else to look. I've scoured the
> Internet with no success.

Try a kit plane. But look into the regs about this and getting it
certified. I would avoid a half done plane. Only fly something that
you built and trust.

[Jim Macklin]

try www.eaa.org and the FAA airframe manual AC65-12 and
AC43.13-1 [available on the FAA web]



"Stubby" > wrote in
message . ..
| Mike wrote:
| > Hi,
| >
| > I'm interested in learning more about airplane
construction, say maybe a
| > Cessna 172. I know the basics of airframes and power
plants, but what
| > I'm having a hard time finding is actual diagrams and
depictions of the
| > actual assembly. For example, wing root connections,
engine mounts,
| > supporting structures, etc. I imagine this might be
available in a
| > mechanics manual, but I don't know where else to look.
I've scoured the
| > Internet with no success.
|
| Try a kit plane. But look into the regs about this and
getting it
| certified. I would avoid a half done plane. Only fly
something that
| you built and trust.

[Gig 601XL Builder]

Mike wrote:
> Hi,
>
> I'm interested in learning more about airplane construction, say
> maybe a Cessna 172. I know the basics of airframes and power plants,
> but what I'm having a hard time finding is actual diagrams and
> depictions of the actual assembly. For example, wing root
> connections, engine mounts, supporting structures, etc. I imagine
> this might be available in a mechanics manual, but I don't know where
> else to look. I've scoured the Internet with no success.
>
> Thanks for your time.


I've got just the book for you. It dosen't cover any one aircraft but is a
basic hand book.

http://www.amazon.com/Standard-Aircraft-Handbook-Mechanics-Technicians/dp/0071348360/sr=8-2/qid=1168456262/ref=pd_bbs_sr_2/102-1284111-2036950?ie=UTF8&s=books

For more detail you might want to look at some of the kit aircraft maker's
websites. They often have sample plains that you can download.

Here's one to start with http://www.zenithair.com/kit-data/college.html I
know they have some CAD drawings that are available online, free.

[Robert M. Gary]

Mike wrote:
> Hi,
>
> I'm interested in learning more about airplane construction, say maybe a
> Cessna 172. I know the basics of airframes and power plants, but what
> I'm having a hard time finding is actual diagrams and depictions of the
> actual assembly. For example, wing root connections, engine mounts,
> supporting structures, etc. I imagine this might be available in a
> mechanics manual, but I don't know where else to look. I've scoured the
> Internet with no success.

When I saw how the wings are attached on a Cessna it almost made me not
want to fly one. Not much holding them on. Rational or not, I feel
better in turb in my Mooney knowing the entire cabin is sitting on the
one piece wing.

-Robert

[Mike[_11_]]

Stubby wrote:
> Mike wrote:
>> Hi,
>>
>> I'm interested in learning more about airplane construction, say maybe
>> a Cessna 172. I know the basics of airframes and power plants, but
>> what I'm having a hard time finding is actual diagrams and depictions
>> of the actual assembly. For example, wing root connections, engine
>> mounts, supporting structures, etc. I imagine this might be available
>> in a mechanics manual, but I don't know where else to look. I've
>> scoured the Internet with no success.
>
> Try a kit plane. But look into the regs about this and getting it
> certified. I would avoid a half done plane. Only fly something that
> you built and trust.

I'm afraid I would be far from building a kit plane, but at least there
would be no doubts about safety, provided I was qualified and *knew*
what I was doing ;)

I take no shortcuts myself, and I agree with your thinking. Thanks for
the advice.

--
Mike

[Mike[_11_]]

Jim Macklin wrote:
> try www.eaa.org and the FAA airframe manual AC65-12 and
> AC43.13-1 [available on the FAA web]
>
>
>
> "Stubby" > wrote in
> message . ..
> | Mike wrote:
> | > Hi,
> | >
> | > I'm interested in learning more about airplane
> construction, say maybe a
> | > Cessna 172. I know the basics of airframes and power
> plants, but what
> | > I'm having a hard time finding is actual diagrams and
> depictions of the
> | > actual assembly. For example, wing root connections,
> engine mounts,
> | > supporting structures, etc. I imagine this might be
> available in a
> | > mechanics manual, but I don't know where else to look.
> I've scoured the
> | > Internet with no success.
> |
> | Try a kit plane. But look into the regs about this and
> getting it
> | certified. I would avoid a half done plane. Only fly
> something that
> | you built and trust.
>
>

Jim, as always, thanks. I'll check the EAA and FAA site.

--
Mike

[Mike[_11_]]

Gig 601XL Builder wrote:
> Mike wrote:
>> Hi,
>>
>> I'm interested in learning more about airplane construction, say
>> maybe a Cessna 172. I know the basics of airframes and power plants,
>> but what I'm having a hard time finding is actual diagrams and
>> depictions of the actual assembly. For example, wing root
>> connections, engine mounts, supporting structures, etc. I imagine
>> this might be available in a mechanics manual, but I don't know where
>> else to look. I've scoured the Internet with no success.
>>
>> Thanks for your time.
>
>
> I've got just the book for you. It dosen't cover any one aircraft but is a
> basic hand book.
>
> http://www.amazon.com/Standard-Aircraft-Handbook-Mechanics-Technicians/dp/0071348360/sr=8-2/qid=1168456262/ref=pd_bbs_sr_2/102-1284111-2036950?ie=UTF8&s=books
>
> For more detail you might want to look at some of the kit aircraft maker's
> websites. They often have sample plains that you can download.
>
> Here's one to start with http://www.zenithair.com/kit-data/college.html I
> know they have some CAD drawings that are available online, free.
>
>

This looks like a great book from the preview pages I looked at; exactly
what I was hoping to come across.

Likewise, looks like you hit the nail on the head with the Zenith Air
site. Thanks!

--
Mike

[Mike[_11_]]

Robert M. Gary wrote:
> Mike wrote:
>> Hi,
>>
>> I'm interested in learning more about airplane construction, say maybe a
>> Cessna 172. I know the basics of airframes and power plants, but what
>> I'm having a hard time finding is actual diagrams and depictions of the
>> actual assembly. For example, wing root connections, engine mounts,
>> supporting structures, etc. I imagine this might be available in a
>> mechanics manual, but I don't know where else to look. I've scoured the
>> Internet with no success.
>
> When I saw how the wings are attached on a Cessna it almost made me not
> want to fly one. Not much holding them on. Rational or not, I feel
> better in turb in my Mooney knowing the entire cabin is sitting on the
> one piece wing.
>
> -Robert
>

I'm guessing that's why there's wing struts :) How many bolts secure the
wings to the fuselage?

--
Mike

[Gig 601XL Builder]

Mike wrote:
> Gig 601XL Builder wrote:
> Likewise, looks like you hit the nail on the head with the Zenith Air
> site. Thanks!

Glad I could be of help. I guess I should have also pointed you my own
website where there are lots of photos of a 601XL being built.

www.peoamerica.net/N601WR

[Chris]

"Robert M. Gary" > wrote in message
oups.com...
>
> Mike wrote:
>> Hi,
>>
>> I'm interested in learning more about airplane construction, say maybe a
>> Cessna 172. I know the basics of airframes and power plants, but what
>> I'm having a hard time finding is actual diagrams and depictions of the
>> actual assembly. For example, wing root connections, engine mounts,
>> supporting structures, etc. I imagine this might be available in a
>> mechanics manual, but I don't know where else to look. I've scoured the
>> Internet with no success.
>
> When I saw how the wings are attached on a Cessna it almost made me not
> want to fly one. Not much holding them on. Rational or not, I feel
> better in turb in my Mooney knowing the entire cabin is sitting on the
> one piece wing.
>
> -Robert
>

Try standing at the back of an empty 757, on a positioning leg. I could
swear that you can see the fuselage gently flex as it flies- a bit like a
fish going through water.
Now that does scare the sh1t out of you.

[Mike[_11_]]

Chris wrote:
> "Robert M. Gary" > wrote in message
> oups.com...
>> Mike wrote:
>>> Hi,
>>>
>>> I'm interested in learning more about airplane construction, say maybe a
>>> Cessna 172. I know the basics of airframes and power plants, but what
>>> I'm having a hard time finding is actual diagrams and depictions of the
>>> actual assembly. For example, wing root connections, engine mounts,
>>> supporting structures, etc. I imagine this might be available in a
>>> mechanics manual, but I don't know where else to look. I've scoured the
>>> Internet with no success.
>> When I saw how the wings are attached on a Cessna it almost made me not
>> want to fly one. Not much holding them on. Rational or not, I feel
>> better in turb in my Mooney knowing the entire cabin is sitting on the
>> one piece wing.
>>
>> -Robert
>>
>
> Try standing at the back of an empty 757, on a positioning leg. I could
> swear that you can see the fuselage gently flex as it flies- a bit like a
> fish going through water.
> Now that does scare the sh1t out of you.
>
>

I certainly believe that. I was on a flight out west a while ago, and I
guess the pilot realized he was going to overshoot the centerline on the
turn to final, so he/she banked more suddenly than usual. Definitely
heard the flex, that's for sure :).

--
Mike

[Robert M. Gary]

Mike wrote:
> Robert M. Gary wrote:
> I'm guessing that's why there's wing struts :) How many bolts secure the
> wings to the fuselage?

On the Cessna I don't remember how many "wing nuts" there were holding
the wing on, I just remember the very small area in which the wing
attaches to the body. There must be insane amounts of stress on that
small area of metal.

On the Mooney, there is but one single wing. The spar runs right under
the seats. No one has problems with wings coming off but the Mooney
design makes me more comfortable.

-Robert

[Jim Macklin]

link to
http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/99C827DB9BAAC81B86256B4500596C4E?OpenDocument

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/E533BB05389C90E486256A54006E47B2?OpenDocument

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/66AB237BAF7184A0862569F1005F7733?OpenDocument



"Mike" > wrote in message
...
| Jim Macklin wrote:
| > try www.eaa.org and the FAA airframe manual AC65-12 and
| > AC43.13-1 [available on the FAA web]
| >
| >
| >
| > "Stubby" > wrote in
| > message
. ..
| > | Mike wrote:
| > | > Hi,
| > | >
| > | > I'm interested in learning more about airplane
| > construction, say maybe a
| > | > Cessna 172. I know the basics of airframes and power
| > plants, but what
| > | > I'm having a hard time finding is actual diagrams
and
| > depictions of the
| > | > actual assembly. For example, wing root connections,
| > engine mounts,
| > | > supporting structures, etc. I imagine this might be
| > available in a
| > | > mechanics manual, but I don't know where else to
look.
| > I've scoured the
| > | > Internet with no success.
| > |
| > | Try a kit plane. But look into the regs about this
and
| > getting it
| > | certified. I would avoid a half done plane. Only fly
| > something that
| > | you built and trust.
| >
| >
|
| Jim, as always, thanks. I'll check the EAA and FAA site.
|
| --
| Mike

[Dave[_3_]]

Ummm.. re" things that move..float or fly..."

Those that don't bend or flex, - break..

:)

Dave



On Wed, 10 Jan 2007 16:41:32 -0500, Mike > wrote:

>Chris wrote:
>> "Robert M. Gary" > wrote in message
>> oups.com...
>>> Mike wrote:
>>>> Hi,
>>>>
>>>> I'm interested in learning more about airplane construction, say maybe a
>>>> Cessna 172. I know the basics of airframes and power plants, but what
>>>> I'm having a hard time finding is actual diagrams and depictions of the
>>>> actual assembly. For example, wing root connections, engine mounts,
>>>> supporting structures, etc. I imagine this might be available in a
>>>> mechanics manual, but I don't know where else to look. I've scoured the
>>>> Internet with no success.
>>> When I saw how the wings are attached on a Cessna it almost made me not
>>> want to fly one. Not much holding them on. Rational or not, I feel
>>> better in turb in my Mooney knowing the entire cabin is sitting on the
>>> one piece wing.
>>>
>>> -Robert
>>>
>>
>> Try standing at the back of an empty 757, on a positioning leg. I could
>> swear that you can see the fuselage gently flex as it flies- a bit like a
>> fish going through water.
>> Now that does scare the sh1t out of you.
>>
>>
>
>I certainly believe that. I was on a flight out west a while ago, and I
>guess the pilot realized he was going to overshoot the centerline on the
>turn to final, so he/she banked more suddenly than usual. Definitely
>heard the flex, that's for sure :).

[Anno v. Heimburg]

Robert M. Gary wrote:

> On the Cessna I don't remember how many "wing nuts" there were holding
> the wing on, I just remember the very small area in which the wing
> attaches to the body. There must be insane amounts of stress on that
> small area of metal.

Most of the lift is transferred via the struts, not at the wing root (now
I'll be darned if I can remeber where I read that...). The wing basically
pulls on the strut, and the wing root only has to keep it from tipping one
way or another.

Anno.

[Bill Watson]

The more you know the more you can do.

Nothing like assembling a sailplane, loading it full of water and
bombing down a ridge at red-line for a few hours.

Then you just pull the wings and tail back off and trailer it home.

Robert M. Gary wrote:
> Mike wrote:
>> Hi,
>>
>> I'm interested in learning more about airplane construction, say maybe a
>> Cessna 172. I know the basics of airframes and power plants, but what
>> I'm having a hard time finding is actual diagrams and depictions of the
>> actual assembly. For example, wing root connections, engine mounts,
>> supporting structures, etc. I imagine this might be available in a
>> mechanics manual, but I don't know where else to look. I've scoured the
>> Internet with no success.
>
> When I saw how the wings are attached on a Cessna it almost made me not
> want to fly one. Not much holding them on. Rational or not, I feel
> better in turb in my Mooney knowing the entire cabin is sitting on the
> one piece wing.
>
> -Robert
>

[[email protected]]

Robert M. Gary wrote:
> Mike wrote:
> > Robert M. Gary wrote:
> > I'm guessing that's why there's wing struts :) How many bolts secure the
> > wings to the fuselage?
>
> On the Cessna I don't remember how many "wing nuts" there were holding
> the wing on, I just remember the very small area in which the wing
> attaches to the body. There must be insane amounts of stress on that
> small area of metal.
>
> On the Mooney, there is but one single wing. The spar runs right under
> the seats. No one has problems with wings coming off but the Mooney
> design makes me more comfortable.
>
> -Robert

The 172 has a 7/16" bolt on the front spar attach, and a 3/8" at
the rear, IIRC without going downstairs and looking it up. Both are in
double shear. The bolt is stronger than the aluminum fittings, and the
fittings are much stronger than they look or need to be. The airplane
is rated for 3.8g positive, with 150% design limits beyond that, and I
can't remember the last time I heard of a 172 shedding a wing unless
the pilot tried to fly through a thunderstorm, in which case he'd have
died anyway. The stabilizer is weaker than the wing in many light
aircraft.
The struts are connected with 1/2" bolts in double shear.

The Mooney's one-piece wing spar is made of many smaller
pieces, all held together with tiny rivets. No stronger than the 172, I
bet. The Mooney's POH should give a g rating for the airframe.

Which reminds me: a friend recently told me of an accident in
the Southeastern US where a new Commercial pilot flew a Monney into a
thunderboomer at night. They found the wreckage scattered far and wide,
and the Mooney engineers that examined the bits and pieces estimated
that the aircraft experienced an upward acceleration of between 20 and
23 Gs. The passenger, complete with seat, went through the bottom of
the airplane and was found some distance behind the rest of the mess.
Even if the airplane had held together the occupants would have been
incapacitated or killed by the damage wrought by the acceleration.

Dan

[Robert M. Gary]

wrote:
> Robert M. Gary wrote:
> > Mike wrote:
> > > Robert M. Gary wrote:

> The 172 has a 7/16" bolt on the front spar attach, and a 3/8" at
> the rear, IIRC without going downstairs and looking it up. Both are in
> double shear. The bolt is stronger than the aluminum fittings, and the
> fittings are much stronger than they look or need to be. The airplane
> is rated for 3.8g positive, with 150% design limits beyond that, and I
> can't remember the last time I heard of a 172 shedding a wing unless
> the pilot tried to fly through a thunderstorm, in which case he'd have
> died anyway. The stabilizer is weaker than the wing in many light
> aircraft.

Agreed. I understand 172's are not falling from the sky, just an
emotional reaction to seeing what is actually holding the wings on. I
wonder what holds the wings on the C-177 if the struts old the wings on
the c-172.

> The Mooney's one-piece wing spar is made of many smaller
> pieces, all held together with tiny rivets. No stronger than the 172, I
> bet. The Mooney's POH should give a g rating for the airframe.

The 3.8g limit you mention for the c-172 is just a function of the
certification category. Since the Mooney and the 172 share the same
category they are both 3.8g's with 150% minimum overdesign by
definition. Note sure what the actual structural limits are though. The
manufactors don't tell us the actual limits, just the certification
limits.

The Mooney is known for being amazingly strong though. Rememeber the
picture of the 201 coming off the line with several dozen people
standing on the wing? They flew that plane afterwards w/o problem. I
have a friend who survived a nasty accident in his 201 and credits the
steel tube cabin for saving his life.

> Which reminds me: a friend recently told me of an accident in
> the Southeastern US where a new Commercial pilot flew a Monney into a
> thunderboomer at night. They found the wreckage scattered far and wide,
> and the Mooney engineers that examined the bits and pieces estimated
> that the aircraft experienced an upward acceleration of between 20 and
> 23 Gs. The passenger, complete with seat, went through the bottom of
> the airplane and was found some distance behind the rest of the mess.
> Even if the airplane had held together the occupants would have been
> incapacitated or killed by the damage wrought by the acceleration.

Do you have a reference for this? A possible date range, the state if
happened in or something I can search on? I'd like to pull up the NTSB
on it.

-Robert

[[email protected]]

Robert M. Gary wrote:
> wrote:
> > Robert M. Gary wrote:
> > > Mike wrote:
> > > > Robert M. Gary wrote:
>
> > The 172 has a 7/16" bolt on the front spar attach, and a 3/8" at
> > the rear, IIRC without going downstairs and looking it up. Both are in
> > double shear. The bolt is stronger than the aluminum fittings, and the
> > fittings are much stronger than they look or need to be. The airplane
> > is rated for 3.8g positive, with 150% design limits beyond that, and I
> > can't remember the last time I heard of a 172 shedding a wing unless
> > the pilot tried to fly through a thunderstorm, in which case he'd have
> > died anyway. The stabilizer is weaker than the wing in many light
> > aircraft.
>
> Agreed. I understand 172's are not falling from the sky, just an
> emotional reaction to seeing what is actually holding the wings on. I
> wonder what holds the wings on the C-177 if the struts old the wings on
> the c-172.
>
> > The Mooney's one-piece wing spar is made of many smaller
> > pieces, all held together with tiny rivets. No stronger than the 172, I
> > bet. The Mooney's POH should give a g rating for the airframe.
>
> The 3.8g limit you mention for the c-172 is just a function of the
> certification category. Since the Mooney and the 172 share the same
> category they are both 3.8g's with 150% minimum overdesign by
> definition. Note sure what the actual structural limits are though. The
> manufactors don't tell us the actual limits, just the certification
> limits.
>
> The Mooney is known for being amazingly strong though. Rememeber the
> picture of the 201 coming off the line with several dozen people
> standing on the wing? They flew that plane afterwards w/o problem. I
> have a friend who survived a nasty accident in his 201 and credits the
> steel tube cabin for saving his life.
>
> > Which reminds me: a friend recently told me of an accident in
> > the Southeastern US where a new Commercial pilot flew a Monney into a
> > thunderboomer at night. They found the wreckage scattered far and wide,
> > and the Mooney engineers that examined the bits and pieces estimated
> > that the aircraft experienced an upward acceleration of between 20 and
> > 23 Gs. The passenger, complete with seat, went through the bottom of
> > the airplane and was found some distance behind the rest of the mess.
> > Even if the airplane had held together the occupants would have been
> > incapacitated or killed by the damage wrought by the acceleration.
>
> Do you have a reference for this? A possible date range, the state if
> happened in or something I can search on? I'd like to pull up the NTSB
> on it.
>
> -Robert

Last summer, Texas/Louisiana neighborhood, I think. The
details were in the story, not the time and place.

Dan

[george]

Bill Watson wrote:

> The more you know the more you can do.
>
> Nothing like assembling a sailplane, loading it full of water and
> bombing down a ridge at red-line for a few hours.
>
> Then you just pull the wings and tail back off and trailer it home.
>
the size of those pins/bolts that hold the wings on should attract the
attention of any pilot not used to rigging sailpanes :-)

[Mike[_11_]]

wrote:
> Robert M. Gary wrote:
>> Mike wrote:
>>> Robert M. Gary wrote:
>>> I'm guessing that's why there's wing struts :) How many bolts secure the
>>> wings to the fuselage?
>> On the Cessna I don't remember how many "wing nuts" there were holding
>> the wing on, I just remember the very small area in which the wing
>> attaches to the body. There must be insane amounts of stress on that
>> small area of metal.
>>
>> On the Mooney, there is but one single wing. The spar runs right under
>> the seats. No one has problems with wings coming off but the Mooney
>> design makes me more comfortable.
>>
>> -Robert
>
> The 172 has a 7/16" bolt on the front spar attach, and a 3/8" at
> the rear, IIRC without going downstairs and looking it up. Both are in
> double shear. The bolt is stronger than the aluminum fittings, and the
> fittings are much stronger than they look or need to be. The airplane
> is rated for 3.8g positive, with 150% design limits beyond that, and I
> can't remember the last time I heard of a 172 shedding a wing unless
> the pilot tried to fly through a thunderstorm, in which case he'd have
> died anyway. The stabilizer is weaker than the wing in many light
> aircraft.
> The struts are connected with 1/2" bolts in double shear.
>
> The Mooney's one-piece wing spar is made of many smaller
> pieces, all held together with tiny rivets. No stronger than the 172, I
> bet. The Mooney's POH should give a g rating for the airframe.
>
> Which reminds me: a friend recently told me of an accident in
> the Southeastern US where a new Commercial pilot flew a Monney into a
> thunderboomer at night. They found the wreckage scattered far and wide,
> and the Mooney engineers that examined the bits and pieces estimated
> that the aircraft experienced an upward acceleration of between 20 and
> 23 Gs. The passenger, complete with seat, went through the bottom of
> the airplane and was found some distance behind the rest of the mess.
> Even if the airplane had held together the occupants would have been
> incapacitated or killed by the damage wrought by the acceleration.
>
> Dan
>

Thanks for the insight, Dan. I never knew that about the C172 (or should
I say high-wing?). Definitely learned a few more things today.


--
Mike

[Jim Macklin]

Understand that bolts used in aircraft construction are not
"hardware store" items. The steel and the tolerances for
aircraft grade fasteners are better than hardware store
Grade 8 bolts. Beech uses bolts in tension to hold the wing
on the Bonanza, Baron and King Air models. When there is a
crash, the bolts are rarely broken. But if the bolts are
not properly installed and maintained, corrosion can weaken
the bolts causing them to break.

Cessna uses a bolt installed in shear through fittings like
you fingers meshed. This is called "double shear" and as
long as the bolt is a snug fit in the hole the bolt can hold
more load than the airplane is designed to experience.
But a bolt in tension is stronger than a bolt in shear.


"george" > wrote in message
ups.com...
|
| Bill Watson wrote:
|
| > The more you know the more you can do.
| >
| > Nothing like assembling a sailplane, loading it full of
water and
| > bombing down a ridge at red-line for a few hours.
| >
| > Then you just pull the wings and tail back off and
trailer it home.
| >
| the size of those pins/bolts that hold the wings on
should attract the
| attention of any pilot not used to rigging sailpanes :-)
|

[[email protected]]

Jim Macklin wrote:
> Understand that bolts used in aircraft construction are not
> "hardware store" items. The steel and the tolerances for
> aircraft grade fasteners are better than hardware store
> Grade 8 bolts. Beech uses bolts in tension to hold the wing
> on the Bonanza, Baron and King Air models. When there is a
> crash, the bolts are rarely broken. But if the bolts are
> not properly installed and maintained, corrosion can weaken
> the bolts causing them to break.
>
> Cessna uses a bolt installed in shear through fittings like
> you fingers meshed. This is called "double shear" and as
> long as the bolt is a snug fit in the hole the bolt can hold
> more load than the airplane is designed to experience.
> But a bolt in tension is stronger than a bolt in shear.
>

The hardware-store Grade 2 bolts (no marks on the head) is
around 55 to 60 ksi, really dangerous stuff on anything other than your
kid's push kart. Grade 5 (three radial marks on the head) are 120ksi,
same as an AN bolt. The Grade 8 (five radial marks) is 150ksi, better
than the AN bolt.
But the AN bolt is made of 2330 nickel steel, making it more
corrosion-resistant and more ductile, which means it will stretch more
before it breaks. The part will appear loose before it comes off. The
AN bolt's tolerances are a bit better and the thread length is just
what's needed, not the great length of thread on the industrial bolt
that ends up inside the joint where it doesn't support the shear loads
well. And the thread fit is far better on the AN bolt.
Shear strength for steel is typically 70% of tensile.

Someone asked about the Cardinal's (177) wing attach. It's been a
long time, but I think it was something like 1/2" bolts in sextuple
shear, spaced about 7 inches apart. The spar fittings were cast
aluminum.

Dan

[Matt Whiting]

Jim Macklin wrote:

> Understand that bolts used in aircraft construction are not
> "hardware store" items. The steel and the tolerances for
> aircraft grade fasteners are better than hardware store
> Grade 8 bolts. Beech uses bolts in tension to hold the wing
> on the Bonanza, Baron and King Air models. When there is a
> crash, the bolts are rarely broken. But if the bolts are
> not properly installed and maintained, corrosion can weaken
> the bolts causing them to break.
>
> Cessna uses a bolt installed in shear through fittings like
> you fingers meshed. This is called "double shear" and as
> long as the bolt is a snug fit in the hole the bolt can hold
> more load than the airplane is designed to experience.
> But a bolt in tension is stronger than a bolt in shear.

I'd have to pull out my AISC manual to be sure, but I believe that a
bolt in double shear has more capacity than in tension. If you are
comparing single shear to tension, then I agree with you.

Matt

[Jose]

> I'd have to pull out my AISC manual to be sure, but I believe that a bolt in double shear has more capacity than in tension. If you are comparing single shear to tension, then I agree with you.

What is "double shear" and "single shear"?

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

[Robert M. Gary]

wrote:
> Robert M. Gary wrote:
> Last summer, Texas/Louisiana neighborhood, I think. The
> details were in the story, not the time and place.

I'd like to see the actual report on that. I did a search from 1980-now
for fatals in any Mooney that includes the word "thunderstorm" and only
came up with 3, but none mention the pilot having left the aircraft.
This is what I found.
http://www.ntsb.gov/ntsb/brief2.asp?ev_id=20001208X07018&ntsbno=FTW97FA032&akey=1

http://www.ntsb.gov/ntsb/brief2.asp?ev_id=20001206X01424&ntsbno=ATL94FA116&akey=1

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001214X36345&key=1

The only Mooney fatal I could find in the SE last summer was this one
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20060731X01061&key=1

Perhaps that's the one?? The report is only preliminary but doesn't
mention whether the pilot was with the aircraft or not.

-Robert

[Matt Whiting]

Jose wrote:

>> I'd have to pull out my AISC manual to be sure, but I believe that a
>> bolt in double shear has more capacity than in tension. If you are
>> comparing single shear to tension, then I agree with you.
>
>
> What is "double shear" and "single shear"?

It refers to the number of planes in shear. Think of the rivet in a
scissors. There is one shear plane where the two halves of the scissors
meet and are held together by the pin/rivet.

Now think of a sandwich of three pieces of metal held together with a
bolt or pin or rivet. There are now two planes that are in shear and
thus you have twice as much shear resistance of the outer two pieces of
metal are pulled one direction and the middle piece is pulled another
direction.


Matt

[Capt. Geoffrey Thorpe]

"Jim Macklin" > wrote in message
...
<...>
> Cessna uses a bolt installed in shear through fittings like
> you fingers meshed. This is called "double shear" and as
> long as the bolt is a snug fit in the hole the bolt can hold
> more load than the airplane is designed to experience.
> But a bolt in tension is stronger than a bolt in shear.
>


But you don't want to be standing under the wing if someone jerks the stut
off.

Boink!!!

;-)
--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

[Jim Macklin]

Without the strut, which is in tension during normal flight
and compression when at less than zero G, the wing would
just flap up and down.

The close fit of the bolts in shear is required so that
loads are transferred evenly to the structure.The torque on
the shear bolts is minimal and the nut just serves to keep
the bolt from falling off/out.
A bolt in tension is torqued so that the bolt is loaded into
the elastic range and the tight bolt is stretched very
slightly and then, as long as the bolt stays tight, it does
not accumulate stress until the loads exceed the elastic
limit.



"Capt. Geoffrey Thorpe" <The Sea Hawk at wow way d0t com>
wrote in message
...
|
| "Jim Macklin" > wrote
in message
| ...
| <...>
| > Cessna uses a bolt installed in shear through fittings
like
| > you fingers meshed. This is called "double shear" and
as
| > long as the bolt is a snug fit in the hole the bolt can
hold
| > more load than the airplane is designed to experience.
| > But a bolt in tension is stronger than a bolt in shear.
| >
|
|
| But you don't want to be standing under the wing if
someone jerks the stut
| off.
|
| Boink!!!
|
| ;-)
| --
| Geoff
| The Sea Hawk at Wow Way d0t Com
| remove spaces and make the obvious substitutions to reply
by mail
| When immigration is outlawed, only outlaws will immigrate.
|
|

[Mike[_11_]]

Jim Macklin wrote:
> Understand that bolts used in aircraft construction are not
> "hardware store" items. The steel and the tolerances for
> aircraft grade fasteners are better than hardware store
> Grade 8 bolts. Beech uses bolts in tension to hold the wing
> on the Bonanza, Baron and King Air models. When there is a
> crash, the bolts are rarely broken. But if the bolts are
> not properly installed and maintained, corrosion can weaken
> the bolts causing them to break.
>
> Cessna uses a bolt installed in shear through fittings like
> you fingers meshed. This is called "double shear" and as
> long as the bolt is a snug fit in the hole the bolt can hold
> more load than the airplane is designed to experience.
> But a bolt in tension is stronger than a bolt in shear.
>
>
> "george" > wrote in message
> ups.com...
> |
> | Bill Watson wrote:
> |
> | > The more you know the more you can do.
> | >
> | > Nothing like assembling a sailplane, loading it full of
> water and
> | > bombing down a ridge at red-line for a few hours.
> | >
> | > Then you just pull the wings and tail back off and
> trailer it home.
> | >
> | the size of those pins/bolts that hold the wings on
> should attract the
> | attention of any pilot not used to rigging sailpanes :-)
> |
>
>
Here's a good illustration/animation on "double shear" connections:
http://www.ijee.dit.ie/OnlinePapers/Interactive/Philpot/bolted_double.htm

--
Mike

[Mike[_11_]]

Matt Whiting wrote:
> Jose wrote:
>
>>> I'd have to pull out my AISC manual to be sure, but I believe that a
>>> bolt in double shear has more capacity than in tension. If you are
>>> comparing single shear to tension, then I agree with you.
>>
>>
>> What is "double shear" and "single shear"?
>
> It refers to the number of planes in shear. Think of the rivet in a
> scissors. There is one shear plane where the two halves of the scissors
> meet and are held together by the pin/rivet.
>
> Now think of a sandwich of three pieces of metal held together with a
> bolt or pin or rivet. There are now two planes that are in shear and
> thus you have twice as much shear resistance of the outer two pieces of
> metal are pulled one direction and the middle piece is pulled another
> direction.
>
>
> Matt

Here's a good illustration/animation:
http://www.ijee.dit.ie/OnlinePapers/Interactive/Philpot/bolted_double.htm


--
Mike

[Jose]

> Here's a good illustration/animation on "double shear" connections:
> http://www.ijee.dit.ie/OnlinePapers/Interactive/Philpot/bolted_double.htm

Thanks. It's a way to spread the shear load.

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

[[email protected]]

Matt Whiting wrote:

> >
> > Cessna uses a bolt installed in shear through fittings like
> > you fingers meshed. This is called "double shear" and as
> > long as the bolt is a snug fit in the hole the bolt can hold
> > more load than the airplane is designed to experience.
> > But a bolt in tension is stronger than a bolt in shear.
>
> I'd have to pull out my AISC manual to be sure, but I believe that a
> bolt in double shear has more capacity than in tension. If you are
> comparing single shear to tension, then I agree with you.
>
> Matt

That's right. The 70% figure refers to single shear.

I made a mistake on the Grade 8 bolt head marking. It has six
radial marks, not five. Five is a Grade 7, not a common bolt. The
grades go clear to Grade 16, IIRC.

Dan

[[email protected]]

Robert M. Gary wrote:
> wrote:
> > Robert M. Gary wrote:
> > Last summer, Texas/Louisiana neighborhood, I think. The
> > details were in the story, not the time and place.
>

>
> The only Mooney fatal I could find in the SE last summer was this one
> http://www.ntsb.gov/ntsb/brief.asp?ev_id=20060731X01061&key=1
>
> Perhaps that's the one?? The report is only preliminary but doesn't
> mention whether the pilot was with the aircraft or not.
>
> -Robert

That's likely it. The report gives no details whatever of the
condition of the wreckage; perhaps that's forthcoming.

Dan

[Jim Macklin]

Aircraft grade bolt have many standards, more to do with
heat-treating and plating and tolerances on the thread and
shank fit and finish. Aircraft hardware is a detailed
study all to itself.



> wrote in message
oups.com...
|
| Matt Whiting wrote:
|
| > >
| > > Cessna uses a bolt installed in shear through fittings
like
| > > you fingers meshed. This is called "double shear" and
as
| > > long as the bolt is a snug fit in the hole the bolt
can hold
| > > more load than the airplane is designed to experience.
| > > But a bolt in tension is stronger than a bolt in
shear.
| >
| > I'd have to pull out my AISC manual to be sure, but I
believe that a
| > bolt in double shear has more capacity than in tension.
If you are
| > comparing single shear to tension, then I agree with
you.
| >
| > Matt
|
| That's right. The 70% figure refers to single shear.
|
| I made a mistake on the Grade 8 bolt head marking.
It has six
| radial marks, not five. Five is a Grade 7, not a common
bolt. The
| grades go clear to Grade 16, IIRC.
|
| Dan
|

[karl gruber[_1_]]

> Jim Macklin wrote:
>> Understand that bolts used in aircraft construction are not "hardware
>> store" items. The steel and the tolerances for aircraft grade fasteners
>> are better than hardware store Grade 8 bolts. Beech uses bolts in
>> tension to hold the wing on the Bonanza, Baron and King Air models. When
>> there is a crash, the bolts are rarely broken.

Well, Beech used to use bolt in tension on the King Air. But a bunch of them
had their wings fall off.

Now they use bolts in shear.

Karl
N185KG

[Jim Macklin]

I have not looked at a recent King Air, but I think that
they still use the traditional Beech bath-tub fitting and
tension bolts.


"karl gruber" > wrote in message
...
|
| > Jim Macklin wrote:
| >> Understand that bolts used in aircraft construction are
not "hardware
| >> store" items. The steel and the tolerances for
aircraft grade fasteners
| >> are better than hardware store Grade 8 bolts. Beech
uses bolts in
| >> tension to hold the wing on the Bonanza, Baron and King
Air models. When
| >> there is a crash, the bolts are rarely broken.
|
| Well, Beech used to use bolt in tension on the King Air.
But a bunch of them
| had their wings fall off.
|
| Now they use bolts in shear.
|
| Karl
| N185KG
|
|