Pull plane by tail hook

Checkout the numbers on towing gliders.

The number is based on the gross weight of the glider multiplied by
a fudge factor. There is a lot of stored energy when you pull with this
much force, be aware of breaking a springy rope. Might be good to
put a weak link on the plane end so that a weak link break will take
the rope away from the plane.

As I recall, a 1000 lb breaking strength isn't out of reason at all.

The towplane scenario pretty closely simulates the load direction
when pulling the plane backward into a hanger.



In article iKBZb.371333$na.564927@attbi_s04, (Ben Jackson)
wrote:
In article ,
Tarif Halabi wrote:

Is it ok to pull my Piper Archer by the tail hook back into the hanger?
Does any one know if that will cause any damage?

If your Archer is like my Comanche the tail ring is where you attach a
big honking (300lb?) weight while you're jacking up the wings. It must
be stronger than it looks! I've been considering doing the same thing
as you.

I just rechecked the regs. Tow rope weak link can not be stronger
than twice the weight of the sailplane. Sailplanes sometimes exceed 1000
pound gross weight.

The weak link must not be less than 85 percent of the gross weight
of the sailplane.

Using this range, 850 to 2000 pounds on the tail of a towplane is not
out of reason. Another place in the installation design of tail
hooks calls for loads to stay within 30 degrees of backwards, as I
recall. I would try to keep the load as straight aft as possible.

In article . net,
(d b) wrote:

Checkout the numbers on towing gliders.

The number is based on the gross weight of the glider multiplied by
a fudge factor. There is a lot of stored energy when you pull with this
much force, be aware of breaking a springy rope. Might be good to
put a weak link on the plane end so that a weak link break will take
the rope away from the plane.

As I recall, a 1000 lb breaking strength isn't out of reason at all.

The towplane scenario pretty closely simulates the load direction
when pulling the plane backward into a hanger.



In article iKBZb.371333$na.564927@attbi_s04, (Ben Jackson)
wrote:
In article ,
Tarif Halabi wrote:

Is it ok to pull my Piper Archer by the tail hook back into the hanger?
Does any one know if that will cause any damage?

If your Archer is like my Comanche the tail ring is where you attach a
big honking (300lb?) weight while you're jacking up the wings. It must
be stronger than it looks! I've been considering doing the same thing
as you.

On Sat, 21 Feb 2004 14:06:51 GMT, (d b) wrote:

Using this range, 850 to 2000 pounds on the tail of a towplane is not
out of reason. Another place in the installation design of tail
hooks calls for loads to stay within 30 degrees of backwards, as I
recall. I would try to keep the load as straight aft as possible.

That's the other factor of course. I've only seen tailhook installation on
taildraggers, but I doubt that, on trigear airplanes, they merely unscrew
the tiedown ring and screw in the hook release mechanism. There's probably
reinforcement that's added as well, which would make moot any comparison to
pulling the plane by the stock tiedown ring.

On taildraggers, the line releases are generally attached to the tailwheel
spring...which, of course, already has a heavy-duty attachment.
Homebuilders and antique owners use the same devices to secure planes
during handpropping. See:

http://www.bowersflybaby.com/tech/tailhook.html

Ron Wanttaja

Ron Wanttaja wrote:

: That's the other factor of course. I've only seen tailhook installation on
: taildraggers, but I doubt that, on trigear airplanes, they merely unscrew
: the tiedown ring and screw in the hook release mechanism. There's probably
: reinforcement that's added as well, which would make moot any comparison to
: pulling the plane by the stock tiedown ring.

FWIW, the banner tower based at my field uses a Cessna Hawk XP. The banner
tow point is the tail tiedown. I asked if there are any reinforcements
added, and he said "No.".

--
Aaron Coolidge (N9376J)

Towhook is available as standard equipment on all C182's. No reinforcements
added. THE 182 has been towing for more than 40 years now. The hook
bolts in place of the tiedown ring. It will tow a considerable amount of
weight, to understate things a bit. It's bad form to break the rope on tow,
but it can happen.


In article ,
wrote:
On Sat, 21 Feb 2004 14:06:51 GMT, (d b) wrote:

Using this range, 850 to 2000 pounds on the tail of a towplane is not
out of reason. Another place in the installation design of tail
hooks calls for loads to stay within 30 degrees of backwards, as I
recall. I would try to keep the load as straight aft as possible.

That's the other factor of course. I've only seen tailhook installation on
taildraggers, but I doubt that, on trigear airplanes, they merely unscrew
the tiedown ring and screw in the hook release mechanism. There's probably
reinforcement that's added as well, which would make moot any comparison to
pulling the plane by the stock tiedown ring.

On taildraggers, the line releases are generally attached to the tailwheel
spring...which, of course, already has a heavy-duty attachment.
Homebuilders and antique owners use the same devices to secure planes
during handpropping. See:

http://www.bowersflybaby.com/tech/tailhook.html

Ron Wanttaja