Pipers/Strutural Engineering/Doors

The only single-engine piston aircraft that I can think of that Piper
has put a door on each side of the fuselage is the Tomahawk.
Except for the addition of a couple wing ribs for wing walk area and a
door frame, are there any structural reasons why a pilot side door
could not be added? Now that Piper has gone to the overhead panel, the
left sidewall is clear of any "controls". (Is the fuel selector still
there? It could be relocated to the center console as it is on the
Saratoga.)

It adds more weight than you might think. The area around the door has to
be reinforced. Make a paper box and feel how stiff it becomes when you tape
the final side and then cut a jarge hole on one side and note how much
stiffness it loses.

Mike
MU-2


"EDR" wrote in message
...
The only single-engine piston aircraft that I can think of that Piper
has put a door on each side of the fuselage is the Tomahawk.
Except for the addition of a couple wing ribs for wing walk area and a
door frame, are there any structural reasons why a pilot side door
could not be added? Now that Piper has gone to the overhead panel, the
left sidewall is clear of any "controls". (Is the fuel selector still
there? It could be relocated to the center console as it is on the
Saratoga.)

"Mike Rapoport" wrote in message news
It adds more weight than you might think. The area around the door has to
be reinforced. Make a paper box and feel how stiff it becomes when you tape
the final side and then cut a jarge hole on one side and note how much
stiffness it loses.

Yes. It's pretty amazing what a hole does to the strength. I have a baggage
door mod on my Navion (it was a factory option). There are extra structural
members and a zillion rivets to support a foot square hole in the side.

-Ron

In article . net, Mike
Rapoport wrote:

It adds more weight than you might think. The area around the door has to
be reinforced. Make a paper box and feel how stiff it becomes when you tape
the final side and then cut a jarge hole on one side and note how much
stiffness it loses.

I understand the torsional rigidity issue.
Cessna does it, suspending the fuselage from the wing.
Beech did it with the Musketeer line.
I would think the wing on the bottom would make it easier because the
wing center section spar box and not the fuselage structure is not
carrying the load.
How much weight are we talking about? 25 pounds?
The weight's of Pipers and Cessna's seem pretty comparable across the
product lines.

Is the question more one of economics?

EDR wrote:
In article . net, Mike
Rapoport wrote:


It adds more weight than you might think. The area around the door has to
be reinforced. Make a paper box and feel how stiff it becomes when you tape
the final side and then cut a jarge hole on one side and note how much
stiffness it loses.


I understand the torsional rigidity issue.
Cessna does it, suspending the fuselage from the wing.
Beech did it with the Musketeer line.
I would think the wing on the bottom would make it easier because the
wing center section spar box and not the fuselage structure is not
carrying the load.
How much weight are we talking about? 25 pounds?
The weight's of Pipers and Cessna's seem pretty comparable across the
product lines.

Is the question more one of economics?

I would not be willing to pay 25 Lb in our clubs Archer for a second
door. I find 3 adult men and normal luggage puts me at full GW.

John Roncallo

I would not be willing to pay 25 Lb in our clubs Archer for a second
door. I find 3 adult men and normal luggage puts me at full GW.

True. But with the 1460 pound useful load of our Pathfinder (Cherokee 235)
they could easily have sacrificed 25 pounds of structural reinforcement in
exchange for the added convenience and safety.

I still believe that Piper's decision to forego the pilot-side door in the
235/236 line has proven to be a many multi-million dollar mistake for Piper
over the years.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

How expensive would it have been to get a second door certified? I wonder
why nobody has developed a second door STC if it is so desirable and easy to
do. The whole success of the Cherokee line was based on commonality of
parts and low cost.

Mike
MU-2


"Jay Honeck" wrote in message
news:kXPFb.633938$Fm2.569782@attbi_s04...
I would not be willing to pay 25 Lb in our clubs Archer for a second
door. I find 3 adult men and normal luggage puts me at full GW.

True. But with the 1460 pound useful load of our Pathfinder (Cherokee
235)
they could easily have sacrificed 25 pounds of structural reinforcement in
exchange for the added convenience and safety.

I still believe that Piper's decision to forego the pilot-side door in the
235/236 line has proven to be a many multi-million dollar mistake for
Piper
over the years.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

In article kXPFb.633938$Fm2.569782@attbi_s04, Jay Honeck
wrote:

I still believe that Piper's decision to forego the pilot-side door in the
235/236 line has proven to be a many multi-million dollar mistake for Piper
over the years.

Yep, Cessna outsells Piper 2:1 or even 3:1, depending on the model.

"EDR" wrote in message
...
In article . net, Mike
Rapoport wrote:

It adds more weight than you might think. The area around the door has
to
be reinforced. Make a paper box and feel how stiff it becomes when you
tape
the final side and then cut a jarge hole on one side and note how much
stiffness it loses.

I understand the torsional rigidity issue.
Cessna does it, suspending the fuselage from the wing.
Beech did it with the Musketeer line.
I would think the wing on the bottom would make it easier because the
wing center section spar box and not the fuselage structure is not
carrying the load.
How much weight are we talking about? 25 pounds?
The weight's of Pipers and Cessna's seem pretty comparable across the
product lines.

Is the question more one of economics?

With a high wing aircraft there is already additionaly structure present to
transfer the load of the wing to the gear. Of course, you are right, a
secon door adds cost. I don't know how much weight but these planes are
pretty limited already.

Mike
MU-2

Mike Rapoport wrote:
With a high wing aircraft there is already additionaly structure present to
transfer the load of the wing to the gear. Of course, you are right, a
secon door adds cost. I don't know how much weight but these planes are
pretty limited already.

Excellent point!
I totally didn't think of that structure.