Aerostar Wing Spar

Tantalum

Tantalum

Final Approach
Joined
Feb 22, 2017
Messages
9,228
Display Name
Display name:
San_Diego_Pilot
Possibly a really dumb, but hopefully a quick question with a quick answer

As some of you may have found I have a mild Aerostar obsession... but I don't understand where or how the wing actually connects to the fuselage.. does the wing spar pass through the middle of the cabin? I've seen photos of interiors and it appears to be an open tube inside, so do the wings just attach onto the side of the fuselage with no central spar or "wing box"? If so that seems like it could be a structurally weak (or conversely very heavy) part of the fuselage there

There was a fairly detailed cutaway I saw on FlightGlobal but it didn't really reveal what I was looking for

Didn't know if someone familiar with with the plane knew how the wing was actually attached to the plane in a structurally sound manner
 
However it is attached, I'd say Ted Smith designed it in a structurally sound manner. Jimmy Franklin used to put one (Zar) through its paces on the air show circuit. Seen it in person myself.

 
Velocity173 said:
structurally sound
Click to expand...
That's an impressive video, and I've read elsewhere that the plan was overbuilt using wing skins "twice as thick" and triple wing spars etc., and that Ted Smith was no stranger to design. That video certainly lends proof to that. But still, looking at them and the inside it's hard to picture in my minds eye how it attaches just to the side of the fuselage like that

Oh well... doubt I'll ever get to own one, but you can always dream!
 
Tantalum said:
That's an impressive video, and I've read elsewhere that the plan was overbuilt using wing skins "twice as thick" and triple wing spars etc., and that Ted Smith was no stranger to design. That video certainly lends proof to that. But still, looking at them and the inside it's hard to picture in my minds eye how it attaches just to the side of the fuselage like that

Oh well... doubt I'll ever get to own one, but you can always dream!
Click to expand...

I'd love to own one as well. Always been a fan of the type. Just don't think I could afford twin operating costs.
 
The Aerostar design is unique in many ways. Each wing is a separate unit that attaches to the spar carry through structure - in a similar manner to many aircraft designs. What is unique is that the skin on the wings is much thicker than found on most other aircraft. Thus the skins contribute a considerable amount of both flexural and torsional strength to the wing (which is normally absorbed primarily by the spars). The result is a very strong structure. The objective, as I understand it, is that Ted Smith envisioned the same basic Aerostar airframe to support much larger engines (including jets) and the resulting increases in speed. I believe that a jet-powered Aerostar was built in the past few years. It is a fantastic airplane. Some bad accidents (mostly pilot error) have given the design a bad name. Ted Smith was also the principal designer of the Aero Commander twin (my favorite twin, having owned one many years ago). We can all dream!
 
Not trying to downplay the Aerostar at all, but most any demonstration by Jimmy Franklin was impressive. The most impressive airshow I have ever seen was a private practice flight he did in a Kitfox. All Positive G Maneuvers, but is was impressive because the plane was so slow the whole airshow took place within about 1/4 mile radius of where I was standing.

Brian
 
brcase said:
Not trying to downplay the Aerostar at all, but most any demonstration by Jimmy Franklin was impressive. The most impressive airshow I have ever seen was a private practice flight he did in a Kitfox. All Positive G Maneuvers, but is was impressive because the plane was so slow the whole airshow took place within about 1/4 mile radius of where I was standing.

Brian
Click to expand...

What about the jet Waco? Of course it's been copied but he was the first. ;)
 
Somewhat familiar with the airplane, but never knew it was an aerobat.
I wonder if the video was sped up. It looks a bit fast.
 
Velocity173 said:
What about the jet Waco? Of course it's been copied but he was the first. ;)
Click to expand...

Might have been a bit of my perspective also I was standing on a hill about 75 feet above the runway about 3-500 feet from the runway. Private demonstration so we could get a way with that. Really liked the Jet Waco, really liked the idea of trying to get my multi engine rating in one:). But airshow arena for it was a lot larger than for the Kitfox, which can be good for larger crowds.

Brian
 

Smith (Piper); Model PA 60-601; Aerostar; Wing Structural Damage; ATA 5740


While complying with Aerostar Service Bulletin (SB) 600-136, the technician discovered the left wing

attachment fittings were cracked.

The left wing forward- and aft-wing attachment fittings (P/N’s 200012-001 and 200010-001) were

severely cracked and in danger of allowing wing separation. According to the submitter, these defects


were caused by poor design of the wing attachment fittings. Additionally, it is possible that the high

number of operating hours may have produced metal fatigue and stress, which contributed to the cracks.

Operators of like aircraft are urged to have these wing fittings inspected and comply with the data

contained in SB 600-136 as soon as possible.

Part total time-12,948 hours.

https://www.faa.gov/aircraft/safety/alerts/aviation_maintenance/media/2001/2001_09_Alert.pdf
 
brcase said:
Not trying to downplay the Aerostar at all, but most any demonstration by Jimmy Franklin was impressive. The most impressive airshow I have ever seen was a private practice flight he did in a Kitfox. All Positive G Maneuvers, but is was impressive because the plane was so slow the whole airshow took place within about 1/4 mile radius of where I was standing.

Brian
Click to expand...

Was the Kitfox the Chartreuse/Maroon "Speedster"? I saw that act at Oshkosh the first time I attended and was extremely impressed. Great flying, close to show center the entire time, and very quiet, which I prefer to the roar of transonic props from the unlimited aerobatic acts.
 
Timbeck2 said:
The Aerostar's I'm most familiar with don't have wings.
Click to expand...

Evidently someone forgot to check those wing attach fittings...:eek:
Either that, or the kids in your hood got tired of jacking cars?
 
@GlennAB1 wow, that doesn't sound good... I can't help but wonder about that attachment just looking at it

@Pilawt glad they didn't move forward on that to be honest...
 
The jet version looks pretty sick

 
Great... we will have all these airplanes doing 0.68 in the high flight levels gooing everyone up.
 
@asicer looks pretty good as a turboprop, love the exhaust stacks
 
GRG55 said:
Evidently someone forgot to check those wing attach fittings...:eek:
Either that, or the kids in your hood got tired of jacking cars?
Click to expand...

I doubt a wing was ever thought of.

1557247711_7b3c5220bc_z.jpg
 
Last edited:
Tantalum said:
Possibly a really dumb, but hopefully a quick question with a quick answer

As some of you may have found I have a mild Aerostar obsession... but I don't understand where or how the wing actually connects to the fuselage.. does the wing spar pass through the middle of the cabin? I've seen photos of interiors and it appears to be an open tube inside, so do the wings just attach onto the side of the fuselage with no central spar or "wing box"? If so that seems like it could be a structurally weak (or conversely very heavy) part of the fuselage there

There was a fairly detailed cutaway I saw on FlightGlobal but it didn't really reveal what I was looking for

Didn't know if someone familiar with with the plane knew how the wing was actually attached to the plane in a structurally sound manner
Click to expand...

So far nobody has answered your question. It is a little hard to explain without a picture but essentially the carry through structure is "U" shaped and is part of the lower half of the cabin. In each wing there is two main spars that attach to the carry throughs and a third spar that support the flaps and control surfaces. The spars bolt to the carry through structure similar to any other aircraft. I do not know if the carry throughs are one piece or it is two separate carry throughs. And for the record they are very strong.
 
ronnieh said:
but essentially the carry through structure is "U" shaped and is part of the lower half of the cabin
Click to expand...
Interesting, thanks! I imagine that U-carrythrough must see some immense loads, wonder if Ted designed mid wing for mostly aesthetic reasons or if there was an aerodynamic speed rational behind it
 
Tantalum said:
wonder if Ted designed mid wing for mostly aesthetic reasons or if there was an aerodynamic speed rational behind it
Click to expand...
Probably "packaging" more than aerodynamics. Compare it to his previous brainchild, the twin-engine Aero Commanders. Both have easy step-up into the low-slung cabin; but the wing-mounted engines need to be high enough to keep the props off the ground. The mid-wing accomplishes that (barely) with main landing gear legs of a more reasonable length (and weight) than on the Commanders. Smith's original intent was that this design ultimately be the basis of a complete line of aircraft, from single-engine piston through twin jet.
 
Tantalum said:
Interesting, thanks! I imagine that U-carrythrough must see some immense loads, wonder if Ted designed mid wing for mostly aesthetic reasons or if there was an aerodynamic speed rational behind it
Click to expand...
As does any carry through.
 
Umm, I guess. Would have to give that question to an engineer type.
 
GlennAB1 said:
Aerostar fuselage has to be reinforced much like the DC-10 #2 engine inlet for vertical stab.
Click to expand...
Good point, that's a lot of added structure. There was a YouTube video showing the md-11 doing stall tests and the amount of shaking that number two engine saw was absolutely crazy. My brother, who incidentally is an engineer for Pratt, jokingly remarked with me that that number two engine was basically just offsetting the added weight and drag from itself. Clearly tongue in cheek but funny.

Too bad the tri Jets didn't see much commercial success though, I thought they had a pretty badass ramp appeal to them

Around 3:20 in
 
Tantalum said:
True, but that U shape seems like it would be a less optimal design than just a straight beam.
Click to expand...
Define optimal. Having a pax climb over a beam through the middle of the cabin would probably hinder sales just a bit.
 
A mid-wing design is the most aerodynamic efficient design. This information is based on discussions with Aerostar Aircraft Corp (AAC) who holds the type certificates; some of the company heads were engineers on the original aircraft and worked with Ted Smith.
I had an Aerostar for a couple of years. I got to sit in the jet version, and missed a flight in it by a couple of days. AAC was looking to raise funds to bring the jet version into production about five years ago, no idea of the status of that project.

Tim
 
tspear said:
I had an Aerostar for a couple of years. I got to sit in the jet version, and missed a flight in it by a couple of days. AAC was looking to raise funds to bring the jet version into production about five years ago, no idea of the status of that project.
Click to expand...
Lucky! I would love to own one some day. How come you sold?

The jet looked very promising, it wasn't just vaporware, they had a flying example out that got a decent amount of press...
 
You must log in or register to reply here.
Back
Top