Thickness of 6061-T6 Wing Ribs

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

pfarber

Well-Known Member
Joined
Feb 21, 2019
Messages
824
Location
Dollywood
Read the book, Northrup's Flying Wings by Garry R. Pape. Jack Northrup's tailess aircraft designs and prototypes were way ahead of their time.
Gotha and Horton would like a word with you.

When they are done laughing at you, Hienkel and Messerschmitt would like to speak to you.

The only thing Norton really figured out was the split aileron for yaw control. The delta wing was pretty much evolutionary vs revolutionary after the war.

Fun fact, one of Norton's great grand kids was is in my A&P class. Wasn't really part of the Norton legacy, but still had some extremely cool swag.
 
Last edited:

Marc Bourget

Well-Known Member
Joined
Feb 28, 2011
Messages
409
Location
Stockton, California
Gosh, reading this thread in consideration of the years of mentoring received from John Thorp, I'm reminded of Richard Bach's Jonathan Livingston Seagull's comment"

"First start with level flight"

Loads on ribs are more in compression than tension so you may be relying on the wrong strength of material property. That said, 6061 and 2024 are so close in the relevant property that 6061 is a reasonable substitute and easier for form.

The T-18 flap rib is less than 10" long and has some serious forming included in the design.

Good luck!
 

wktaylor

Well-Known Member
Joined
Sep 5, 2003
Messages
347
Location
Midwest USA
[U]Marc Bourget...[/U] How/when did You get to know John Thorp? Lucky guy.

Dang. John Thorp was amazing. When he spoke, quietly, everyone in the room turned to him and listened intently.

We lived in Costa Mesa, then Hemet, CA when dad was building his T18 in the late 1960s/early 1970s... so I was kinda young. Went to Thorp's workshop in Burbank-at-the-park regularly for many years. I got to go with dad on the weekend trips [my Aunt/Uncle lived in Burbank so we always stopped-in]. When I reached early college age his wisdom and career path finally became evident... especially when he talked about this street-race-cars and various professional engineering jobs. He had fun and was a real all-around pro-engineer! It was tough to see him attacked by Alzheimer's 1980s.

NOTE1.
When it came to ribs [wing and stabilizer] I sincerely DO NOT remember his option for 6061-T4 over 2024-T3 at 0.025... even though the forming was a whole lot easier... I remember him defaulting to 0.032... but maybe that was only for my dad's special 'wet-wings'. Maybe the had the 6061-T4 age-baked to -T62?
 

Marc Bourget

Well-Known Member
Joined
Feb 28, 2011
Messages
409
Location
Stockton, California
Wil,

Since I was present during a some of those conversations at Marmay Place, I can confirm (this is also in the T-18 Newsletters) that the .025 was increased to .032 because of adding fuel. Your Dad ended up with 2024 ribs from my project. They were made from 2024-O and heat treated at Aztec in Costa Mesa.

John initial diagnosis was Parkinson's but dementia may have developed after that.

I agree with your thoughts on his cars, the Model J, Dusenberg, the Cadillac engine in the '40 Ford, the Porsche 911 cooling modification that allowed deleting the fan and muffler, but still passed the standard sound test.

Do you remember Reader's Digest and the article series on "My Most Unforgettable Person"? Well, John was that for me.

Onward and upward
 

BBerson

Light Plane Philosopher
HBA Supporter
Joined
Dec 16, 2007
Messages
15,216
Location
Port Townsend WA
When it came to ribs [wing and stabilizer] I sincerely DO NOT remember his option for 6061-T4 over 2024-T3 at 0.025... even though the forming was a whole lot easier... I remember him defaulting to 0.032... but maybe that was only for my dad's special 'wet-wings'. Maybe the had the 6061-T4 age-baked to -T62?
Post 29
 

wktaylor

Well-Known Member
Joined
Sep 5, 2003
Messages
347
Location
Midwest USA
Marc... Wow... I never knew.

During those years [mid-late 1960s into the early 1970s] I was kinda young [mid-to-late teens] and didn't appreciate the diverse community of T18 builders in SoCal... I only remember John Thorp vividly and Von Parker.

NOTE1. Starting in 1979 I was fortunate to work with Von at Piper Aerostar Santa Maria CA for ~2-years... got to know and appreciate him at the same level as JT... but as an aviation metal craftsman... especially tooling and complex sheet metal fabrication... and he was a true and honorable gentleman. What a complimentary/special team these two men made!

NOTE2. Referring to MMPDS-15 [Replace MIL-HDBK-5] for mechanical allowables for 2024-T3 clad sheet and 2024-T42 clad sheet [both 0.010-to-0.062 thick] and 6061-T4/-T42 and -T6/-T62 bare sheet [0.010-to-0.249 thick]. The strength/toughness rankings are pretty unambiguous: 2024-T3 clad sheet is superior to 2024-T42 HT clad sheet with is superior to 6061-T6/-T62 bare sheet which is substantially superior to -T4/-T42 bare sheet. I've tried looking at various perspectives... especially ease of fabrication... which makes 6061-T4/-T42 the winner... but NOT the obvious choice for optimum aircraft structure: strongest, toughest for the least [minimum] weight.

OH WELL... human memory [early-on] is a poor recording device.... seems to get better with age in the important aspects.
 

Marc Bourget

Well-Known Member
Joined
Feb 28, 2011
Messages
409
Location
Stockton, California
Will,

Don Pridham was always very complimentary of you. Confirmed for me from my reading of your efforts with Eng-Tips forum. I've quoted you often to others.

Memory is a fickle thing. Recall me delivering the wing parts in my purple Chevy Van?

I can remember target shooting with Don Pridham. First time I shot a .45 ACP. First shot, dead on, hit 18" to the right, so I moved the aim point to the left and the next round hit about 24" to the right of the target. Don laughed at my frustration.

Did your Dad assign you the task of making sure your neighbor didn't throw any more motorcycle spark plugs across the fence onto the runway? That was the ugliest leading edge ding I ever saw in a propeller !!!

Memories, like the shadows of my mind!
 

wktaylor

Well-Known Member
Joined
Sep 5, 2003
Messages
347
Location
Midwest USA
Marc... Thanks again for Your help in the early 1970s... Dad appreciated it.

Don Pridham was actually my high school shop teacher [Estancia, Costa Mesa CA]. He really understood how to teach and motivate kids of all kinds/walks-of-life... his classes were tough, but fun. Don sure loved aircraft... and took a powerful interest in Dad's T18 project. He helped A LOT to get N455DT to 'first flight' [from our Hemet dirt airfield]. I think he even flew chase in his Mooney. He certainly helped in subsequent maintenance, painting, mods, 'crew chief duties', etc for many of dads NAA/FAI record flights. I called him in 2016 after dad 'passed' [Dec 2015]... that was hard... Don sounded tired.

It's always amazing how... after honest reflection... I find that many wonderful people have allowed me [us] to 'stand on their shoulders' to become who I am [we are]... and how I now have that duty to help others stand taller/higher/smarter. I am the gray haired guy I used to go-to for help. 'Pay-back' is a serious/wonderful experience. DANG.

For grins...
Dad was a fighter pilot, always, first and foremost in life. Even with us [family]. Here is how fighter pilots of all sizes, shapes, shades and personalities actually see themselves...
Fighter-Pilot self-portrait~A-37Org~July2018.jpg
 

wktaylor

Well-Known Member
Joined
Sep 5, 2003
Messages
347
Location
Midwest USA
Marc... Dohhhh… Sorry for miss-spelling Parker's first name... NOT Von Parker... actually-> Vaughn Parker. DANG.
 

Marc Bourget

Well-Known Member
Joined
Feb 28, 2011
Messages
409
Location
Stockton, California
Hey, Wil, Let he who is without dyslexia cast the first dispersion! :^)

Vaughn was pretty a authoritarian guy, but I don't think he would have minded unless he had previously spelled his name to you personally!

Onward and upward
 
Top