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  • June Project of the Month (Click "x" at right to dismiss)
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Stearman project

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Harvey

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#1
I've been restoring this 1942 Stearman N2S-3 (the Navy's version of the venerable Army PT-17) since 1997. I brought it home in boxes and thought I'd have it flying within a couple of years. (Ha, Ha, Ha, Ha, Ha, Ha, Ha, Ha, Ha, Ha, Ha, Ha,gasp, cough, cough, cough...). What you see in the pictures is about 50% original and 50% replacement (most of which was handmade). My desire was to maintain its original appearance but with a few subtle upgrades. The main improvement is a Jacobs R755 275hp engine and Ham-Standard 2B20 constant speed prop (firewall forward from a 1951 Cessna 195) to replace the original 225hp Continental and wood prop. (She crop-dusted with a 600hp Pratt & Whitney after the war.) Other noteworthy improvements are a complete electrical system (lights, radios, electric starter), redline disc brakes, and smoke system (it IS a biplane after all!)

It should be finished "soon".

Harvey

P9130415a.JPG P2280424.JPG P9130417.JPG P1010014.JPG P1010017.JPG P1010018.JPG
 
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stevecmo

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#2
Wow Harvey, now that what I call a project! Very nice work. Thanks for sharing. We'll be looking for future updates.

Steve
 

Harvey

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#3
I was adding this picture of the Jacobs engine to the original post when my editing capabilities timed out.

P2280426a.JPG
 

Harvey

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#4
I'm especially proud of the electrical control box (4th picture down in the original post). Only the last version of the airplane included an electrical system and mine wasn't one. So, unless my wife was willing to learn how to handprop an aircraft engine (which she was most assuredly wasn't!!!), I needed to install an electric starter, a battery to power the starter, and an engine-mounted alternator to charge the battery. Since all of this was being added to the airplane, I might as well add lights. (Running out of daylight while still an hour from home field can be a major inconvenience). And what the heck, might as well use some of that new electricity to power a radio and transponder. (Do ya see how this stuff snowballs???)

Anyway, since the electrical system is new to this plane, I had to come up with a control box that was functional but looked like it belonged. I don't know why but most Stearman restorations that include a new electrical system have a half-assed switch and breaker panel that doesn't fit in with the otherwise-fine restoration job. I needed desperately to avoid that! The box that you see in the picture was entirely designed, fabricated, installed, and wired by me. I even added the Boeing logo in the bottom left corner to suggest authenticity (but for anyone who thinks I'm BS-ing them, I added "HLH 2003" in the bottom right corner; my initials and the year that I designed the box).

The small box (marked "Interphone") under the electrical box is the jack box for the pilot's headset and controls the plane's intercom system (also my design). There's a matching jack box in the front seat for the passenger's headset.

Similar to the electrical box, I installed the radios to the lower rear of the front seat (the rear seat is the pilot's seat) in a special-built case that mimics the originally installed Map Case. This new radio case is shown in the sixth picture of the original post.

Can you tell that I'm proud of how it's all turning out??? :))

Harvey
 
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twstoerzinger

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#5
Great looking restoration Harvey.
You are proving the old saying that airplane builds/rebuilds are always 90% complete and 50% to go.
What do you figure that "shaky Jake" will add to the cruise speed over to original 225?
Terry S.
 

xalky

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#6
Hell....I'd be proud too! What an awesome project, and a bit ambitious too, I might add. I can't wait to see this plane all buttoned up and flying.
 

FanMan

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#7
Nice!

I used to rent a Stearman back in the late 1970s for the princely sum of $50/hour wet (when a C-150 was $15). As a broke (is there any other kind?) college student I couldn't do it as often as I wanted. Yours looks a lot nicer than the beat up one I flew!

C6-Day10035.jpg

That's me in the blue shirt, with the suave instructor who was teaching me aerobatics. I was a lot skinnier back then...

C6-Day10035.jpg
 

Terry Werm

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#8
Very nice, Harvey. I have long been a fan of flight, and especially of biplanes, but have never had the time or money to pursue it in earnest. Keep up the great work and please be sure to continue to share your project with us!
 

Harvey

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#9
What do you figure that "shaky Jake" will add to the cruise speed over to original 225?
Terry S.
Terry,

I doubt that it'll add much to the top speed, if anything at all. (All the drag of two wings and all of the interbracing wires will be unchanged.) But the extra horsepower and constant speed prop will give a shorter take off run and better climb rate.

Harvey
 
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n3480h

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#10
Wow Harvey, that's beautiful work. Please keep us updated as progress continues.

Tom
 

astjp2

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#11
Those A-9 magneto switches are rare as hen's teeth. Looks good. I have a Taylorcraft that took me 3 years. I understand the time it takes to rebuild an airplane. As an IA, I have helped in several others too. Tim
 

Harvey

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#12
As an IA, I have helped in several others too. Tim
Yeah, I couldn't have tackled this job if I wasn't an IA myself. Paying someone else just to do the 337s would've driven me to bankruptcy. :banghead:

Harvey
 

David

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#13
Harvey that's a super nice project! You are a dedicated and persistent individual!!

If you ever fly into Angelina "International" let me know and I will come give it a look for sure!

David
 

woodchucker

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#15
where are the completed pics.. you never finished this post. Would love to see the plane out on the tarmac , or in the air, with engine and prop.
 

ewkearns

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#16
Awesome! You must have a stack of 337s the size of a New York City phonebook...... Flustered
 

Harvey

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#17
Woodchucker,

The plane isn't completed yet. I ran into a bureaucracy roadblock with the FAA. The problem was that the FAA had disapproved my engine conversion. To remind you, my Stearman was originally certificated with a 220hp engine and I was trying to install a 275hp engine. Unfortunately, the FAA's current guidance at the time (obviously written by government lawyers who don't know beans about aircraft) limits engine changes to +/- 10% of the originally-approved horsepower. Otherwise, one has to go through a full-blown STC (Supplemental Type Certificate) application process with engineering analysis', flight trials with a certified and FAA-approved test pilot, etc. I was told that this would cost between $50,000 and $100,000 with NO guarantee of approval at the end. (Now comes the silly part.) I argued that the Stearman was originally certificated with 220hp and 450hp engines and that my intended 275hp installation falls within the 220hp and 450hp approved limits. The FAA said no, the regs don't read that way. I could go +/- 220hp OR I could go +/- 450hp but anything in between is unapproved. In other words, the FAA would allow me to install an engine as small as 198hp (220-10%) or as large as 495hp (450+10%) but they're not sure if the plane it would safely fly with 275hp!!! And they weren't going to budge from their position!!! So I retreated to my corner to lick my wounds for awhile!

However, about a year ago, I discovered that someone else had recently jumped through the FAA's hoops and was awarded an STC to do exactly what I was trying to accomplish, and his STC was granted duplication approval by the feds! So I purchased a copy of his STC and I'm now good-to-go on my own conversion! I've been working on my Stearman for about three weeks now. It won't fly this year (I still have a long ways to go) but probably next year.

The absurdity of all this is that the FAA approved almost every engine known to man on the Stearman airframe back in its crop dusting days (mine dusted with a 600hp engine!) and the only time there was a problem was when someone hit a barn. The old-time feds knew this but all of the new feds have grown up with very little aviation common sense. As far as they know, a "round" engine is what hangs under an airliner's wing!

Harvey
 
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Harvey

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#18
Ewkearns,

You're not too far off!

Harvey
 

woodchucker

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#19
I am aware of how absurd the FAA can be. I think common sense is lacking everywhere in govt. I'm sorry to hear that you got caught in the bureaucratic nonsense.
 

ewkearns

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#20
Ewkearns,

You're not too far off!

Harvey
That A/C is old enough that you should be able to find some existing field approvals signed by a DAMI. If you find one, they carry the same weight as an STC good for ANY aircraft with the same TCDS or AS......
 

Harvey

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#21
Ewkearns,

What you say is true ONLY for those STCs that have been granted "duplication" approval. Most STCs nowadays are "One Time" STCs that apply ONLY to the aircraft it's written and approved for. (There's a LOT that's changed in Part 43 that you old-timers :grin: used to take for granted!)

I was lucky to recently find a duplicable STC that did exactly what I was trying to do!

Harvey
 

ewkearns

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#22
Ewkearns,

What you say is true ONLY for those STCs that have been granted "duplication" approval. Most STCs nowadays are "One Time" STCs that apply ONLY to the aircraft it's written and approved for. (There's a LOT that's changed in Part 43 that you old-timers :grin: used to take for granted!)

I was lucky to recently find a duplicable STC that did exactly what I was trying to do!

Harvey
No. If the paperwork was approved by a Designated Aircraft Maintenance Inspector(DAMI) (not an IA) it is good for all. DAMIs ceased to exist in 1956, but from around the end of WWII until then, their signature carried an ENORMOUS amount of weight. If you can find any of Bill O'Brien's writings on this, you'll have the full explanation. I think one of them was titled something about a "... 500 Pound Gorilla..." Your IA should know this....

I was teaching Part 43 up until 3 years ago, so I don't think I'm that out of touch. Don't lose sight of the fact that the certification basis for your aircraft is CAR Part 3, NOT FAR Part 23. Once you start "improving" the aircraft to Part 23 standards with Part 43 methods, you start down a slippery slope that allows the FAA to require any expensive and unwarranted alterations to airframe, powerplant, appliances, and anything else they can dream up.
 

FanMan

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#23
You guys are reminding me why I only own experimental aircraft...
 

Harvey

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#24
ewkearns,

I AM an IA. Being a CAR3-certified aircraft only allows me greater leeway in parts substitution. Engine changes are another story and don't fall under the protection of CAR3 anymore.

I met and talked with Bill O'Brien about a dozen or so years ago at an IA renewal Seminar in Houston. He politely listened to my dilemma and just shook his head and apologized for not being able to help me because the FAA's lawyers had his, and the FSDO inspector's hands tied. Engine changes above/below 10% of the original horsepower can no longer be approved at the FSDO level but only in the FAA's Ok-City engineering offices, and they won't even touch such a request without pre-approved DAR and DER evaluations already attached.

It was Bill who made the statement that I quoted earlier about "...every engine known to man was bolted to the Stearman airfarme...".

Aviation lost a good man when Bill passed away!

Harvey
 
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ewkearns

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#25
Yeah, I liked Bill a lot.... and met him fairly often, as the school I taught at hosted pilot and mechanic FAA events. I remember his distaste for the lawyers. It really got under his skin that they would never actually define the term "airworthy" because they (in their words) wanted "wiggle room." That fuzzy math concept is probably a lot of what you are running uphill against. I'll bet that the 10% foolishness is more "policy" or "interpretation" than law. But, I saw this coming, years ago, as some FSDOs began to just flatly refuse to do field approvals. Period. That created a frenzy of FSDO shopping until the old hands, who took field approvals in stride, retired. Now, the FAA newbies look at it as something Regional, Oklahoma City, DERs, and DARs need to worry with, not them. I let my IA go when I retired. Don't miss it a bit....
 

Harvey

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#26
Guys,

I've recently done some extensive repairs to my rudder frame (made up of welded 4130 steel tubing) and now I need to get the whole thing normalized (stress relieved). I've never had this done before. Can someone walk me through the process?

Thanks,

Harvey
 

astjp2

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#27
Heat with a torch until it is red then let it air cool...that is all I do when doing 4130 repairs. Did you Tig? if so did you preheat? That is common when tig welding to do also. Tim
 

astjp2

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#28
The term Airworthy is not speciffically defined in the FAR's, but it has been litigated to mean: Meets Type design and is in condition for safe flight
 

Manderioli

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#29
Love the project. I built a scale nitro powered model with my grandfather when I was a young boy. Partly because the Stearman was the first plane he learned to fly at the age of 19 during WWII. After training with the Stearman, he moved on to the SNJ-T6. Then he went into cargo type planes like the DC series and others.

I have always wanted to acquire a Stearman or SNJ but realize the cost to rebuild, maintain, and fly is out not economical right now.
 

ewkearns

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#30
Hmmmmm, I see some issues. If indeed, it is true that, "now I need to get the whole thing normalized," that implies heating the *entire* structure to (probably) 1600° F (check with the steel manufacturer). Heating the entire unsupported structure, for this process, is probably more of an exercise in inducing warpage than anything else. You may actually need a normalized and machined fixture to ensure that no warpage occurs sduring heat treatment. Or, you may consider straightening after the heat treatment, which kinda defeats the whole idea.. If the assembly is warped, after welding, and a close inspection can't relate given warpage to obviously induced welding stresses, you may end up with a real mess after normalizing.

It won't be much help, but you will probably need to cite and follow AC 43.13-1B CHG §4-1(c) and documents included by reference.
 
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