Bigger Bearhawk, a.k.a. "Expedition"

[Chris In Milwaukee]

Hi all,

I had discussed this project with jaredyates earlier, and up to now have been hesitant to bring it up with this group. After weighing the pros and cons of doing so, given the sensitivity of the topic of modifying the trusty Bearhawk airframe, it was deemed that it would not be inappropriate in this forum given the passion we all share for the Bearhawk. So with that in mind, and because I made mention of this in an earlier thread, I'd like to announce "Project Expedition".

This plane is an adaptation of the Bearhawk that meets my "wants" in an aircraft of the type. It is not endorsed by "The Bob" in any way, but he and I had a long discussion about it at #OSH15, and he encouraged me to use his ideas and made suggestions of how he would improve it based on his experiences with the Bearhawk design. He said there is nothing as satisfying as designing, building, and flying your own aircraft, and was very supportive of this project. So here I go!

The aircraft is essentially 15% larger than the original Bearhawk 4-place in every dimension, and adapts the Patrol (2-place) Riblett GA30-413.5 airfoil to the 4-place airframe (per Bob's recommendation).

Mission:

• Utility Plane
• Taildragger
• 3500 pounds targeted gross weight
• Metal Wing (38 feet in span, 210 ft^2 area)
• Rag and Tube Fuselage
• 4-6 places capable (but mainly 4 plus "stuff")
• Wide body and comfortable (48+ inches in the front seats)
• Rigged for 8.5+ tires, skis, floats
• 260-300+hp engine

I was originally targeting the Jake 275 and the C-195 FWF as the engine of choice for this design. But given the "short" posture of the cabin compared to a C-195 and similar, I wasn't terribly satisfied with the potential loss of visibility over the nose. The M-14P is a better choice, as it's 10 inches smaller in diameter, 360hp, and it can be configured to minimize loss of visibility. Battson had described the Bearhawk's visibility in great detail in past posts. If all else fails, the trusty 260-300hp Lyc (I)O-540 from a Cherokee Six/Lance/Saratoga will be the answer.

It's not as easy as "just making it 15% bigger", of course. The entire structure is being reanalyzed (fuselage, wings, gear) and updated as appropriate. With the aid of some good math, a mechanical engineer, and our good friends Bruhn, Peery, Raymer, Niu, and others, this is an exciting project that will bring my dream plane to fruition.

The wings thread you have seen in the Patrol forum is the construction of the wings for this plane. The wing I'll be building: 2015-12-05_19-21-42.jpg

As described previously,

• Riblett GA30-413.5 airfoil
• 75 inches chord
• Overall 38 feet in span
• 210 square feet wing area
• Integral tanks hold ~80 gallons total (the usual strap-in aluminum tank, extended one bay)

One other difference you'll notice about the one above that makes it a bit different from the Patrol wing is the spacer between the wing root and where the flap begins. That's there because the Patrol is slab-sided, but the 4-place airframe bows out there a bit. That keeps the flap from touching the side of the aircraft--just like the 4-place NACA wing does. Otherwise, for all intents and purposes, it's a Patrol wing, albeit two feet longer and a 10 inches greater in chord.

So that's the cat, and it's out of the bag! I'm happy to share my progress with you as the project progresses. Because it's certainly Bearhawk inspired, I believe it can live peacefully among its smaller (but no-less capable) siblings. However if anyone opposes its presence, I'm happy to let this be the last post, and you can follow its progress on Homebuilt Airplanes.

Rest assured that I love the Bearhawk, and it will always be in my heart!

Best regards,
Chris

[LukeS]

Ambitious! Good luck, and if you start to build it, can I come see! It's a short drive from Monroe to Marshfield.

[Chris In Milwaukee]

It's already begun, sir! Please feel free to stop in! Wings are in work now.

[patrickh99]

Sounds like a great future airplane. I would love to stop by sometime to see it as well, maybe once I get my BH flying. You are not too far the the Chicago 'burbs.
Please keep the updates coming here.

Maybe you can call it a 'BearEagle'

[Chris In Milwaukee]

It's going to be a long-term project, like all scratch-build project. You're welcome any time!

[whee]

Very cool Chris! Good for you building the plane the way you want it. Sounds Sherpa ish.

[Chewie]

I'm impressed! Did Bob have any thoughts or advice on testing?

[marcusofcotton]

After talking with you at OSH about your interest in the Howard and C195, I was very surprised to see you jump into a Patrol project - now it makes sense!

[Chris In Milwaukee]

I was wondering who was going to notice that :-)

[Chris In Milwaukee]

Very cool Chris! Good for you building the plane the way you want it. Sounds Sherpa ish.

Sherpa is a super cool plane, but boy is it expensive! It's way larger and heavier than what I'm after, but I admit I have looked over every photo I could find of it to see how it was put together.

[Chris In Milwaukee]

I'm impressed! Did Bob have any thoughts or advice on testing?

Structural testing or flight testing? Structural testing will be done primarily through computation at the moment, but I will likely subject one of the wings to physical load testing to make sure it meets the specs I'm after. Bob suggested I look at the Patrol plans to see how he did things a bit differently with the wings. Things he learned about building the 4-place were incorporated into the Patrol, he tells me. Interestingly, much of what we discussed was recently published in the Bearhawk Magazine that Mark Goldberg produces. If you haven't seen that publication, I hope you're able to secure a copy from Mark. It's amazing!

The fuselage has a couple of spots I'm concentrating on, based on experiences I've learned from a few others. Landing gear will receive a bit of attention as well.

As far as flight testing, Bob didn't offer any advice there. Honestly, however, I have a long road ahead of me, as every scratch builder does. We have a lot of amazing talent in this group, and a lot of "been there, done that" experience. jaredyates has put together a wonderful test program for his airplane, and I hope to be able to tap into his brain when the time comes (should he open the door). In that time frame, I also hope to improve my own tailwheel experiences so that I am better able to "feel" what's going on around me. I started flying a C-140 this past summer, and I hope to be able to move up to larger, more powerful equipment as the years progress, helping me prepare for the moment that this one flies for the first time. Some Stearman time would certainly be welcomed!

[Chris In Milwaukee]

After talking with you at OSH about your interest in the Howard and C195, I was very surprised to see you jump into a Patrol project - now it makes sense!

It will be about the same dimensions as a C-195 or Howard, both inside and out, except that the fuselage isn't as tall. But I expect it to be roomy and quite comfortable. It will also be in the same weight class as the C-195. The Howard is a much heavier airplane (by about 1000 pounds), but no less desirable!

[lsa140]

I'm glad you decided to share your project on the forum, and will enjoy seeing it come together.

[tailwind]

We miss everything about our 195 except the engine. In my opinion it is not the best short field back country choice. It will be interesting to watch your project progress.

[Chris In Milwaukee]

Thanks for that bit of info. I wondered if it would be a reasonable choice. Your experience helps to validate that.

[mswain]

Chris, Thanks for sharing your project. I look forward to seeing your progress.

[DRLPatrol]

I'm glad you decided to share your project on the forum........

I second that.

Doug

[Yadama]

Post some photos Chris, keen to see what the wings look like..