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Likes: Hello, looking for any paperwork that may help with installation of a O-320 b2b on a J5A using the Stoddard 501 mount. Thanks
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Hello, looking for any paperwork that may help with installation of a O-320 b2b on a J5A using the Stoddard 501 mount. Thanks
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You’ll probably need a one-time stc. Last time I tried to do a field approval for a bigger engine (o-290 on an -11), I was told they won’t field approve anything over a 10% hp increase from stock. Anything more requires a one-time stc with flight testing, etc. I had a previous field approval with a rpm restriction to stay within the 10% hp increase, but they wouldn’t go for that. Ymmv…
I have a 337 somewhere I think. Let me go look.Originally Posted by Deepseat
Current policy is 110% of HP on the TCDS is the maximum for a field approval. Any more than that you have to go STC. Only option would be a pre October 1955 337 for the same installation.
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According to TC A-725 the largest engine would be a 0-235-B of 104 hp. So for a field approval your limit would be 114.4 hp. How would you approach a proposal to install the 0-320-B2B if it were derated to 114 hp by way of an rpm limitation which could be done by painting a red line on the tachometer? And how would you approach an additional limitation of the full 2700 rpm limited for one minute for take off? Isn't the 110% limitation based upon maximum continuous power? Thus a red line at 2700 rpm with a yellow arc down to the 114.4 hp rpm.
NX1PABC12D-4-85 liked this post
For context, this aircraft is Restricted category for banner towing operated to CAM-8. Currently has a O-290 D2 installed by STC. I’m trying to gather supporting documentation for an 8110. The O-320 installation has been done many times by field approval in the past but we all know that the field approval avenue really isn’t feasible any more. It’s essentially a one place airplane with the O-320. Not practical for normal category but works great for banner towing.
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Last edited by Deepseat; 04-26-2023 at 06:07 PM.
What Pete describes is exactly what I tried pitching when I tried it; even without the 2700 rpm part, they basically laughed at that idea even though it’s been done in the past.
Be cheaper to sell, and get a 160 Super Cub. Look for a light one.
As a DER doing 8110-3 major alterations I’m still limited to the 110% hp of the original TCDS power. In todays FAA to increase more than 10% you have to go STC.
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Does this also apply to restricted category airplanes?
NX1PA
Yes, all part of the AFS-300 Job Aid.
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skywagon8a thanked for this post
We installed a 180 in a J-5 banner plane. PM me. Wayne
Curious if the J-5 has wood spars or aluminum and if this would be a limiting factor in what you’re trying to do.
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Interesting that it’s thought to be a 1 place aircraft. My J-5 with PA-12 metal spar wings, PA-18 tail feathers, Stoddard mount, a fitted 0-320 B2B turns the scales at just over 1000lbs (1030 by memory) which gives a useful load of 470. It’s not a whole lot but it’s really good enough for the sort of fun flying I do with no real baggage.
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'There can be no liberty unless there is economic liberty".
Margaret Thatcher
Banner planes are frequently certified in Restricted category. As in modified on 337's and not STC. If certified under Part 3 or Part 8 it gives you more room to make mods. You take everything out of the plane that isn't functioning, like all upholstery etc. as weight is critical in (professional) banner towing. You aren't allowed passengers other than crew necessary to operate the aircraft for the special purpose - like a flight engineer on an old 727/747, hence single seat.
J-5's had wood spars. Some have had PA-12 wings installed as the airframes are nearly identical except for the size of a few tubes in the tail and near the firewall.
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