What do you guys think about the possibility to get a gross weight increase STC based on what is already approved per the TCDS? It seems obvious, to me, that the wood spar wing is structurally capable to handle the increasesd weight as it is already approved to be operated at 1800 lbs. when EDO 2000 floats are installed. On the same note there are no other changes made to the fuselage/ landing gear when the ACA wings and struts are installed allowing a 1800 lbs gross weight. What do you guys think? Has anyone every gone thru the STC process?
7GCBC Gross Weight Increase
- Thread starter deere_345
- Start date
Floats used to be considered lifting bodies. Thus, they used to give a free 5% in CAR 4a. That was before Part 23 came into play.
I am not sure how Edo got 1800 over 1732 (like the PKs).
As a DER, I'll tell you its not cheap or easy or fast. Going to need a ground up load analysis done (to determine loads); then you can get a load test done (basically plan to buy a complete and new wing). If the wing is rigid enough you might slip through flutter requirements (good luck with that one). The steal connections should be okay for fatigue, but you'll need a fatigue boxed DER to tell you that. Since its your STC, you will likely have to run the full flight test for performance to complete your flight manual under the newer rules. Noise test rules have changed too; so you'll have to redo that too after you have your documented performance. I would guess $40-90K and about 18-24 months.
Sounds like I am trying to poop on your party, but welcome to my world.
I am not sure how Edo got 1800 over 1732 (like the PKs).
As a DER, I'll tell you its not cheap or easy or fast. Going to need a ground up load analysis done (to determine loads); then you can get a load test done (basically plan to buy a complete and new wing). If the wing is rigid enough you might slip through flutter requirements (good luck with that one). The steal connections should be okay for fatigue, but you'll need a fatigue boxed DER to tell you that. Since its your STC, you will likely have to run the full flight test for performance to complete your flight manual under the newer rules. Noise test rules have changed too; so you'll have to redo that too after you have your documented performance. I would guess $40-90K and about 18-24 months.
Sounds like I am trying to poop on your party, but welcome to my world.
Ok, so a gross weight increase is not feasible. On the other hand spending 20K on ACA wings is not a wise investment on an aircraft that is only worth 40K. I guess the only other way is to increase the useful load by decreasing the empty weight. The first place that I need to start is with a diet, I know that loosing a few LBS. myself would help. As for the aircraft, what kind of diet should I put it on? A few items that come to mind are:
1) Light weight starter
2) Light weight alternator ( Is one approved for the 7GCBC?)
3) Moving the battery to the firewall and using a motocycle battery, as one member has suggested/done. (What are the chances of getting a FSDO to field approve this other than in Alaska?)
4) Remove upholstery from the interior.
5) Use a light weight covering system when the aircraft is recovered. (What system is the lightest? I've only used Poly Fiber.)
6) Remove uneeded insturments ( Leave only the FAR/VFR required insturments)
Any other ideas that you guys have to lighten up a 7GCBC. Just trying to make it a true two place aircraft and be able to take a few gallons of fuel along, at the same time being legal.
Thanks
1) Light weight starter
2) Light weight alternator ( Is one approved for the 7GCBC?)
3) Moving the battery to the firewall and using a motocycle battery, as one member has suggested/done. (What are the chances of getting a FSDO to field approve this other than in Alaska?)
4) Remove upholstery from the interior.
5) Use a light weight covering system when the aircraft is recovered. (What system is the lightest? I've only used Poly Fiber.)
6) Remove uneeded insturments ( Leave only the FAR/VFR required insturments)
Any other ideas that you guys have to lighten up a 7GCBC. Just trying to make it a true two place aircraft and be able to take a few gallons of fuel along, at the same time being legal.
Thanks
There is a light weight aircraft battery approved for the 7GCBC on the tech data.
Enersys SBS J16 is the model.
I googled this up: http://www.odysseybatteries.com/battery/sbsj16.htm
For use in the rear mounted battery, you basically have these wood block spacers. If you still have the rubber box; I can't be sure how well that would work.
Enersys SBS J16 is the model.
I googled this up: http://www.odysseybatteries.com/battery/sbsj16.htm
For use in the rear mounted battery, you basically have these wood block spacers. If you still have the rubber box; I can't be sure how well that would work.
Thanks for the reply, Jerry. What do you mean by the Enersys SBS J16 is approved on the tech data? Do you mean the type cert. data sheet? I looked at the TCDS and didn't see the battery listed. I also looked at Odyssey batteries website, they are showing the battery is approved on the PA18/PA19, but no mention of the 7 series aircraft. Can you give me more details, such as, can the battery be mounted on the firewall? Does ACA have an installation kit?
Thanks
Thanks
Its not on the TCDS yet
Its an optional battery listed on drawing 4-1782 (rear mounting, aluminum box, has wood spacer blocks, easy retro)
and 4-2024 for the firewall mounting (not easy retro, but posible).
No kit, but could parts could be gathered. Second one requires some fuselage welding flush with the firewall, so its not easy to get in there. Also, you'd be rewiring the airplane, which also cant be fun while its covered. But then, anything is posible with money.
Its an optional battery listed on drawing 4-1782 (rear mounting, aluminum box, has wood spacer blocks, easy retro)
and 4-2024 for the firewall mounting (not easy retro, but posible).
No kit, but could parts could be gathered. Second one requires some fuselage welding flush with the firewall, so its not easy to get in there. Also, you'd be rewiring the airplane, which also cant be fun while its covered. But then, anything is posible with money.