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Making it Lighter...

bill.hutchison

Well Known Member
My RV6A is one of the heavier ones out there. I didn't build it, and it's a lovely little flying machine-as is, so I don't think I can really start drilling lightening holes in it. 180hp O360 and a CS Prop, slider canopy.

That means removing stuff. It's got pretty bog-standard instruments and radio stack (SL30, GNC250) and it's got some nice leather seats. I've been toying with the idea of going to a glass panel for IFR but somehow I think that might add weight instead of subtracting it.

Y'all got some ideas that I, as a newbie here, haven't thought of in terms of putting my RV6A on a diet?
 
Not sure what panel you've got in there now, but here's a datapoint for you. We recently got the Dynon HDX dual-screen STC in our 172, versus the original steam gauges, Century autopilot and King radios/GPS. The airplane weighed in 57 pounds lighter after the change. That old stuff is heavy.
 
Another data point. Installed dual G5s in a Cherokee 140, removing the vacuum system and associated equipment resulted in about 5.5 lbs useful load gain. Lots more old round gauges that weigh far more than an EFIS.
 
Swap to a Lithium battery and save at least 10 lbs straight up.

I went from a lithium to a SLA (because I couldn't get a quick replacement for my lithium) and there was a noticeable difference in the handling, particularly landing.
 
Hi Bill

Some ideas have already been mentioned. Here a couple more:

Panel I swopped my steam gages against a dual Garmin G5 + Navigator configuration. Fully redundant since each G5 can be swiftly switched to function as either ADI or HSI and each has a back-up battery. I have no other back-up instruments as such, not even a wishkey compass. Part of the kit, an iPad mini and an iPhone with up to date nav software on them.

Starter/alternator Lightweight versions of those are available. Care not to jeopardise an eventual tail heavy ship, though looking at your data, it shouldn't be a problem.

Lighting When I bought my ship it still had those heavy Wheelen power supplies. Installing LED lighting all round will help.

Interior You mention leather seats, guess heavy, but probably nice and comfy. Insulation, carpets, sound insulation material, all that stuff is heavy.
 
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Over the past two years my Rocket lost 59 pounds. The single biggest loss was swiping the original PC 925 battery for an EarthX 900. This alone accounted for 21 pounds between the battery and the associated changes to the mounting structure. The rest of the weight loss came from updating my original panel to a dual screen Garmin setup and swapping out the original lighting system with LEDs. During this process I got rid of a lot of excess wire weight by eliminating unnecessary runs and also optimizing the wire sizes. When I originally built the airplane I had upsized just about every wire. Don’t underestimate the amount of weight the internal wiring of your airplane adds.
 
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The lighter battery is an easy win, but if you can then move that lighter battery closer to the starter and reduce the length of the battery cable, it's a win/win. If you can then reduce the guage size of the cable (because it's shorter), that's a win/win/win. I didn't go Lipo on the Rocket, but I did move the starter battery out of the tailcone and way forward, and went smaller. I went from a PC925 and 15 feet of #00 cable to a PC525 and 3feet of #6 wire. Starts great and lost a LOT of weight.

Also agree with sizing wire properly. The guy who built mine apparently got a great deal on #14 wire, because the whole airplane was full of it - including the long runs out to the tips and tail for nav lights. I switched to LED and #22 wire.

Also look at dumping all the ducting and hardware for heated air and replace with an electrical plug and heated vests. The clothing is lighter than the hardware and you get to leave it in the closet for warm weather flying.
 
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+1 save weight and relationships

Also look at dumping all the ducting and hardware for heated air and replace with an electrical plug and heated vests. The clothing is lighter than the hardware and you get to leave it in the closet for warm weather flying.

After a lot of work trying to warm up the -9A for my cold-sensitive Ace Copilot, I discovered that better clothing was really the key to solving the problem. She LOVED the heated down vest I got her. I power the heated clothing with batteries to reduce wires in the cockpit and facilitate use of the stuff outside the aircraft.
 
I recently swapped a metal Hartzell BA prop for a composite Whirlwind three-blade 300 series and saved about 26 pounds on the RV-8. Our -6 tends towards being tail heavy already though, so that weight savings on the nose might not be a huge help in the CG department....
 
Maybe re-weigh the plane with known accurate scales before sending it Weight Watchers. Sometimes you get a surprise!
Always good to do a W&B & get a baseline before starting a course of mods.
 
....Sometimes you get a surprise!....

That's too true.

I sold a plane to a friend and bought its replacement. When I was able to borrow some calibrated aircraft scales, we weighed both. His came out 50 pounds under the expected weight and mine came out 50 pounds over.

Dave
 
Empty weight is 1116, but it’s an o360 with a Hartzell CS.

my -6A came in at 1115. I've got the same 0-360 and Hartzell CS prop plus full IFR avionics capability including autopilot.. I'm not sure with all that stuff how much lighter the plane could be. That prop and governor sure ain't light.

I've also got an old school six pack with vacuum system and when I had a vacuum pump failure I took everything associated with it (AH, DG, pump, filters, etc) out of the plane. I was surprised that the weight savings was only about 10lbs. I was going to put in some sort of efis but given my current flying mission and financial considerations I decided to put in another vacuum pump and reinstall all the stuff that goes with it. No regrets.
 
Empty weight is 1116, but it’s an o360 with a Hartzell CS.

You are not way out of line for a RV6A with 180HP CS Prop .... the previous suggestions
Battery
Starter
Alternator
Replace Mechanical Inst Panel with Glass

There is stuff you can't help easily. Heavy paint... seriously... some planes painted by hot rod painters will lay it on thick and heavy. Primed inside and out adds weight although again it can be done with with light coats and not add weight...

Upholstery... if you have deluxe interior with every surface padded and covered that adds weight, but also comfort and sound deading.

Keep in mind up to the 90's Mr. Van on his RV3, RV4 and RV6 demo planes featured fixed wood props and O320's as the base line... often day vfr... his prototypes were light. I have flown some very light RV's and they are a delight. However HP an CS prop has it's advantage.... but it comes at a cost of limited payload and less of a light feel... however even a higher weight RV's (within limits) it is still a delight to fly.
 
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