Ideas for weight reduction?

[Richard]

I'm looking to reduce some weight on my T model. Currently 3049 lbs empty weight. Would like to shed some fat. Any ideas?

[kevin]

Hi Richard,

Some ideas:

Carry less fuel (duh).

Newer, lighter, avionics and instrumentation is the easiest from every perspective but your wallet. Also, remove instruments and avionics that you don't use.

Remove seats you don't use.

If you are really serious, removing the carpeting, sidewalls, etc will shed some weight. Also, the seat material used by Cessna in the 60's and 70's can be replaced with better, lighter material today.

Stripping to metal and repainting sometimes nets a reduction in weight. Or don't paint it, just polish it, that is good for weight reduction.

Removing old, unused wiring (which I think you have already done, along with most or all of these suggestions) will reduce weight.

Depending on your mission, you can remove optional equipment list deice equipment, strobe lights. You can also replace old, heavy lighting equipment with new, lighter equipment.

You can dump the gear doors with the RT Aerospace mod. Or do your own mod (which would be quite a challenge) and remove actuators as well as the doors (but I think you get to redesign the powerpack/controller for the gear).

Remove the heater, wear a jacket. Who wants to fly where it is cold anyway?

Remove intercoolers if you have them.

Install Innodyne turbine engines when they become available. (OK, I am really reaching now, but I know you, you are probably already working on this ;-).

Remove copilot's control wheel and associated "stuff". Again, this is a "do your own mod" type of thing.

Depending on your mission, remove one alternator. Use a lighter battery if can find one.

Those are the things that come to mind immediately, although I can think of several more, all "your own mod" kind of things that I think you have alreay considered, like electronic ignition, lighter turbocharger, etc.

Hope some of that helps.

Kevin

[Richard]

Does greatly. I've wondered about small alternators. I've asked, but seems like there were mixed reviews.

Loose the intercoolers!!! I like them too much.

Heater... hmmm. That's a good one.

Props....

Nope, use all the seats. 5 kids.

Would fiberglass parts (cowling, skin...) make a big change? I know someone was working on carbon fiber cowling for the skymasters at one time. Owen Bell I think was working on this.

Titanium gear ....? Can you say e-x-p-e-n-s-i-v-e!!!

Just for giggles. I've never liked the idea of lighting off some AV fuel to get warm. Other day while up we did it... we turn the thing on. What do you know. Everyone survived. It's a new unit. Installed in 2000..... never used until then.

[hharney]

MY 3 BLADE MT'S GAINED ME 60 LBS.
NOT BAD

[Dave Underwood]

I got the original weight and balance and equip list and compared it to the current weight with "an expert".

We then measured the paint thickness in about 10 places and that explained the weight gain. When the plane was last painted, they did not do a complete strip.

Oh well, I too am fighting the weight gain that comes with age.

New radios, updated wiring and cleaning up years of accumulation under the floor gained most of it back.

Dave

[sunnysky]

Lightweight starters are now available.
Sunnysky

[Richard]

Let me start with an obvious statement. I love Skymasters. Second, I love to tinker. As a senior engineering project I'm looking at a few things:

• Composite control surfaces - duplicating ailerons, flaps, elevator, and rudders from lightweight carbon fiber or similar materials. (Carbon Fiber doesn't like aluminum too well)

• Composite and redesigned front cowling.

• Redesigned turbo mounting brackets.

• Composite valve covers. (stamped steel ones are heavy)

• One piece carbon fiber panel completely redesigned.

• Lighter weight 4 blade composite blades.

• Lighter modern turbo chargers.

• Lighter aluminum oxygen tanks, replacing the steel ones.

• Redesigned cast aluminum yoke with simplified version for right side.

• Lighter weight cable pulley system and motor for cowl flaps.

• Lightweight 28V replacement alternators.

• I also have the original drawings and parts for the roller rockers that were stc'd for the IO-360. Since CAD is my specialty, I'm considering redesigning them and producing them. Weight difference is minor, but valve guide longevity is greatly enhanced. They stopped production of these units because owner got burnt out (plus their wasn't enough orders to hire them out).

• Machined 7075 engine spacers instead of heavy steel (expansion characteristics will play a part and need to recalculate torque)

• If you want to get really radical (and money is no object) they are starting production on a stc’d titanium rods for this engine. $600-$900 a rod!!!!

• Lightweight ceramic or other material, lifters.

• Lightweight pushrods.

• Newer, stc’d lightweight 3 ring pistons. (almost in production)

• Redesigned flap control, removal of follow up cable system.

• Removal of fire breathing combustible heater. Use oil cooler as cabin heater.

• Titanium fasteners where possible.

Any other ideas that I could look at? Project will start in the summer. We will pick items on the list that offer the greatest reduction first. Project will be supervised by a PHD of aerospace engineering from NASA. (got lucky there). All projects will be submitted to DER for approval. We are hoping to get the plane on its own experimental ticket with the engineering that is going into it.

[Richard]

An idea of panel redesign.

[WebMaster]

I would caution you to consider the effects on weight and balance when you make significant changes to the weight of the aircraft, particulary when you change rudders and elevators. Another thing to consider when you go to change flight control surfaces is the possible effect of flutter on the changed mass of the units.
Twin Commanders have a new SB, SB235 that directly affects composite units. You might want to take a look at that. In addition, it calls for checking the mass of the units, since weights or paint may be applied that changes the overall weight of the unit, and that affects it's resistance to flutter.

[Richard]

Great feedback. This is true, mass will have to be taken into consideration. The downside as well is that weight reduction is minor with control surfaces anyways.

Each one of these ideas will be researched and documented. Most of these may not even be possible (within reason). All these things will be taken into consideration for the final ok in May. More than likely, due to time constraints, project choices will be limited to 1-2 projects in addition to the 4 bladed props.

We are currently modeling the original cowling system now. Looking at not only weight reduction, but drag reduction. One idea someone had was a plenum baffle for the front engine. This would allow some room for aerodynamic refinements in the cowling. Looks quite extensive though.

The main objective here is engineering a real world possible solution. From research, documentation, to implementation, then verification of research figures. All the stuff that makes a good engineer.

Don’t you have an engineering background Larry? Would you be interested in checking out some of our research when we get it done?

[WebMaster]

Industrial Engineer, haven't done any serious engineer work in a long time. Now do MIS stuff. No brainer. (it's all 1's and 0's, right Kevin??)
Oh, and on the moment thingie, if you have ever seen a Soloy Silver Eagle 210, they have a really ugly nose, sticks way out there. Now, part of the reason is that there is some plumbing at the rear of the engine that must be accomodated, but a significant portion of the reason is the change in the weight of the engine, and by sticking it way out there, they maintain the same CG on the airframe. Skymasters would have the same issues if we could ever get an Innodyn turbine installed.

Another thought, Richard, is that I remember reading that when they did the Chelton EFIS in a Citation (which was a 4 tube display, all the AHRS stuff, GPS, etc), they were able to reduce weight by 30 pounds. It seems to me the best increase in functionality and reduction in weight can be tackled at the panel, depending of course with what you are starting with. Fortunately, it is relatively near the CG.

Also, I'm a little suprised by your empty weight. Mine is (I think) 3081 (maybe 3051), with the cargo pod on. I'll check with my mechanic in the AM. It's lighter now, no rear engine at the moment

Mine is '69 337D, so same basic airframe as yours. Mine has really old radio stuff. I have dual KX-175, old audio panel, old loran, DME-64 (analog), Terra transponder and Terra ADF, with a King needle, King KT-76 second transponder, and RDR 160 radar, in a pod, with an green cathode tube display. Now, you would think that all that stuff on would make mine a lot heavier than yours, especially when you consider that the pod is 38 pounds all by itself. The radar display is not light, the pod is two men and a boy to lift. I seem to remember that you don't have de-ice boots, and I know that the plumbing and boots are not light. Also, with boots you get a substantially increased front vacuum pump. I have dual steel oxygen bottles, and all the plumbing for the 6 seats.

All in all, I would think there would be a huge difference in your empty weight and mine.

Are you going to load up the kids and come to Key West??

[Dave Underwood]

Best weight reduction idea I can offer on this New Year's eve is to leave wife and kids at home whenever you fly. Also leaves more room for beer or wine.

All the Very Best to you all and have a great New Year. Hope to see you all in Key West this spring.

Warm Regards - Dave Underwood

[SkyKing]

Richard,

Perhaps you should consider removing the front engine and accessories, changing the nose or extending the front structure, and either go to a larger rear engine or TP. Attached is a unit already converted, N84NX.

SkyKing