Looks great to me!  How many operating features will it have?

Thanks
Bill

Jim...Seeing your thread made me post 2 pictured from Dad's WW2 pics. These two were in New Guinea. I was rather amazed at how shiney the C-45 was, so figured it was probably pretty fresh off the boat from the USA. We have one parked on the ramp near where we fly stunt at Auburn Muni. I'm always amazed at how small the props are, relative to the cowls.  Steve

Jim...Seeing your thread made me post 2 pictured from Dad's WW2 pics. These two were in New Guinea. I was rather amazed at how shiney the C-45 was, so figured it was probably pretty fresh off the boat from the USA. We have one parked on the ramp near where we fly stunt at Auburn Muni. I'm always amazed at how small the props are, relative to the cowls.  Steve

Steve:

The engines were 9 cylinder Pratt & Whitneys, which dictated the diameter of the cowl. But, prop shaft to the body was just a little over four feet, which dictated an approximate eight foot diameter propellor. It does look small compared to what the engine could handle. At least they ran a variable pitch.

JHF

CB:

I only build for myself. I would be concerned about not doing good enough for others.

Not much to teach either that another 70 years of building model airplanes would not cover.

JHF

Jim,
That thing is looking just super great!!  I love the detailing start you have, can't wait to see it in person!!

Steve:

The engines were 9 cylinder Pratt & Whitneys, which dictated the diameter of the cowl. But, prop shaft to the body was just a little over four feet, which dictated an approximate eight foot diameter propellor. It does look small compared to what the engine could handle. At least they ran a variable pitch.

JHF

Hi guys,
The Twin Beech was designed with certain engine types and propeller parameters in mind. Most engines were in the 350 to 450 hp range and the propeller length was a known. All P&W R-985 engines are equipped with 8 foot props. Some early versions were variable pitch which required the pilot monitor the RPM and adjust it manually. Some were two position props, T/O and cruise.  Later WWII versions had constant speed props where the governor kept the rpm at a preselected value set by the pilot, and after WWII the most of the military and civilian airplanes were equipped with full-feathering, constant speed propellers.

The Model 18 design was built for these types of engines, Jacobs, Wrights and Pratt & Whitneys which were all about the same displacement (915, 975 and 985 ci respectively) and turn the same diameter props. There was no shortening of the blade diameter to fit it to the design, the designers drew up the airplane to fit the equipment available.

As for the modelers thinking that the blades are too short compared to the cowling, in racing the blades are shortened to allow RPM overspeed and keep the blade tips from supersonic speeds. Overspeeding allows the engine to make more BMEP, more pitch is used for greater speed per rpm and the diameter reduction allows this. That is where you find Wasp Jr. (P&W R-985) horsepower ratings of 575 hp. This is what is listed in many written accounts for the R-2 Gee Bee. The cowling was about the same diameter of the Staggerwing and Twin Beech, and the prop was several inches shorter than 8 feet.

The NACA cowlings on the Twin Beech and the Staggerwing, AT-6, etc, are very aerodynamic. Inside of the cowling are inter-cylinder and cylinder head baffles that direct air through the fins of the cylinders. This internal aerodynamic flow is as important as it's external shape and the size. The speed ring is very close in diameter of the engine itself for smallest frontal area, and is kept from moving forward by clamping them down around the cylinder mounted anchors. If these weren't in place the speed ring would "fly" forward into the prop. The forward thrust propulsion of the prop is mostly done by the outer half of the blade diameter and the shape of the blade shank at it's root is completely round, it only begins to form an airfoil about 14 inches up from the blades exit of the hub itself. Where the blades are an airfoiled shape, they are about inline with the airfoiled curve of the speed rings external shape. This actually accelerates the air across the speed rings external aerodynamic shape aiding in thrust.

It all works in harmony and provides an efficient aerodynamic package of, power section making hp to turn the prop to blow air across the external and internal shapes to provide thrust to propel the airplane as well as cool the cylinders. This as well, the oil, which has a cooler which intakes it's air between two of the cylinders inside of the cowling. I can assure all that the acceleration and climb performance of the Beech 18 at gross weight outperforms every modern twin engine piston twin. The reason being is that it has the biggest engines and props. Also it's high speed abilities are in line with the more modern piston twins, the airplane will cruise at 165 mph true at low power and 235 mph at high power, this providing the pilot with a huge envelope in which to suit the profile of any flight.

I love the subject of your build, Jim. I've 2000 plus hours in the Twin Beech and still fly one every once in a while, still love it's strength and power.

Chris...       

Hi Jim,
Just for your info, I flew two different E-18's with three bladed Hartzell propellers. It was an STC available for all versions of the Model 18. They were lighter, slightly smaller in diameter and very fast-feathering.
Chris...

Jim,

Your model is beautiful, you've done quite a job with it! Kudos!!

Can't wait for color!

Charles

Fabulous, Jim!
Chris...

 Very nice job, looks awesome. I wish I could do such a job.

Hi guys:

One more post of the C45J finally in color and with the flight options control box constructed.

Picture No. 1 is of the right quadrant with the color applied. It is sitting on its gear. Much to my chagrin, the landing gear motion has stiffened up a lot during construction. I have a lot of loosening up to do. Now I also have a lot of detail to add (radio antennae and wires, pilots, engines, etc.).

Picture No. 2 is the left rear.

Picture No. 3 is of the inside of the flight control box. The box is a project box that I bought from Radio Shack. The control system is Clancy Arnold's four channel system with four slide potentiometers. The top two are throttles, the center one is retracts and the bottom one is flaps. The assembly is powered with a nine volt battery that is sitting in place, but not mounted yet. There is an on/off switch at the top of the box. The wires leading to the control lines come out of the back of the box. This was necessary because the removable face plate faces the airplane. The whole assembly attaches to a Brodack control line handle.

Picture No. 4 is of the other side of the flight control box (the side that faces the pilot). I have yet to label the box.

This takes my C45J (Navy Beech D18) fairly well through the interesting stuff. The rest is just the boredom of details, so I think I am finished with this post. The model will be at the Nats, hope to see you all there.

Jim Fruit

Jim
The plane looks great and the control handle is neater inside than mine. 

I am Left Handed and fly with my left hand.  To fly your model I would have to hold the handle up side down and fly the entire flight "inverted".  LOL

Clancy

Clancy:No, you could fly left handed. You would just have to control "cross handed". LOLJHF

Clancy,

If you flew standing on your head, would that solve the problem?

Hey! Clancy, we have to talk!

I got flaps, throttle, and retracts, not to mention gear doors! Similar to Jim's setup. I gotta pick Jim's mind also.

What inspiration, Jim does great work!

Charles

Hi Jim,

Tat looks simply awesome.  Outstanding job!  I am really hoping to get to he NATS, maybe I will be able.

Tell us how she flies, OK?

Bill

Thanks, Clancy. Kind words for an unfinished airplane. Listen to what Clancy says guys, low wattage for this electronic work. I was frying slide potentiometers and did not even know it.

Jim Fruit

Hi guys,
The Twin Beech was designed with certain engine types and propeller parameters in mind. Most engines were in the 350 to 450 hp range and the propeller length was a known. All P&W R-985 engines are equipped with 8 foot props. Some early versions were variable pitch which required the pilot monitor the RPM and adjust it manually. Some were two position props, T/O and cruise.  Later WWII versions had constant speed props where the governor kept the rpm at a preselected value set by the pilot, and after WWII the most of the military and civilian airplanes were equipped with full-feathering, constant speed propellers.

The Model 18 design was built for these types of engines, Jacobs, Wrights and Pratt & Whitneys which were all about the same displacement (915, 975 and 985 ci respectively) and turn the same diameter props. There was no shortening of the blade diameter to fit it to the design, the designers drew up the airplane to fit the equipment available.

As for the modelers thinking that the blades are too short compared to the cowling, in racing the blades are shortened to allow RPM overspeed and keep the blade tips from supersonic speeds. Overspeeding allows the engine to make more BMEP, more pitch is used for greater speed per rpm and the diameter reduction allows this. That is where you find Wasp Jr. (P&W R-985) horsepower ratings of 575 hp. This is what is listed in many written accounts for the R-2 Gee Bee. The cowling was about the same diameter of the Staggerwing and Twin Beech, and the prop was several inches shorter than 8 feet.

The NACA cowlings on the Twin Beech and the Staggerwing, AT-6, etc, are very aerodynamic. Inside of the cowling are inter-cylinder and cylinder head baffles that direct air through the fins of the cylinders. This internal aerodynamic flow is as important as it's external shape and the size. The speed ring is very close in diameter of the engine itself for smallest frontal area, and is kept from moving forward by clamping them down around the cylinder mounted anchors. If these weren't in place the speed ring would "fly" forward into the prop. The forward thrust propulsion of the prop is mostly done by the outer half of the blade diameter and the shape of the blade shank at it's root is completely round, it only begins to form an airfoil about 14 inches up from the blades exit of the hub itself. Where the blades are an airfoiled shape, they are about inline with the airfoiled curve of the speed rings external shape. This actually accelerates the air across the speed rings external aerodynamic shape aiding in thrust.

It all works in harmony and provides an efficient aerodynamic package of, power section making hp to turn the prop to blow air across the external and internal shapes to provide thrust to propel the airplane as well as cool the cylinders. This as well, the oil, which has a cooler which intakes it's air between two of the cylinders inside of the cowling. I can assure all that the acceleration and climb performance of the Beech 18 at gross weight outperforms every modern twin engine piston twin. The reason being is that it has the biggest engines and props. Also it's high speed abilities are in line with the more modern piston twins, the airplane will cruise at 165 mph true at low power and 235 mph at high power, this providing the pilot with a huge envelope in which to suit the profile of any flight.

I love the subject of your build, Jim. I've 2000 plus hours in the Twin Beech and still fly one every once in a while, still love it's strength and power.

Chris...       

Interesting stuff.  This is the first time I heard that the props turn at engine RPM, rather than being geared-down like most others.  It must be the last that breed.  I can see that supersonic tip speed would be an issue.  But on the other hand, the engines are more inboard and the flying props are near-scale on a model.

The Beech 18 was called the "Colonel-killer" in the Air Force.  The theory being that it was used to get causal flying time by aging officers with sometimes bad results.

While in Wichita, I heard a rumor that the FAA tried to ground the fleet under what proved to be a bogus airworthiness directive.  The owners (who were no slouches) lawyered-up and proved that modern airplane makers had drummed the thing up to get rid of Beech 18's so they could sell new planes.  The planes owners prevailed.

Multi-engine tail-draggers are a piece of work on the ground.  I always felt that the double rudders on the Beech 18 would have given it something of an advantage over the single-rudder DC-3.  On the ground, the single rudder is no rudder at all.

Some people wonder why so many planes have double rudders.  They never taxied a Gooney Bird.  I think of the B-24 & B-25 as overkill: both double rudders and tricycle gears.

Guys:

Thanks for all of your comments on this project. It has been fun.

I attended the Scale Nats in Muncie this week end. The old C45J is no more. I pancaked the airplane during a flight, causing enough damage that I could not continue. I was so disgusted with myself that I left early. The model is not destroyed, but it would take major effort to repair and I don't have that kind of time. If I repaired it, I would still have a small winged, heavy (5.2 pounds/approx. 2 pounds per sq.ft.), complicated airplane. And I would still have an airplane that struggles with effortless flight. Besides, I don't fix airplanes, I just enjoy building them. The C45J did score second high static to John Brodak's great goodyear racer. Recently, I have been building more and more complicated airplanes, without much success. I watched most of the other guys flying their obviously lesser weight per sq. ft. airplanes and had somewhat of an epiphany. I believe I am going to go back to simpler, larger winged airplane and try to keep the weight down. To tell the truth, this is where my previous models were most successful. To add to that, my flying abilities have gone to h... in a handbasket due to lack of practice and advancing age. I think I will build a large enough model so that I don't need a glass-smooth surface to practice on. Larger wheels/larger wings/lesser weight per sq.ft., that should help.

As per usual, I have a tendency to ramble when a simple sentence would have sufficed. The C45J "est kaput". Thanks again for all of your comments.

Jim Fruit

Hi Jim,

I am really sorry to hear of the mishap with that awesome model.  I am not "into" scale (yet) but I believe you have it right about larger, lighter wing loading models being better.  My first foray into SCALE will be a Sterling kit Great Lakes Biplane.  I can build it fairly light and the real one doesn't have a lot of "working functions".  I am using a J.Roberts 3 line on this one and using only throttle.  I hope to go to Clancy's electronic system fairly soon.  Or maybe the 2.4gh if/when they are approved.

Good luck with the next one!
Bill

 Somehow I'd lost track of this one, it came out GREAT Jim! That orange/white NAVY scheme looks great on almost any model.

 I don't recognize it, what station does the lettering below the NAVY on the fuse represent?

 Ahh, this one...

Bill, there is nothing wrong with the J Roberts system.

Without saying anything against the J Roberts system, I did see a crash recently that would have been avoided with an electronics system.  The plane caught the lines in the weeds while taxiing, circled in, then went to half throttle and crashed.  With electronic control my friend would have been able to cut the throttle.

But even after watching that, I still think I'll go three-line if I'm doing a scale plane that's just elevator-throttle.

My first foray into stunt will be a Sterling kit Great Lakes Biplane.

Scale?

I notice that Brodaks has three-line bellcranks.  I'm told that they don't harmonize well with J. Roberts handles -- you either want to go all Brodaks or all J Roberts.

And Jim -- I'm sorry to hear about the plane.  It's hell to put so much work into one and have it die an early death.

Tim:

Thanks for the condolences. It is just a model however, no one was on board. We did receive quite a scare at the Nats. One of the guys that was flying one of the two huge B-17's that were there was injured in the crash of his plane. I was helping Rich Schaeffer with his plane in the other circle at the time, so I did not see it happen. I just heard it. I looked up to see the plane in about 2" pieces and he was laying on the pavement (and not moving). He did stay on the pavement until the EMT's showed up. Don't know exactly what happened, but it could have been serious.

As far as my flight went, I just believe lack of flying experience overcame me. I knew that the plane had a tendency to hunt, which would tell me that it was still tail heavy. I did not want to add any more nose weight because it was a tail dragger and I was afraid of nose over. I was so rattled at the time of the first flight that I now remember that I had not even extended the flaps. This lack of lift probably also contributed to the plane not wanting to stay up at a slower speed. That is the end of that. Until I can get my flying abilities back, I am going much more simple (with more practice).

JHF

Scale?

I notice that Brodaks has three-line bellcranks.  I'm told that they don't harmonize well with J. Roberts handles -- you either want to go all Brodaks or all J Roberts.

Thanks, Tim, I missed that even after going back an re reading the post.  I have both J.Roberts B/Cs and handles plus Brodak B/Cs and handle.  I have been told that the two systems do not work together very well so I will keep them separate.

I am stuck right now on what engine to use in the Great Lakes.  I was thinking an OS .40LA but it doesn't fit too well.  Might have to go to a smaller engine of some type.  All the parts are now built and waiting for assembly.  Gotta make a decision on the engine before I can go forward.

Bill

Chris:

Thanks for the kind words, I have always enjoyed your comments. I really like your choice of the YAK 18PM because of the tricycle retractable gear. That selection virtually eliminates the dreaded nose over and, of course, the retracts offer another flight option. Selection of the subject that naturally lends itself to the current scoring system is often difficult at best. In my opinion, I see the natural selection to be retracts, twin engines, flaps and tricycle gear. For this reason, my next subject was going to be a North American AJ-1 Savage. I had just about completed the plans for the AJ-1, but I am setting them aside for a while to do the simpler approach that I have previously mentioned. I need to get better at the second half of the hobby - flying. Thanks again.

JHF

I would like to offer some comments on the philosophy of selecting a subject for a scale model. First I believe that any model, simple or complex, can be competitive and building something that turns you on (provides the motivation for a complex project) is the top priority.

Beyond that I have some preferences. I don't like tricycle gear because of the potential to lose flight points on take off and landing. Many prototypes have a long nose gear (F7F, P-38, Ta-154). Built to scale length this can cause a model to "wheel barrow" on takeoff. In this situation the main gear lifts off before the nose wheel and the model runs along with only the nose wheel on the ground. Really bad deal on a full-size airplane and something I believe a flight judge ought to severly downgrade. Charlie Bauer's Ta-154 does this as did Lynn Greene's P-38 several years ago. On landing the long strut can also cause a problem with the angle of attack required to hold it off. Again full-size airplanes land main gear first. Most of the tricycle gear models I have watched will snap the nose gear to the pavement immediately after the mains touch rather than allowing the pilot to gradually and softly lower the nose wheel. Again I think a score downgrade would  be appropriate. The AJ-1, IIRC, does not sit with the exagerated angle of attack that the F7F and P-38 do, so maybe not an issue. A tail dragger provides the option of a two or three-point landing as fits the conditions. Many of the tricycle gear models I have seen just shorten the nose gear and ought to be downgraded in static.

Twins face an inherent weight penalty vs a single. I have built three for C/L competition, an XF-5-F and dH Hornet for profile and a Henschel 129 for FAI. The Skyrocket was somewhat successful, but mostly a learning experience as my first C/L scale model. Only real negative aspect was the thin scale airfoil. The others were reasonably successful. The Hornet was motivated by "love," the Henschel by practicality. Consider wing area vs total volume of fuselage and nacelles to try to keep the wing loading reasonable (1930's bombers good; post WWII cargo planes bad). The Henschel has simple geometry in the retracting gear. There is only one gear cover door and it does not sequence like the doors on a B-25. It has simple slotted flaps, one per wing. No complex fowler flaps. It carried bombs externally, no need for bomb bay doors.

In general I try to stay away from narrow landing gear--WWI or many bipes. They really tend to cause a C/L model to tip up on the left wing during ground handling maneuvers. That ought to cost flight points deduction.

I like my models big, big really does fly better. My better models are in the 700 to 800 square inch wing area range.

Chuck

Thanks guys for your comments, all interesting.

Chris: The AJ-1 holds a special interest for me. My parents bought me a Berkeley kit of one in the early 50's and it made a nice little scale model. I wanted to do a more legitimate rendition of the subject in their memory. I know what you mean about building light. Three years ago I built a Luscombe Phantom way too light (4 pounds on 660 square inches). In the first test flight, a slight Lake Michigan breeze vaulted the the model four feet into the air before I had any appreciable forward speed. It scared me so much that I set it back down immediately, causing landing gear damage. This one I will repair. I will have to cut back into the airplane to install a more substantial landing gear.

Chuck: I have seen what you are referring to in Charlie's Ta 154 and Lynn's P 38. Sometimes this can be helped by telescoping landing gear struts. It is interesting how you and I differ about tricycle gear as opposed to tail draggers. I believe that I have seen more nose overs with a tail dragger than I have seen issues with nose wheels. I believe that the best demonstration with either approach will because the pilot has practiced enough. This is where I have failed. I lost my flying buddy some time ago and it has been a good fifteen years since I have been able to get in any flying. Fortunately, electrics may change that.

Fred: I have already started with my design of my next,simpler model. It is going to be of the first rendition of the Rearwin Speedster with the Cirrus engine. All subsequent Speedsters used Menasco engines, so this subject will be very unique. The model will be totally adjustable (CG, leadout position and angle of attack), so I hope to get it to fly so that I am not afraid of it. It will be about 600 sq. in., and I am hoping for 5 to 6 pounds. I was planning to make it to FCM this year, but the Beech demise makes that impractical. The Beech could be repaired, but I hate fixing airplanes. Besides, after repairing it I still would have a less than ideal flying airplane. I would rather pursue a better flying model so that I can get some practice in. This is one of the reasons that I set the AJ-1 aside. On paper, it looked very similar to the Beech that did not succeed.

Jim Fruit

Luscombe Phanton, Rearwin Speedster, man I'm lovin' that stuff.
Chris...