How many engines does the D-18/C-45 require?

Two — one per nacelle. Ziroli specifies 2x 38–50cc gas, both identical. Note the engines have an asymmetric offset: right engine 3° right 2° down, left engine 0° left 2° down. This is per the plan and important to get right during installation.

What is the engine offset on the D-18/C-45?

The engines have an asymmetric offset per the plan: right engine 3° right and 2° down; left engine 0° (no left) and 2° down. This is unusual compared to most twins and is important to build correctly — have your engines on hand before construction begins so you can verify the mounting angles.

Kit Cutters Completion Guide

Nick Ziroli Giant-Scale Short Kit

114" Beechcraft D-18 / C-45

The classic twin that defined light transport aviation for half a century — Beechcraft's most enduring design in giant scale.

Buy the Kit — $504.00 See Everything You Need

Wingspan

114 in

Length

80 in

Scale

1/5

Wing Area

1,950 sq in

Weight (AUW)

38–45 lb

Power

2× 38–50cc gas

Skill

Advanced

A Legend, Faithfully Cut

The Beechcraft Model 18 — known as the D-18 in civilian trim and the C-45 Expeditor in military service — is one of the most versatile and long-lived light transports ever built. First flown in 1937, it served the USAAF and US Navy through WWII in transport, navigation training, and bombardier training roles. Civilian D-18s continued flying passenger and cargo routes well into the 1970s, and a handful are still airworthy today. Nick Ziroli's 1/5 scale design captures that twin-radial, twin-tail silhouette with one detail worth noting upfront: the engines have an asymmetric thrust offset per the plan, which must be set correctly during installation.

Kit Cutters supplies the precision laser-cut wood. This guide covers the rest: the honest, model-specific list of what you'll buy to complete it, with real sources for every part.

114-inch Ziroli Beechcraft D-18 C-45 giant-scale RC transport in flight

What's in the Box?

Included in the Short Kit

Precision laser-cut wood parts only — ribs, formers, shaped parts
Three-piece wing rib set
Twin nacelle structure parts
Fuselage formers and shaped parts

⬇ Download Pack List (PDF)

Required Separately

Plans / building instructions (buy from Ziroli — copyright)
Spars, sheeting, and stick balsa
2× engines or motors (one per nacelle)
Cowls (one per nacelle), canopy and cones set
Landing gear, covering, electronics, servos, hardware

Everything Else You Need to Complete This Kit

Model-specific, with real sources. The D-18/C-45 has an asymmetric engine offset per plan — right engine 3° right 2° down, left engine 0° left 2° down. Have your engines on hand before building the nacelles.

Power System

The D-18/C-45 requires TWO matched engines — one per nacelle. Ziroli specifies 2× 38–50cc gas. Electric twins are a popular modern choice. Note the asymmetric engine offset specified on the plan.

GAS — designer spec

Engines (×2)	2× matched 38–50cc gas, one per nacelle. DA-35, DA-50R, or Zenoah 38. Must be identical.	Desert Aircraft
Engine offset	Asymmetric per plan: right engine 3° right, 2° down · left engine 0° left, 2° down. Have engines on hand before building nacelles.	Per plan
Fuel tanks (×2)	B&B Specialties or Dubro tank, one per nacelle, sized to engine	Ziroli
Props (×2)	Matched pair; size per engine and nacelle clearance	Builder preference

ELECTRIC — popular modern choice

Motors (×2)	2× matched outrunners, ~38–50cc class equivalent, one per nacelle. Must be identical.	Specialty RC retailer
ESCs (×2)	2× matched ESCs, one per motor. Program identically; drive from a single throttle channel via Y-harness.	Specialty RC retailer
Battery	6S–8S LiPo; balance battery position carefully for CG	Specialty RC retailer
Props (×2)	Matched pair; size to motor and nacelle clearance	Specialty RC retailer

Heads up — Both engines or ESCs must be tuned identically and driven from a single throttle input. Asymmetric thrust on a twin at low speed is a serious handling problem. Also note the plan's asymmetric engine offset angles — these must be replicated during nacelle construction.

Cowls

Designer sells

Beech D-18/C-45 fiberglass cowl (×2)

Multi-layer fiberglass. 8"L · 9"H front · 9.25"H rear · 9"W front · 9.25"W rear. Sold individually — you need two.

Ziroli

Sold individually — order two, one per nacelle.

Canopy & Cones

Designer sells

D-18/C-45 canopy and cones set

Vac-formed .040" PET-G canopy with frames molded in (12"L · 5.5"H · 11"W) + 2 sets of side windows + nose and tail cones in .050" white styrene. Complete set — one purchase covers all glazing and cones.

Ziroli

The D-18/C-45 canopy set is more comprehensive than most — it includes the canopy, two sets of side windows, and the nose and tail cones. One purchase covers all external transparent and semi-transparent fittings.

Landing Gear

Tricycle retracts

Main retracts — Geartech	Beech D18/C-45 Geartech replacement for Robart. CNC machined in Germany. Only retract option currently available.	Ziroli
Air kit	Robart 157VRX w/ tank & quick disconnects	Ziroli
Main wheels	Dubro rubber tire with aluminum hub — sized to suit the D-18/C-45 gear	Ziroli

The Geartech retract set is the only currently available option — the original Robart units are no longer in production. Robart's Scale D-18 Tuff Treads are model-specific wheels with machined aluminum hubs designed for the D-18/C-45.

Servos

6+ channels

Ailerons	2× 90+ oz-in, ball bearing (1" up / ½" down throw per plan)	Builder preference
Elevators	2× 90+ oz-in, ball bearing (1.25" up / .25" down per plan)	Builder preference
Rudders	2× 90+ oz-in, ball bearing — one per vertical tail (1.5" each direction per plan)	Builder preference
Flaps	2× 120+ oz-in, metal gear, ball bearing (45–50° down per plan)	Builder preference
Throttles	2× 50 oz-in (or Y-harness to single channel)	Builder preference
Gear	1× 50 oz-in	Builder preference

Note the twin rudders — the D-18/C-45's distinctive twin-tail design has a separate rudder servo for each vertical stabilizer. Plan for at least 7 channels (ailerons, elevators, twin rudders, flaps, throttle, gear).

Covering & Finishing

Airframe	1 oz fiberglass cloth + ZAP Z-poxy finishing resin (Ziroli's recommendation)	Chief Aircraft / specialty
Elevator & rudders	Iron-on cloth (Solartex)	Specialty RC retailer
Vinyl graphics — GTMO	US Navy "GTMO" (Guantanamo Bay) scheme	Ziroli

Scale Accessories

All from Ziroli

Dummy radial engines (×2)	Vacuum-formed dummy engines (scale radial look inside each cowl) — buy two	Ziroli
Pilot figure	WWII American USAAF or WWII US Navy Pacific — choose to match your scheme	Ziroli

Hardware

Wing tube set	1.25" × 30" and 7/8" × 30" aluminum wing tubes (two sizes required for D-18)	Ziroli
Control horns & linkages	Sized per plan; twin rudder setup requires careful routing	Specialty RC retailer
Hinges	Flat hinges or Robart hinge points	Robart / specialty

Detailed Specifications

Wingspan	114 in
Fuselage length	80 in
Scale	1/5 (2.4" = 1 ft)
Wing area	1,950 sq in
Weight (AUW)	38–45 lb
Wing loading	45–53 oz/sq ft
Power	2× 38–50cc gas (one per nacelle)
Engine offset	Right: 3° right, 2° down · Left: 0° left, 2° down (asymmetric — per plan)
Wing	Three-piece, with flaps (45–50° down)
Tail	Twin vertical tails — 2× rudder servos required
Gear	Tricycle retracts — main gear into nacelles
Cowl	8"L · 9"H front · 9.25"H rear · 9"W (need ×2)
Wing washout	2–3° at wing tip (jig built)
Min. radio channels	7+ (twin rudders = 2 channels)

Specs from Ziroli's published Beech D-18/C-45 plan. Note the asymmetric engine offset — right engine 3° right 2° down, left engine 0° left 2° down — which must be set during nacelle construction. The plan includes a separate instruction guide in addition to the plan sheets.

Nick Ziroli

Pioneer of giant-scale RC aviation, known for meticulous scale accuracy and structural integrity. Ziroli sells all model-specific accessories for the D-18/C-45 directly — cowls, the comprehensive canopy and cones set, model-specific Robart wheels, Geartech retracts, and the US Navy GTMO vinyl graphics scheme.

(631) 467-4765 · Plans must be purchased separately from Ziroli (copyright).

Get Ziroli Plans

The Build Journey

The D-18/C-45 is a substantial twin-engine build with a twin-tail requiring careful servo planning. The asymmetric engine offset is the most builder-specific detail — have your engines on hand before you build the nacelles. Treat these ranges as a rough sense of scope.

Where a short kit saves you time

Ziroli's plans include full-size templates for all parts. The D-18/C-45's three-piece wing, twin nacelle structures, and twin-tail make for a substantial parts list from raw stock. A Kit Cutters short kit removes the entire cutting stage.

Plans only (hand-cut)

You trace and cut every rib, former, and nacelle part from raw stock, then build.

more time, lower part cost

Short kit (laser-cut)

All parts arrive laser-cut and labeled. Skip straight to assembly.

less time, cleaner fit

The four stages of assembly

Stage 1: Fuselage Assembly

The D-18/C-45's distinctive rounded fuselage with its greenhouse cockpit.

Align and pin main fuselage formers
Build the cockpit area
Install nose gear retract bay
Fit canopy and cone mounting

Stage 2: Wing & Nacelle Assembly

Three-piece wing with twin nacelles — set the asymmetric engine offsets here.

Build the center wing section
Build port and starboard outer panels
Build both engine nacelles with correct offsets
Install main gear retract bays

Stage 3: Twin-Tail Assembly

The D-18/C-45's signature twin-tail — requires two rudder servos.

Build the horizontal stabilizer
Build elevator surfaces
Build port and starboard vertical fins
Build and install twin rudders

Stage 4: Systems & Final Assembly

Twin-engine installation, gear plumbing, and pre-flight.

Install both engines / motors with correct offsets
Fit cowls and canopy set
Plumb tricycle gear system
Match and sync both throttle inputs before first flight

Frequently Asked Questions

The short kit is laser-cut wood parts only. To complete it you'll also need the Ziroli plans, spars and sheeting, two matched engines or motors, cowls (one per nacelle), the canopy and cones set, landing gear, covering, and radio gear. The "Everything Else You Need" section above lists each item with a source.

Two — one per nacelle. Ziroli specifies 2x 38–50cc gas, both identical. Note the engines have an asymmetric offset: right engine 3° right and 2° down; left engine 0° left and 2° down. This is per the plan and important to replicate correctly during nacelle construction.

Yes — electric twins are a popular modern choice. Two matched outrunners in the 38–50cc class on 6S–8S LiPo, driven by matched ESCs from a single throttle channel via Y-harness. Use identical components and confirm both motors spool identically before the first flight.

The D-18 is the civilian Beechcraft Model 18, one of the most successful light transport aircraft ever built. The C-45 Expeditor is the military version, used by the USAAF and US Navy in WWII primarily for light transport, navigator training, and bombardier training. Both versions are covered by the Ziroli plan.

Plans are purchased separately from Nick Ziroli at ziroligiantscaleplans.com (copyrighted). Kit Cutters supplies the laser-cut wood; Ziroli supplies the plans and model-specific accessories.

The Beech D-18/C-45 canopy and cones set includes one vac-formed canopy (12" × 5.5" × 11") with frames molded in, two sets of side windows, and the nose and tail cones in .050" white styrene. It's a complete set — all the transparent and semi-transparent external fittings in one purchase.

The engines have an asymmetric offset per the plan: right engine 3° right and 2° down; left engine 0° (no left offset) and 2° down. This is unusual compared to most twins. Have your engines on hand before construction begins so you can verify the mounting angles during nacelle building.

114" wingspan, 80" length, 1,950 sq in of wing area at 1/5 scale. Typical all-up weight is 38–45 lb with a wing loading of 45–53 oz/sq ft. These figures come from Ziroli's published D-18/C-45 specification.

Ready to Build Your Beechcraft D-18 / C-45?

Buy the 114" D-18/C-45 Kit — $504.00

Prices and availability are subject to change — verify on each vendor's site before ordering. Kit Cutters supplies laser-cut wood parts only; plans and accessories are sold by their respective vendors.

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