Aeroplane – June 2018

Los Angeles

Philadelphia

New York

Houston

Chicago

Los AngelesLos Angeles

Philadelphia

New YorkNew York

Houston

Philadelphia

New York

PhiladelphiaPhiladelphia

New York

Chicago

Fuselage Metal semi-monocoque
construction (some load carried by
the skin). No need for internal
bracing saves weight and clears
space for payload/passengers.
Streamlined design reduces drag
and exudes modernity

Wings Cantilever outer panels

joined to constant-chord centre

section with three main spars and

streamlined engine nacelles.

Structure is strong, aerodynamically

clean and relatively light

Landing gear

Retracts into nacelles,

reducing drag

Split flaps Safely lower

landing speed and distance

Propellers Constant

speed mechanism

automatically swivels

blades to optimum

angle for set rpm

NACA cowlings Direct cooling

airflow to hottest engine

components and reduce drag,

improving fuel efficiency

Engines Reliable and

efficient air-cooled radials

with enough surplus power

to drive auxiliary systems

Hydraulic system

Engine-driven

pumps supply

pressure to operate:

Wheel brakes

Wing flaps

Landing gear

Pump

Controls

Cowl flaps

Autopilot

Heat and ventilation system

Exhaust heat exchangers supply hot air

to cabin. Vents supply cool air

De-icing system Exhaust

air from engine vacuum

pumps inflates shoes on

wing and tailplane leading

edges to break up ice

How the DC-3 performed against

contemporary types

Production of the DC-3/C-47

and other variants dwarfed that

of other transport types in WW2

Service ceiling (m)

Cruising speed (km/h)

Passengers Seven

rows of seats carry

21 passengers in

relative comfort,

making the DC-3

economically viable

Sperry autopilot
Maintains heading
and pitch, relieving
pilot workload

The DC-3: a thoroughly modern airliner Performance compared Production

Ranges (km)

100 150 200 250 300 350

5000

6000

7000

8000

DC-3 and main variants

Total 16,079

L2D (Japanese licence-

built version) 487

Li-2 (Russian licence-

built version) 4,937

C-47 and other US-built

military variants

10,048

Ju 52 4,845

C-46 3,181

C-54 1,170

DC-3 607

2

3

1

5

4

Vacuum pump

De-icing shoes

Air supply

Cold Hot Conditioned

Heat exchanger

Mixer

Boeing 247

1,296

Trimotor

885

DH86

1,223

DC-3

2,400

1

(^23)
4
5
Boeing 247
10 passengers
Ford Trimotor
17 passengers
DH86 Express
10 passengers

DC-3

21 passengers

importantly, it exceeded the 247 on

cruising speed and, crucially, range.

Both the 247 and the DC-3

used semi-monocoque, all-

metal fuselage and wing designs,

the result of metallurgical

improvements and reliability in

mass production. When the DC-3

was fi rst built, metal fatigue was

not a known risk, and while the

design can today be regarded as

‘over-built’, it has categorically

proven more than adequate in this

respect. Structural failure is still

not a signifi cant concern, even

a good half-century beyond any

possible service life that could

originally have been envisaged.

Like the metal structure, the

continuous process of engine

refi nement by both Wright and

Pratt & Whitney gave the aircraft

levels of powerplant reliability,

durability and maintainability that

were rare for its day. Feathering

propellers were a technological

improvement that made engine-

out reliability viable. Numerous

other innovations, illustrated above,

combined to create an aircraft that

was not just an effective airliner,

but one safer than those that had

gone before, that was profi table and

attractive to fl y in as a passenger.

The new DC-3 was also able

to benefi t from having already

effectively been tested in service.

The sole DC-1 essentially acted

as a prototype for the family,

with the slightly longer DC-2

being a production version. In

the course of their use, problems

with landing gear collapses were

overcome, and yaw controllability

issues and limitations fi xed

with a revised vertical stabiliser.

Nevertheless, the DC-3’s airframe

and aerodynamic design remained

largely unmodifi ed from the fi rst

airframe onwards. They were used

as glider tugs and bombers; they

were put on fl oats, fl own as gliders,

and equipped with two (and three)

turbine engines, but the airframe

was right from the start.

While the DC-3 and DST

were successful in their own right,

the massive quantity of military

production in World War Two

meant the type became a widely

used and understood standard for

transport and passenger aircraft,

and benefi ted from a global

supporting infrastructure.

The technology that combined to make the DC-3 an unbeatable success

AEROPLANE JULY 2018 http://www.aeroplanemonthly.com 83

WORDS: JAMES KIGHTLY

ARTWORK: IAN BOTT

Today several hundred are

active and airworthy — reliable

numbers are hard to pin down.

Some are still freighting, from

the Arctic to the Antarctic, while

others continue the long tradition

of the type’s testbed work,

including recent trials of MQ-9

Reaper UAV equipment — and

that’s before considering those

fl own purely as historic aircraft.

Even in 2018, there is no real

end of DC-3 operations

in sight.

One of the most signifi cant modifi cations was the C-47 amphibian

with wheeled fl oats. VIA JAMES KIGHTLY

82-83_AM_BriefingFile_July18_CC C.indd 83 04/06/2018 07:18