Editors note:
The Design Analysis article was originally
published in the July, 1944 issue, Volume 43, number
7, of Aviation magazine, published by McGraw­Hill
Publishing Company of New York, NY, USA.
The article on design refinements was originally
published in the July, 1945 issue, Volume 44, number
7, of Aviation magazine, published by McGraw­Hill
Publishing Company of New York, NY, USA.
This reconstruction is derived from microfilm. The
source is University Microfilms International,
Publication No. 364 (Aviation Week and Space
Technology), Reel No. 20 (January 1944 – December
1944) and Reel No. 21 (January 1945 – December
1945). The source was tightly­bound volumes, so that
there is some distortion of the images, especially near
the binding. It has not been practical to remove or
compensate for all the distortions, so none of the
illustrations in this reconstruction should be considered
reliable sources as to fine details of shape, proportion or
spatial relationship. The distortions are, in general,
small, and should not detract from a general
appreciation of arrangement and relationship.
The editor has attempted to represent the original
layout of the article, but there are some exceptions.
Limitations in the compositing tools cause a difference
in the text flow relative to the illustrations, compared to
the original, so that some changes have been made, to
compensate partially for that effect, and the tabular data
have been removed from the flow of text and brought
JL McClellan: P51 draft
together on a single page after the text, partly to make
them more accessible, and partly to sidestep problems
with page layout. The Design Analysis article was one in a series of
design analyses published in Aviation during the war
years, between May 1943 and November 1945. The
subjects were the Bell P­39 Airacobra, Curtis C­46
Commando, Fleetwing BT­12, Douglas A­20 Havoc,
Bristol Beaufighter (British), deHavilland Mosquito
(British), North American P­51 Mustang, Lockheed P­
38 Lightning, Focke­Wulf FW­190 (captured German),
Boeing B­17 Flying Fortress, North American B­25
Mitchell (specifically, the B­25H and B­25J models),
Mitsubishi “Zeke 32” Hamp (captured Japanese),
Consolidated Vultee B­24 Liberator, Fairchild C­82
Packet, and Messerschmitt Me­262 (captured German),
with one article dealing specifically with the Me­262's
Jumo 004 jet engine. Some of the analyses were
authored by senior members of the design teams at the
original manufacturers, while others were written by
staff editors of Aviation magazine.
The original articles were copyright to their
respective sources — the employers of the authors,
following general practice of the time.
This reconstruction is compilation copyright JL
McClellan, 2005.
Copyright 2005
p 1 of 32
DESIGN ANALYSIS NO. 7
The North American P-51 “Mustang”
By WILLIAM R. NELSON, West Coast Editor, “Aviation”
AVIATION'S graphic and thoroughly detailed engineering dissection of NAA's great fighter ― initially completed less than four
months after design inception, then fourfoldly hailed for lowaltitude cooperation, dive-bombing versatility, high-altitude
fighting speed, and long-range prowess.
P
RIOR TO WORLD WAR II it was
generally agreed among
aeronautical engineers and
military aviation authorities that it
was impracticable, if not
impossible, to design an airplane
capable of accomplishing more than
one type of military operation.
The record of North American's
P­51 Mustang fighter proves,
however, that it is both possible and
practical to create a single basic
design that can be modified, as
JL McClellan: P51 draft
military needs dictate, to keep
abreast of requirements. Among
single­seat, single engine fighters,
the Mustang has been credited as
the best low­altitude cooperational
craft, the most versatile dive
bomber, the fastest high­altitude
fighter, and the plane with the
greatest range.
All this has been achieved by a
plane whose basic design and most
of its original specifications
remained unchanged. New models
Copyright 2005
incorporated equipment and design
refinements but retained the
desirable advantages of preceding
versions.
The original Mustang, designed
and built for the British in less than
120 days, was intended for low and
medium altitude work. It was a
low­wing all­metal monoplane
powered by a 12­cyl., V­type
Allison engine of 1,150 hp., and it
was credited with close to 400 mph.
speed. RAF pilots said it was
highly maneuverable, had no
“cranky” characteristics; and, for
those early days, it was heavily
armed, with .50­cal. guns, one on
each side of the engine, and one .50
and two .30­cal. guns in each wing.
A gun camera was mounted in the
left wing.
p 2 of 32
Tabulated weights of
principal assemblies.
In its P­51 version for the
USAAF, the Mustang ­­ retaining
its high maneuverability with
somewhat increased speed – quickly
acquired fame as a “train buster” by
virtue of its two 20­mm. cannon in
each wing. Stripped of guns and
with a K­24 camera, it became a
widely used scouting and
reconnaissance plane.
The invasion of Sicily was
highlighted by reports of a
phenomenal new “secret” fighter­
dive bomber. This craft – which
combat men quickly dubbed the
Invader – was the A­36 version of
the Mustang. Retaining the
characteristics of its fighter and
level­bomber forbears, the A­36 was
equipped with dive brakes, two 500­
lb. bombs, and six 50­cal. machine
guns. Next revision retained the basic
design and uses of previous models,
but increased the speed with single­
stage, single­speed supercharger.
Auxiliary fuel tanks gave
considerably increased range.
Carried were wing bomb racks and
four 50­cal. guns, two in each wing,
maintaining striking effectiveness
against ground targets.
Packard-built Rolls-Royce “Merlin”
1,500 hp. engine used in “Mustang.
JL McClellan: P51 draft
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p 3 of 32
1. Radiator forward air scoop
2. Radiator forward air duct
3. Coolant radiator assembly
4 Oil radiator cover
5. Oil radiator
6. Oil cooler air inlet door
7. Spinner assembly
8. Engine mount front frame assembly
9. Engine mount assembly
10. Engine top cowling RH
11. Engine top cowling LH
12. Wing nose assembly
13. Wing panel RH
14. Wing tip RH
15. Aileron RH
16. Aileron trim tab
17. Windshield
18. Cockpit exit hatch
19. Cockpit exit hatch panel LH
20. Cockpit exit hatch panel RH
21. Radio access window RH
22. Radio access window LH
23. Oxygen access door
24. Oxygen rear door
25. Fillet
Another revision introduced the
1,500 hp. Packard­built, Rolls­
Royce Merlin engine with two­
speed two­stage supercharger. Also
added were removable bomb racks,
JL McClellan: P51 draft
26.
27.
28.
29.
30.
31.
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35.
36.
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38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
Fillet
Fillet
Elevator
Elevator trim tab
Vertical stabilizer
Vertical stabilizer tip
Rudder trim tab
Rudder
Elevator trim tab
Elevator
Horizontal stabilizer
Fillet
Tail wheel unit assembly
Tail wheel door LH
Tail wheel door RH
Radiator aft air scoop
Cover
Fuselage forward section
Coolant radiator access cover
Wing flap
Wing center rib
Wing­to­fuselage fillet
Wing­to­fuselage fillet
Gun bay door
Ammunition bay door
51.
52
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
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75.
depth charges, chemical tanks, and
auxiliary fuel tanks. Armament
was four 50­cal. guns. Speed and
ceiling both went up, whereupon
the Mustang was officially credited
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Bomb rack
Aileron trim tab LH
Aileron LH
Wing tip LH
Wing panel LH
Landing light
Landing light cover
Landing gear fairing
27” smooth contour wheel
Main landing gear shock strut
Wing­to­fuselage fairing
Wing nose assembly
Main landing gear access cover
Intermediate rear engine cowling
Wing center bulkhead
Exhaust stack fairing
Firewall assembly
Main gear fairing door
Fuel tank door
Fuel tank
Engine lower aft cowling
Engine lower intermediate cowling
Engine lower forward cowling
Engine intermediate cowling LH
Engine intermediate cowling RH
with the highest ceiling (“over
40,000 ft.”) and the greatest speed
(“over 425 mph.”) of any fighter in
existence. Soon the Mustang was
accompanying our heavy bombers
p 4 of 32
Three-view drawing of P-51 “Mustang” , with leading dimensions.
JL McClellan: P51 draft
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p 5 of 32
on their longest missions, since it
possessed the longest range of any
single­engine fighter in the war.
These achievements are, from an
engineering standpoint, remarkable
– because they were accomplished
by a plane that does not to any
extent embody previously unknown
engineering features, but rather
employed refinements of know
accepted practices.
Such performance is attained by
close attention to aerodynamic
cleanness of design, employing an
efficient, low­drag, laminar­flow
airfoil, a modification of an NACA
design. Second­degree curves,
calculated as mathematical
expressions, are employed for
external lines of fuselage, fillets,
ducting, and air scoop.
The air scoop is located below
and just aft of the center of the
fuselage, where it was found by
wind tunnel tests to create less drag,
while operating efficiently. Both oil
and coolant radiators are contained
in the air scoop.
An identifying feature of the
Mustang is the square wing and tail
surface tips, which tended to prevent
stalling and to maintain excellent
aileron control.
The fuselage, of semi­monocoque
construction, is divided into three
main sections: Engine mount, main,
and rear section, all joined with
bolts. With exception of cockpit
armor fore and aft, fuselage is
entirely Alclad and aluminum alloy
extrusions.
Engine mount is a box beam of
Alclad sheet and extruded parts,
designed so that the engine can be
removed as a unit. Mount is
attached at the firewall by four bolts.
Main fuselage section is
constructed around four 24ST
extruded longerons, intermediate
frames, Alclad covering, and
stringers. Stainless steel sheet and
armor plate firewall form forward
bulkhead. A turnover truss of 24ST
extrusions and formed sheet protect
the pilot. Upper longerons are
extruded H­sections which extend
aft from firewall, tapering to T­
section and terminating near rear
section. Lower longeron, H­beam
and U­channel, extends full length
of section.
Eight riveted and bolted
assemblies which comprise main
fuselage section may be removed
JL McClellan: P51 draft
Five main sections of P-51
Exploded drawing of engine
cowling and framework.
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p 6 of 32
Engine controls. (1) Engine throttle control;
(2) throttle stop release; (3) throttle name
plate; (4) adjustable throttle stop; (5) quadrant to bellcrank flexible control; (6), (11),
(12), (15), (16), (25) fairleads; (7) flexible
control; (8) propeller control bracket; (9)
propeller control bellcrank; (10) emergency
boost control handle; (13), (14), (17), &
(18) control rods to jackshaft; (19) carburetor air control; (20) flexible air control; (21)
air control support; (22) jackshaft, hot air
control; (23) hot air door actuating rod; (24)
air shut-off control rod; and (25) shut-off rod
support.
Exhaust system and vent lines. (1) Exhaust
shroud to keep heat from sparkplugs; (2)
gasket, with lockplate (3) and nut (4) which
hold jet exhaust stacks (5) in place in
fairing (6); (7) drain from mixture boost (8);
(9), (10), & (11) blast tubes for cooling
sparkplugs situated on exhaust side of
cylinders; and (12) & (13) parts forming
generator blast system for cooling
purposes.
Main air scoop,situated beneath fuselage, is fitted with adjustable discharge flaps or
scoops to regulate airflow through both oil and engine coolers.
JL McClellan: P51 draft
Copyright 2005
and replaced as units. They are:
Firewall, turn­over truss, upper
deck, left and right side panel
subassemblies, radio shelf, web
assembly, and lower section with air
scoop.
Comfort and safety are given
consideration in the design of the
cockpit seat, which accommodates
the seat­type parachute and has a
kapok back­cushion life preserver,
provisions for heating and cooling,
and protecting armor plate at the
firewall and seat.
The combination armor­plate
firewall protects the pilot from line
of level flight to approximately 20
deg. below it, also against fire from
the engine. Firewall is face­
hardened steel armor, except a
section at center of stainless steel to
provide room for oil tank. Aft
protection is provided by two plates
of face­hardened steel behind the
seat.
Protection and visibility are
afforded by windshield, rear
window, and cockpit enclosure.
Forward flat section of windshield is
bullet­proof, 5­ply laminated glass,
1­1/2 in. thick, slanted 31 deg. from
vertical, being the best compromise
p 7 of 32
Fuel system. (1) Fuel strainer; (2) Parker primer pump' (3) engine driven fuel
pump; (4) selector valve with handle; (5) booster pumps on tanks; (6) fuel
gages; Outer streamlined tanks, used for ferrying or for long distance flights,
are droppable via the bomb release. Primer, operated manually, draws fuel
from strainer and injects it directly into engine.
Engine mount. Detail A is Lord shear rubber bushing;
B, front Lord mounts; C, carburetor air inlet
JL McClellan: P51 draft
Copyright 2005
p 8 of 32
Engine coolant system. Here (1) is coolant header tank, vented at 2, which connects through pipe 3 to radiator 4,
returning liquid by pipe 5, to pump 6.
Supercharger cooler is supplied by 7 and
8. System is filled at plug 9.
Air ram scoop for carburetor. By
operating shutter at left and blast gate
at right, pilot can regulate both
temperature and pressure of air going
into carburetor. Detail (upper left)
shows construction of vibrationabsorbing connection to base of
carburetor.
JL McClellan: P51 draft
Copyright 2005
p 9 of 32
Oil system showing hopper tank at center with dilution solenoid above
and radiator at rear. Oil leaves engine by upper of two pipes (lower left),
going directly to radiator, thence to top of tank, through hopper in tank,
and back to engine oil pump through large pipe from bottom of tank.
Small pipe leading into deliver pipe at lower left is for oil dilution.
JL McClellan: P51 draft
Copyright 2005
p 10 of 32
Wing panel is built up on 19 pressed ribs and two spars of 24ST
Alclad. Insert shows proportion of wing surface taken up by flap
and aileron. Wing tip has single spar and pressed end. Details are
for visibility, protection, and
aerodynamic contouring. Side and
upper panels of windshield are of
3/16­in. safety plate and transparent
plastic. Windshield cowling extends
from lower forward end of glass to
firewall and down to upper
longeron.
Over instrument panel a shroud,
integral with windshield, extends aft
with a circular rubber extrusion to
JL McClellan: P51 draft
forgings. Detail A is front spar-to-fuselage bracket; B is pilot's footrest and seat bracket and C is rear spar-to-fuselage connecting
bracket. Others are aileron and flap hinge brackets.
protect pilot. This shroud supports
windshield defroster, optical gun
sight, and hand­holds, and it also
eliminates instrument glare in the
window glass.
Cockpit enclosure consists of
upper and side plastic panels, each
in two sections, forward one
forming a sliding window with
locking handle. Right upper panel
hinges upward; left panel hinges
Copyright 2005
downward against fuselage. Both
have locks controlled from inside
and outside. Hood is attached by
four hinges on upper longerons. An
emergency release permits enclosure
to be removed or jettisoned in
emergency.
Aft windows of molded Lucite fit
fuselage contour and are removable
for access to radio behind pilot. Aft
of radio, plywood bulkhead prevents
p 11 of 32
Flaps are made of 24ST with Alclad
skin. Stiffness is provided by 15
main ribs and 13 nose ribs.
draft and keeps objects from rolling
aft and fouling controls. Nut plates
at center of bulkhead secure oxygen
bottles.
The rear fuselage section consists
of two 24ST longerons, a shelf and
five formers of 24ST, three solid
bulkheads, and Alclad skin.
Wing is cantilever stressed­skin
design in two sections, bolted at
center. Each consists of main panel,
removable tip, aileron, and full
trailing­edge flap. Wing has angle
of incidence of approximately 1 deg.
at root and dihedral of 5 deg. along
25 percent chord line, to give
stability.
The 25 percent chord line is
perpendicular to longitudinal axis of
airplane. Wing area, including
ailerons, is 233.19 sq. ft., with span
of 36 ft. 5/16 in. and a taper ratio
of .499.
Main wing panel consists of a
main spar, rear spar, pressed ribs,
and extruded stringers covered with
alloy sheet. Space is provided at
inboard end for self­sealing fuel cell,
part of which is located in fuselage.
A gun bay is in each wing panel to
accommodate guns, ammunition
containers, and chutes. Main
landing gear retracts into wheel bay
in the inboard leading edge.
Main structural member of wing
is forward or main spar, of two
sections of of 24ST sheet spliced
together. Inboard spar section is
fabricated of .129­in. thick 24ST,
with angle flanges along both upper
and lower edges for spar caps. A .
25­in. thick 24ST bar is riveted to
inner side of upper cap between
stations 0 and 85.5.
Rear spar is formed of two sheets
of 24ST spliced at station 128.6.
Upper cap is reinforced by a .091
24SO angle between stations 0 and
92.5. Ribs and formers are
approximately 12.5 in. apart and are
of 24SO, heat­treated after forming
to 24ST. At leading edge, wing has
sweepback of 3 deg. 35 min. 32 sec.
Aspect ratio is 5.815.
Each aileron has two spars and
twelve flanged ribs covered with
Ailerons are built of 24ST with
plastic tab. A metal diaphragm
retains aerodynamic smoothness of
joint with wing.
JL McClellan: P51 draft
Copyright 2005
p 12 of 32
Main fuselage with firewall, front and rear wing attachment fittings, Fuselage wing fittings are forgings carrying bolts for attachment of
and airscoop underneath. Details A and B are forged fittings wings.
through which pass bolts holding engine mount and firewall.
24ST. The forward spar is U­
shaped 24ST Alclad, and ribs are
24SO hat­treated to 24ST. Trailing
edge is 24ST sheet reinforced with
aluminum supports and plastic ribs.
Three aileron hinge brackets bolted
to the forward spar provide bearing
attachment points.
Ailerons are dynamically and
statically balanced. Internal
aerodynamic balance is obtained by
a diaphragm attached to forward
edge of aileron and sealed to the rear
spar by fabric strip.
JL McClellan: P51 draft
Phenol­fiber trim tabs are
mounted in each aileron by three
hinge bearings. A metal horn tab
provides attachment for actuating
rod. Left tab, adjustable in flight,
is operated by a knob on control
pedestal. Angular travel, 10 deg.
up and 10 deg. down, is limited by
stops on cables.
Ailerons are conventionally
controlled by the stick, and to meet
variations in specifications they can
be connected for angular travel of
10, 12, or 15 deg.
Copyright 2005
Structure of the 24ST Alclad­
covered wing flaps is two Alclad
spars, 13 nose ribs of 24SO heat­
treated after forming to 24ST, 15
main ribs, and a series of rolled­
section stringers, all of 24ST. The
flap trailing edge is formed from a
single 24ST sheet reinforced with 27
tapered hat­section supports. The
flaps are hinged on three sealed ball
bearings, and are hydraulically
controlled by a lever selects and
holds any corresponding position of
the flaps.
p 13 of 32
Main fuselage is built on four extruded 24ST
longerons with heavy frames and a few light
stringers. Turnover truss is built of 24ST
extrusions and sheet for pilot protection. Web
assembly is shown at bottom
Stabilizer is full cantilever, no­
adjustable, with detachable tips, and
is fixed at a positive 2­deg. angle of
incidence relative to the longitudinal
axis of the airplane. Forward and aft
spars are of 24ST Alclad. Flanged
ribs are formed of 24SO Alclad
heat­treated to 23ST, as are six
extruded stringers. Dual stringers
are on the lower covering.
Stabilizer tips are of 52S, 1/2­H
stock on two ribs. Area is
approximately 28 sq. ft., and span is
13 ft. 2­1/8 in.
Elevator incorporates 18 flanged
ribs, front spar, trailing edge, and a
short intercostal beam, all 24ST
Alclad. Covering is fabric with
Alclad leading edge extending to
main spar, except for that portion cut
out for elevator hinge fitting. Right
and left elevators are
interchangeable, fastened to
stabilizer with five sealed ball
bearing hinges, and are statically
and dynamically balanced. Static
balance is by a 13­1/4­lb. lead
weight attached to outboard end of
leading edge. Total elevator area is
approximately 13 sq. ft., and angular
movement by the control stick is 30
deg. up and 20 deg. down. Each
JL McClellan: P51 draft
elevator has an adjustable trim tab
approximately 4­11/32 in. by 32­
1/16 in.
Fin is composed of front and rear
spars of 24ST Alclad and ribs
covered with 24ST Alclad sheet.
Tip is on two ribs, and skin is
stiffened spanwise by light rolled
stringers. Area of fin is 9.61 sq. ft.,
and it is set 1 deg. to the left of
center line of rear beam.
Rudder consists of spar, 20
flanged Alclad ribs, V trailing
edge, and a short beam in front of
trim tab, which is covered with
fabric, and 24ST sheet covers
leading edge back to main spar,
except cut­out for rudder hinge
fitting. The rudder is hinged to fin
with three sealed ball bearings and
is dynamically balanced by means
of 16.6­lb. lead at top. An
additional balance weight at
bottom of leading edge reduces
static unbalance. Area is 10.4 sq.
fr. and angular movement is 30
deg. each side of neutral.
Operation is by pedals through
cables.
Phenol­fiber trim tabs on
elevators and rudder are hinged by
three sealed needle bearings.
Copyright 2005
Rudder tab is controllable from
cockpit, and angular travel is 10 deg.
up and 25 deg. down, limited by
stops on cable.
Landing gear is three­point, with
two 27­in. main wheels and full­
swiveling, steerable 12.5 in. tail
wheel, hydraulically retractable.
Main wheels retract into wing wells
and tail wheel into fuselage, all fully
enclosed.
Except for hydraulic main gear
down­lock pin, landing gear locks
are actuated from the control handle
bellcrank. Cables from bellcrank
actuate tail gear up­latch and down­
lock pin. A push­pull rod from the
lower end of the control handle
works lock system in main wheel
bay.
Main landing gear magnesium
support casting is bolted to front
spar at the outboard end of the
wheel well. Hydraulic struts on the
front spar retract the gear inboard.
A spring­loaded, hydraulically
controlled pin locks main gear
down.
Tail gear is mounted on a
magnesium casting bolted to lower
longerons. Shock strut assembly
includes cylinder, piston, torque
p 14 of 32
Cockpit inclosure, with floating back cushion and armored
Heavily framed center glass (top left) is bullet proof.
seat back.
tube, and post housing which
supports axle. Gear is steered by
cables from rudder bellcrank.
Fairing doors are hinged at side, and
a link pulls them up as gear is
retracted. Tail wheel is unlocked
with stick in the forward position
during taxiing and parking.
Emergency lowering of landing
gear is accomplished by pushing
down control handle at left of seat,
also relieving hydraulic pressure in
retracting struts with emergency
knob in cockpit, which causes dear
to drop of its own weight. Pilot then
yaws plane until gears engage
downlocks.
Cylinder, connected to brake by
aluminum alloy tubing, furnishes
pressure for the Goodyear multiple
disk brake, via separate hydraulic
system controlled by pedals. This
pressure is relieved by a spring
when pedal is released. Parking
brake is controlled by depressing
brake pedals and pulling knob below
instrument panel. Pressure is
retained until released by depressing
both brake pedals.
Latest model of P­51 is powered
by a 12­cyl. Packard­built Rolls­
Royce 1,500 hp. V­1650 liquid­
cooled engine having an after­cooler
to reduce charge temperature.
Induction system employs a two­
speed, two­stage supercharger with
low­gear ratio of 6.391:1 and high­
gear ratio of 8.095:1. Pilot may
Fuselage rear frame, with diagram giving
positions of elevator and rudder control
frames and fin attachment forging.
JL McClellan: P51 draft
Copyright 2005
p 15 of 32
Left: Rudder is fabric-covered 24ST leading edge under fabric. Right: Two views of fin. This is built of 24ST Alclad with rolled
Plastic tab is carried on three hinges. Rudder-operating horn is a stringers and is covered with Alclad sheet.
forging (shown at bottom of rudder, both views)
Elevator is built of 24ST frame with fabric covering. Leading edge Stabilizer is full cantilever type with Alclad frame and covering.
is 24ST under fabric. Trim tab, made of plywood, is operated by Half-hard 52S is used for the tips, built on two ribs.
horn near center. Balance weights are concealed in stabilizer.
Elevator control is through 3-bolt coupling at inside end.
JL McClellan: P51 draft
Copyright 2005
p 16 of 32
P-51 Cockpit Layout
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Cockpit fluorescent light
Crash pad
Fluorescent light
Gun sight
Throttle
Compass
Clock
Suction gage
Manifold pressure gage
Remote contactor
Altimeter
Directional gyro
Flight indicator
JL McClellan: P51 draft
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
Tachometer
Oxygen flow blinker
Mixture control
Propeller control
Boost control
Landing gear indicator
Airspeed indicator
Bank­and­turn indicator
Rate­of­climb indicator
Coolant temperature indicator
Oil temperature and fuel and oil gage
Oxygen regulator
Enclosure for emergency release handle
Copyright 2005
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
Engine instruction plate
Control stick grip
Gun and bomb control panel
Parking brake control handle
Parking brake instructions plate
Engine primer
Oxygen pressure gage
Oxygen system warning lamp
Bomb control switch
Landing gear controls
Booster pump switch
Supercharger control
Supercharger warning light
Starter switch
Oil dilution switch
p 17 of 32
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
Ignition switch
Compass light control
Gun sight light control
Left hand fluorescent light control
Fuel valve control
Hydraulic pressure gage
Emergency fairing door control
Hydraulic hand pump
Airplane restriction plate (top)
Cockpit enclosure handle
Generator­disconnect switch
Battery­disconnect switch
Pitot heater switch
JL McClellan: P51 draft
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
Landing light switch
Position light switches
Ammeter
RH fluorescent light switch
Circuit­breaker switch
SCR­522 radio control box
Cockpit light
SCR­535 radio control box
Map case
(Restricted)
Right fuel tank gage
Hot air control
Pilot's relief tube
Sliding window lock handle (below)
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69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
Carburetor mixture control
Signal pistol discharge tube
Coolant radiator scoop control
Oil radiator scoop control
Quadrant friction control
Flap control handle
Carburetor air control
Rudder trim tab control
Aileron trim tab control
Elevator trim tab control
Bomb control anti­salvo guard
Left fuel tank gage
Defroster control
p 18 of 32
Rudder controls with rear wheel steering mechanism at A and wheel lock at B. C is
heavy rear bracket for carrying rear steering stresses.
select cold rammed air; cold,
unrammed filtered air; or unrammed
hot air, as necessary. The Bendix­
Stromberg double­throated, injection
type, updraft carburetor is fitted with
a double­diaphragm acceleration
pump, automatic mixture control,
fuel pressure regulator, fuel control
unit, and throttle.
Automatic manifold pressure
regulator limits maximum boost
when below full throttle and
maintains predetermined pressure
for any given position of throttle
lever.
Ignition is provided by two
magnetos of the rotating magnet
type, the right hand one being
connected to booster coil which
supplies high tension current when
starting.
Engine mount consists of two Y­
shaped 24ST box beams stiffened by
built­up cross members of 24ST
Alclad. Forward frame incorporates
leading edge, and front duct section
of carburetor air scoop and aft frame
attaches to the two beams near the
center. Engine is supported on
rubber mountings between side
beams. Mount is attached to
firewall by four bolts.
Cowling, providing maximum
accessibility to both engine and
accessories, consists of 24ST Alclad
formers and seven removable
panels.
With adoption of Rolls­Royce
engine, the Mustang was equipped
with 11 ft. 2 in. four­blade Hamilton
Standard Hydromatic propeller,
controlled by a governor which
maintains selected propeller speed.
Spinner is a streamlined spun­shell
of aluminum alloy.
Fuel is supplied from self­sealing
cells, one in each wing, and form
auxiliary tanks when fitted. Fuel
flows from tanks through a
submerged booster pump to dual
check valve, then through selector
valve and strainer to engine­driven
fuel pump and carburetor. When
auxiliary tanks are used, fuel passes
through the selector valve to main
fuel line. The booster pumps which
boost fuel to engine pump at high
Guns and armor. (1) & (2) Ring sights;
(3) & (5) ammunition boxes; (4) machine
guns; (6) & (7) ammunition chutes; (8),
(9), (11) & (13) armor plate; (10) bulletproof windshield; (12) optical gun sight;
(14) detachable Plexiglas side panels.
JL McClellan: P51 draft
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p 19 of 32
altitudes operate as emergency
pumps in event of engine­pump
failure. Only one booster pump is
operated at a time.
Fuel strainer and hand­operated
engine priming pump are provided,
and entire system is suitable for
aromatic fuels. Droppable ferrying
or combat may be installed on bomb
racks when bombs are not being
carried, fuel being withdrawn by
engine­driven pump. Pressure is
supplied to ferrying tanks by
connecting them to vacuum pump
exhaust.
Oil flows from bottom of 12.3­
gal. oil tank (forward of firewall) to
oil pump which delivers through
Cuno filter to moving parts of
engine. Scavenger pump in sump
delivers it to oil tank, either directly
through a thermostatic control valve,
having a by­pass, or to radiator and
then back to tank, depending upon
oil temperature.
Self­thawing oil radiator is
forward of coolant radiator inside
scoop. Airflow through scoop is
regulated by outlet flap,
thermostatically controlled. Flap
Fuselage electrical installation, showing control above air scoop for automatic
regulation of oil and coolant temperatures, storage batteries, navigation light
(upper right) and (detail A) methods of making connections.
Left landing wheel of “Mustang”.
(1) Shock strut; (2) fairing; (3)
wheel with dust cap; and (4) 27in. tire.
JL McClellan: P51 draft
Copyright 2005
p 20 of 32
Control stick. Center connection operates
elevators, while rocker with forked ends moves
ailerons.
to pump, through radiator and
supercharger case, and through a
jacket between supercharger
impellers, cooling air before it
passes into second stage impeller
chamber. Coolant then passes into
heat exchanger and cools air from
the second stage before returning to
expansion tank. Scoop with
thermostatic exit flaps provides air
for oil, engine, and after­coolant
radiators and is located beneath
fuselage aft of cockpit, where it
causes less drag than if farther
forward. At high speed, jet action
from the heated air compensates to a
large degree for internal air drag.
Flame­dampening exhaust stacks on
either side contribute to speed by
exerting a jet­propulsion effect of
approximately 200 hp.
The Mustang's electrical system is
24­v. d.c., single wire, grounded
type, most of the wiring open,
supported by clips. Engine wiring,
because of possible radio
interference and vibrational stress, is
shielded and supported by conduit.
can be controlled form the cockpit
for emergency operation, and a
surge valve, integral with
thermostatic valve, permits cold oil
at excessive pressure to by­pass
radiator completely and return to
tank.
Three systems – engine oil,
engine coolant, and aftercooler –
cool Mustang's Rolls­Royce engine.
Engine cooling system utilizes a
centrifugal pump which delivers
coolant into jacket on lower exhaust
side of each cylinder block, whence
it passes to cylinder head through
transfer tubes and out through
manifolds on intake side of head,
discharging into header on front of
engine, from which it flows through
radiator.
Secondary after­cooling system,
which reduces temperature of
supercharged fuel­air mixture,
consists of expansion tank, heat
exchanger, and coolant pump.
Coolant flows from expansion tank
Elevator and elevator tab controls are by cable from cockpit. Tab rear controls are
detailed at A. Cable to tabs is operated by handwheel, to which is connected an
indicator driven by small gears, as shown in detail B.
JL McClellan: P51 draft
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p 21 of 32
Current is supplied by a 34 amp.­
hr. battery, aft of seat, charged by
engine­driven
generator.
Connection with electrical system is
through solenoid switch. A 100­
amp. high speed generator supplies
current through a relay, which
serves as generator cutout. A
voltage regulator maintains potential
at 28.
JL McClellan: P51 draft
Aileron and trim tab controls. Detail A shows
operating mechanism of left hand tab, controlled from cockpit by turning knob. Travel
of cables is restricted by stops, and
adjustments are made by means of
turnbuckles. B is detail of right aileron tab
adjustment, set on ground and shows
method of attaching and actuating aileron
cables by link from stick adjustment.
Radio equipment consists of sets
for communication with other
aircraft or ground. Antenna is a
fore­and­aft, vertical­mast type.
Receivers and transmitters are aft
of seat.
Gunnery equipment consists of
four fixed .50­cal. guns in pairs in
wings, in canted position, rotated
60 deg. to prevent protuberances.
Copyright 2005
They are adjusted to converge fire
with center line of airplane at 300
yd. Lateral adjustment of 1/2 deg. is
provided on either side, and guns are
quickly removable through doors in
upper wing surface. Ammunition is
fed to top sides of guns through
stainless steel chutes. Cases and
links are ejected through metal
chutes in lower wing skin. All four
p 22 of 32
guns fire simultaneously, control
being by switch on control stick.
Sighting is through optical gun sight
or auxiliary ring­and­bead sight.
Electric heaters are attached to each
gun, permitting them to function at
temperatures as low as ­70 deg.
A removable, streamlined bomb
rack is provided on each outer wing
panel for bombs up to 500 lb., depth
charges, chemical, or auxiliary fuel
tanks. Fusing of bombs is
electrically controlled from
cockpit, and bombs can be dropped
in a dive, level flight, or 30­deg.
climb. Sway braces are integral
with racks.
Dimensions and Leading Particulars
GENERAL
Span.....................................................37.03 ft.
Length (overall)...................................32 ft. 2­3/8 in.
Length (tail wheel on ground).............30 ft. 8 in.
Height (tail wheel on ground, propeller vertical at top)..............12 ft. 6 in.
WINGS
Airfoil section......................................NAA low drag
Chord at root........................................8 ft. 8 in.
Chord near top (215 in. from
fuselage center line).....................4 ft. 2 in.
Incidence (variable).............................Approx 1 deg.
Sweepback. ..........................................3 deg. 35 min. 32 sec
Dihedral (at 25% line) ........................5 deg.
STABILIZER
Span.....................................................13 ft. 2­1/8 in.
Maximum chord...................................2 ft. 6 in.
Incidence..............................................2 deg.
Dihedral...............................................(none)
FUSELAGE
Width (max.)........................................2 ft. 11 in.
Height (max.).......................................6 ft 3­7/16 in.
Length (without engine mount, front of heat exchanger to tip of tail).....................................24 ft. 2½ in.
Length (with engine mount, tip of propeller shaft to tip of tail).........30 ft. 9 in.
AREAS
Wings (less ailerons)...........................220.55 sq.ft.
Ailerons (total).....................................12.64 sq.ft.
Flaps (total)..........................................32.6 sq.ft.
Stabilizer (including elevators)............27.85 sq.ft.
Elevators (including tabs)....................13.05 sq.ft.
Elevator trim tabs (total)......................2.00 sq.ft.
Vertical stabilizer.................................8.83 sq.ft.
Rudder (including tabs).......................10.25 sq.ft.
Rudder trim tabs (total).........................82 sq.ft.
LANDING GEAR
Type.....................................................Hydraulic, retracting,
conventional, 3­wheel
Tread....................................................11 ft. 10 in.
Shock struts .........................................Air­oil combination
Wheels (Magnesium alloy construction)
diameter.......................................27 in.
Tires (all­weather tread).......................27 in.
Brakes..................................................Disk, hydraulic
Oleo travel. ..........................................8 in.
ENGINE
Type.....................................................Packard­built Rolls Royce
Designation..........................................V­1650­3
Number of cylinders............................12
Gear ratio.............................................21:44
Coolant (70% water and 30% ethylene
glycol by volume)........................Type D: Spec AN­E­2
PROPELLER
Type.....................................................Hamilton Standard Hydromatic
Diameter..............................................11 ft. 2 in.
Blades..................................................4, paddle type
Pitch setting (hydraulic controlled)
Low..............................................24 deg.
High.............................................65 deg.
SETTINGS & RANGE OF MOVEMENT OF CONTROL
SURFACES
Stabilizer, fixed....................................2 deg.
Vertical stabilizer, fixed offset
(from fuselage centerline)............1 deg.
Deg.
Ailerons, wing. Up travel (from neutral)...............10 .........................................12
.........................................15
Down travel (from neutral)..........10
.........................................12
.........................................15
Elevators
Up travel......................................30 Down travel.................................20
Rudder
Right............................................30
Left..............................................30
Flaps....................................................50
Trim tabs
Elevator
Up................................................10
Down. ..........................................25
Rudder
Right............................................10
Left..............................................10
Aileron
Up................................................10
Down. ..........................................10
Tolerance on control surfaces movements
In. at Max Chord
2.2
2.7
3.3
2.2
2.7
3.3
8.63
5.9
13.5
13.5
20.5
approx. ±¼ deg.
TAIL GEAR
Type.....................................................Hydraul., retract., steerable
Shock strut. ..........................................Air­oil combination
Wheel dia.............................................12.5 x 4.5 in.
Tire (channel tread)..............................12.5 x 4.5 in.
Oleo travel. ..........................................7.50 in.
JL McClellan: P51 draft
Copyright 2005
p 23 of 32
Aerodynamic, Weight, and Servicing Refinements
Featured in North American P-51
C
ONTINUED ADVANCES in
engineering of the Mustang
reflect improvements of
specific interest to the aircraft
designer. Among these are
betterments in such installations as
landing gear fairing door, landing
light, gun and ammunition chutes,
and the armored firewall.
Fairing Door
This hydraulically operated
inboard unit, covering the wheel
well, is hinged close to the airplane
centerline, and is designed to open
to permit extension of the landing
gear and then close after the gear
and then close after the gear is
extended. Eliminating a source of
drag, the door has an area in excess
of 4 sq. ft. and thus adds
considerably to the lifting area of the
wing – an important factor as
takeoff with heavy bomb load under
each wing.
Also, gravel and dirt from the
propeller blast are prevented from
entering the wheel well
compartment and coming into
contact with landing gear and door
lock mechanisms, hydraulic lines,
coolant pipes, and wiring circuits
immediately accessible through the
door opening.
Landing Light
NAA engineers found that the
leading edge was not the most
desirable location for the landing
light, since the Mustang wing is
comparatively thinner because of its
laminar flow design. Curvature of
the lens also caused refraction.
By relocating the light in the
wheel well, lighting efficiency has
been improved by about 40 percent.
In its new location, the installation
is readily accessible for quick
replacement, the light beam is not
obstructed, and intersection with the
propeller arc is below the pilot's line
of vision.
Control switch for the light is
mounted on the pilot's switch panel.
A spring­loaded safety switch,
actuated by the support arm for the
light, is connected in series with the
JL McClellan: P51 draft
Providing additional lifting area of
over 44 sq. ft., P-51 landing gear
inboard fairing door, seen at top in
normal closed position when gear is
extended, opens (as shown at
right) to permit wheel to be
retracted, then closes again, Installation
protects
gear
mechanisms and plumbing from
gravel and dirt, and presents no
interference to flow to airscoop.
Also visible is landing light
relocated from wing. When gear is
retracted, fairing on strut contacts
roller under lamp housing and
pushes unit into recess.
control switch, and breaks the
circuit when the landing gear strut
fairing pushes the light upward into
the wheel well.
Armament Access
Gun and ammunition bay doors
on the P­51 embody good design
for quick and easy access to
armament compartments.
Access to the bays in either wing
is obtained by loosening two
Copyright 2005
fasteners which safety two cover
latch handles, swinging the handles
up, and opening the forward cover.
Rear cover of the gun bay may then
be lifted out to fully expose the three
.50 cal. guns.
Access to the ammunition bay is
provided by raising a handle in the
gun bay to free one side of the
ammunition bay cover, which then
may be lifted out. This gives access
to the three ammunition belts.
The two removable doors are
p 24 of 32
First steps for quick access to gun and ammunition bays of
Mustang is loosening of two fasteners in the cover latch handles.
This permits raising of cover over forward part of gun bay.
With hinged cover raised, rear cover of gun bay may then be
removed by pushing forward, Access to ammunition bay on right is
had by raising short lever to free one side of ammunition bay cover.
With ammunition bay cover unlocked, it is pulled backward and lifted out with aid of
handhold at right. Note that rear cover of gun bay has been removed at the left.
In replacement procedure, rear cover of gun bay or ammunition bay cover may be installed first.
JL McClellan: P51 draft
Copyright 2005
p 25 of 32
Here (left) is seen stainless steel shell
ejection chute after some thousands of
rounds had been fired. Note result of
peening action of shell cases. Shown at
right, at conclusion of same number of
rounds, is new phenolic fiber chute with
similar material for striking plate. It exhibits
superior characteristics.
replaced first, and the hinged gun
bay door is closed last. This
interlocking door arrangement
greatly speeds work of armament
men when servicing the guns and
reloading between combat missions.
Shell-Ejection Chutes
Phenolic fiber shell­ejection
chutes recently designed for the
Mustang have been found superior
to stainless steel for this purpose,
after exhaustive firing tests.
Impact of the .50­cal. brass shell
cases against the ejection chute
edges caused warping of the
stainless steel, which would not
return to its original formed shape.
Also, peening action of the empty
cases against rivets on the inside of
the striking plate damaged them so
severely that t the end of some 4,230
rounds the plate fell off.
The fiber chute acted as a cushion
for the shell cases, and after firing
more than 10,000 rounds,
examination showed the new
installation to be superior.
Also, phenolic fiber chutes are
quicker to manufacture—requiring
only about 25 min. compared to
more than 1 hr. for the stainless steel
chutes.
Firewall
Designed to save weight and
material, the firewall on the P­51 is
fabricated of armor plate and does
double duty by serving as a
structural member attaching to upper
and lower longerons, and providing
protection for the pilot from frontal
enemy gunfire. The installation thus
eliminates the need for the usual
stainless steel firewall with
additional backing of armor plate.
Armor-plate firewall on P-51 takes place of
conventional stainless steel installation
and serves structural purpose in addition
to affording gunfire protection.
JL McClellan: P51 draft
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p 26 of 32
North American P­51 Has Novel Design Features
.
Laminar flow wing, structural aluminum engine mount, small
cross-sectional fuselage — are all incorporated in fighter,
prototype of which was test flown within 120-day schedule
Prototype of the North American P­51 Mustang 120 days of beginning of preliminary design. Dive
fighter (left) on which design and construction details bomber version (right) is being built on same
have just been released, made its first test flight within production lines as fighter.
ONE HUNDRED AND
TWENTY DAYS from the
beginning of preliminary design to
delivery of the first plane –
completely designed for quantity
production. This was the record
established by North American
Aviation on its P­51 Mustang.
Although large numbers of the
type have now been in action for
some time, and a dive bomber
version has already gone into
production, design and
construction details have just been
released.
The race against time began in
Despite design-production schedule allowing but 120 days, North
American engineers decided on laminar flow wing, never before used.
Final foil, however, was quite different from that developed by NACA,
to which NAA engineers give full credit for research work. Not flush
riveting by which aluminum alloy skin is attached. Well for fully
retractable main landing gear is at lower right.
JL McClellan: P51 draft
Apr. 1940, when the British
Purchasing Commission opened
negotiations with North American
for production of a fighter plane
incorporating all the combat
knowledge gained to that time by
the RAF, the AAF, and the
company. The commission
P-51's full cantilever, stressed skin wing consists of two panels
bolted together at center. Main and rear spars are flanged aluminum
alloy; remainder of wing structure consists of extruded stringers and
pressed ribs. Although designed in remarkably short time, plane was set
up for quantity production methods. Here fuselage is lowered into
position for mating with wing during production.
Copyright 2005
p 27 of 32
Mustang purportedly presents smallest cross­sectional fuselage
area ever designed behind Allison engine. Side panel (left) of fuselage
main section is actually a beam, the structure comprising two longerons
forming the beam caps and skin forming the webs, reinforced by vertical
originally asked that North
American build a fighter type
already in production, but J.L.
Atwood, NAA vice­president, sold
its members on the new craft, which
didn't yet exist.
To complete the design, for which
more than 2,800 original drawings
were made, Chief Design Engineer
Edgar Schmued divided the work
among specialized engineering
groups, who worked with skeleton
specifications made up from
sketches and verbal instructions.
Despite the time limit, North
American decided to use a laminar
flow wing, even though this type
had never been used before.
Although the laminar flow section
designed and wind tunnel tested by
the NACA – to which NAA
engineers give full credit for
research – was used as a basis, the
P­51 wing section, as finally
perfected, differed considerably
Of full cantilever, stressed skin
construction, the wing consists of
two panels bolted together at the
center plane of the fuselage. Both
main and rear spars are flanged
aluminum alloy sheet construction,
with flap and aileron hinge supports
mounted on the rear spar.
Remainder of the wing structure
consists of extruded stringers and
pressed ribs, with skin covering of
aluminum alloy. Fuel tanks are
located between the spars on both
sides of the centerline, with a
JL McClellan: P51 draft
frames. Behind cockpit, longerons extend into semi­monocoque
structure reinforced by vertical frames, In production, panels go into
jigs (right) when turnover structure (inverted “V” unit at center) is
installed.
structural door in the under side of
each wing section to facilitate their
installation and removal.
Next to the laminar flow wont,
North American engineers consider
the outstanding factor in the P­51's
aerodynamic efficiency to be the
fuselage, which has what is
believed to be the smallest cross­
sectional area ever put behind an
Allison engine.
In keeping with size and shape of
the fuselage, a new idea was tried in
the form of a semi­spherical, molded
plastic windshield. Wind tunnel tests
delighted the engineers, but flight
test proved tough on pilots, for the
curved glass distorted ground
appearance and made landings
extremely difficult. A conventional
Structural aluminum engine mount, replacing conventional welded steel type, was
designed into P­51to facilitate installation and removal as well as to save weight, simplify
construction, and provide easy access for field maintenance. Engine cowling consists of forward
ring and seven detachable panels to provide maximum accessibility for maintenance.
Copyright 2005
p 28 of 32
windshield, placed at a 40­deg.
angle to horizontal line of flight, was
then installed.
The cockpit itself is under a flush
type canopy with an upper and right
side section hinged to open for
pilot's entrance and exit. Sliding
windows are built into both side
sections, and the entire enclosure
may be jettisoned as a unit for
emergency egress of the pilot.
The fuselage is divided into three
sections: engine, main, and tail, all
of which are attached by bolts. At
the cockpit, or main section, the
fuselage construction consists of two
beams. The structure comprises four
longerons, two on each side of the
cockpit forming the beam caps and
the skin forming the webs,
reinforced by vertical frames. Aft of
the cockpit, the longerons extend
into semi­monocoque structure
reinforced by vertical frames.
The ethylene glycol engine
coolant and oil radiators are set in
the bottom of the fuselage, aft of the
cockpit, enclosed in a duet with an
adjustable air scoop. On initial flight
tests the engine overheated, and
wind tunnel tests shewed that the
disturbed boundaries of air under the
wing and fuselage prevented a clean
flow of air through the scoop.
Lowering the entrance lip of the
scoop approximately 1 in. from the
fuselage bottom cured the trouble
without affecting performance.
Empennage is a full cantilever
structure with semi­monocoque fin
and stabilizer. The full cantilever,
metal­covered horizontal stabilizer
consists of two spars, aluminum
alloy ribs, and extruded stringers,
and it is built as one unit with
detachable tips. Elevators are of
fabric covered aluminum allow
construction, consisting of a front
spar, short intercostal rear spar,
flanged ribs, and metal leading and
trailing edge sections. Both elevators
– which are interchangeable – are
statically balanced and fitted with
trim tabs controllable from the
cockpit.
Vertical stabilizer is a full
cantilever,
semi­monocoque
structure comprised of forward and
rear spar, flanged ribs,a nd extruded
stringers.
Power plane it one Allison V­
1710­F3R liquid cooled engine
equipped with ramming type air
intake for altitude operation,
JL McClellan: P51 draft
swinging a three­blade Curtiss
electric constant speed propeller of
10 ft. 9 in. dia. The close­fitting
cowling around the power plant
consists of a forward ring and
seven detachable panels for
maximum accessibility.
To speed engine installation and
removal and also to provide case of
access, light weight, and simplicity
of construction, and original
structural aluminum mount was
designed to replace the
conventional welded steel .
To eliminate the chance of
engine failure because of long lines
from the oil tank to the engine the
tank was located just above the
engine ahead of the firewall. Oil
pressure at any attitude of flight
was assured through a swivel unit
arranged to be under oil at all
times, so the liquid would feed in a
vertical climb even though the tank
was only one­quarter full.
In the ordinal design, the
carburetor air intake was set over
the engine, with the opening well
back from the propeller. On flight
tests, however, the engine cut out
under certain high speed conditions
and instruments indicated a
peculiar pulsation effect in the air
scoop. Further flight and wind
tunnel tests indicated a repetition of
the old boundary­layer air trouble
and revealed that an air “beat”
from the propeller was being
transmitted through the intake to
the carburetor. To overcome the
first condition, the scoop was
raised slightly. the second trouble
was eliminated by lengthening the
scoop to a point just behind the
propeller where air was picked up
before the pulsation had been set
up.
All three units of the
hydraulically operated landing gear
rare fully retractable, with the main
units being fitted with hydraulic
brakes. Wheel wells are covered by
hydraulically operated fairing to
eliminate drag when the gear is in
down position. The tail wheel,
steerable within the range of rudder
pedal travel can swivel 360 deg.
The tail wheel also employs a
simple surging orifice replacing the
normal metering pin to regulate the
amount of oil flowing from one
strut cylinder to the other under
landing impact. Its development
was brought about during design,
Copyright 2005
when it was found the originally
scheduled unit could not be
delivered on time by the
manufacturer. NAA engineers
designed and built the type now
used, then turned the drawings over
to the original producer. (Also see
pages 147, 183, and 255 of Feb.
Aviation.)
Specifications and
Performance Data
Span.............................37 ft. 5/16 in.
Length........................32 ft. 2­7/8 in.
Height.................................8 ft. 8 in.
Total wing area.............233.19 sq.ft.
Weight.................................7,724 lb.
High speed (approx)
400 mph.
Engine.....................Allison V­1710­
F3R V­type ethylene glycol cooled
p 29 of 32
Exploded view of North American P-51 Mustang engine mount,
shows how built-up box beam side member (A) is used in
conjunction with extrusions, such as at (B) and (C). Carburetor air
inlet (D) is casting. Engine is attached to mount at four points; that
is, at Lord mounts (E) — which are also shown on small sketch of
complete unit — and Lord shear rubber bushings (F). Mount is
attached to armor plate firewall by four nickel steel bolts at points
(G) and is so designed that engine can be removed as a unit.
Lifting lugs (H) can be used either to lift engine and mount, or
hoisting complete airplane
North American P-51 Mustang has been called one of the most
aerodynamically advanced aircraft in service today. In this cut­
away illustration, re­drawn from Flight, many of interesting
structural details are revealed. Reading counter­clockwise, they
include: Rear shutter of air scoop “A,” containing oil and engine
radiators “B” and “C,” re­ spectively. Warm air is taken to cockpit
through pipe “D.” Front shutter of scoop is at “E,” air entering at
“F.” “G” is 70­gal. self­sealing gasoline tank, and three
JL McClellan: P51 draft
Copyright 2005
ammunition containers are at “H” for machine guns “I.” Another
ammunition container is at “J” for machine gun “K.” Carburetor air
intake is at “L,” air being taken to down­draft carburetor through
duct “M,” just in front of 10 gal. oil tank “N.” Bullet­proof glass
“O” is part of standard armor. Over­turn structure is at “P.” Ship's
battery is depicted at “Q,” radio units are seen at “R,” and the
oxygen containers of the craft are at “S.”
p 30 of 32
JL McClellan: P51 draft
Copyright 2005
p 31 of 32
JL McClellan: P51 draft
Copyright 2005
p 32 of 32