Fairchild 24

F-24
275px
1944 Fairchild Argus III (G-BCBH)
Type	STOL bush plane
Manufacturer	Fairchild
Maiden flight	1932
Produced	1932-1948
Number built	over 1780

The Fairchild Model 24, a four-seat, single-engine monoplane light transport aircraft that was used by the US Army Air Corps as the UC-61. The Model 24 was itself a development of previous Fairchild models and became a successful civil and military utility aircraft.

Design and development

Fairchild Aircraft was hit hard by the Great Depression in the early 1930s as airline purchases disappeared consequently the company attention turned to developing a reliable and rugged small aircraft for personal and business use. The model 22 became somewhat of a hit and led directly to the new and much improved Model 24 which gained rapid popularity in the early 1930s, noted for its pleasant handling characteristics and roomy interior. Having adapted many components from the automotive industry (expansion-shoe brakes and roll-down cabin windows), the aircraft was also affordable and easy to maintain. In production continuously from 1932 to 1948 the aircraft remained essentially unchanged aerodynamically and internally, with the simple addition of extra passenger seating and optional equipment. The first models were equipped with only two seats, but in 1933 a third seat was installed and by 1938 a fourth was added. The interior was first created for the Model 24 in 1937 by noted American industrial designer Raymond Loewy. A minor airframe revision was made in 1938 with the redesign of the vertical fin and re-designation from C8 to F24G onwards.

In an innovative concept, the aircraft was available with two powerplants, Warner's reliable Scarab and Fairchild's in-house 200 hp Ranger series in the F24C-8-D, E and F. Initially the 1932 model Fairchild 24C-8-B utilized a reliable and popular Warner 125 hp radial engine, and the Fairchild 24C-8-C utilized the Warner 145 hp radial. American Cirrus and Menasco Pirate inline engines were also occasionally utilized in some earlier Fairchild 24s. Later models such as the popular 24Ws upgraded to the 165 hp Warner Super Scarab.

Designed for operations from relatively unimproved grass airfields, the sturdy undercarriage construction utilized a vertical oil dampened cylinder above the wheel with a pivoting strut attached to the lower fuselage. The result was a complex but undeniably solid undercarriage that could absorb large amounts of shock and was also adapted for the fitting of twin floats for water-based operations.

The sturdiness of construction of the aircraft has ensured many have survived to this day. Some suggest the massive spruce main-spars can be loaded up to 10g, and whilst that figure is unproved, all pre-war utility category aircraft were designed to withstand at least 4.1g as opposed to the 3.8g post-war design limit standard.

The Fairchild 24 built by Krieder-Reisner Aircraft, Hagerstown, Maryland, a division of Fairchild Aviation Corporation, remained in production from 1932 to 1948, essentially the same airframe but with various powerplant and configuration enhancements. In all, Fairchild constructed over 1500 Model 24s, with an additional 280 being constructed by the Texas Engineering & Manufacturing Company (TEMCO) in Dallas when that company purchased the manufacturing rights after World War II.

Operational history

File:DSC02032 edited.JPG

Australian Fairchild 24 Argus VH-AZL

In civil use, the aircraft was a quick sales success with prominent businessmen and Hollywood actors purchasing the aircraft. In 1936, the US Navy ordered Model 24s designated as GK-1 and JK-1 research and instrument trainers. The type was also utilized by the US Army as a light transport and by the Coast Guard, with the designation J2-K. The Civil Air Patrol operated many Fairchild UC-61/24s and some aircraft were fitted with two 100 pound bombs for what became successful missions against German U-boats off the east coast of the United States in the early stages of the Second World War. The UC-61 was also procured by the US Navy as the GK-1 and by the British as the Fairchild Argus.

In 1941, the United States Army Air Force (USAAF) placed an initial order for 163 Fairchild C-61s, however via Lend-Lease, 161 of these were shipped abroad. Under the auspices of this program, the majority of the 525 Warner Scarab Fairchild 24s/C-61s went to Great Britain. Most of these aircraft saw service as Argus Is and improved Argus IIs and were allocated to a newly formed adjunct of the RAF, the Air Transport Auxiliary. An additional 306 Ranger powered Argus IIIs were also used by the Air Transport Auxiliary. In British service, the majority of the Argus type operated with the Air Transport Auxiliary ferrying RAF aircrew to and from Maintenance Units and operational bases.

The Argus I was a Warner Scarab equipped aircraft identified by its wind-driven generator located on the starboard struts, and was equipped with a black-painted propeller. The Argus II was also a Scarab powered aircraft, usually with a transparent cabin roof. This mark was certified for heavier operational weight than the Mark I and was identified by its yellow propeller. The Argus III was equipped with the six cylinder inverted inline Ranger engine.

Postwar

The aircraft served with military forces as diverse as Finland, Thailand, Israel, Canada, the United States and Australia and to a lesser extent, commercial operators.

Flying the Fairchild 24

The casual observer first notes the imposing size of the Fairchild 24. When on the ground, the impression is of a solidly built utility aircraft.

Closer inspection however reveals certain unexpected refinements. As one approaches either door, the factory-fit handles are reminiscent of a 1930s automobile, and indeed that is apparently their origin (said to be similar to those from a 1935 Plymouth). To step up into the spacious cabin, one utilises a small permanent step protruding from the side of the fuselage. Etched on the step surface is Pegasus – the Fairchild Corporation winged horse logo.

Typical of most aircraft of the era, the fuselage is of fabric-covered tubing with the only external metal surfaces being those around the engine compartment.

When seated in the cabin, the impression is again of ruggedness. In addition to normal doorposts, two metal beams run rearward from behind the instrument panel into the overhead wing-root area, transferring engine-weight loads more directly to the wing's load-carrying members. These have the additional benefit of being well placed handgrips to aid the less agile in entering the cabin! The automotive theme is again recalled by the two roll-down window mechanisms in each door.

The Fairchild 24 has been the subject of only one FAA Airworthiness Directive (FAA AD 47-50-9, relating to a landing gear oleo link), possibly a record for any airframe.

If original, the forward seats may still be configured for a pilot sitting only on a parachute (i.e. no upholstery on the base). A deep cushion however is now invariably substituted for the parachute, necessary to allow adequate forward vision to normal-height pilots.

The 165 hp Warner Super Scarab radial and the 200 hp Ranger inline engine most commonly powered the Fairchild 24. The following relates to procedures for the Scarab and varied to a degree for specific serial numbers.

As with all radials, prior to commencing start it is imperative (by some process) to turn the engine over in order to clear lower cylinders of pooled residual lubricating oil. The hydraulic properties (i.e. its near-imcompressibility) of this oil are such that it has the potential to literally blow off a lower cylinder head when another cylinder fires. In smaller radials such as the Scarab, it is possible to turn a propeller by hand prior to engine start and thus manually allow this fluid to escape. On the larger radials this is achieved by rotating the propeller by activating the starter motor without having the ignition system energized.

The actual starting procedure for the Scarab is similar to various radials and with six pumps of the fuel primer, the engines will start up easily, even after prolonged periods of inactivity.

Many Warner Scarab powered aircraft have a "Spark Retard" lever that improves starts by allowing the piston to travel closer to the top dead centre of its stroke within the cylinder before the spark ignites. Additionally there is often another press-button control (referred to as a "Shower of Sparks"), a device that also assists the start process. A rewarding cloud of white smoke characteristic of all radials accompanies each start.

Once started, the engines can take some time to warm up to normal operating temperatures. In warmer climates however, the Scarabs can then tend to operate at the upper end of their recommended oil temperatures and consequently some owners have modified engine cowlings with extra ram air ducting.

Again the automotive link becomes evident when taxiing the Fairchild. The very wide-track nature of the undercarriage and the various conditions found when taxiing necessitates wheel brake installation on this aircraft. The brakes themselves are of an expanding-tube type (vintage 1932 Detroit), hydraulically expanding in response to pressing the top of the rudder pedals. Taxiing is relatively straightforward, with occasional dexterous jabs of the brakes and the usual turns to ensure all is clear ahead.

Takeoff is reasonably undemanding. The aircraft is quite pitch-sensitive and it is important to have the overhead rotating trim handle correctly positioned (more nose-down with more people aboard). Rudder effectiveness improves markedly as expected when the tail raises and at lighter weights the aircraft literally leaps into the air. At heavier weights though, the Fairchild can consume surprising amounts of runway and it cannot really be classified as a STOL aircraft. With its large split flaps it can certainly land on a short airstrip but getting airborne again in that field length may prove problematic.

A speed of 65 knots (120 km/h) is an ideal climb speed although forward visibility improves at higher speeds. Climb rate, whilst not outstanding, is adequate and cruising handling characteristics are particularly pleasant and 100 knots (186 km/h) is the normal cruise airspeed at 65% power. The aircraft also has phenomenal range. The Warner 165 hp Fairchild 24 will fly for 5 ¾ hours; its no-wind range is 639 nautical miles (1200 km).

In the stall the aircraft handles much like any contemporary light aircraft and with its nicely harmonized push-pull rod and cable activated flight controls, steep turns in the Fairchild are most satisfying. Peripheral visibility can tend to be impeded by the various struts and window or door frames in the cabin area and this can make sequences such as formation flight a little more challenging, however the visibility on approach is equal to that of most modern high-wing light aircraft.

On approach, the first stage of the two-stage flaps is helpful in increasing the glide angle, but the second (60°) stage creates a particularly spirited descent. At lighter weights, an approach speed of 65 knots (120 km/h) is used. As the result of a number of landing incidents, the ATA increased the required approach speed when fully loaded with pilots, parachutes and baggage to 80 knots (150 km/h) to provide a sufficient stall margin.

Landings in up to moderate crosswinds are straightforward. The Fairchild seems most comfortable in the slightly tail-down "wheel landing" configuration. Three-point landings are not impossible by any means (the ATA Handling Notes required a three-point landing when the rear seats were unoccupied), however the reduced forward visibility makes this type of landing somewhat more challenging.

The large oil dampened oleos compress more than 8 inches (20 cm) during landing, assisting in providing a comfortable touchdown and the large rudder is effective until about 10 knots (20 km/h). The wheel tread is in excess of 9 feet (2.75 m) wide and can pose directional difficulties should one main gear pass through softer ground or standing water. However the brakes are quite effective and easily able to keep the Fairchild tracking in a straight line.

In all, the classic design of the Fairchild 24 as well as its splendid flight characteristics has made it an affordable and popular antique. The fact that many of these aircraft have had actual service with the Civil Air Patrol or the RAF’s Air Transport Auxiliary further heightens the privilege of restoring, owning or operating these classic aircraft.

Variants

UC-61 Argus

Military version of the Fairchild Model F24W-41 powered by a 165hp R-500-1, 161 built.

UC-61A Argus

Military version of the Fairchild Model F24W-41 with radio and 24-volt electrical system, 509 built and three impressed civilian aircraft.

UC-61B

One impressed Model 24J powered by a 145hp Warner Scarab radial.

UC-61C

One impressed Model 24A-9.

UC-61D

Three impressed Model 51As.

UC-61E

Three impressed Model 24Ks.

UC-61F

Two impressed Model 24R-9s.

UC-61G

Two impressed Model 24W-40s.

UC-61H

One impressed Model 24H powered by a 150hp Ranger 6-410-B.

UC-61J

One impressed Model 24-C8F two-seater, powered by a 150hp Ranger 6-390-D3.

UC-61K Forwarder

Final production variant powered by a 200hp L-440-7, 306 built.

UC-86

Nine impressed Model 24R-20s bowered by 175hp L-410.

GK-1

Thirteen Model 24W-40 impressed by the United States Navy.

J2K-1

United States Coast Guard version of the Model 24R, two built.

J2K-2

As J2K-1 with detailed changes, two built.

Argus I

Royal Air Force designation for the Model 24W-41 (UC-61), 118 under Lend-Lease

Argus II

Royal Air Force designation for the Model 24W-41A (UC-61), 407 under Lend-Lease

Argus III

Royal Air Force designation for the Model 24R (UC-61K), 306 under Lend-Lease

Operators

Template:AUS

• Royal Australian Air Force

Template:Country data Canada

• Royal Canadian Air Force

Template:CZS

• Czechoslovakian Security Aviation Unit

Template:ISR

• Israeli Air Force

Template:FIN

• Finnish Air Force

Template:THA

• Royal Thai Air Force

Template:UK

• Royal Air Force

Template:Country data United States

• United States Army Air Force
• United States Marine Corps
• United States Navy
• United States Coast Guard

Survivors

Converted military aircraft became popular postwar as personal transports and many survive to this day. Extremely solidly built, the aircraft survives in reasonably large numbers. Primarily, this popularity is probably due to affordability. Prices for low hour examples of the aircraft typically range between US $50,000 to US $90,000 (2006 values) and some of the most pristine examples can be seen annually at the EAA fly-in at Oshkosh, Wisconsin.

Aircraft museums worldwide are restoring examples for display (such as G-AIZE at the RAF Museum at Cosford).

Specifications (UC-61)

Data from {name of first source}

General characteristics

• Crew: one, pilot
• Capacity: 3 passengers
• Length: 23 ft 10 in (7.27 m)
• Wingspan: 36 ft 4 in (11.08 m)
• Height: 7 ft 8 in (2.34 m)
• Wing area: 193 ft² (17.9 m²)
• Empty weight: 1,813 lb (822 kg)
• Max takeoff weight: 2,882 lb (1,307 kg)
• Powerplant: 1× Ranger Engine L-440-5 inline, 200 hp (149 kW) or Warner Scarab 165 hp radial

Performance

• Maximum speed: 108 knots (124 mph, 200 km/h)
• Range: 404 nm (465 miles, 748 km)
• Service ceiling: 12,700 ft (3,870 m)

See also

Related development
Fairchild 22

Designation sequence

Fairchild

21 - 22 - 24

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Fairchild 24".