Douglas A-26 Invader

https://en.wikipedia.org/wiki/Douglas_A-26_Invader

The Douglas A-26 Invader (designated B-26 between 1948 and 1965) is an American
twin-engined light bomber and ground attack aircraft. Built by Douglas Aircraft
Company during World War II, the Invader also saw service during several major
Cold War conflicts. A limited number of highly modified United States Air Force
aircraft served in Southeast Asia until 1969. It was a fast aircraft capable of
carrying a large bomb load. A range of guns could be fitted to produce a
formidable ground-attack aircraft.

A re-designation of the type from A-26 to B-26 led to confusion with the Martin
B-26 Marauder, which first flew in November 1940, some 20 months before the
Douglas design's maiden flight. Although both types were powered by the widely
used Pratt & Whitney R-2800 Double Wasp eighteen-cylinder, double-row radial
engine, they were completely different and separate designs — the Martin bomber
originated in 1939, with more than twice as many Marauders (nearly 5,300)
produced in comparison to the Douglas design.

The A-26 was originally built in two different configurations. The A-26B had a
gun nose, which originally could be equipped with a combination of armament
including .50 caliber machine guns, 20mm or 37mm auto cannon, or even a 75mm
pack howitzer (which was never used operationally). Normally the gun nose
version housed six (or later eight) .50 caliber machine guns, officially termed
the "all-purpose nose", later commonly known as the "six-gun nose" or "eight-gun
nose". The A-26C's "glass" nose, officially termed the "Bombardier nose",
contained a Norden bombsight for medium altitude precision bombing. The A-26C
nose section included two fixed M-2 guns, later replaced by underwing gun packs
or internal guns in the wings.

After about 1,570 production aircraft, three guns were installed in each wing,
coinciding with the introduction of the "eight-gun nose" for A-26Bs, giving some
configurations as many as 14 .50 in (12.7 mm) machine guns in fixed forward
mounts. An A-26C nose section could be replaced with an A-26B nose section, or
vice versa, in a few man-hours, thus physically (and officially) changing the
designation and operational role. The "flat-topped" canopy was changed in late
1944 after about 820 production aircraft, to a clamshell style with greatly
improved visibility.

Alongside the pilot in an A-26B, a crew member typically served as navigator and
gun loader for the pilot-operated nose guns. In an A-26C, that crew member
served as navigator and bombardier, and relocated to the nose section for the
bombing phase of an operation. A small number of A-26Cs were fitted with dual
flight controls, some parts of which could be disabled in flight to allow
limited access to the nose section. Access was through the lower section of the
right-hand instrument panel, which was open to allow access to the nose for the
bombardier, who would normally sit next to the pilot. This was similar to
British designs like the Lancaster, Blenheim/Beaufort, Wellington, etc. A
tractor-style "jump seat" was located behind the "navigator's seat." In most
missions, a third crew member in the rear gunner's compartment operated the
remotely controlled dorsal and ventral gun turrets, with access to and from the
cockpit possible via the bomb bay only when that was empty. The gunner operated
both dorsal and ventral turrets via a novel and complex (and problematic)
dual-ended periscope sight, which was a vertical column running through the
center of the rear compartment, with traversing and elevating/depressing
periscope sights on each end. The gunner sat on a seat facing rearward, and
looked into a binocular periscope sight mounted on the column, controlling the
guns with a pair of handles on either side of the column. When aiming above the
centerline of the aircraft, the mirror in the center of the column would flip,
showing the gunner what the upper periscope was seeing. When he pressed the
handles downward, as the bead passed the centerline the mirror would
automatically flip, transferring the sight "seamlessly" to the lower periscope.
The guns would aim wherever the periscope was aimed, automatically transferring
between upper and lower turrets as required, and computing for parallax and
other factors. While novel and theoretically effective, a great deal of time and
trouble was spent trying to get the system to work effectively, which delayed
production, and it was difficult to keep maintained in the field even once
production started.


Role
Ground attack
Light bomber

Manufacturer
Douglas Aircraft Company

First flight
10 July 1942

Retired
1980 Colombian Air Force

Primary users
United States Army Air Forces
United States Air Force
United States Navy
French Air Force

Number built
2,503

Unit cost

US$242,595 (1942)


Variants
On Mark Executive, Marketeer, and Marksman

Pacific

The Douglas company began delivering the production model A-26B to the United
States Army Air Forces (USAAF) on 10 September 1943, with the new bomber first
seeing action with the Fifth Air Force in the Southwest Pacific theater on 23
June 1944, when Japanese-held islands near Manokwari were attacked. The pilots
in the 3rd Bomb Group's 13th Squadron, "The Grim Reapers", who received the
first four A-26s for evaluation, found the view from the cockpit to be
restricted by the engines and thus inadequate for low-level attack. General
George Kenney, commander of the Far East Air Forces stated that, "We do not want
the A-26 under any circumstances as a replacement for anything."

Europe

Douglas needed better results from the Invader's second combat test, so A-26s
began arriving in Europe in late September 1944 for assignment to the Ninth Air
Force. The initial deployment involved 18 aircraft and crews assigned to the
553d Squadron of the 386th Bomb Group. This unit flew its first mission on 6
September 1944. No aircraft were lost on the eight test missions, and the Ninth
Air Force announced that it was happy to replace all of its A-20s and B-26s with
the A-26 Invader.

The first group to fully convert to the A-26B was 416th Bombardment Group with
which it entered combat on 17 November, and the 409th Bombardment Group, whose
A-26s became operational in late November. Due to a shortage of A-26C variants,
the groups flew a combined A-20/A-26 unit until deliveries of the glass-nose
version caught up. Besides bombing and strafing, tactical reconnaissance and
night interdiction missions were undertaken successfully. In contrast to the
Pacific-based units, the A-26 was well received by pilots and crew alike, and by
1945, the 9th AF had flown 11,567 missions, dropping 18,054 tons of bombs,
recording seven confirmed kills while losing 67 aircraft.

Korean War

B-26s were credited with the destruction of 38,500 vehicles, 406 locomotives,
3,700 railway trucks, and seven enemy aircraft on the ground. On 14 September
1951, Captain John S. Walmsley, Jr. attacked a supply train. When his guns
jammed, he illuminated the target with his searchlight to enable his wingmen to
destroy the train. Walmsley was shot down and posthumously awarded the Medal of
Honor. Invaders carried out the last USAF bombing mission of the war 24 minutes
before the Armistice Agreement was signed on 27 June 1953.

Southeast Asia

the On Mark Engineering Company of Van Nuys, California was selected by the Air
Force to extensively upgrade the Invader for a counterinsurgency role. The first
production flight of the B-26K was on 30 May 1964 at the Van Nuys Airport. On
Mark converted 40 Invaders to the new B-26K Counter-Invader standard, which
included upgraded engines, propellers, and brakes, re-manufactured wings, and
wing tip fuel tanks, for use by the 609th Special Operations Squadron. In May
1966, the B-26K was re-designated A-26A for political reasons (Thailand did not
allow the U.S. to have bombers stationed in country at the time, so the Invaders
were redesignated with an "A", for attack aircraft) and deployed in Thailand to
help disrupt supplies moving along the Ho Chi Minh trail. Two of these aircraft
were further modified with a Forward Looking Infrared (FLIR system) under
project Lonesome Tiger, as a part of Operation Shed Light.


Specifications (A-26B-15-DL Invader)

General characteristics
Crew: 3
Length: 50 ft 0 in (15.24 m)
Wingspan: 70 ft 0 in (21.34 m)
Height: 18 ft 3 in (5.64 m)
Wing area: 540 ft² (50 m²)
Empty weight: 22,850 lb (10,365 kg)
Loaded weight: 27,600 lb (12,519 kg)
Max. takeoff weight: 35,000 lb (15,900 kg)
Powerplant: 2 × Pratt & Whitney R-2800-27 "Double Wasp" radial engine, 2,000 hp
(1,500 kW) each

Performance
Maximum speed: 355 mph (308 kn, 570 km/h)
Range: 1,400 mi (1,200 nmi, 2,300 km)
Service ceiling: 22,000 ft (6,700 m)
Rate of climb: 1,250 ft/min (6.4 m/s)
Wing loading: 51 lb/ft² (250 kg/m²)
Power/mass: 0.145 hp/lb (108 W/kg)

Armament

Guns:
6 or 8 0.50 in (12.7 mm) M2 Browning machine guns in solid, "all purpose" nose:
or 2 0.50 in (12.7 mm) M2 machine guns in glass "bombardier" nose
Up to 8 0.50 in (12.7 mm) M2 machine guns paired in four optional under wing
pods: or 3 0.50 in (12.7 mm) M2 machine guns in each outer wing panel
2 0.50 in (12.7 mm) M2 machine guns in remote-controlled dorsal turret
2 0.50 in (12.7 mm) M2 machine guns in remote-controlled ventral turret

Rockets: Up to 10 5-inch (12.7 cm) HVAR rockets on "zero length" launch pylons,
five under each outer wing panel
Bombs: Up to 6,000 lb (2,700 kg) capacity - 4,000 lb (1,800 kg) in the bomb bay
plus 2,000 lb (910 kg) carried externally on underwing hardpoints





*