Nederlandse Modelbouw en Luchtvaartsite

Dutch Modelling and Aviation

In Memoriam

Klaas Willem Jonker
† April 30, 2018

On Monday 30 April 2018, Wilko Jonker died after a long illness at the age of 58. He leaves behind a wife and two children. The Dutch military aviation and plastic modeling were his hobby and on this website he shared all the knowledge he has collected over the years. His hobby has been able to distract him from the persistent disease in his body until the last week of his life. The contacts with other hobbyists were a major support for him.

This website will be maintained by different people for as long as possible, so that other enthusiasts can continue to benefit from extensive content.

Consolidated B-24D & -J Liberator


In 1938, Consolidated Aircraft received the request to produce B-17s. The chief engineer, David Davis, however, came with its own wing design with a 15% reduction in air resistance. A rough draft was made of a four-engine aircraft with this wing.
The USAAC ordered in March 1939 the construction of a prototype of the Consolidated Model 32, USAAC designation XB-24. The aircraft with two tailfins had a unique construction of the bomb bay, which consisted of two parts, they rolled up like garage doors. The crew went through the bomb bay inside the aircraft. Equipped with four Pratt & Whitney R-1830-33 Twin Wasp engines of 1100 hp each unit had a maximum speed of around 440 km/hr. Furthermore, it was the first heavy bomber of the USAAF with a nose wheel undercarriage.

Even before the first flight was made Consolidated received an order to built seven test aircraft, designated YB-24. France also placed an order, which later went to the RAF.

Mid 1939 the USAAF ordered 120 units of the B-24, of which 20 examples were handed over to the RAF as Liberator I, which used them, equipped with radar and four 20mm cannons used in the nose , for anti submarine warfare.
Because the performance was disappointing, the XB-24 was ordered with four turbo-charged engines, Pratt & Whitney R-1830-43 of 1200 hp each, which gave the aircrfat, now designated XB-24B a top speed of nearly 500 km/hr. The XB-24B was equipped with self-sealing fuel tanks, and a larger span.
The stability and maneuverability of the B-24, would be improved with one vertical tail fin in place of the standard double tail. The B-24ST and XB-24K were equipped with a single fin and demonstrated this fact. The B-24N was the first version with a single tail that would enter production, but the order was canceled because of the end of the war. Only the B-24 derivative PB4Y Privateer went into production.

The B-24C was the first version in which the war experiences of the British were processed, though just nine examples were ordered  which didn't enter operational service.

The first operationally deployable version was the B-24D, of which over 2700 were produced in a variety of sub-variants or production blocks.

In order to meet the demand for more firepower the B-24H was released with an Emerson A-15 nose turret and an improved tail and dorsal turret.

The B-24J appeared and was different from the B-24H especially the applied Convair A-6A nose turret, because the A-15 turret was not sufficiently available. Furthermore, the B-24J had an improved C-1 autopilot, new M-series bomb aim system, an improved fuel supply and an electronic control system of the turbo-superchargers.

The weight of the B-24 rose during development which had a negative impact on performance because the engines remained the same. A total of over 6600 examples of the B-24J were produced on all production lines.


Prototype; first flight on December 29, 1939.
Pre production version. Seven examples built. six of them delivered to RAF as LB-30; The seventh aircraft was delivered to USAAC as 40-702.
first production version; Ordered on April 27, 1939. One modified YB-24: added were de-icing boots; leading edge slots were omitted.
First real production version with improved aerodynamics. Nine examples were delivered to USAAF Ferrying Command and twenty examples were delivered to RAF as LB-30B .
  • Liberator B Mk I: 20 examples. Proved to be unusable for operational use. Some were modified to GR.I and used for anti submarine patrol missions.
one modified and improved XB-24 with four Pratt & Whitney R-1830-41 turbo-supercharged radial engines of 1200 hp each replacing the Pratt & Whitney R-1830-33 of 1000 hp. Top speed was about 60 km/hr higher. Because of the turbo-superchargers the cowlings were more oval in shape.
Negen examples of the production version of the XB-24B, equipped with a hydraulic Consolidated A-6 turret with two .50 machine guns; a Martin dorsal turret.
  • Liberator B Mk II: 165 examples for RAF comparable with B-24C; First version suitable for operational use. Extended nose and enlarged fuselage and British equipment.
First version entering large scale production. Improved B-24C with four Pratt & Whitney R-1830-43 supercharged engines. Initially a ventral Bendix turret, because of problems later replace by a single .50 inch machine guns in a "tunnel". later also a Sperry turret was added.
The last series of the B-24D had two machine guns mounted under the nose.
2696 examples were built at several production lines.
  • XF-7: photo recce version of the B-24D.
  • Liberator B Mk III: British version with .303 inch Browning machine guns, Boulton Paul tail turret and other British equipment. The Martin dorsal turret was maintained. 156 examples built.
  • Liberator B Mk IIIA: Lend-Lease B-24Ds with US equipment and armament.
  • Liberator B Mk V: B-24D version with enlarged fuel capacity and same armament as Liberator Mk III.
  • Liberator GR Mk V: Modified B-24D for RAF Coastal Command for anti submarine warfare equipped with search radar and a search light.
experimental version of B-24D with tail of a Douglas B-23 Dragon. This configuration proved to be more stable and more manageable.
one modified B-24D, developed from B-24ST with tail of a Douglas C-54. Was further developed to PB4Y-2 and B-24N.
over 800 examples of a Ford bult version  of the B-24D with Pratt & Whitney R-1830-65 engines and no ventral turret. Mainly used for training purposes.
  • Liberator B Mk IV: never delivered RAF version of the B-24E.
One modified B-24D for testing of thermal de-icing.
25 examples of the North American built B-24S with a Sperry turret and three machine guns in the nose.
  • B-24G-1: As B-25G but with a A-6 nose turret; 405 examples built
3100 examples with heavier frontal armament; an electrical operated Emerson A-15 turret; strengthened airframe; modified tail turret and an Martin A-3 dorsal turret. The position of the side gunners had windows added.
  • F-7: photo recce version of the B-24H.
  • Liberator B Mk VI: RAF version with Boulton Paul tail turret, same armament as B-24H.
6678 examples of a further improved version: the A-15 turret was replaced by a hydraulic Consolidated A-6 turret. Further an improved aut pilot and bomb aim installation was added.
  • F-7A: photo recce version of the B-24J with three cameras in the nose and three ind the bomb bay.
  • F-7B: Idem with six cameras in the bomb bay.
  • Liberator B Mk VIII: RAF version to the B-24J.
  • Liberator C Mk VI: transport version of the Liberator B Mk VIII.
  • Liberator GR Mk VIII: Modified B-24J for RAF Coastal Command use for Anti submarine warfare.
  • Liberator C Mk VIII: RAF modified transport version of the Liberator GR Mk VIII.
  • Liberator GR Mk VI: RAF Coastal Command designation to the B-24G/H/J type for long distance patrol.
1667 examples of a lighter version of the B-24J, in which the turret Sperry ventral turret was replaced by a ring arrangement with two machine-guns, and the A-6B tail turret replaced by a M-6A turret.
  • RB-24L: trainer for B-29 air gunners with same armament as B-29.
  • TB-24L: idem with added radar equipment.
2593 examples of this last, further improved version van B-24L with further weight savings; a light weight version of the A-6B tail turret; open positions for the side gunners; re introduction of the Sperry ventral turret and, later a wind screen with less bars.
re-design of B-24J with a single tail and an Emerson 128 turret in the nose and fixed tail guns, One example built.
seven examples of the pre-production version of the XB-24N
one modified B-24D for testing a fire extinguisher.
one General Electric modified B-24L with radar operated tail turret (as used in the Boeing B-47 Stratojet.
one modified B-24D with extra armament. To be used as an escort aircraft. The performance was very disappointing.
C-87 Liberator Express:
First transport version suitable for twenty passengers.
  • AT-22 or TB-24: C-87 version for training of flight engineers.
  • RY-2: U.S. Navy designation of the C-87.
  • Liberator C Mk VII: RAF designation of the C-87.
VIP transport version with four R-1830-45 engines and and sleeping accommodation for sixteen passengers.
  • RY-1: U.S. Navy designation of the C-87A.
Armed transport version. Not produced.
976 examples of the B-24D, B-24J, B-24L and B-24M for US Navy.
  • PB4Y-1P: photo reconnaissance version.
PB4Y-2 Privateer:
version with enlarged single tail and other modifications.
  • RY-3:transport version of the PB4Y-2.
    • Liberator C Mk IX: RAF designation for RY-3/C-87C
    • C-87C: USAAF designation for the RY-3.
Never built patrol version with two engines


Technical information Consolidated B-24D Liberator Mk.III
Length: 20,45 m Wingspan: 33,52 m
Height: 5,46 m Wing area: 97,35 m2
Empty weight: 16 780 kg Max. start weight: 28 123 kg
Max. speed: 434 km/hr Cruising speed: 382 km/hr
Range: 3684 km Service ceiling: - m
Engine type: Four Pratt & Whitney R-1830-43 Twin Wasp rated 1200 hp each.
Crew: Nine men
Armament: About nine machine guns. Bombs.


Technical information Consolidated B-24J Liberator GR.Mk.VI
Length: 20,45 m Wingspan: 33,52 m
Height: 5,46 m Wing area: 97,35 m2
Empty weight: 17 236 kg Max. start weight: 27 240 kg
Max. speed: 482 km/hr Cruising speed: 447 km/hr
Range: 2465 km Service ceiling: - m
Engine type: Four Pratt & Whitney R-1830-65 Twin Wasp rated 1200 hp each.
Crew: Eight men
Armament: About ten machine guns. Bombs..