B-25 Mitchell vs Japanese Destroyer

Battle of the Bismarck Sea 1943

Mark Lardas, Jim Laurier

• Publisher: Osprey Publishing
• Year: 2021
• Print ISBN: 9781472845177
• eBook ISBN: 9781472845184
• Edition: 1
• Topic: History
• Subtopic: 20th Century History
• Index: History

Throughout the first year of the war in the Pacific during World War II the USAAF was relatively ineffective against ships.

Indeed, warships in particular proved to be too elusive for conventional medium-level bombing. High-level attacks wasted bombs, and torpedo attacks required extensive training. But as 1942 closed, the Fifth Air Force developed new weapons and new tactics that were not just effective, they were deadly. A maintenance officer assigned to a B-25 unit found a way to fill the bombardier's position with four 0.50-cal machine guns and strap an additional four 0.50s to the sides of the bomber, firing forward. Additionally, skip-bombing was developed. This called for mast-top height approaches flying the length of the target ship. If the bombs missed the target, they exploded in the water close enough to crush the sides. The technique worked perfectly when paired with "strafe" B-25s.

Over the first two months of 1943, squadrons perfected these tactics. Then, in early March, Japan tried to reinforce their garrison in Lae, New Guinea, with a 16-ship convoy – eight transports guarded by eight destroyers. The Fifth Air Force pounced on the convoy in the Bismarck Sea. By March 5 all eight transports and four destroyers had been sunk

This volume examines the mechanics of skip-bombing combined with a strafing B-25, assessing the strengths and weaknesses of the combatants (B-25 versus destroyer), and revealing the results of the attacks and the reasons why these USAAF tactics were so successful.

TECHNICAL SPECIFICATIONS

B-25 MITCHELL

The B-25 was a semi-monocoque aircraft using aluminum for both the structural elements and the skin. It was a mid-wing aircraft with retractable tricycle landing gear, a horizontal stabilizer set at the top of the fuselage, and twin rudders. Monocoque construction is one where all structural loads are supported by the aircraft’s skin. In semi-monocoque construction, while the skin supplies some of the strength, the framing provides most of the aircraft’s structural strength. It offers structural redundancy, allowing the skin and frames to share the load.

The primary structural material used in the B-25 was aluminum. Weighing one-third of an equivalent volume of steel, aluminum is corrosion-resistant and easy to manufacture, making it an ideal structural and covering material for aircraft. It was also stronger and easier to work with than the wood and fabric used in previous generations of aircraft.

The B-25 used aircraft construction techniques typical of the period. These included transverse frames on the wings and fuselage, and fuselage frames that were linked together with metal stringers, while the wings used full cantilever construction. The mid-wing had a center section anchored to the fuselage, with the inner wing panels running to the engine mounting. The outer wings bolted onto the center wing section. The skin was attached to the frames with aluminum rivets. Removable panels were secured using Dzus fasteners. The aircraft was not intended to be pressurized, so its profile was that of a rounded rectangle, maximizing usable internal volume.

This standard B-25C, assigned to the Fifth Air Force’s 38th BG in November 1942, reveals how lightly armed these aircraft were when they initially arrived in New Guinea. It has a flexibly mounted 0.50-cal. machine gun for the bombardier, and a fixed weapon of the same caliber in the lower right side of the nose. (NARA)

The fuselage had three main structural components: forward, middle, and tail. The forward section contained the nose, with the bombardier’s station or nose guns and the flightdeck where the pilot, co-pilot, and navigator worked. In later versions (B-25H onward), it also contained the dorsal turret. The middle section held the bomb-bay and a passage linking the forward and rear fuselage. The rear section comprised everything aft of the bomb-bay. In the B-25C/Ds that fought at Bismarck Sea, it also contained both turrets. In later versions, the waist and tail guns were located there.

The aircraft’s main landing gear retracted into the engine nacelles, while the nose leg and wheel were housed in a compartment below the flightdeck. Tricycle gear offered two advantages over conventional tailwheel gear during take-off and landing. The former gave the pilot better visibility, especially on take-off, and made the aircraft less susceptible to nose-overs. On landing, it reduced the possibility of ground looping, while also offering better crosswind performance during the final approach.

These advantages compensated for the complexity of adding a retractable nose gear. Except for aircraft already in production (such as the Lockheed Hudson), all American multi-engined military aircraft procured after 1940 used tricycle landing gear. B-25s had a tail skid to protect the rear fuselage should the pilot over-rotate the aircraft on take-off.

The B-25 was a hauler. It could carry nearly 50 percent of its empty weight in payload – fuel, bombs, and ammunition. While long-range missions reduced bombload due to balancing fuel against bombs carried, the aircraft’s ability to carry so much weight made it extremely versatile. This attribute also permitted the type of field modifications that led to the development of strafer versions of the B-25.

B-25C MITCHELL STRAFER COCKPIT

1. Altimeter correction card

2. Pilot’s clock

3. Static pressure selector valve

4. Pilot direction indicator

5. Free air temperature indicator

6. Altimeter (behind control column)

7. Radio compass

8. Directional gyro

9. Airspeed indicator

10. Turn-and-bank indicator

11. Accelerometer

12. Turn-and-bank needle valve

13. Flight attitude indicator

14. Rate-of-climb indicator

15. Nose wheel turn indicator lights

16. Magnetic compass

17. Compass correction card

18. Section (vacuum) gauge

19. Remote-reading compass

20. Autopilot oil pressure gauge

21. Autopilot directional gyro unit

22. Autopilot turn-and-bank gyro unit

23. Manifold pressure gauge

24. Oil pressure gauge

25. Main tanks fuel level indicator

26. Auxiliary...

Table of contents

• Cover
• Title Page
• Table of Contents
• Introduction
• Chronology
• Design and Development
• Technical Specifications
• The Strategic Situation
• The Combatants
• Combat
• Statistics and Analysis
• Aftermath
• Further Reading
• eCopyright