Aircraft Quiz #80

[Doug Robertson]

What was the very first operational military bomber to feature machine gun turrets?

1. Manufacturer?

2a. Military nomenclature/s?, 2b. Nickname?, 2c. Total built? 2d. For who? Bonus for what was weird about the total built?

3. Engines' make?

4. Date of first flight?

5. What distinction did it have re it's bomb sight? Be specific.

[SunvisorFlyer]

I don't have all the answers for this one:

1. Boulton Paul Aircraft Ltd.

2a. P75
2b. Overstrand
2c. 28
2d. Royal Air Force
2e. The first four were converted P29 Sidestrand Mk IV aircraft

3. Bristol Pegasus II M3

4. 1933

5. ??

[Doug Robertson]

Well, I have to call you on a technicality here, but appreciate your very quick response and diligence with these quizzes. The RAF's 1933 Boulton Paul P75 had a SINGLE enclosed, powered machine gun nose turret, but I asked for the very first bomber featuring machine gun turrets-meaning turrets in the plural.

And, I have to wonder if there was any bomb load and bomb sight on the tube and fabric P75 biplane?

[SunvisorFlyer]

I can't believe I missed that! (and in terms of a bomb sight, I would guess no)

Perhaps instead we should be talking about this:

1. Glenn L. Martin Company

2a. B-10
2b. ?
2c. 121 to US, 348 total
2d. US Army Corps and other international operators
2e. Record keeping was spotty and designations for prototypes, conversations, and production aircraft weren't always consistent?

3. Wright SR-1820-E cyclone engines

4. 1932

5. Not so sure about this one either

[Doug Robertson]

Well-good enough, Sunvisor Flyer! Congratulations!

The Martin B-10 all metal monoplane twin engine bomber of 1932 was a revolutionary military bomber design, quickly replacing tube and fabric open cockpit bombers of the era. It had the first multiple gun turrets-two-nose, dorsal and ventral tunnel guns, retractable landing gear, internal bomb carriage, streamlined all metal construction, multiple engines, larger wingspan, enclosed cockpits and max speed over 210 mph with 1,240 mile range! This eclipsed any biplane bombers and even exceeded in speed ANY contemporary world military fighters!

Here are the answers.

1. Glenn L. Martin Company. Design was privately funded.

2a. B-10. 2b. "Flying Whale". 2c. 342 were built. 2D. 153 for US Army Air Corps, 189 B-10 variants for export. BONUS-This was a "first" -building more of a military aircraft for export than for the US Army Air Corps.

3. Most B-10s were built with two Wright R-1820-33 Cyclone radials, but 32 were built with two Pratt & Whitney radials as B-12s.

4. First flight was on Feb. 16, 1932. Remarkable as design was conceived in same year 1932.

5. The Martin B-10 was the first aircraft to test the famous Norden bomb-sight.

The Martin B-10 design concepts directly led to the famous Boeing B-17 Flying Fortress in the late 1930s but was eclipsed by the B-17 before World War II. The B-10 had a crew of four-one pilot, one radio operator, two gunners with three .30 caliber machine guns-nose turret, ventral tunnel and rear dorsal turret.

The Martin bomber also served with Argentina, China, Netherlands, Philippines, Thailand, and Turkey. Last continuous use was by Thailand finally retired in 1949! The B-10 won the Collier Trophy in 1932 with presentation by US President Franklin Delano Roosevelt.

I thank all who pondered this quiz.

[moxy]

Well done to Sunvisor Flyer.

Thanks for the further information Doug.

As a matter of interest the Boulton & Paul Overstrand despite it's appearance had a bomb load capability of 1500 pounds. I believe it used the CSBS for bomb aiming i.e. the Course Setting Bomb Sight developed by a chap called Wimperis in 1916 who worked for the Royal Naval Air Service. Coincidentally an Overstrand was used to test the ABS, Automatic Bomb Sight being developed by the RAE at Farnborough when they heard rumours of the bombsight being developed by the Dutch (of German and Austrian ancestry) engineer Carl Norden whilst he was employed by Sperry.

I have a soft spot for the Overstrand as my father flew in them with 101 Bomber Squadron, Royal Air Force. The 101 squadron badge actually incorporates a castle turret which was added when they received the Overstrand. This being the first RAF bomber to have a power operated Turret.

Regards
Rob

[Doug Robertson]

Many Thanks Rob, your quiz inputs are always appreciated-they add nicely to the quiz aircraft information.

I neglected to state the Martin B-10 could carry 2,260 lb of bombs. In addition to a transceiver antenna, the B-10B also had an ADF antenna for homing and navigation.

The US Army accepted the aircraft in the same year as the concept design, first flight and production deliveries-in 1932! That wouldn't happen in the present era.

Specs for Martin B-10B Bomber

Max speed-213 mph
Cruise speed-193 mph
Max range-1,240 miles
Weight loaded-16,400 lb
Wing span-70'6"
Length-44'9"
Height-15'5"