B-25: From the Father of the US Air Force

In the spring of 1939, the USAAC (United States Army Air Corps) requested a new medium sized bomber. North American Aircraft took up the challenge and indeed were awarded the contract. Their design was the B-25 ‘Mitchell’ and it took off straight from the drawing board – almost literally in fact; no prototype approval step was required! The accelerated process found the first example taking to the skies on 19th August 1940 with North American Test Pilot Vance Breese at the controls and his colleague Test Engineer Roy Ferren by his side. Following an intensive testing program the first mission ready aircraft were delivered as an initial batch of five to the US Army Air Corps just six months later, this being February 1941. 

North American was no stranger to the pressures of development, production and making deliveries; indeed they were one of the largest aircraft manufacturers of the time and they took much praise for being the first company to simultaneously produce trainers, fighters and bombers (T-6 ‘Texan’, P-51 ‘Mustang’ and B-25 ‘Mitchell with ‘T’ meaning Trainer, ‘P’ for Pursuit and ‘B’ for Bomber!). 

A plane by any other name just wouldn't have been the same! – the B-25 was named in honour of he who became known as the 'Father of the United States Air Force': Brigadier General William Lendrum Mitchell, or ‘Billy’ to his friends.

 Billy Mitchell was born just after Christmas all the way back in 1879! He served in France during World War I and was the first US officer to fly over German Lines. By the end of the conflict, he was in command of all the US aerial units serving in France. After returning to the US in 1919, Mitchell advocated for a separate Air Force, in fact he felt so strongly about it he was considered a little too outspoken at times and was heavily reprimanded for it. However, his beliefs and passion continued nonetheless, and he supported, encouraged, and pushed every angle he could to develop aviation and it's innovation in military application. His voice was at last recognised as being the foundation block for the eventual decision to have a separate aerial military organisation, and they called it the United Stated Air Force on 18th September 1947 – 11 years after his passing. As a means of recognition, he was posthumously awarded the Congressional Gold Medal for his efforts and vision. 

“ The B-25 was yet another triumph for manufacturer North American. Not only was it a dependable workhorse and in general, a reliable steed. But for one mission only – it was also a carrier deck aircraft too! ”

But back to the aircraft: The B-25 was well liked by its pilots and its crews, although they most probably concluded that conversation in later years care of a hearing aid such was the deafening sound from its two huge 14 cylinder Wright Cyclone engines! Each producing some 1,700 horse power. A pair of Hamilton Standard props, measuring some 3.8 meters in diameter, pulled the aircraft through the air. 

The aircraft was built with an all-aluminium skin airframe and with fabric-covered flight controls. Its rather iconic twin fin and rudder system was designed to give sufficiently manageable handling in the event of losing an engine in combat, as well as giving some redundancy in yaw control if one rudder was damaged or even destroyed during a mission.

The first nine B-25s had a constant dihedral wing from root to wingtip but this was found to give some stability issues. So, the tenth aircraft found a solution in leaving a reasonable amount of dihedral from the route to engines ( > 4.5° ) but ‘flattening off’ the wing from outboard of the engines to the tip ( < 0.5° ). This worked a treat and all subsequent B-25s had this "gull wing" looking configuration. 

Crew access was through a belly hatch aft of the cockpit. A hinged door, which included a drop-down step, helped get a leg up and provided just about enough room to climb aboard. Access into the pilots seats was tricky if you hadn’t mastered the contortions required to manoeuvre into the tightly packed front seats; but like all good aircraft; “once you're in, you're in!” 

The B-25 had a heavy focus of deployment in the Pacific theatre with perhaps the best known mission led by Lt. Col. James “Jimmy” Doolittle; he and his fellow airmen (5 crew per plane) flew 16 B-25s from US Aircraft Carrier "USS Hornet" to attack the Japanese in 1942 following the devasting blow at Pearl Harbour some four months earlier. Dolittle's ambitious mission required his fleet of B-25's to undertake an extensive weight reduction program, and the pilots needed to train specifically for the task of flying a ‘bomber’ off an ‘aircraft carrier’!

The mission was planned with a specific range based geographic launch position, but as the carrier closed in on the designated spot, they became aware of a Japanese picket ship in the area and therefore risked being identified by Japanese forces. Doolittle and his colleagues in Fleet Command had the unenviable task of calling the go / no go and had precious moments to decide. They were still some 200 miles short, and the B-25's were already stretched on range. Even if all went to plan it was a push to complete the mission as briefed. The decision was a ‘go’ and on 18th April 1942, all 16 B-25's rolled their wheels along the carrier deck and took off into certain uncertainty. 

Dolittle himself was first to get airborne at the controls of serial number 2344, being at the front, he had only 142m of runway deck in front of him! An astonishing job! Doolittle was awarded the Medal of Honor by President Franklin D. Roosevelt for his “conspicuous leadership above the call of duty” and in later years was promoted to a Four Star General (honorary) by President Ronald Reagan.

North American built just over 9,800 aircraft by the time production ended in 1945. With around 40 of them still flying today. Indeed, it was the highest production number of a medium sized bomber built by the US and was the third most produced American bomber overall! The B-25 served in every theatre of World War II and was still in service until as late as 1979. Post military applications found some future life for the aircraft in the form of aerial firefighting and utility flying. 

The B-25 was yet another triumph for manufacturer North American. Not only was it a dependable workhorse and in general, a reliable steed. But for one mission only – it was also a carrier deck aircraft too! and there’s not too many aircraft that can say that given it’s only ocean going design brief at conception was that it would make a good coastal patrol aircraft! I can only wonder what the original design engineers must have said when they heard that more than a dozen of their aircraft was going to be flown off the "USS Hornet" sailing in the Pacific!

Wingspan: 20.3 m
MGW: 15,873 kg
Powerplant: Curtiss-Wright R-2600 (x 2), 1,700 hp (each)
VNE: 290 mph
Cruise speed: 230 mph
Service ceiling: 24,200 ft