Until the arrival of the Grumman Gulfstream I in 1958, the Lockheed Jetstar in 1960 and the Hawker Siddeley HS.125 in 1962, there weren’t any aircraft that were designed specifically as business transports.
From the end of the Second World War until the 1960s, most companies had the option of buying up surplus Douglas DC-3 or C-47 aircraft; you could get a small piston-engined aircraft from the likes of Cessna, Beech, or Piper or a refitted surplus bomber. This latter option was clearly the high end as ex-bomber aircraft usually had a speed and range advantage over both the DC-3 and smaller piston aircraft.
In those days, these executive conversions were the cream of the crop for business aviation and were the 1950s counterpart to today’s Gulfstreams and Global Express bizjets. A whole new industry developed in the post-war era to cater to this high-end market.
One of the more common executive conversions, from several companies, used the North American B-25 Mitchell as the base aircraft. They were inexpensive to acquire, readily amenable to modification, and had a reputation as good-handling aircraft (which was why there were so few B-26 executive conversions after the Second World War). However, years before the market-boom of the 1950s, North American Aviation itself pioneered the concept of using the B-25 as an executive transport.
The very first B-25 Mitchell to be converted just so happened to be the very first B-25 Mitchell with the serial number 40-2165.
The prototype production B-25 that made its maiden flight in 1940. It had been modified in several ways as the flight test program proceeded and by 1942 it was deemed to have cost too much to have had it modified to the standard that was being delivered to the USAAF, so it sat in a corner of the North American Aviation’s facility at Mines Field (today’s LAX).
At this point in the B-25 program, North American now had two plants running at full capacity turning out Mitchells – the Fairfax plant in Kansas City, Kansas, and one at Hensley Field in Dallas (which later became NAS Dallas). In addition, North American executives and engineers were regularly moving amongst the suppliers nationwide as well as Washington DC and Wright Field in Dayton, Ohio, where the USAAF’s technical division was located.
During the war, airline service wasn’t dependable as most of the air capacity was used by the military to support the war effort and, by comparison, travel by train was too slow. Dutch Kindelberger, president of North American Aviation, ordered the stored prototype to be converted into an executive transport.
Seven passenger seats were installed, two ahead of the bomb bar and five in the aft fuselage. The bomb bay became a baggage compartment and bunks were installed above it. Four windows were installed in the aft fuselage for the passenger cabin and the glass nose was made solid with a smooth aluminum skin. Carpeting, upholstery and extensive soundproofing were also added as well as a small bar – something not highlighted or admitted to by North American (this got the aircraft the nickname ‘Whiskey Express’). It was used extensively by the North American corporate brass until January 1945 when it had to be scrapped after a runway overrun at Mines Field.
The second B-25 modified by North American belonged to USAAF General Henry ‘Hap’ Arnold. While visiting the Inglewood facility at Mines Field one day, Arnold got to see the Whiskey Express and as the Chief of Staff, he decided he needed one too.
This was 1943 and production was rapidly accelerating in the B-25 program, so it was easy to divert a B-25C from production to be fitted out by North American to a similar standard as the Whiskey Express. After the war, General Arnold’s personal transport was purchased by Howard Hughes who used it for another twenty years before it was retired.
The same year that Arnold got his own B-25, a B-25J was taken off the production line in Kansas City and flown to Inglewood on a ‘secret’ mission. Tail number 43-4030 was fitted out to become the personal transport for General Dwight Eisenhower.
Unlike Arnold’s B-25 which had olive drab upholstery, Ike’s Mitchell had a more stylish blue interior. Clamshell doors were fitted to the nose for easy access to the extra communications and navigation equipment and more floor space in the aft fuselage was created by moving the gunner’s aft hatch further back, giving the rear cabin more seating and a drop leaf table. Overhead luggage racks were also installed and extra fuel tanks were fitted to the bomb bay to give it more range.
Officially it was designated an RB-25J to hide its true nature as Ike’s personal transport, but as the war in Europe progressed, it was re-designated CB-25J and when Eisenhower moved up to larger aircraft as the Supreme Allied Commander, the CB-25J was passed on for use by lower ranking generals and was used by the USAF post-war until it ended up in the possession of the South Dakota Air and Space Museum where it can be seen today.
In 1944, General Arnold traded up to a newer Mitchell transport. Maybe it was knowing Ike had a nicer one than him (who really knows?), but tail number 44-28945 was taken from the production line and fitted out identically to the Eisenhower’s aircraft. Arnold used it until 1946, but it remained in USAF use for a number of years flying colonels around well into the 1960s.
When the Whiskey Express was scrapped, the North American brass decided a replacement was needed. The same month that the Whiskey Express had its accident, a B-25J was pulled from the production line and fitted out to nearly the same standards as Eisenhower’s aircraft and Arnold’s second aircraft. But knowing the war was soon to be over, North American decided to go the extra mile thinking there might be a post-war market for the company in such a conversion (years before any such companies specializing in such conversions were in that business). Extra navigational equipment as well as a cabin heater were added and in March 1945 it entered service.
Between flying for North American executives, it was flying a test program to get certification as an executive transport. But on 27 February 1946 during a test flight out of Mines Field over the Pacific, the flight crew radioed a mayday that a wing was on fire before the aircraft tragically exploded.
North American decided it had had enough of the conversion market after that tragic loss, but in 1950 with the rise of aftermarket companies that were doing the very same thing North American had done during the Second World War, they decided to take a second shot at the executive transport market.
A surplus B-25J was used and this time a new nose, that was 14 inches wider, was added which allowed room for four passenger seats ahead of the bomb bay but behind the flight deck in addition to the aft fuselage cabin. The bomb bay was permanently closed and replaced with a baggage door with an electric lift at the front. Because of the wider nose, a new windshield was needed; the windshield from the Convair 240 worked perfectly. To reduce noise, a circular exhaust collector was used on the engines instead of having several separate exhaust stacks. Nicknamed the ‘Bulbous Nose B-25’, it had the tail number N5126N.
Flight testing began but on 25 March 1950 it ended tragically for a second time when N5126N broke up in a thunderstorm over Arizona killing seven North American flight crew and engineers. With that loss, North American decided to abandon the project.
Through the 1950s though, the USAF still had quite a few B-25s flying as transports on strength, and contracted the Hayes Aircraft Company in Birmingham, Alabama and the Tucson, Arizona, branch of Hughes Tool Company to carry out conversion work on the B-25s. While not as extensive as the Bulbous Nose B-25 aircraft, they definitely drew upon North American’s work. Many of these converted B-25s became trainer aircraft with the military through the 1960s, not just with the USAF but also the Royal Canadian Air Force.