While they may lack the size and speed of contemporary jetliners, turboprop aircraft play a vital role in keeping the world moving. Such planes provide useful services to remote communities whose facilities can’t support larger aircraft. Elsewhere, they serve lower-demand but important routes, some of which help regional travelers feed into longer-haul mainline networks. Let’s explore the story of Japan’s forgotten turboprop: the NAMC YS-11.
Replacing the DC-3
Following the conclusion of the Second World War, the Douglas DC-3 was a common sight on Japanese domestic services. This tail-dragging, propeller-driven airliner has gone down in history as the most-produced commercial aircraft family in history. Douglas produced over 16,000 examples, although it is worth noting that most were military versions.
However, production of the aircraft ended in 1950. This prompted Japan’s Ministry of International Trade and Industry (MITI) to consider its replacement going forward. It elected to produce such an aircraft itself, rather than importing one as it had done with the DC-3. This led to the formation of a joint venture between various companies in 1957.
Stay informed: Sign up for our daily and weekly aviation news digests.
The engineering specialists involved included, to name just a few, Fuji (Subaru’s parent company), Kawasaki, Mitsubishi, and Shin Meiwa. The grouping became known as the Nihon Aeroplane Manufacturing Company (NAMC) two years later, in 1959.
Built to compete
In order to ensure the project’s success, NAMC built its DC-3 replacement with specifications that matched or bettered those of other turboprops of the time. For example, with a projected onboard capacity of 60 passengers, the low-winged monoplane that it dubbed the YS-11 had 50% more seats than the Dutch Fokker F27 ‘Friendship.’
The YS-11 was a twin-engined design, while some of its contemporaries had four. Despite this, its twin-turboprop setup was able to match the British Vickers Viscount in terms of performance. In terms of price, it was comparable with the Martin 4-0-4 from the US.
What’s in a name?
The plane’s name reportedly stems from the Latin alphabet spellings of the Japanese words for ‘transport’ and ‘design.’ These are yusō and sekkei respectively, hence the ‘YS’ prefix. These words were chosen from the full name of the Association for Research on Transport Aircraft Design (Yusōki sekkei kenkyū kyōkai). But what about the number 11?
The use of 11 in the plane’s name refers to two aspects. The first 1 is the designation for the Rolls-Royce Dart RDa.10/1 engines which NAMC selected to use on the aircraft, as these had been numbered as 1 on the list of potential candidates.
Similarly, the second 1 refers to the set of specifications that NAMC opted to use for the project. Once again, the set chosen was one of several plans, with one such set even having been designated as ‘plan 0.’ Interestingly, while outside observers came to think of the plane as the ‘YS-eleven,’ its designers referred to it as the ‘one-one’ on this basis.
Entry into service
Having nailed down the name and concept for its new aircraft, NAMC began constructing prototypes. The first of these made its maiden test flight on August 30th, 1962, with the second following four months later, on December 28th that year.
Testing the aircraft was not easy, with several issues arising. Among these, sideways maneuvers proved particularly unsafe, with the propellers’ wake forcing the aircraft to veer to the right despite counteractive rudder inputs. Despite these problems, the aircraft did have the honor of carrying the Olympic flame in 1964, just before Tokyo hosted the games.
After two years of prototype testing, the first production example of the YS-11 took to the skies on October 23rd, 1964. Although the plane’s official launch customer was Toa Airways, the honor of the first YS-11-operated revenue-earning flight fell to ANA in March 1965.
Toa Airways commenced services with the YS-11 early the next month. The airline merged with Japan Domestic Airlines in 1971 to form Toa Domestic Airlines, which itself became Japan Air System in 1988. The carrier was merged into Japan Airlines in 2006.
Where did it fly?
As we have established, NAMC had initially designed the YS-11 to replace the Douglas DC-3 in the Japanese domestic market. However, it actually ended up serving a myriad of operators based all over the world. While the type did, of course, see extensive service in Japan in both commercial and military capacities, this was far from its only hotspot.
For example, the aircraft had a surprisingly strong presence in the US market. Indeed, Piedmont Airlines was a particular fan of the Japanese turboprop, as it was perfectly suited to the mountainous airports that made up a significant chunk of its network.
Indeed, according to the New York Times, Piedmont’s president Thomas Davis said that “the YS‐11 was the only one we could find which would do it on an economical basis.” Piedmont was the type’s largest foreign operator, amassing a fleet of 21 examples by 1970.
Furthermore, Piedmont was far from the only US operator of the YS-11. Indeed, the type also saw service at big names like Hawaiian Airlines and Pacific Southwest Airlines. Several countries far and wide also had multiple YS-11 operators, and they included Argentina, Brazil, Canada, Gabon, Indonesia, Mexico, the Philippines, South Korea, and Thailand.
The forgotten turboprop
Despite the widespread nature of the YS-11’s operations, its sales did begin to stall in the 1970s. While a competent aircraft, it was hard to find more customers as Jpan had no track record of producing airliners in the post-war era. It also became a loss-maker after the Smithsonian Agreement (1971) led to an appreciation in the value of the Japanese yen.
With these factors in mind, production was terminated in the early 1970s. In May 1973, Japan’s Maritime Self-Defence Force took delivery of the 182nd and final YS-11 ever to be produced. As time has gone by ever since, the aircraft has been quietly forgotten.
It flew its last commercial service in Japan in 2006, and, by 2018, just one was left in service. For a long time, the YS-11 remained Japan’s only post-war production airliner. In more recent years, it has begun work on a regional aircraft known as the Mitsubishi SpaceJet.
However, the ongoing coronavirus pandemic and testing taking longer than expected have caused the program to be paused. Only time will tell whether the SpaceJet will ever enter service, or if, like the NAMC YS-11, it will be quietly forgotten.
Did you know about the NAMC YS-11? Perhaps you even flew on one back in the day? Let us know your thoughts and experiences in the comments!