In the end, the YS-11 had shown that Japan was capable of building an airliner, but NAMC had racked up a huge debt, and the type is generally regarded as a commercial failure.

Large numbers of the type continued to be in service until 2006, at which point tighter Japanese aircraft regulations imposed by the Ministry of Land, Infrastructure, Transport and Tourism necessitated either the withdrawal or refitting of all YS-11s.

[3] Furthermore, while this requirement had been conceived primarily in a commercial context, there was an early recognition of the value for multiple branches of the Japanese Defense Agency (JDA) to be readily able to adopt the type as well; as a philosophy, this not only extended to the prospective airliner itself, but the various technologies involved in its development and manufacture.

[10] Furthermore, according to author Stephen C Mercado, due to the lack of available domestic technology at the time, several of the key aircraft systems, such as cabin pressurization, were copied from foreign sources; such information was gleaned from a combination of Japanese airlines, trading companies and diplomats.

[4] Throughout the YS-11's production lifetime, its electronic equipment, avionics, mechanical and fuselage components were supplied by a combination of Japanese companies and foreign suppliers.

[11] There was also an acute lack of safety during sideways maneuvers; the wake of the propeller produced abnormal forces that inclined the aircraft to the right; all of the rudders were ineffective; and the maneuverability was worst of all.

[10][11] Prior to applying for certification, the FAA had been involved in the programme at NAMC's invitation, performing informal project reviews so that defects could be identified and eliminated early on.

[4] During the late 1960s, a lack of significant international sales led to the programme incurring persistent losses, the outstanding debt eventually growing to $600 million.

[2] Due to the organisation of the programme, the aircraft manufacturers themselves did not have any of this debt apportioned to themselves, NAMC being held solely responsible; Mercado criticised this approach as it meant there was no incentive for the individual companies to make cost savings while simultaneously guarantee profit to them on every plane produced.

This failure to address a crucial factor in acquiring new customers has been attributed as a major contributing cause of the programme's poor commercial reception.

[13] The end of the YS-11 programme was precipitated by the 1971 Smithsonian Agreement, which led to an appreciation in the value of the Japanese yen and the resulting impact upon the nation's economy.

Initial attempts were made to market the airliner towards various countries across Southeast Asia; at one point, the Japanese government was allegedly encouraging such sales as a form of war reparations.

[4] Seeking to make the aircraft more attractive to the highly active North American market, NAMC decided to develop the YS-11A, a new variant which possessed a higher gross weight.

During 1966, a lease agreement was signed between NAMC and Hawaiian Air Lines, a move which was hailed as the "first step" in the programme's new America-focused campaign.

After evaluating numerous aircraft around the world, the company determined that the Japanese airliner was the most suitable; according to Piedmont's president, Thomas H Davis: "The YS‐11 was the only one we could find which would do it on an economical basis".

Nor was it rare for NAMC to have to sell the YS-11 at a discount, as this was Japan's first commercial airliner since the end of World War II, and had no proven track record.

Moreover, because multiple companies were involved with the aircraft manufacturing, it was unclear who held ultimate responsibility, nor could the price of delivered parts be reduced.

[4] The YS-11 was slowly phased out by Japanese airlines up until the early 2000s, at which point the withdrawal rate spiked in response to new directives issued by the Ministry of Land, Infrastructure, Transport and Tourism that required all commercial aircraft in Japan to be fitted with a Traffic Collision Avoidance System (TCAS); any aircraft lacking TCAS were forced to cease operations at the end of 2006.

[21] Former and present operators of the NAMC YS-11 include: Argentina Aruba Brazil Brunei Canada Democratic Republic of the Congo Egypt Gabon Gambia Greece Indonesia Ivory Coast Japan Mexico Peru Philippines South Korea Taiwan Tanzania Trinidad and Tobago Thailand United Arab Emirates United States JSDF delivery breakdown: