NHK has learned that the operational availability rate of Osprey transport aircraft deployed by Japan's Ground Self-Defense Force stands at less than 40 percent.
Ospreys were introduced to Japan from the United States at a cost of about 174.7 billion yen, or 1.1 billion dollars. They have been deployed in stages since 2020, with a total of 17 Ospreys based as of June 2024.
But a source familiar with the matter says the average operational availability rate stood at 36.5 percent in fiscal 2024.
The source says the rate was 12.5 percent in fiscal 2021, when the number of Ospreys was increased from four to nine, 33.9 percent in fiscal 2022 with a fleet of 13, and 34 percent in fiscal 2023 with 14 aircraft in service.
Regularly scheduled maintenance work was cited as a primary factor for the low operational availability rate in fiscal 2024, accounting for 22.3 percent of reported causes.
Other cited factors included malfunctions, such as warning lights not turning on properly, which accounted for 21.2 percent.
Personnel shortages caused 13.6 percent of maintenance delays, while parts delays from the US accounted for 6.5 percent.
The source says maintenance worker shortages and parts delays are major GSDF concerns, and measures such as prioritizing staff for maintenance are under consideration.
GSDF officials declined to comment on the Osprey availability rate, saying operational readiness is secured.

Quiz 1:
What is the approximate cost of the Ospreys introduced to Japan from the United States?
A. 17.47 billion yen
B. 174.7 billion yen
C. 17.47 billion dollars
D. 174.7 billion dollars

Quiz 2:
According to the article, what was the average operational availability rate of the Ospreys in fiscal 2021?
A. 34 percent
B. 36.5 percent
C. 12.5 percent
D. 33.9 percent

Quiz 3:
What percentage of reported causes for the low operational availability rate in fiscal 2024 were attributed to regularly scheduled maintenance work?
A. 22.3 percent
B. 21.2 percent
C. 13.6 percent
D. 6.5 percent

[Answer block]
Answers:
Quiz 1: B
Quiz 2: C
Quiz 3: A