因為戰機型號是1961年後美國三軍共同編碼，越晚研發的編號越後面。

F-22 操作的問題
F-22 值得注意的事故

In November 2011, a Pentagon study team identified the following 13 areas of concern that remained to be addressed in the F-35:

1. The Helmet mounted display system does not work properly.
2. The fuel dump subsystem poses a fire hazard.
3. The Integrated Power Package is unreliable and difficult to service.
4. The F-35C's arresting hook does not work.
5. Classified "survivability issues", which have been speculated to be about stealth.
6. The wing buffet is worse than previously reported.
7. The airframe is unlikely to last through the required lifespan.
8. The flight test program has yet to explore the most challenging areas.
9. The software development is behind schedule.
10. The aircraft is in danger of going overweight or, for the F-35B, too heavy for VTOL operations.
11. There are multiple thermal management problems. The air conditioner fails to keep the pilot and controls cool enough, the roll posts on the F-35B overheat, and using the afterburner damages the aircraft.
12. The automated logistics information system is partially developed.
13. The lightning protection on the F-35 is uncertified, with areas of concern.
資料來源

2009 年時一架 F-22 的 flyaway cost 為 1.5 億美元
2012 年時一架含武器系統的 F-35A 的 flyaway cost 為 1.97 億美元
2012 年時一架含武器系統的 F-35B 的 flyaway cost 為 2.377 億美元
2012 年時一架含武器系統的 F-35C 的 flyaway cost 為 2.368 億美元
資料來源︰維基英文版

PAK FA
PAK FA 的座艙罩為兩片式而非一片式
一片式座艙罩的匿蹤性優於兩片式
目前的戰機只有 F-22 及 J-20 採用一片式座艙罩

原來還有這差別...學到一課了 :D

PAK FA還在早期階段，
贏得競標時的XF-22跟現在的F-22也是差很多的，
現在還在研發階段的機種以後會變成什麼樣誰也說不準

F-22的價格是假設美軍再多定100架所得到的成本。

也必須看座艙罩上的玻璃

F22有鍍膜
J-20還沒有