KC 135 -- Refueling tanker (Boeing 707) since 1957
My father also spent years toiling on trying to make the F-104 Starfighter, which had been ultra-state of the art in the 1950s (twice the speed of sound), less lethal to its poor pilots. After Air Force pilots had grown terrified of it, the Lockheed brass "persuaded" the West German defense minister to buy it in the 1960s, so my dad had to work a lot of long nights trying to figure out how to keep what had been originally intended as essentially a high-altitude kamikaze interceptor to shoot down Soviet nuclear bombers in case of WWIII from killing so many West German pilots who had been sold it as an all-purpose low level all-weather fighter-bomber, a sort of A-10 Warthog with 7-foot wings.
The exceptionally brave Italian Air Force kept flying the F-104 until 2004. My father once asked an Italian air force general what their secret was since the West Germans were always complaining about how often their pilots crashed the F-104: "Why don't you crash?"
"Oh, we crash," the Italian general replied. "We just don't complain about it."
The state of the art progressed incredibly rapidly in aircraft design in the middle half of the 20th Century, but not all that much since then. (Stealth was a radical innovation at first, but with the computing power available now it's becoming easier to incorporate it into a conventional plane: recent stealth planes such as the F-22 don't look as weird as the Stealth Fighter.)
Pentagon officials ... cannot say when Lockheed will deliver the 8.6 million lines of code required to fly a fully functional F-35, not to mention the additional 10 million lines for the computers required to maintain the plane. The chasm between contractor and client was on full display on June 19, 2013, when the Pentagon’s chief weapons tester, Dr. J. Michael Gilmore, testified before Congress. He said that “less than 2 percent” of the placeholder software (called “Block 2B”) that the Marines plan to use has completed testing, though much more is in the process of being tested. (Lockheed insists that its “software-development plan is on track,” that the company has “coded more than 95 percent of the 8.6 million lines of code on the F-35,” and that “more than 86 percent of that software code is currently in flight test.”) Still, the pace of testing may be the least of it. According to Gilmore, the Block 2B software that the Marines say will make their planes combat capable will, in fact, “provide limited capability to conduct combat.” What is more, said Gilmore, if F-35s loaded with Block 2B software are actually used in combat, “they would likely need significant support from other fourth-generation and fifth-generation combat systems to counter modern, existing threats, unless air superiority is somehow otherwise assured and the threat is cooperative.” Translation: the F-35s that the Marines say they can take into combat in 2015 are not only ill equipped for combat but will likely require airborne protection by the very planes the F-35 is supposed to replace.
But do I want to risk my life on the freeway to Google's hit or miss attitude? We'll see.