Recently, I read that Gene Roddenberry purposefully placed the name Noonien into his Star Trek works as he was trying to contact an old friend of his, Kim Noonien Singh. Khan Noonien Singh and Doctor Noonien Soong were named so because of this. Did Singh ever contact Roddenberry because of Star Trek. I am aware that this may seem off-topic, so feel free to mark it as such, administrators.
According to this story - no, his attempts (both with Khan and Soong) did not attract the intended attention:
Back in the day, when Roddenberry was flying his combat missions with the 394th Bomber Squadron, 5th Bomber Group, 13th Air Force in a B-17 Flying Fortress, he met a Chinese pilot who became his friend. After the war, he lost contact with the man, named Kim Noonien Singh.
It is worth noting that according to Marc Cushman's "These Are the Voyages: Season One" - it was indeed Roddenberry who changed the name of the character to Khan Noonien Singh from the original name(s) written by Gene Coon. There is, however, no detail in Cushman's work as to the source of the name.
Roddenberry is reported to have named the character of Khan Noonien Singh after his old war buddy hoping that the original would notice and try to contact him again.
Sadly, the character of Khan failed to gain the attention of Roddenberry’s former comrade.
Roddenberry tried again to hail down the Chinese pilot he once knew in the much later series Star Trek: The Next Generation, which began in 1987...this time, Roddenberry had the “father” of Data (the ship’s android crew member) named Dr. Noonien Soong. Once again, Roddenberry’s noble pre-Facebook and Google attempts to find his long-lost friend failed.
Additionally, there is another Singh in TOS - that of Lt. Singh in "The Changeling"
Looks like, at least one of the original sources for this story is this book
I think most people here have a misunderstanding of Chinese names in English before standardized pinyin made the spellings more standard. Kim is often used to denote the Chinese name of Jin and as you can guess from just reading it it does sound a lot like Singh. A lot of Chinese names before pinyin simply used whatever English words that existed for an approximation, hence a very common name like Li can also be spelt like Lee (eg. Bruce). So most likely his name is Jin (Kim, Singh) Noonien and because Chinese names are surname first given name second, something to make it easy for others they says they are Noonien Kim/Singh to avoid the confusion. I think Gene isn’t that dumb to mistake a Chinese pilot with an Indian one. Further more Chinese pilots of RoC are more likely to fly with USAF while Indians would serve in RAF. So it’s very likely this pilot is an officer of the Republic of China airforce on loan flying with the Americans, hence there’s scant records of him.