I ask you why do assume that they are not accurate? Are Americans inherently more honest then Vietnamese or Russians? I don't think so. There are always two sides to a story. Often people forget that and I thought someone should mention the other prospective. I have studied the Vietnamese People's Army Air Force;and in my opinion, as well the Russians and the Americans the VPAAF is a well trained, professional AF. So why would I write off their claims. Like most air arms VPAAF pliots needed to meet at least 2 of 3 criteria; produce gun camra footage, eyes witness or weakage to get a confirmed kill. These were meretriciously scrutinized, for historic record and propaganda; as well providing empirical proof of effective defense to their Soviet and Chinese advisers.
Also while I have utmost respect for the American fighting men and women, do I trust the US governments word? "NO" The US gov. lied and did plenty of underhanded things during Vietnam War era, for example the fabricated attacks by torpedo boats in the gulf of Tonkin, or the CIA backed coup and assination of South Vietnam's Presdent Diem. Would I put lying about Aircraft losses and/or their causes above them? NO
Thank You
I'm not assuming greater honesty on one side or the other, though you seem to. If we assume equal honesty, we must assume US statistics on own losses to be more accurate than N. Vietnamese claims. They know what they lost. Sometimes, they did not know the cause, & they may have a loss attributed to ground fire, or unknown, which was actually in air-air combat. Cross-checking N. Vietnamese & US records has identified the causes of many US losses, but also shows that many claims do not correspond to a loss, & that multiple claims sometimes correspond to a single loss.
One need not assume N. Vietnamese dishonesty for this to be so. It is notoriously difficult to work out exactly what happened after an air combat. Things happen fast. In one case written up (IIRC) by Toperczer, an F-8 was last seen by the N. Vietnamese trailing smoke & going down over the DMZ. It was perfectly reasonable to assume it was shot down. It actually landed, damaged but still (just) flyable, at an airfield in S. Vietnam, & was repaired & returned to service, by which time the pilot (uninjured) had been back in action for weeks. AFAIK, that's still logged as a kill for the VPAAF pilot.
As for the accuracy of US statistics: the USA was not, in the 1960s, a society in which it was possible to conceal the losses of aircrew, & there is no evidence of falsification of USAF & USN records of aircraft losses, which are far more open than those of N. Vietnam.