What is the UFO incident in Southeast Asia?

1966, an American invading army encountered a UFO during an operation, which took place in Nha Trang, Vietnam. This was revealed by American Staff Sergeant Wayne dalrymple 1966 in a letter to his parents on June 20th. He wrote in the letter:

"At 2 1 45 last night, about 4,000 officers and men of our battalion fell into panic. I was scared. Last week, our army received a large generator, a movie projector and several copies. We were watching a movie when suddenly a very strong light came at us from somewhere. At first we thought it was a glowing rocket, but it wasn't. Strong light comes from the north and is a flying body, which is slow and fast. The jet fighter pilot sitting next to me said that the glowing object was 8000 meters away from us. At this time, we all became excited. The monster descended slowly and stopped in the air between 100 and 150 meters above our heads. The small valley where we live and the surrounding mountains are illuminated as bright as during the day. After a while, it rose to the sky again and suddenly disappeared. What is disturbing is that there is something wrong with the generator in the barracks. This may have nothing to do with uninvited guests. Anyway, the generator doesn't work, and the barracks are dark inside and outside. At the air base 800 meters away, several generators also failed. Two planes were waiting for take-off orders on the runway when their engines suddenly stopped running. In this whole four minutes, cars and planes seem to be dead. Eight bulldozers that were building roads on the mountain also turned off at the same time, and the lights dimmed together. A large number of soldiers arrived by plane that afternoon. They panicked, afraid that they would not be able to return to the headquarters. The radio station here broadcast the news about it. Do you know where it is? We did see UFOs. "

"We estimate that this dazzling luminous object is about 16 meters in diameter, with a clean and smooth surface and no accessories. It is a complete luminous sphere. The plane with stalled engine is an "air attack fighter" and eight huge bulldozers are D-9 civil machinery. They are busy cleaning a hillside and preparing to deploy Falcon missiles. Six D diesel generators run well and can generate 100 kW of electricity, but they stopped when UFOs appeared. Four minutes later, the UFO disappeared and all six generators started automatically at the same time. I am responsible for keeping these six machines running normally. Afterwards, I checked one by one and everything was normal. Fortunately, there was no plane in the air at the time of the incident. When our barracks fell into darkness, the general oil tanker moored in the nearby bay also lost power. How dangerous. "

At that time, the American military situation in Vietnam was very bad, and the battlefield was losing ground and morale was low. After learning about the Nha Trang case, the invading army headquarters held a meeting overnight to discuss various security measures to ensure the emotional stability of the army. On June 20, a senior commander announced to the Nha Trang Guard that the luminous object was a sounding balloon with military significance and it was not allowed to talk about it in the future. However, on this very day, Staff Sergeant Wayne Dallimp wrote the above letter to his parents on the other side of the Pacific Ocean, and the American UFO Organization (MUFON) quickly got a copy of the letter.