loud triangular craft with 3 lights over rural Schuylkill County, PA in 1977

[This report was originally handwritten by my father, who died in 1998. He was a U.S. Navy veteran who worked on airplane electronics, so he was generally familiar with aviation technology. I was 12 at the time of the sighting, and my brothers were 9 and 7. I have only a vague recollection of the incident. Some years later, my mother also had an encounter with a UFO - a lighted, spinning disc she saw late at night on the neighbor's lawn. She's reluctant to discuss the incident for fear people will think she's crazy, but I hope to eventually write down her account of the experience and share it with NUFORC.]  The Mysterious Lights  It was somewhere between 8:30 and 9:00 p.m., say about 8:45. The date was March 2, 1977.
 The kids were watching Grizzly Adams on TV and I just sat down myself, as I had just finished showering. [My wife] was in the bathroom, bathing.
 We heard a noise, a low roar much as a jet, but it sounded low, too low for a jet. I expected it was a helicopter, actually I believed it was a number of helicopters, because it did not sound like it was high enough to be a jet. The noise slowly became very loud, you could feel the vibrations!  Now I became puzzled, my mind expected certain familiar things to take place, and when they didn't, I was puzzled. I expected the "slap-slaps" the helicopter rotors make, but there wasn't any. Now I decided to investigate. The kids also were puzzled and said, "What’s that noise?" "Airplanes," I said. "Stay here, I'm going to see what I can see." I was sort of afraid of what I might find and didn't want the kids involved if it was bad.
 I went outside and saw 3 bright lights moving slowly, from northwest to southeast. They seemed low and close. The noise was very loud. My first impression was that it was 3 airplanes spaced in a triangular formation. They were not directly overhead but past me, and moving very steadily away from me. The lights were bright and they did not change relationship to each other, and I looked for but could not see the expected blinking red and green airplane running lights.
 This viewing occurred in a very short time span, say 10 or 15 seconds. I had on my eyeglasses, but decided to get my binoculars in the closet just inside the door. I ran in the house and took them out of their case but fumbled with the lens covers and wasted too much time returning outside. By now the lights were well past my observation point but still visible to me. I put the glasses on them and had only a second or two before the lights were obstructed by the branches of a leafless tree. I looked for another few seconds and only could see 3 bright lights. I took down the glasses and was going to move so the tree would not obstruct my view. I looked around and decided no other place gave an unobstructed view and put the glasses back up. I only found one light and just as I did, it went out. I presumed it went behind a tree branch, waited for it to reappear, but it didn’t, so I presumed it went over the horizon.
 During the viewing interval, the noise remained strong for quite some time, even though the lights steadily moved away from me. When I had the binoculars the noise was diminishing, but I don't remember how it ended, whether it just stopped or droned on out of earshot.
 [My father added the following notes to his account some time afterward:]  This write-up was done after an interval of weeks after the incident. I wish I had done it the very next day.
 .. One point that my story doesn't make very well, the noise was TREMENDOUS! It was the most distinctive aspect of this tale, not the 3 lights, although the lights were unusual and important to the incident.
The source of this report describes herself as someone who writes frequently.  Given how well this report is composed and written, we suspect that the self-description is accurate.  We wish that all reports were written this professionally.  Moreover, we wish that others, also, would attempt to "capture" the sightings of UFO's that their parents, grandparents, and great-grandparents have had over recent decades.  Our special gratitude to the party who submitted the report!!  PD