Sunday, November 8, 2009

Wierdness in the air last night....


Men In Black and their Nifty Toys....

Hehe, so last night, I step out for a smoke. I wander out into the driveway and am gazing up at the stars in a clear sky, when I hear a bit of rotor thump. Now, I'm no expert when it comes to flying machines. I'm not one of those who can sit around drinking a cup of coffee, hear the tiniest bit of engine noise in the air, and be able to identify what it is, how fast it's moving, and what direction it's going.

I did, however, grow up on and around small airfields. My grandfather was a pilot, and had a small, grass strip runway, so I've been around small craft most of my life, and am familiar with how they move, etc.

Anyway, I hear this bit of rotor thump from a helicopter, look around, and catch sight of an aircraft off to my north. I assume it was a helicopter, or rotary-winged aircraft for you sticklers, mainly because of the rotor thump I heard. It being pretty dark outside, what with it being night and all, I couldn't get a silhouette to look at and identify. The first thing I noticed that was odd, was that it had a red light on the nose, with an amber/orange blinking light flashing underneath and to the rear. I don't know what configuration of lights aircraft are supposed to run, but I don't recall ever seeing solid red and flashing orange on an aircraft as a kid.

The second thing that struck me as being odd, and this was really odd, was that as I was watching it fly almost due South towards me, I suddenly stopped hearing the rotor thump. I listened for a moment, and realized that I could hear, faintly, an engine running, but could no longer hear the thump of the rotors. Me being a fairly curious guy, I decided I'd watch this thing to see what else was going to happen.

So I watch this craft come towards me, closer and closer. I notice that it's fairly high up in the air. Most of the time when I see helicopters flying over the mountains, they're normally only clearing the mountains by a couple of hundred feet or so. This one last night was easily over eight hundred feet up, and probably closer to a thousand feet up. Now, that could be strictly because of the darkness and not taking chances, but I noticed it, so thought I'd mention it as well. So I watch this thing, heading towards the mountain I live on, hearing the engine noise get slowly clearer and more distinct, much as you can hear a car better the closer it gets.

As it gets closer to the mountain, probably a mile or less North of my position, it suddenly bears off to the West, and does a little curly-cue maneuver at about the spot where it looks like it would be over a small university ball field that's a few miles from my house. The little maneuver takes a few seconds, then this thing starts bee-lining due East from that position. I stand there watching it go across the sky North of my position, and suddenly realize that the lights have changed on it. It no longer has a steady red and flashing orange, but now has a steady green on the nose, and flashing white underneath. It retains this light scheme for the remainder of the time I can see it.

It heads East for a couple of miles maybe, and starts swinging back South, at about the point that it would start crossing over a nearby rural highway. As it starts swinging South, it looks like the southern movement, is just part of an arc described as they're moving West. This time, I'm looking at it as it moves South of my house, and it comes to a stop, hovering, about where I'd guesstimate it to be above a local, community ball field.

Interestingly enough, as it's hovers for a few seconds, I suddenly hear a half dozen or so rotor thumps, which disappear again, as the aircraft starts heading due North again. It passes maybe half a hundred yards West of my position, and of course, way on up, so I can only ever see the lights, and hear the hum of the engine. I continues to watch it as it headed North, until I lost it over the crest of the next mountain. This whole observation lasted probably ten minutes, or less.

I have to admit, that it was a fairly odd experience. I've never seen anything like it. As I mentioned, I'm no expert, but have we got helicopters in the air that somehow can silence their rotor thump, but not their engine noise? If so, could someone point me in the right direction to learn a bit about them?

Hope everyone is having a good weekend!



Crucis said...

The "thump" comes from the rotor tips being supersonic. If the rotor speed dropped, you could hear the engine but not the rotors. Fixed wing A/C have a white light on the nose and a red light on the tail visible from the rear (think anti-collision lights. They also have a red light on the right wing, a green light on the left wing to visually indicate direction. Newer aircraft also have a strobe mounted. There is also a white landing light on the underside. Usually the landing light is on only for takeoff and landing.

Air pollution and.or smoke can make these colors, mostly often the red, change color.

Casey said...

Thanks for the response Crucis. I did remember the light sequence for fixed wings correctly, but didn't want to assume anything for the rotary wing.

Also, I didn't realize the thump was from the rotor tips going supersonic, that's definitely interesting to know.

There was no smoke or clouds in the air last night, and being out of the city and up on a mountain top, I think I'm fairly clear of the majority of pollution.

That's why the whole thing struck me as odd. I definitely saw steady red on the nose, and an amber/orange blinker underneath. I watched it on approach for several minutes before it hooked West the first time around, and the colors changed. Then they maintained that same coloring for the rest of the maneuver, including loops that should have exposed all side of the aircraft.

That's one of the reasons I found it odd. A red light on an aircraft isn't unusual, except when it's the only light, then it goes away and is replaced by a green light.

The whole experience is just a bit peculiar....