Observation on 737 in the rain
Observation on 737 in the rain
(OP)
Over the last summer, I was sitting in the window seat of a Boeing 737, on the right side, just in front of the wing root, directly inline with the inlet of the turbofan. It was raining and there was quite a bit of water standing on the tarmac.
After pushback, the engines spooled up. I watched the vortices generated by the rapidly inrushing air turn into a “Snake” of water and air, pulling forward from the engine about 3 meters, then turning 90 degrees downward to the ground. The snake was about 30 inches in diameter and as long as the engines were at taxiing speed, the snake was consistent, becoming more visible as we taxied through water puddles.
When we reached the runway, the engines spooled to takeoff power and the snake stretched out almost out of sight of the window, but still staying attached to the ground.
As we approached takeoff speed, the snake disappeared but it stayed visible to just before rotate velocity.
In all of my flights over 40 years, I have never seen such a sight. I never realized the drop in air pressure would vaporize the water so visibly. Opinions?
After pushback, the engines spooled up. I watched the vortices generated by the rapidly inrushing air turn into a “Snake” of water and air, pulling forward from the engine about 3 meters, then turning 90 degrees downward to the ground. The snake was about 30 inches in diameter and as long as the engines were at taxiing speed, the snake was consistent, becoming more visible as we taxied through water puddles.
When we reached the runway, the engines spooled to takeoff power and the snake stretched out almost out of sight of the window, but still staying attached to the ground.
As we approached takeoff speed, the snake disappeared but it stayed visible to just before rotate velocity.
In all of my flights over 40 years, I have never seen such a sight. I never realized the drop in air pressure would vaporize the water so visibly. Opinions?
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RE: Observation on 737 in the rain
One time we took off from Albany, NY ~30 min late, and arrived at Atlanta, GA ~10 min early. Along the way, at altitude, I noticed a very odd thing; a step change in the index of refraction of the air, in a vertical spanwise plane, above the thickest part of the wing. I had to look it up when I got home, right after changing my shorts; it was a shock front.
I think the plane was a 727, still my favorite, and fuel was much cheaper than time in those days. You know how the pilot throttles back when the plane reaches altitude? He never did, until it was time to land.
Mike Halloran
Pembroke Pines, FL, USA
RE: Observation on 737 in the rain
RE: Observation on 737 in the rain
http://tinypic.com/471s47c.jpg
RE: Observation on 737 in the rain
RE: Observation on 737 in the rain
Mike Halloran
Pembroke Pines, FL, USA
RE: Observation on 737 in the rain
TTFN
RE: Observation on 737 in the rain
The combination of the 737 with the big air inlet (I suppose the Airbus is the same), my seat, me observing the engine inlet, and Saturn rising allowed me to see the anomoly.
Truly unique, will remember that one.
Franz
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RE: Observation on 737 in the rain
RE: Observation on 737 in the rain
I've been about 20 feet from an engine that took a vortex into the core - makes quite a loud bang... (fortunately it was on a ground test stand and I was in a control room at teh time).
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and the slight oops...
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RE: Observation on 737 in the rain
Jeff