Britannia191a From United Kingdom, joined Nov 2004, 262 posts, RR: 0 Posted (8 years 3 weeks 4 days 9 hours ago) and read 11334 times:
I just wondered if anyone else has since this. After many years of looking at planes I was watching an American Airlines flying at FL340 and listening to 135.575 Manchester Area at the same time. I noticed an unusual wave like a heartbeat but a very fast one in the trail behind the Boeing 767. it was very noticeable because it appeared right close behind and not one of those where it was just the wind dispersing it. After that occurance I heard the AA pilot report moderate turbulance and requested immediate descent to a lower altitude.
The trail hicup was the AA plane experiencing the moderate turbulance as it flatlined again after that. Anyone had any experience of seeing this from the ground.
Spacecadet From United States of America, joined Sep 2001, 3968 posts, RR: 10
Reply 3, posted (8 years 3 weeks 4 days 4 hours ago) and read 10728 times:
If you train your eyes on a specific point on a plane as it flies by, and it's flying low enough (ie. takeoff or landing), you can often see turbulence by the movement of the engines and wings in flight. You need to pick a specific reference point to look at on the plane and keep your eyes, there, though; otherwise, your own eyes will bounce around too much to see what the plane is doing. That's just how I naturally look at things, though, so I often see this. I live right near JFK so I'll see turbulence on landing and takeoff every few days.
I'm tired of being a wanna-be league bowler. I wanna be a league bowler!
UAL747 From , joined Dec 1969, posts, RR:
Reply 4, posted (8 years 3 weeks 4 days 2 hours ago) and read 10525 times:
Quoting Britannia191a (Thread starter): I just wondered if anyone else has since this. After many years of looking at planes I was watching an American Airlines flying at FL340 and listening to 135.575 Manchester Area at the same time. I noticed an unusual wave like a heartbeat but a very fast one in the trail behind the Boeing 767. it was very noticeable because it appeared right close behind and not one of those where it was just the wind dispersing it. After that occurance I heard the AA pilot report moderate turbulance and requested immediate descent to a lower altitude.
It's quite possible. The wings are flexible, especially toward the thinner, narrow tips. Any condensation over the wing and behind in the lower pressure areas may display different characteristics while the airfoil slightly changes shape due to the turbulence.
As far as low altitude, it's sometimes hard to spot, even with close up video camera. I mean, look at it this way. When you are driving down the interstate in your car, you notice when your car hits a bump because you are very near, in this case, inside of the moving object. However, just look at the car a few meters in front of you and you don't know when they hit small bumps or not.
Flexing of the wings during turbulence is BEST seen by passengers sitting directly over the wing where they can look straight out on the wing. The perception of the eye on the wing is that it is shorter, however, you can see the bend upward much better from this vantage point than you can from the front or back. The 744 is the best example I can think of to see wingflex, followed closely by the 777 and A330/340.
AlexPorter From , joined Dec 1969, posts, RR:
Reply 5, posted (8 years 3 weeks 3 days 23 hours ago) and read 10024 times:
I've seen it near PHX, but it is much easier to see on short final, when planes are low to the ground and moving slow. With ground objects to compare it to, it is easy to see when wings rock a bit. Works best on windy days and when there is a north or south crosswind.
ABQopsHP From United States of America, joined May 2006, 883 posts, RR: 2
Reply 6, posted (8 years 3 weeks 3 days 22 hours ago) and read 9524 times:
Over ABQ we see lots of contrails. And yes on occasion I have seen the "hick up" or "heartbeat" you mentioned. I have had the scanner on to one of the ABQ centre frequencies, and heard crew members reporting turbulence, and requesting change of altitudes or ride reports.
Aviateur From United States of America, joined Apr 2004, 1367 posts, RR: 11
Reply 8, posted (8 years 3 weeks 3 days 22 hours ago) and read 9134 times:
You are likely describing one of the effects of wake turbulence on the plane's contrail.
Vortices also cause contrails to spin/rotate in tight, circular patterns. It's hard to see from a distance, but I notice this all the time from the cockpit, following other aircraft along the north Atlantic tracks.
[Edited 2008-01-15 18:24:57]
Patrick Smith is an airline pilot, air travel columnist and author
747fan From United States of America, joined Jun 2007, 1206 posts, RR: 1
Reply 10, posted (8 years 3 weeks 3 days 20 hours ago) and read 7671 times:
Quoting UAL747 (Reply 4): As far as low altitude, it's sometimes hard to spot, even with close up video camera
Quoting Spacecadet (Reply 3): I live right near JFK so I'll see turbulence on landing and takeoff every few days.
I spot fairly frequently out at SDF to watch all the UPS heavies depart in the afternoon, and one day last week it was VERY windy there (winds out of the SW at about 25-30 w/ gusts to around 40). There was obviously a cold about to move in that night, and nearly every plane I saw depart you could see being buffeted around by the wind. Not to mention that I could see the actual wingflex (especially noticeable on the 747's I saw as well as a WN 737). I've seen turbulence like this occur a multitude of times on windy/stormy days and was actually on a plane into SDF that landed in a 25-30 mph. crosswind (we were landing towards the south, the wind was out of the SW or WSW). That was definitely a fun approach ... not to mention the downwind leg was even choppier when we broke through the thick nimbostratus clouds. I did see one or two pax utilize the barf bags.
DurangoMac From United States of America, joined Dec 2006, 802 posts, RR: 0
Reply 11, posted (8 years 3 weeks 3 days 19 hours ago) and read 7236 times:
I've never seen it from the ground for an aircraft at cruise but I did see and EMB-120 trying to land in SGU with a very strong cross wind and strong gusts. That plane was buffeted all over the place, I'm glad I wasn't on it and not surprised the pilots decided to go around and try form the other direction.
Rampkontroler From United States of America, joined Sep 2001, 859 posts, RR: 6
Reply 12, posted (8 years 3 weeks 3 days 19 hours ago) and read 7072 times:
I don't think he's talking about flexing wings at all. While it would most likely be happening, that's not what I think he's claiming to see. What I think he is talking about are visible "bumps" and bends in an otherwise smooth contrail, and would that be indicative of an aircraft actually traveling through turbulence?
Beautiful, but deadly to aircraft (and the occupants thereof...).
Well, "potentially" deadly....
I understand why one must approach lennies with trepidation, but to say they are deadly to aircraft is a falsehood. Me and my friends have been flying in and around lennies for years and have lived to tell the tale.
All the flight weather training I recieved in the Air Force used the words deadly when talking about mountain wave turbulence. Just because you lived to tell the tale might prove your point or it might prove you are just lucky. Below is a story about another lucky crew but they had ejection seats.
Revelation From United States of America, joined Feb 2005, 15134 posts, RR: 27
Reply 16, posted (8 years 3 weeks 3 days 11 hours ago) and read 3894 times:
Quoting Fsnuffer (Reply 15): Just because you lived to tell the tale might prove your point or it might prove you are just lucky.
Well, there's risk every time you leave the ground, but you already know that.
Mountain wave is just like electricity: It's potentially deadly, but handled with care, it can be put to great use. In my case, the use is to get a glider to soar tens of thousands of feet above the earth. If your goal is to get from A to B or to defend our country, there is no good reason to fly in mountain wave.
I also handle electricity every day: I just make sure it's in insulated wires before I pick it up!