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How Close Is Too Close?  
User currently offlineMSN007 From United States of America, joined Sep 2009, 126 posts, RR: 0
Posted (2 years 7 months 3 weeks 6 days 8 hours ago) and read 5190 times:

After looking at this picture following the link, I am wondering how close is to close?

http://www.airliners.net/photo/Turki...lines/Boeing-777-3F2-ER/2043884/L/

32 replies: All unread, showing first 25:
 
User currently offlinetimz From United States of America, joined Sep 1999, 6822 posts, RR: 7
Reply 1, posted (2 years 7 months 3 weeks 6 days 8 hours ago) and read 5193 times:

6000 ft is definitely not too close.

User currently offlinePe@rson From United Kingdom, joined Jan 2001, 19215 posts, RR: 52
Reply 2, posted (2 years 7 months 3 weeks 6 days 8 hours ago) and read 5179 times:

It's just an illusion.


"Everyone writing for the Telegraph knows that the way to grab eyeballs is with Ryanair and/or sex."
User currently offlineSEPilot From United States of America, joined Dec 2006, 6897 posts, RR: 46
Reply 3, posted (2 years 7 months 3 weeks 6 days 8 hours ago) and read 5078 times:

Aircraft are normally separated at those altitudes (I believe it is over 31,000 ft) by at least 2000 feet unless reduced separation is in place in which case the minimum is 1000 feet. And that is for planes traveling in opposite directions; in the same direction the separations double. Since the listed separation is 6,000 feet and the planes are obviously traveling in the same direction reduced vertical separation is obviously being used.


The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineYflyer From United States of America, joined Feb 2007, 1022 posts, RR: 1
Reply 4, posted (2 years 7 months 3 weeks 6 days 7 hours ago) and read 4903 times:

Photos taken through a telephoto lense can be very deceptive. Here's another example of the same phenemonon with an explanation of why the planes aren't as close as they appear to be:

http://www.snopes.com/photos/airplane/closedhl.asp

Unfortunately the link in that article appears to be dead, but here's another good explanation of the "compression" phenomonon with telephoto lenses:

http://www.learnmyshot.com/Telephoto...+Compression+and+the+Angle+of+View


User currently onlineXFSUgimpLB41X From United States of America, joined Aug 2000, 4195 posts, RR: 37
Reply 5, posted (2 years 7 months 3 weeks 6 days 6 hours ago) and read 4804 times:

Those aircraft are a mile apart vertically.  


Chicks dig winglets.
User currently offlineCargolex From United States of America, joined Apr 2010, 1263 posts, RR: 8
Reply 6, posted (2 years 7 months 3 weeks 6 days 6 hours ago) and read 4763 times:

Quoting SEPilot (Reply 3):
unless reduced separation is in place in which case the minimum is 1000 feet.

What circumstances cause reduced separation to be applied? Too much traffic in the airway? Weather?


User currently offlinePapaChuck From United States of America, joined Aug 2010, 136 posts, RR: 0
Reply 7, posted (2 years 7 months 3 weeks 6 days 6 hours ago) and read 4678 times:

The reduced separation mentioned above is RVSM, or Reduced Vertical Separation Minimum. Without RVSM, aircraft above FL290 are required to have 2000' vertical separation, with 1000' vertical below that. With properly equipped RVSM aircraft (and most big jets are these days), 1000' vertical separation is used up to FL410. Above that, it becomes 2000' again. 99% of the jets today, plus many high performance turboprops, are RVSM equipped. Aircraft cross paths 1000 feet apart all day, every day.

PC



In-trail spacing is a team effort.
User currently offlineSEPilot From United States of America, joined Dec 2006, 6897 posts, RR: 46
Reply 8, posted (2 years 7 months 3 weeks 6 days 6 hours ago) and read 4657 times:

Quoting PapaChuck (Reply 8):
Without RVSM, aircraft above FL290 are required to have 2000' vertical separation

Thanks for the correction; I couldn't remember what altitude it started at.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineRoseFlyer From United States of America, joined Feb 2004, 9612 posts, RR: 52
Reply 9, posted (2 years 7 months 3 weeks 6 days 5 hours ago) and read 4560 times:

On top of that, the 777 crew probably could see the A330 for at least half an hour since at the higher altitude he was making a contrail. At first judging by relative size I thought the A330 was a 737.

It's always fun when in traffic like that to just watch the other airplanes. I remember being in a 757 as we overtook a E190 which was only 4,000ft lower. The E190 was in view for a good 15 minutes.



If you have never designed an airplane part before, let the real designers do the work!
User currently offlineKELPkid From United States of America, joined Nov 2005, 6372 posts, RR: 3
Reply 10, posted (2 years 7 months 3 weeks 6 days 5 hours ago) and read 4416 times:

One of my most vivid memories as an airline passenger was watching a TWA 727 fly below us at 2,000   They were making contrails, and flew below us at a 90 degree angle (roughly) to our path over Utah. The whole encounter lasted about a second or two...wish I'd had a camera ready. Would have been film back in those days   No warning from the flight deck, either. Was on an HP 737.


Celebrating the birth of KELPkidJR on August 5, 2009 :-)
User currently offlinepilotpip From United States of America, joined Sep 2003, 3150 posts, RR: 11
Reply 11, posted (2 years 7 months 3 weeks 6 days 4 hours ago) and read 4400 times:

Quoting KELPkid (Reply 10):
One of my most vivid memories as an airline passenger was watching a TWA 727 fly below us at 2,000 They were making contrails, and flew below us at a 90 degree angle (roughly) to our path over Utah. The whole encounter lasted about a second or two...wish I'd had a camera ready. Would have been film back in those days No warning from the flight deck, either. Was on an HP 737.

If I made a PA announcement every time traffic came into view you would be complaining that I was making too many PA announcements.  

This is one of the perks of the job. Coolest one I've had was while in the 145 over Kansas going to DEN. Had a UA 747 overtake us 2000 feet above on the same airway late at night. Full moon and snow on the ground made it so bright I could see the logo on the tail. Was fun watching it creep up behind us on the TCAS.



DMI
User currently offlineSAAFNAV From South Africa, joined Mar 2010, 271 posts, RR: 1
Reply 12, posted (2 years 7 months 3 weeks 6 days 3 hours ago) and read 4319 times:

Even when you are 1 000' apart, but heading straight on... Quite interesting watching it!

Over Africa we, and I believe most other big carries fly a 2nm Right Offset, as there is no radar coverage.



On-board Direction Consultant
User currently offlineNorthwest727 From United States of America, joined Jul 2005, 491 posts, RR: 0
Reply 13, posted (2 years 7 months 3 weeks 5 days 12 hours ago) and read 4082 times:

Quoting pilotpip (Reply 11):
Quoting KELPkid (Reply 10):
One of my most vivid memories as an airline passenger was watching a TWA 727 fly below us at 2,000 They were making contrails, and flew below us at a 90 degree angle (roughly) to our path over Utah. The whole encounter lasted about a second or two...wish I'd had a camera ready. Would have been film back in those days No warning from the flight deck, either. Was on an HP 737.

If I made a PA announcement every time traffic came into view you would be complaining that I was making too many PA announcements.

This is one of the perks of the job. Coolest one I've had was while in the 145 over Kansas going to DEN. Had a UA 747 overtake us 2000 feet above on the same airway late at night. Full moon and snow on the ground made it so bright I could see the logo on the tail. Was fun watching it creep up behind us on the TCAS.

I remember as a kid, nearly 16 years ago, while flying on a WN 737 enroute CLE-STL-PHX, the crew told us to look up. I remember seeing a UA twin (don't remember what twin) fly above about 2000ft, with contrails, at roughly a 45º angle from our course. Upon passing over us, the UA aircraft began a turn and then paralled us! (although it was a bit faster.) I didn't have a camera nor know how to use one, but it left a very vivid memory, and the crew even called it out for us!

Back to the topic, I think SEPilot is right. If I am not mistaken though, doesn't RVSM begin around FL280?


User currently offlinePapaChuck From United States of America, joined Aug 2010, 136 posts, RR: 0
Reply 14, posted (2 years 7 months 3 weeks 5 days 11 hours ago) and read 4070 times:

RVSM airspace begins at FL290, but that can be a bit misleading. A non-RVSM aircraft at FL290 cannot have an RVSM aircraft pass above it at FL300. Eastbound non-RVSM aircraft are typically capped at FL270 for this reason.

Also, it is fairly common for non-RVSM high-performance jets to cruise at FL430 and above. Once they reach FL430, RVSM doesn't matter any more. ATC just needs to be prudent and use 2000' vertical separation while climbing and descending these aircraft through RVSM airspace.

PC



In-trail spacing is a team effort.
User currently offlineNorthwest727 From United States of America, joined Jul 2005, 491 posts, RR: 0
Reply 15, posted (2 years 7 months 3 weeks 5 days 10 hours ago) and read 4035 times:

Quoting PapaChuck (Reply 14):

Thanks, makes a lot of sense now. Unfortunately, I'm still a piston driver, so I have yet to make it up to the Flight Levels...someday, someday.


User currently offlinesoon7x7 From , joined Dec 1969, posts, RR:
Reply 16, posted (2 years 7 months 3 weeks 5 days 3 hours ago) and read 3897 times:

They can't be that close as Air Berlin the only one laying out a contrail. Telephoto compression I suspect Telescope/ Hubbell?). Now the shot here below was close laterally and also consider I was in a 767 so three of us were in formation. Too bad the quality is so bad.
767,767,777race


User currently offlinePapaChuck From United States of America, joined Aug 2010, 136 posts, RR: 0
Reply 17, posted (2 years 7 months 3 weeks 4 days 23 hours ago) and read 3829 times:

Amazing shot, but again the perspective is making it seem as if the aircraft are closer than they really are. Note the abundant blue sky backdrop and the great look at the bellies. This is indicating that the camera was angled up. Looks like a vertical stack with the United bird at the top. I'm willing to bet there was 2000' vertical and a couple miles lateral between each aircraft. Also note the United bird is a 777, throwing the proportions off a bit. Again, great shot, but the telephoto effect is playing games with us.

PC



In-trail spacing is a team effort.
User currently offline817Dreamliiner From Montserrat, joined Jul 2008, 2331 posts, RR: 1
Reply 18, posted (2 years 7 months 3 weeks 4 days 10 hours ago) and read 3663 times:

Quoting soon7x7 (Reply 16):

That's a really cool shot!

I remember just a couple weeks ago when I was flying on AA 211 to JFK I spotted what appeared to be a UA/CO star alliance 777 flying in our direction. Although it didn't appear to be 2000ft above us, because it looked kinda close, but maybe it was.



Reality be Rent. Synapse, break! Vanishment, This World!
User currently offlinesoon7x7 From , joined Dec 1969, posts, RR:
Reply 19, posted (2 years 7 months 3 weeks 4 days 10 hours ago) and read 3660 times:

Quoting PapaChuck (Reply 17):


Negative...While both were a bit higher than my aircraft, the two pictured were same level...no tricks here...

Quoting PapaChuck (Reply 17):
I'm willing to bet there was 2000' vertical and a couple miles lateral between each aircraft.


Way off...
I was so amazed when I saw this I knocked the girl seated next to me out of her seat when I instinctively jumped up to the overhead baggage bin for my camera bag. (All apologies after the shot is taken)...Even the flight attendant was surprised to see the three of us in this cozy three way race back to the states..


User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 20, posted (2 years 7 months 3 weeks 4 days 8 hours ago) and read 3619 times:

Quoting soon7x7 (Reply 19):
Quoting PapaChuck (Reply 17):
I'm willing to bet there was 2000' vertical and a couple miles lateral between each aircraft.


Way off...

They may be at the same flight level, but there's a lot of lateral separation there...the angular size of the 777 against the 767 shows that pretty clearly.

Tom.


User currently offlineunattendedbag From United States of America, joined Oct 2003, 2326 posts, RR: 1
Reply 21, posted (2 years 7 months 3 weeks 4 days 5 hours ago) and read 3565 times:

Quoting MSN007 (Thread starter):
After looking at this picture following the link, I am wondering how close is to close?

Just looking at the picture isn't enough. If it was, this would be a close call too!


View Large View Medium
Click here for bigger photo!

Photo © Martin Wagner




Slower traffic, keep right
User currently offlinetimz From United States of America, joined Sep 1999, 6822 posts, RR: 7
Reply 22, posted (2 years 7 months 3 weeks 4 days 3 hours ago) and read 3526 times:

Quoting soon7x7 (Reply 19):
While both were a bit higher than my aircraft, the two pictured were same level.
If they were, UA was... maybe 10 nm beyond Delta? And Delta was 5 nm from you?


User currently offlinePapaChuck From United States of America, joined Aug 2010, 136 posts, RR: 0
Reply 23, posted (2 years 7 months 3 weeks 3 days 21 hours ago) and read 3409 times:

I'm sorry, but there is absolutely no way that those two aircraft are at the same flight level. To get those two aircraft in the same photo at the same flight level, you would also had to have been at the same flight level. If that were the case, unless both aircraft were in a bank to the right, you should be seeing none of their bellies. If you were looking up to catch the Delta bird above you, another aircraft at the same altitude five miles further away would be completely out of sight below the frame. You have to consider the distances involved. It is deceiving from the pic, but trust me, the 777 is higher than the 767.

PC



In-trail spacing is a team effort.
User currently offlinetimz From United States of America, joined Sep 1999, 6822 posts, RR: 7
Reply 24, posted (2 years 7 months 3 weeks 3 days 8 hours ago) and read 3284 times:

We can do a pretty good job of proving that, if we can assume that the Delta 763 is wings-level.

If it is, comparing the wingspan of its image on the screen with its length we see it's 25 degrees above a horizontal line from the camera. So if it's 2000 ft higher than the camera it's 4700-4800 feet away, and (comparing the 767 and 777 lengths) the 777 is 11000+ feet away. If the 777 were also 2000 feet above camera level, it would be 9+ degrees above a horizontal line from the camera, or 15+ degrees below the 767.

Which is impossible, since the 767's length subtends 2+ degrees at the camera (it's 176 feet long and 4700+ ft away).

Likewise if the 767 is 4000 or 6000 or 8000 feet above the camera.


25 Speedbird128 : Why no contrails for the 777? The 777 is lower than the Air Berlin, and you were lower than the 777. I'd fly offset regardless of radar coverage. SLO
26 Post contains images soon7x7 : You guys crack me up...if had my 600mm lens in my lap your arguments may hold water however the largest focul length lens I had available was a 200mm.
27 Post contains images PapaChuck : I crunched a few numbers myself. Grab a ruler and a calculator and follow along. Just make sure nobody's watching, because onlookers will point and la
28 soon7x7 : I applaud your enthusiasm...BUT...Having been a pilot for nearly 30 years (really good at realizing apparent distances) and a surviving full time avi
29 mandala499 : Lateral... on different levels... the question is... how different? So we get onto: RVSM require vertical separation of 1000ft... so two aircraft goi
30 tdscanuck : I think we're overthinking this...how close were they to you? From that, you can get a pretty good estimate of how far apart they each are just by th
31 Post contains images PapaChuck : Are we over-thinking this? Absolutely. It's what we do around here. One of the first lessons we learn in ATC 101 is that vertical is the easiest way t
32 timz : The photo evidence is good, and it shows the 777 was at a higher altitude than the 767. (That's assuming the 767 was wings-level; if we can't assume
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