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Landing Spacing  
User currently offlineIPFreely From United States of America, joined Dec 2006, 229 posts, RR: 0
Posted (7 years 2 months 2 weeks 4 days 3 hours ago) and read 3523 times:

I was looking at Google Earth and noticed an airplane is captured just before landing at SAN. Pretty neat. I wondered if I would be able to see another airplane on approach, so I scrolled over a little, and there was another one, close behind the first. Very close, just a little over 1/2 mile in fact. If they're landing at about 130 kts, this means they're about 20 seconds apart, not counting for the fact that the gap will close when the first airplane lands and starts braking.

Isn't that a little too close?

Both appear to be Southwest 737's, one in old colors and one in new.

http://i59.photobucket.com/albums/g282/I_P_Freely/SAN800.jpg

18 replies: All unread, jump to last
 
User currently offlineDC10sRULE From Canada, joined Oct 2006, 172 posts, RR: 0
Reply 1, posted (7 years 2 months 2 weeks 4 days 2 hours ago) and read 3489 times:

I suspect that somewhere between the 2 aircraft might be a border where two or more photos are joined - in other words the two aircraft might not have been captured in real time on the approach.

However, assuming 1/2 mile spacing was in effect, then the 2nd aircraft likely overshot due to the previous arrival very likely still being in their way.

I don't know what standard spacing is used at KSAN, but at CYYZ, the closest spacing that the arrival controller will hand off to the tower is 2.5 miles. Visual approaches with 2 miles spacing can also work with proper runway and wind conditions. 1/2 mile spacing with 2 B737s not good.

Hope this helps.

JA

 crowded   crowded 



Giggity-Giggity..!
User currently offlineIahflyr From United States of America, joined Jun 2005, 4790 posts, RR: 23
Reply 2, posted (7 years 2 months 2 weeks 4 days 1 hour ago) and read 3452 times:

2.5 NM spacing if no wake turbulence separation is required.....the FAA requires this to be runway specific for that airport that is approved to go down to less than 3 NM on final, again no wake turbulene separation issue.

I don't think your 1/2 behind that first aircraft is accurate. If the #2 aircraft was that close they will in most cases be making another approach.



Any views shared are strictly my own and do not a represent those of any former employer.
User currently offlineThenoflyzone From Canada, joined Jan 2001, 2254 posts, RR: 12
Reply 3, posted (7 years 2 months 2 weeks 3 days 20 hours ago) and read 3352 times:

Standard terminal spacing, when all the conditions are met, is 3 nm.

If a terminal controller wants to squeeze in planes tighter than that (visual approaches excluded), the Civil aviation authoritiy of that country has to approve it. CYYZ is the only canadian airport with such an approval.

This being said, once the planes at YYZ are inside the marker, they are towers control, and tower can apply visual separation, thus the 3nm separation standard becomes irrelevant. Obviously, when the weather is bad, tower cannot take control of aircraft, which means the terminal controller is responsible of aircraft separation all the way to touchdown, in which case 3nm would be needed.

Now, as for wake turbulence, the separation goes as follows.

Heavy behind a heavy: 4nm

Medium behind a heavy : 5nm

Light behind a heavy : 6nm

Light behind a medium: 4nm

heavy aircraft, based on ICAO criteria, are aircraft with a maximum takeoff weight of 136 tonnes or more.

Medium aircraft : More than 5.7 tonnes - less than 136 tonnes

Light aircraft: 5.7 tonnes or less of MTOW

hope this helps!

Thenoflyzone



us Air Traffic Controllers have a good record, we haven't left one up there yet !!
User currently offlineIAHFLYR From United States of America, joined Jun 2005, 4790 posts, RR: 23
Reply 4, posted (7 years 2 months 2 weeks 3 days 8 hours ago) and read 3241 times:

Quoting Thenoflyzone (Reply 3):
Standard terminal spacing, when all the conditions are met, is 3 nm.

Negative.....The FAA allows for less than 3 NM when ALL conditions are met, runway occupancy time of 50 seconds or less average has been documented and approved for reduced separation on final, no wake turb issues for the following aircraft and a few more, 2.5 NM separation on final inside of 10 miles from the runway is legal separation even in IFR weather.

Some places such as ORD and IAH have applied for a waiver to take the 2.5 NM separation out to 20 miles from the runway.....ORD's may already have been approved, IAH still pending at this time...there may be other facilities also that have requested the same.



Any views shared are strictly my own and do not a represent those of any former employer.
User currently offlineThenoflyzone From Canada, joined Jan 2001, 2254 posts, RR: 12
Reply 5, posted (7 years 2 months 1 week 2 days 5 hours ago) and read 3134 times:

Quoting IAHFLYR (Reply 4):
Negative.....The FAA allows for less than 3 NM when ALL conditions are met

Granted, nevertheless, STANDARD terminal spacing for the majority of US airports is still 3 nm. The busier hubs like ATL, ORD, IAH have waivers but that's details, Just like YYZ is the only one that has a waiver to go down to 2.5 NM in Canada.



us Air Traffic Controllers have a good record, we haven't left one up there yet !!
User currently offlineIAHFLYR From United States of America, joined Jun 2005, 4790 posts, RR: 23
Reply 6, posted (7 years 2 months 1 week 2 days 5 hours ago) and read 3117 times:

Quoting Thenoflyzone (Reply 5):
STANDARD terminal spacing for the majority of US airports is still 3 nm. The busier hubs like ATL, ORD, IAH have waivers but that's details



Quoting Thenoflyzone (Reply 3):
Standard terminal spacing, when all the conditions are met, is 3 nm

So is this standard with conditions or what???  Confused

I would suggest that a standard at busier hubs like ATL, ORD, IAH with waivers would be 2.5 for those runways the waivers are in place for, otherwise 3 is the standard. Redardless, the object is to land.  Smile



Any views shared are strictly my own and do not a represent those of any former employer.
User currently offlineChuchoteur From France, joined Sep 2006, 750 posts, RR: 0
Reply 7, posted (7 years 2 months 1 week 2 days 5 hours ago) and read 3112 times:

Plane Landing As Seen From Satellite (Google Earth) (by Vunz Jul 6 2005 in Civil Aviation)

discussed extensively on several other threads...

the satellite images are taken with a time lapse between them, and overlaid.
hence the appearance of reduced separation.

a couple of other airports show the same characteristic as well


User currently offlineThenoflyzone From Canada, joined Jan 2001, 2254 posts, RR: 12
Reply 8, posted (7 years 2 months 1 week 2 days 2 hours ago) and read 3054 times:

Quoting IAHFLYR (Reply 6):
So is this standard with conditions or what???

In order to provide terminal control with 3nm spacing between 2 aircraft, you need to have the following.

#1 TCU (Terminal control Unit) service is provided.

#2 You have a 60 NM or less radius on your radar screen.

#3 The aircraft are situated withing 80 NM of a radar antenna

#4 The altitude indicators for both aircraft are displayed on the radar screen, or

both aircraft are below 15 000 ft ASL .



These are the basic conditions required to provide 3NM spacing in a TCU.



us Air Traffic Controllers have a good record, we haven't left one up there yet !!
User currently offlineXJRamper From United States of America, joined Dec 2003, 2451 posts, RR: 51
Reply 9, posted (7 years 2 months 1 week 2 days 2 hours ago) and read 3041 times:

I thought that minimum spacing for Category III aircraft was 6000 feet.

XJR



Look ma' no hands!
User currently offlineIAHFLYR From United States of America, joined Jun 2005, 4790 posts, RR: 23
Reply 10, posted (7 years 2 months 1 week 2 days 1 hour ago) and read 2999 times:

Quoting Thenoflyzone (Reply 8):
In order to provide terminal control with 3nm spacing between 2 aircraft, you need to have the following.

That may very well be true but not in the U.S. airspace, that is to what my posts are directed toward, I am barely smart enough to keep our requirements straight let alone the requirements of other countries.  Smile

Quoting XJRamper (Reply 9):
I thought that minimum spacing for Category III aircraft was 6000 feet.

Correct for runway separation of course which is different that RADAR separation on final when not applying visual separation.



Any views shared are strictly my own and do not a represent those of any former employer.
User currently offlineThenoflyzone From Canada, joined Jan 2001, 2254 posts, RR: 12
Reply 11, posted (7 years 2 months 1 week 2 days 1 hour ago) and read 2979 times:

Quoting IAHFLYR (Reply 10):
That may very well be true but not in the U.S. airspace

That's because the FAA does not follow ICAO standards.



us Air Traffic Controllers have a good record, we haven't left one up there yet !!
User currently offlineIahflyr From United States of America, joined Jun 2005, 4790 posts, RR: 23
Reply 12, posted (7 years 2 months 1 week 2 days ago) and read 2942 times:

Quoting Thenoflyzone (Reply 11):
That's because the FAA does not follow ICAO standards.

I sure like our rules much better than

 down 

Quoting Thenoflyzone (Reply 8):
In order to provide terminal control with 3nm spacing between 2 aircraft, you need to have the following.

#1 TCU (Terminal control Unit) service is provided.

#2 You have a 60 NM or less radius on your radar screen.

#3 The aircraft are situated withing 80 NM of a radar antenna

#4 The altitude indicators for both aircraft are displayed on the radar screen, or

both aircraft are below 15 000 ft ASL .



These are the basic conditions required to provide 3NM spacing in a TCU.

Sorry, just my opinion.....
 cheerful 



Any views shared are strictly my own and do not a represent those of any former employer.
User currently offlineHighFlyer9790 From United States of America, joined Jul 2005, 1241 posts, RR: 0
Reply 13, posted (7 years 2 months 1 week 1 day 22 hours ago) and read 2917 times:

Quoting Thenoflyzone (Reply 3):
heavy aircraft, based on ICAO criteria, are aircraft with a maximum takeoff weight of 136 tonnes or more.

136 tonnes = 340,000lbs

i thought 250,000 was the point where "heavy" is appended to the call sign?



121
User currently offlineIAHFLYR From United States of America, joined Jun 2005, 4790 posts, RR: 23
Reply 14, posted (7 years 2 months 1 week 1 day 22 hours ago) and read 2915 times:

Quoting HighFlyer9790 (Reply 13):
250,000

255,000



Any views shared are strictly my own and do not a represent those of any former employer.
User currently offlineTimz From United States of America, joined Sep 1999, 6711 posts, RR: 7
Reply 15, posted (7 years 2 months 1 week 1 day 20 hours ago) and read 2893 times:

Quoting HighFlyer9790 (Reply 13):
136 tonnes = 340,000lbs

300,000 lb you mean. Which was the "heavy" weight until a few years ago.


User currently offlinethenoflyzone From Canada, joined Jan 2001, 2254 posts, RR: 12
Reply 16, posted (6 months 3 weeks 9 hours ago) and read 1705 times:

Quoting IAHFLYR (Reply 10):
That may very well be true but not in the U.S. airspace,

Actually, the FAA has similar conditions that have to be met.

http://www.faa.gov/air_traffic/publications/atpubs/atc/atc0505.html

5-5-4. MINIMA
a. Terminal

1. When less than 40 miles from the antenna- 3 miles.
2. When 40 miles or more from the antenna- 5 miles.
3. For single sensor ASR-9 with Mode S, when less than 60 miles from the antenna- 3 miles.
4. For single sensor ASR-11 MSSR Beacon, when less than 60 miles from the antenna- 3 miles.

Thenoflyzone



us Air Traffic Controllers have a good record, we haven't left one up there yet !!
User currently offlineIAHFLYR From United States of America, joined Jun 2005, 4790 posts, RR: 23
Reply 17, posted (6 months 3 weeks 5 hours ago) and read 1584 times:

Quoting thenoflyzone (Reply 16):
Actually, the FAA has similar conditions that have to be met.

Ya know, I'm so glad I made a 32 year career out of not knowing my separation standards!! What's your point, forgive me as it is six years later from the last post on this thread?



Any views shared are strictly my own and do not a represent those of any former employer.
User currently offlinethenoflyzone From Canada, joined Jan 2001, 2254 posts, RR: 12
Reply 18, posted (6 months 3 weeks 4 hours ago) and read 1537 times:

Quoting IAHFLYR (Reply 17):
What's your point, forgive me as it is six years later from the last post on this thread?

My point was simply to show that the U.S has in fact very similar conditions on how and when 3nm can be applied, unlike what you were trying to convey by saying...

Quoting IAHFLYR (Reply 10):
That may very well be true but not in the U.S. airspace


p.s As for why it took me 6 years to answer, i believe that's because this post was originally on civil av, and airliners has a tendency of moving around threads. I dont come on tech/ops much, and even less a search on tech/ops.

Thenoflyzone

[Edited 2013-10-03 19:34:20]


us Air Traffic Controllers have a good record, we haven't left one up there yet !!
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