Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
How To Enter A Holding Pattern?  
User currently offlineBio15 From Colombia, joined Mar 2001, 1089 posts, RR: 7
Posted (7 years 10 months 3 weeks 5 days 6 hours ago) and read 11406 times:

I have seen holding patterns in which the direction for entering the pattern is opposite to the one of the pattern itself. It's not clear to me how is the pattern supposed to be flown into. Here's a picture of a holding pattern illustrating my question:



If there's an aircraft holding initially, what is the risk of another plane flying into the pattern head on with the plane previously holding? My guess is that this doesn't happen, but instead the way of entering the pattern is to first deviate from the path shown in the chart, and merge with the "downwind" leg in the correct pattern direction (Not fly direct to the intersection). Is this right? Thanks in advance.

Alfredo

8 replies: All unread, jump to last
 
User currently offlineZkpilot From New Zealand, joined Mar 2006, 4773 posts, RR: 9
Reply 1, posted (7 years 10 months 3 weeks 5 days 5 hours ago) and read 11395 times:

There are 3 types of entry into a hold: Parallel Entry, Offset Entry, Direct Entry. Your example is a Parallel Entry.
Parallel entry occurs in the 110deg sector that is heading opposite to the inbound (like your example). The aircraft fly over the beacon, fly along the inbound leg but heading outbound then make a 180 deg turn (towards the outbound and then back onto the inbound).Photobucket - Video and Image Hosting

Offset entry occurs on the remaining 70deg sector heading opposite to the inbound...fly overhead the hold point, fly towards the outbound (less than 30deg from the inbound), then make a turn onto the inbound.Photobucket - Video and Image Hosting

Direct Entry:Take 360deg around the hold point inbound leg. 70deg sector on the holding side of the inbound (ie incl the outbound leg) and that is your direct entry all the way thru to the opposing 70deg angle opposite.
Photobucket - Video and Image Hosting


this page shows it best http://bathursted.ccnb.nb.ca/vatcan/...rchives/20030518/CurrentTopic.html

[Edited 2006-05-29 09:20:07]


54 types. 38 countries. 24 airlines.
User currently offlineZkpilot From New Zealand, joined Mar 2006, 4773 posts, RR: 9
Reply 2, posted (7 years 10 months 3 weeks 5 days 5 hours ago) and read 11388 times:

Quoting Bio15 (Thread starter):
If there's an aircraft holding initially, what is the risk of another plane flying into the pattern head on with the plane previously holding? My guess is that this doesn't happen, but instead the way of entering the pattern is to first deviate from the path shown in the chart, and merge with the "downwind" leg in the correct pattern direction (Not fly direct to the intersection). Is this right? Thanks in advance.

As for this, a/c don't hold in a pattern at the same altitude... they stack them ontop of each other... the pattern is still the same... you could have for example 5 aircraft all holding together but several thousand feet high.



54 types. 38 countries. 24 airlines.
User currently offlineBio15 From Colombia, joined Mar 2001, 1089 posts, RR: 7
Reply 3, posted (7 years 10 months 3 weeks 5 days 3 hours ago) and read 11368 times:

Hi Zkpilot, thanks for the response, it's clear to me now.

----

Taking a closer look at the diagrams I find the pattern entry paths rather odd, specifically the chosen angle, 70°.


For the pattern described above:

* I picture an aircraft going for the parallel entry (#1 on the diagrams), but very close to the direct entry (#3 on the diagrams). That is, very close to the 70° line but still going for a paralell entry path. In this case the aircraft should make a very tight left turn not to go too far off course of the pattern.

* The other case is an aircraft going for a direct entry, but close to the 70° line limiting with the offset entry (#2 on the diagrams). Here it would be necessary to make a tight left turn and then immediately the right turn not to overshoot the pattern on the outbound leg.

I would think that having 90° sections is the more reasonable choice. Having 180° space perpendicular to the pattern for direct entries, and 90° for offset and paralell entries each. Yet, I am certain there is a pretty good explanation for the angle being chosen as 70°. Do you happen to know what is the reason?


Alfredo


User currently offlineThirtyEcho From United States of America, joined Dec 2001, 1639 posts, RR: 1
Reply 4, posted (7 years 10 months 3 weeks 5 days 3 hours ago) and read 11365 times:

Bear in mind that how you enter a hold is your business, as long as you remain within the hold's protected airspace according to ATC's instructions.

The nice diagrams, above, are really only suggestions based on long experience. Some of this is based on the pre-radar notion of timed approaches wherein you were cleared to hold and given a time to depart the holding fix toward the approach fix. Mix that in with a fixed-card ADF or a Four Course Range approach and you'll see why the old-timers had gray hair.


User currently onlineMrChips From Canada, joined Mar 2005, 925 posts, RR: 0
Reply 5, posted (7 years 10 months 3 weeks 4 days 17 hours ago) and read 11325 times:

Quoting Bio15 (Reply 3):

* I picture an aircraft going for the parallel entry (#1 on the diagrams), but very close to the direct entry (#3 on the diagrams). That is, very close to the 70° line but still going for a paralell entry path. In this case the aircraft should make a very tight left turn not to go too far off course of the pattern.

* The other case is an aircraft going for a direct entry, but close to the 70° line limiting with the offset entry (#2 on the diagrams). Here it would be necessary to make a tight left turn and then immediately the right turn not to overshoot the pattern on the outbound leg.

Incorrect - they're both parallel entries.

Why? Because this is a NON-STANDARD hold - all turns are to the left, instead of the right.

Quoting Bio15 (Reply 3):

I would think that having 90° sections is the more reasonable choice. Having 180° space perpendicular to the pattern for direct entries, and 90° for offset and paralell entries each. Yet, I am certain there is a pretty good explanation for the angle being chosen as 70°. Do you happen to know what is the reason?

There is a good reason - it allows you to stay within the protected airspace set aside for the hold. When flying a hold, you use a rate one turn (3 degrees per second), and this can give a rather large turn radius at higher speeds. Utilizing the offset angles prevents pilots from making these huge turns and getting lost in the hold in the process (believe me, it can happen easily).



Time...to un-pimp...ze auto!
User currently offlineCorey07850 From United States of America, joined Feb 2004, 2525 posts, RR: 5
Reply 6, posted (7 years 10 months 3 weeks 4 days 16 hours ago) and read 11325 times:

I'd opt for a teardrop entry myself... Hit the fix, turn to a heading of 134 for a minute, standard rate left turn to intercept the 284 course inbound and you're set

Parallel entry is pointless since you are tracking the same radial off the missed approach to the holding fix. Once you hit the fix and fly outbound for your "entry" you are simply flying along the inbound course. This does nothing to help you enter the pattern.


User currently offlineBio15 From Colombia, joined Mar 2001, 1089 posts, RR: 7
Reply 7, posted (7 years 10 months 3 weeks 4 days 14 hours ago) and read 11303 times:

Quoting MrChips (Reply 5):
Why? Because this is a NON-STANDARD hold - all turns are to the left, instead of the right.

Hi Mr. Chips

I was referring to a hold like the one described on the diagrams posted by zkpilot, which consists of right turns. For the BLAKO hold, imagine the two situations I described, but inverted for the right hand holding pattern.

In other words, entering a hold like BLAKO but heading 360° instead of 104°, according to the reccomendations, should be in parallel, which would force a tight right turn. From that angle it would probably be more convenient to perform a direct entry.


Alfredo


User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 8, posted (7 years 10 months 3 weeks 4 days 14 hours ago) and read 11299 times:

Quoting ThirtyEcho (Reply 4):
Bear in mind that how you enter a hold is your business, as long as you remain within the hold's protected airspace according to ATC's instructions.

Exactly right! In the bad old days there were examiners who would bust you on a checkride for doing - in their opinion - the wrong entry. I'd sure as hell protest that! Worse, they'd look for approaches with high-workload missed approach procedures.

Think of it as a practical matter instead. You have lots of room on the HOLDING side of the radial and lots of room on the OUTBOUND sector. So keep your maneuvering over there. Each one of those entries does that, meets that criteria. Try not to stray over to the NON-holding side and especially so at the FIX end of the pattern. Beyond that, ain't no big!



Happiness is not seeing another trite Ste. Maarten photo all week long.
Top Of Page
Forum Index

Reply To This Topic How To Enter A Holding Pattern?
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
How To Load A Multi-destination Flight? posted Wed Nov 22 2006 19:25:43 by Tobi3334
How To Deal With Air Sickness posted Fri Aug 4 2006 06:14:07 by AAden
How To Read An Airport Chart? posted Wed Jun 7 2006 15:52:53 by AirPacific747
Smoke Across Runway From Local Fire - How To Deal? posted Thu May 25 2006 19:20:26 by JulianUK
How To Get A Summer Airport Job posted Mon Mar 27 2006 23:29:09 by AlexPorter
How To Load A Helicopter Into A 74F? posted Thu Dec 1 2005 12:22:19 by ZakHH
How To Calculate Required Runway Length posted Sun Jul 31 2005 19:51:28 by Mozart
How To Decide Which Aircraft To Send? posted Tue May 31 2005 22:52:58 by ANITIX87
A Tutorial On How To Read Approach Plates? posted Sun May 29 2005 17:04:04 by Mozart
Need Help: How To Make Old 727 Parts Light Up posted Sat Apr 16 2005 07:03:05 by FLY2HMO
How To Become A Commercial Airline Pilot? posted Tue Jul 9 2013 14:50:44 by musicalmartian
How To Deice Inside The Nacelle? posted Sun Mar 3 2013 10:32:04 by abnormal
How To Work Out Fuel Consumption? posted Tue Feb 26 2013 10:09:22 by GAZ787PILOT
How To Get EASA-66 For FAA A&Ps? posted Thu Sep 20 2012 02:07:05 by MQTmxguy
How To Read A Passenger List? posted Mon Jun 25 2012 12:00:37 by CityAirline
How To Change An A320 Wheel (video) posted Sun May 13 2012 22:53:55 by wingscrubber

Sponsor Message:
Printer friendly format