GPS Holding

[Aviator524]

Hello,

I just wanted to get some feedback about GPS Holding. In the AIM 5-3-7 it is stated that GPS holding is subject to the same entry and holding procedures except that distance (NM) are used in Lieu of time values. I have had some people tell me that during a Teardrop or Parallel entry they still use timing (1 minute below 14,000) instead of distance. For example for a GPS hold that has 4 nm legs, the will initiate the hold entry using 1 minute instead of 4 nm. My interpretation of the AIM is that Distance is used for all aspects including the entry, therefore I use 4 nm during hold entries. I just wanted to see if anybody else has some input to GPS holding.

 

[tgrayson]

My interpretation of the AIM is that Distance is used for all aspects including the entry, therefore I use 4 nm during hold entries.

I agree. I don't see how it could be read any other way.

 

[Fly_Unity]

Hello,

I just wanted to get some feedback about GPS Holding. In the AIM 5-3-7 it is stated that GPS holding is subject to the same entry and holding procedures except that distance (NM) are used in Lieu of time values. I have had some people tell me that during a Teardrop or Parallel entry they still use timing (1 minute below 14,000) instead of distance. For example for a GPS hold that has 4 nm legs, the will initiate the hold entry using 1 minute instead of 4 nm. My interpretation of the AIM is that Distance is used for all aspects including the entry, therefore I use 4 nm during hold entries. I just wanted to see if anybody else has some input to GPS holding.

NM is the limit as far as I know. You can do one minute as long as you stay within the DME specified.

I also do the entries as one minute. Had a student try to do a teardrop entry the other day on a 8 DME hold. I teach a 30 degree subtraction from the outbound (for a teardrop) for one minute, then outbound or inbound as long as you remain within the distance specified.

 

[MidlifeFlyer]

I agree. I don't see how it could be read any other way.

I saw a pretty long discussion on another forum with a fairly large contingent reading it the other way - one minute outbound before beginning the 4 NM legs.

No, I didn't agree with them and found the discussion somewhat ludicrous.

 

[dasleben]

I saw a pretty long discussion on another forum with a fairly large contingent reading it the other way - one minute outbound before beginning the 4 NM legs.

No, I didn't agree with them and found the discussion somewhat ludicrous.

So wait, they'd time the outbound in order to make the inbound 4 DME? That's absurd. If the inbound is 4 DME...guess what the outbound will be?

 

[tgrayson]

No, I didn't agree with them and found the discussion somewhat ludicrous.

We had one here a while back and a number of people thought timing was the way to go, too. The only real argument that I recall was that the teardrop entry might carry you outside the protected area if you go the DME distance. My calculations showed the difference minimal.

 

[LV-ARG]

Hello,

I just wanted to get some feedback about GPS Holding. In the AIM 5-3-7 it is stated that GPS holding is subject to the same entry and holding procedures except that distance (NM) are used in Lieu of time values. I have had some people tell me that during a Teardrop or Parallel entry they still use timing (1 minute below 14,000) instead of distance. For example for a GPS hold that has 4 nm legs, the will initiate the hold entry using 1 minute instead of 4 nm. My interpretation of the AIM is that Distance is used for all aspects including the entry, therefore I use 4 nm during hold entries. I just wanted to see if anybody else has some input to GPS holding.

I can see a problem with using distance and tear drop entries

 

[Douglas]

I don't know why you would use time, but I typically turn in after two miles because four miles takes a total of forever.

 

[flymike]

either way as long as you stay on/in the "protected" side of the hold isn't that the main thing.. although this is more of a discussion on specific technique/procedure

 

[MidlifeFlyer]

So wait, they'd time the outbound in order to make the inbound 4 DME? That's absurd. If the inbound is 4 DME...guess what the outbound will be?

The argument goes somehting like this. From the AIM:

==============================
NOTE-
The initial outbound leg should be flown for 1 minute or 1 1/2 minutes (appropriate to altitude). Timing for subsequent outbound legs should be adjusted, as necessary, to achieve proper inbound leg time. Pilots may use any navigational means available; i.e., DME, RNAV, etc., to insure the appropriate inbound leg times.
==============================

For the lower altitude hold, that 's saying that the initial outbound leg is 1 minute regardless of whether or not it will result in a 1 minute inbound and that the adjustments all occur in the subsequent outbounds. The argument is that this note is not dependent on whether it's a timed or distance pattern.

IOW, in a 4 DME hold, you fly the initial entry outbound for 1 minute and then start the 4 NM legs.

Makes no sense to me but that's the argument. And to quite tgrayson, those who make it "don't see how it could be read any other way."

 

[nosehair]

This is one of those times when the AIM is not regulatory. It just doesn't matter as long as you don't exceed the 4 miles.

 

[fholbert]

Hello,

I just wanted to get some feedback about GPS Holding. In the AIM 5-3-7 it is stated that GPS holding is subject to the same entry and holding procedures except that distance (NM) are used in Lieu of time values.

I don't know if that's true. As I approach a timed holding pattern with my 430 the size of the holding pattern on the 430's display changes as I reduce speed.

 

[fholbert]

This is one of those times when the AIM is not regulatory. It just doesn't matter as long as you don't exceed the 4 miles.

If you've ever seen a holding pattern terps the protected airspace is huge, much larger than 4 miles. Especially if faster aircraft may use the pattern.

 

[braunpilot]

Simple answer...Fly Freight. What's GPS? (Yes, I understand that some operators have GPS.)

 

[Blackhawk]

This is one of those cases where I gotta ask... does it really matter as long as you remain in the protected airspace?

 

[MidlifeFlyer]

This is one of those cases where I gotta ask... does it really matter as long as you remain in the protected airspace?

That's a good question. Holding patterns can serve an ATC function. Will ATC vector or clear other aircraft based on where you are expected to be within a holding pattern? Does a turn inbound at 2 miles in a 4 NM hold present a potential for conflict?

There is a small blurb in one of the FAA publications (I forget which) that talks about separation requirements being reduced once an aircraft is "established" in a hold. Any relation to this issue?

 

[Nanopilot]

I think you should use NM during the hold, but you can use whatever you like (time) during the entry.

 

[Xiph]

We had one here a while back and a number of people thought timing was the way to go, too. The only real argument that I recall was that the teardrop entry might carry you outside the protected area if you go the DME distance. My calculations showed the difference minimal.

The concern I've come across is not so much leaving the protected area as it is ending up way off the inbound course when it's time to turn back around, so much so that a standard rate turn is still going to leave you just under a mile off by my calculations (at the speeds common to training aircraft). Granted, you could always reduce your turn rate to try and close that gap, but that seems like more effort than it's worth when you could just go out for a minute and turn inbound at standard rate and end up much closer to your course.