DME Holding entry procedure

[mach tuck]

Hey guys,

when entering a DME hold, what is the proper procedure. Let's say you've been given 5 mile legs. A teardrop entry will work fine for this example. Once you cross over your fix, turn 30 degrees, do you time for 1 minute, or do you fly for 5 miles? The AIM doesn't go into detail, all it says is to use mileage instead of time. That's easy enough to understand but wouldn't flying a heading for 5 even 10 miles or more before properly being establised possibly put you way off course? Thanks for you help.

mach

 

[nosehair]

wouldn't flying a heading for 5 even 10 miles or more before properly being establised possibly put you way off course?

mach

Not in terms of busting airspace. When you have those long legs, your holding airspace width is also largely increased, so no worry there, but as far as flying the pattern, you would have a long, slow turn back in, so it is ok to shorten the leg. The DME distance is a maximum. You can turn within this holding airspace, so I would go 30* for one minute, then parrallel for the remainder of the 5 miles, or actually about 4, then start the turn back in.

 

[Frmr Avro Drvr]

During the entry I would fly my 30* for one minute outbound and then turn back to the fix to enter the hold. Once have have completed the entry procedure, they I would fly the five or ten mile legs. Five or Ten mile legs are really only good if you are flying a faster aircraft. Flying a Cessna 5 miles out gives plenty of time for drift to make a mess of your hold. This actually increases your workload. In light aircraft, IMHO, it is easier to stick with the timing.

 

[bafanguy]

mach tuck,

Good question. I never would've thought of this point.

I know how I did it/saw it done as long as I can remember, but I got out the AIM just to be sure I was recalling what I THOUGHT I was remembering ( there has to be a better way to phrase that ).

My take is that in a DME hold, timing is out, including the entry. AIM, page 5-3-12, para 5, says, "DME holding is subject to the same entry and holding procedures except that distances(nautical miles) are used in lieu of time values." If a time value is part of the entry procedure, that time value is replaced by a DME value, the leg length.

I would think that using one minute during the DME hold entry could run you past the specified leg length if you had a strong tailwind during entry, especially at higher speeds. Flying the entry leg out to the specified DME isn't going to put you outside the hold airspace.

If you look at the diagram on that same page, it shows the turn to the IB leg being started AT the specified leg length DME.

I admit, the AIM and even the FAA Instrument Flying Handbook, are a bit vague. Lots of ways to skin the cat, but this is my take on it based on what I read. If there's a source that says timing is used during entry to a DME hold, I'd be interested to see it.

 

[Tinstaafl]

The standard Sector 2/teardrop entry uses the holding pattern outbound timing up to a maximum of 1 min 30 sec. If the holding pattern timing is greater than 1:30 then the sector 2/teardrop entry should turn to parallel the outbound hold track for the portion remaining after 1 min 30 sec.