DME Hold entry

[paulsalem]

If you have a required Hold for a course reversial at an IAF that has DME legs do you have to go the full length out before turning inbound.

Example:
http://www.naco.faa.gov/d-tpp/0503/05861R25.PDF

Let's say your inbound from the Southwest direct to HOPAX, when you enter the hold (teardrop we'll say) do you have to go outbound for 4DME before turning in bound, then proced to TACOY Or can you just turn inbound after 1min, cross HOPAX and proceed to TACOY?

We're Non Radar so we don't get any of those vector things. And yes, I know I could go to CISBO or DEVAY and not do a PT.

I guess same question would apply if you were just assinged to hold over HOPAX.

Thanks

 

[Lil Jon]

good question. my jepp approach chart legend says to be completed within that distance but they use the standard 10nm in the example.

 

[HMR]

Let's say your inbound from the Southwest direct to HOPAX, when you enter the hold (teardrop we'll say) do you have to go outbound for 4DME before turning in bound, then proced to TACOY Or can you just turn inbound after 1min, cross HOPAX and proceed to TACOY?

We're Non Radar so we don't get any of those vector things. And yes, I know I could go to CISBO or DEVAY and not do a PT.

I guess same question would apply if you were just assinged to hold over HOPAX.

Thanks

Great Question. From AIM 5-4-9(4):
A holding pattern in lieu of procedure turn may be specified for course reversal in some procedures. In such cases, the holding pattern is established over an intermediate fix or a final approach fix. The holding pattern distance or time specified in the profile view must be observed. Maximum holding airspeed limitations as set forth for all holding patterns apply. The holding pattern maneuver is completed when the aircraft is established on the inbound course after executing the appropriate entry. If cleared for the approach prior to returning to the holding fix, and the aircraft is at the prescribed altitude, additional circuits of the holding pattern are not necessary nor expected by ATC. If pilots elect to make additional circuits to lose excessive altitude or to become better established on course, it is their responsibility to so advise ATC upon receipt of their approach clearance.

If you were entering the hold at 200kts (speed limit below 6,000') and had more than a 40kt tailwind, you could easily blow through the 4nm "protected area" in one minute. Therefore, I can see why you'd want to follow DME.

Also reference 5-3-7.

 

[paulsalem]

Well I feel dumb, I read right past that.

Thanks Your Royal Magesty

 

[paulsalem]

The funny thing is, another CFI called HTS approach (our controlling agency), asked the same question, and they said 4DME leg on the entry wasn't required.
However its spelled out in black in white above.

 

[HMR]

I'll bet if you're in a slower A/C where staying within the protected area isn't a problem, ATC doesn't care how you do it as long as you let them know.

As CFII's we teach Parallel, Teardrop, and Direct entries. Remember, those are only "recommended" by the FAA (see AIM 5-3-7(3)(d)). I tend to always use one of those 3 but I've flown with guys who never use them. My old CP used to hit the fix, turn 90 degrees away from the inbound and immediately upon reaching that heading do a standard rate 270 degree turn in the opposite direction. It worked great but I don't know if I'd introduce it to a new Instrument student. As a CFI it's good to CYA and stick to the "black and white".

 

[wheelsup]

My old CP used to hit the fix, turn 90 degrees away from the inbound and immediately upon reaching that heading do a standard rate 270 degree turn in the opposite direction. It worked great but I don't know if I'd introduce it to a new Instrument student. As a CFI it's good to CYA and stick to the "black and white".

I knew a CFI that taught that way - confused the heck out of his instrument students .

~wheelsup

 

[labbats]

Draw it out on chalk, walk it, learn it.

Holding patterns are too abstract otherwise.

 

[A Squared]

I'm not convinced that the AIM excerpt quoted above answers the question, if I understand the question correctly.

As I understand it, the question was "do you have to fly 4 NM legs on the hold, or could you fly, say 3 NM legs?" In other words; "Is the 4 NM a *mandatory* leg length, or a *maximum* leg length?" The AIM only requires that it be "observed" it does not say whether it must be observed as a maximum leg length, or a mandatory leg length. If it is intended as a mandatory length, obviously you must fly 4 nm legs. If it is intended as a maximum, then the maximum is observed by flying 4nm legs, 3 nm legs or 2 nm legs. Merely stating that it must be observed doesn't shed any light on whether it's mandatory or maximum.

In my mind, I don't see any logic to the leg length being mandatory rather than maximum. There's no benefit to it, and presumably regulatory requirements have a reason. There are plenty of reasons for the leg length to be a maximum, it keeps you from hitting hills, trees, radio towers or other airplanes. But if a 4 nm leg will keep you out of the rocks or nearby airspace, a 3 nm leg will too. There's no way you can hit something by flying a leg shorter than specified.

 

[HMR]

There are plenty of reasons for the leg length to be a maximum, it keeps you from hitting hills, trees, radio towers or other airplanes. But if a 4 nm leg will keep you out of the rocks or nearby airspace, a 3 nm leg will too. There's no way you can hit something by flying a leg shorter than specified.

Makes sense to me.

EDIT* Now that you've edited your post it makes even more sense.

 

[A Squared]

Makes sense to me.

EDIT* Now that you've edited your post it makes even more sense.

Yeah, I always think of a better way to explain myself 30 seconds *after* I hit the post button.

 

[FlyingBuckI]

Under radar coverage ATC can sometimes request that you fly different legs/non-standard pattern/etc -- only the inbound course must remain as published.

AIM 5-3-7 states:

a. Whenever an aircraft is cleared to a fix other than the destination airport and delay is expected, it is the responsibility of the ATC controller to issue complete holding instructions (unless the pattern is charted)...

b. If the holding pattern is charted and the controller doesn't issue complete holding instructions, the pilot is expected to hold as depicted on the appropriate chart. ...

(5) DME/GPS Along Track Distance (ATD)

...The controller or the instrument approach procedure chart will specify the length of the outbound leg...

--
This gives the controller the freedom to change the procedure as he sees fit (to a degree). It also gives you the freedom to request an alternate hold if you wish, though no guarantee of approval.

 

[paulsalem]

The actual question was Do you have to fly 4nm outbound on the hold ENTRY.

I think if they put 4nm on there, thats what they want you to fly. If it were a maximum, it would make sense to me that it would be stated that way. Doesn't bother me at all to hold 4nm.

 

[A Squared]

The actual question was Do you have to fly 4nm outbound on the hold ENTRY.

Yes, strictly speaking, that was the question. If however you believe that the holding legs *must* be 4 nm in length, why would a leg on the entry be any different?

I think if they put 4nm on there, thats what they want you to fly.

Can you think of any practical reason why it would be important to ATC for you to fly a full 4NM hold leg?

If it were a maximum, it would make sense to me that it would be stated that way.

Likewise, it could be said that if it were a mandatory length, it would be stated that way. Both the NACO and Jepp IAP legends speak only of "limits" on holds in lieu of PTs, there is no mention of mandatory leg lengths. If you were to look at the Jeppesen plate for that approach, it probably won't have any mention of the 4 NM leg. I say probably, because I don't have the Jepp plate for that approach. I have however looked at several Jepp plates for approaches where the NACO chart shows 4 nm on the hold, and the jepp shows nothing, just the racetrack outline and an altitude....so if the 4 nm is mandatory, how would you know that if you have Jepps? (note the 4 nm leg length is not much different than a 1 min leg at the maximum procedure turn speed of 200 kts, wind of course must be considered.)

The purpose of this hold is to reverse course, get established on the intermediate course and descend from the enroute altitude. (although ATC could issue a hold here for traffic sequencing) Normally, you'd only fly the entry, so if getting established and descending is not a problem, why *would* you fly the entire 4 nm? Can you think of any operational problem which would arise from flying a 2nm entry? There is so much emphasis placed in pimary training on making perfect 1 minute legs, I think that people begin to believe that leg length is actually important. It isn't, except as a maximum. The only people who care about precise 1 minute legs are CFI's and Examiners. In the real world, the only thing ATC cares about is that you don't exceed the limits of the airspace assigned to you for the hold. Other than that, you could be doing figure 8s in the hold, and they wouldn't care.

If you were being held there for ATC purposes, you'd actually *want* to do the full 4 nm legs, it's less work than making 1 minute legs because at 172 speeds 4nm legs means half as many turns, and because watching the DME is easier than timing. That's why you'll hear pilots who are holding for real ask for 5 nm or even 10 nm legs.

 

[HMR]

If you were to look at the Jeppesen plate for that approach, it probably won't have any mention of the 4 NM leg. I say probably, because I don't have the Jepp plate for that approach.

Hey, look at the big brain on A Squared.

You are correct. The Jep plate only shows 4nm in the profile view. The same way it shows 10nm on most other plates. Pilots always (I hope) turn well before the 10nm point on those approaches. Why would this be any different? It's a "maximum" not a "mandatory". Good job!

 

[A Squared]

Hey, look at the big brain on A Squared.

Heheheh, didn't do Brad much good, he still wound up dead <g>

 

[JRSLim]

Jules

Heheheh, didn't do Brad much good, he still wound up dead <g>

Say Hold again -- I dare ya, I double dare ya, Say hold one more time!

 

[A Squared]

Say Hold again -- I dare ya, I double dare ya, Say hold one more time!

W-what????

 

[100LL... Again!]

With a 4nm leg, you would want to modify your teardrop entry a little since flying a 30 degree offset for 4 miles might put you an awfully long way from the inbound course.

I would fly the 30 degree offset for about 45 sec to 1 minute, then parallel the inbound for the rest of the outbound leg.

 

[A Squared]

With a 4nm leg, you would want to modify your teardrop entry a little since flying a 30 degree offset for 4 miles might put you an awfully long way from the inbound course.

I would fly the 30 degree offset for about 45 sec to 1 minute, then parallel the inbound for the rest of the outbound leg.

Not necessarily. The templates which determine protected airspace for holding have enough width to provide protection for a teardrop entry as long as the holding leg, In fact the longer the holding leg, the "fatter" the airspace template is proportionally. you may wish to stay close to the inbound course as a mater of personal preference (I probably would also) but it is not required to remian in hte protected area.