Instrument Procedure Question

[Brasilia Pup]

The 4nm point is the LIMIT of protected airspace for the hold. Do not exceed the 4nm. You can turn inbound in less than 4nm and proceed with the approach.

 

[Jrparne]

Be careful with the term limit. The aim states to use the dme or gps determined distances if they are charted instead of timing. If it says 4 miles you turn at 4 miles. If the approach is running as a gps approach the gps will tell you to conduct the turn at 4 miles, turning early can screw things up down the road.

Yes it is the aim and its recommendations, but in the training setting the aim takes precedence on checkrides...

 

[atpcliff]

This is like a Procedural Track. I have flown with a number of professional (paid) pilot who wanted to turn "early" and not follow the track. I told them that their idea is wrong. It is NOT protected airspace. It is a TRACK and you the approach is designed for you to follow the track as closely as possible.
It is also like a 1 minute holding pattern. You turn at 1 minute, not at 30 seconds.
In the above description 4 miles is NOT the protected airspace. When you turn AT four miles, as depicted, you plane will go OUTSIDE of 4 miles during the turn, as the people who designed the approach planned for your to do. The protected airspace will extend safely beyond the turning radius of your aircraft, which may be very large, for an airplane requiring a fast speed on the approach.

 

[stupidpilot]

This is like a Procedural Track. I have flown with a number of professional (paid) pilot who wanted to turn "early" and not follow the track. I told them that their idea is wrong. It is NOT protected airspace. It is a TRACK and you the approach is designed for you to follow the track as closely as possible.
It is also like a 1 minute holding pattern. You turn at 1 minute, not at 30 seconds.
In the above description 4 miles is NOT the protected airspace. When you turn AT four miles, as depicted, you plane will go OUTSIDE of 4 miles during the turn, as the people who designed the approach planned for your to do. The protected airspace will extend safely beyond the turning radius of your aircraft, which may be very large, for an airplane requiring a fast speed on the approach.

Not necessarily true. You may turn early because the protected airspace left and right of the inbound course is large enough to encompass the airspace you would be in if you turned inbound early. It would be the same amount of lateral protection when performing the straight in approach.

 

[Jrparne]

But why turn early, a gps approach is to be flown as the gps says. It will wait until you are at the 4nm limit to tell you to change track. It is taking into account far more information in determining when and where to turn then you can compute. No where on the gps procedure does it say stay within "4nm" like they do with procedure turns. The procedure turns give you the flexibility to turn early, its a limit, this is not a limit this is a design.

 

[Lynxman]

There is no reason to turn early at all.

 

[stupidpilot]

There is no reason to turn early, I agree. But you are not breaking any rule by doing so. The whole airspace encompassed by the holding pattern is protected and surveyed for obstacles.

 

[NCherches]

Vectors to Final.... problem solved.

 

[Lynxman]

Vectors to Final.... problem solved.

Ya buddy!

 

[A Squared]

This is like a Procedural Track. I have flown with a number of professional (paid) pilot who wanted to turn "early" and not follow the track. I told them that their idea is wrong. It is NOT protected airspace. It is a TRACK and you the approach is designed for you to follow the track as closely as possible.

So, tell me, is there anything which would legally prevent you from turning to your 45 degree out bound leg on procedure turn immediately after passing the IAF, and only flying 45 seconds out bound at a 45 instead of a minute?

I'll save you some trouble, answer is no. So given that the only function of the racetrack pattern is course reversal, what, legally, prevents you from flying the reversal a little closer in. And what would be the practical rationale behind such a regulation?

It is also like a 1 minute holding pattern. You turn at 1 minute, not at 30 seconds.

You got a reference for that? What regulation would you be violating? I can't think of one. When you consider that the purpose of a hold (as opposed to a racetrack reversal on an IAP) is to park you so you're not progressing forward, and you don't stray into rocks, or the path of another plane, I'm having a herd time imagining that it would make anykind of real difference to anyone who matters is you used 30 second legs in lieu of 1 minute lags.