Timing outbound before you start a procedure turn

[aviategw]

Okay, I'm realllly dusting off my memory here, but I have a question on timing outbound for a procedure turn.

I know to turn on the depicted side, to adhere to the depicted minimum altitudes, to complete the maneuver within the distance specified on the profile view, usually 10 NM, and to maneuver at a maximum speed not greater than 200 KIAS, (just under Vne in a Seminole, btw). I've always heard, and always used one minute outbound as the time to fly before you start the procedure turn.

My question: is there a corollary about flying outbound for two minutes if the navaid for the approach is on the field? I.e., if the VOR/NDB that the approach is based off of is physically located on the field, I would then fly outbound for 2 minutes to better set myself up for the approach.

I remember something about this from my original IFR training, but I'm not quite sure how this goes.

Ideas/opinions?

 

[kellwolf]

Re: Timing outbound before you start a procedure t

Honestly, couldn't tell ya. I've only done a hold over a navaid, then shot the approach for that navaid once. That was the NDB at SFB. Held over it for about ten minutes, then did the NDB approach. It was only one min legs for me then.

 

[ananoman]

Re: Timing outbound before you start a procedure t

[ QUOTE ]
My question: is there a corollary about flying outbound for two minutes if the navaid for the approach is on the field? I.e., if the VOR/NDB that the approach is based off of is physically located on the field, I would then fly outbound for 2 minutes to better set myself up for the approach.


[/ QUOTE ]
You are correct. In a Seminole, you are probably flying 110-120 KIAS outbound, or about 2 miles per minute. For an approach with the navaid on the field you will be about 4 miles out prior to starting the procedure turn. This will give you some extra room to loose altitude and find the airport, while keeping you within 10 miles of the navaid.

Just be careful if you start to fly a faster airplane or if you have a big tailwind outbound. You may have to modify this rule to stay within the 10 miles. If you have DME or even better GPS, then you can monitor your distance. When doing NDB approaches I like to put the NDB in the GPS, so I know how far out I am. This can take the guess work out of timing the outbound leg, and lets you know how far you have to go until the navaid once established inbound.

 

[MidlifeFlyer]

Re: Timing outbound before you start a procedure t

There are training and flying preferences but nothing official.

Remember that the barb only tells you which side of the course line to make your turn. On an off-airport FAF, for example, you could legitimately cross the FAF fly outbound zero seconds and start a 180° turn.

The whole idea is to have enough room/time to be completely established once you are inbound on the final approach course, and I think that most CFIIs teach outbound timing 1 minute for an off-airport FAF and 2 minutes for no FAF as =usually= being enough to buy the time you need.

It's not always since your position is wind/groundspeed related. Consider that 1 from the FAF or 2 no-FAF minute outbound flying a CE-172 at 90 KTS indicated with a 20 KT final approach course tailwind .