Question about entering an approach?

[dtuuri]

It's do-able.......but if you were required to cross the Salem VORTAC @ 6000' to initiate you'd better be a-comin' right on down
With a 90 knot approach speed and no wind a 45/180 PT eats up about 3 nm, that is to say from where you begin the 45* turn until you're coming back in and decreasing the distance from the fix will be three miles more than the distance where you started the turn. So let's fly one minute outbound (that's a mile & a half @ 90 kts) plus three more miles in the procedure turn, we're out to 4 1/2 nm, half a mile to spare.
Now if we cross the VORTAC @ 90 knots and maintain that, power back and set up a 1000 fpm descent rate immediately after crossing we'll go from 6000' down to 2500' (that's 3500 feet) in three & a half minutes. 45/180 PT takes a minimum of two & a half minutes plus the outbound minute = 3 1/2 minutes @ 1000 fpm (that's 3500 feet) So now we're established inbound outside the final approach fix just 100' above the FAF minimum crossing altitude, bring a little power back in for a nice comfortable 500 fpm descent rate and just come motoring right on in
OTOH, the 6000' is a maximum altitude I assume designed to keep traffic on this approach from tangling with traffic into Detroit and I doubt Detroit APP CON would keep you up at 6000' until crossing SVM.

Using my "standard" method (Cap'n Ron close your eyes) for 5 mile PTs I know ground speeds up to 120 kts will remain within the limit with the user-friendly 180/45° reversal and no more than one minute outbound. Conservatively adding up the time: 1 min out, 1 min dogleg, 1 min 180° turn, and 2 mins return to the fix gives me 5 mins to lose, say, 3500' or 700 fpm. Somebody trying to use Cap'n Ron's "non-standard" method given in post #2 would be way out of limits. (You can open 'em now Cap'n Ron.)

dtuuri

 

[peerlesscowboy]

Using my "standard" method (Cap'n Ron close your eyes) for 5 mile PTs I know ground speeds up to 120 kts will remain within the limit with the user-friendly 180/45° reversal and no more than one minute outbound. Conservatively adding up the time: 1 min out, 1 min dogleg, 1 min 180° turn, and 2 mins return to the fix gives me 5 mins to lose, say, 3500' or 700 fpm. Somebody trying to use Cap'n Ron's "non-standard" method given in post #2 would be way out of limits. (You can open 'em now Cap'n Ron.)

dtuuri

Yeah Dave, my first thought was if I was caught flatfooted and did this cold on the fly was;
slow 'er down to cross at 90 knots, immediately after crossing pull the power back and set up a 1000 fpm descent, fly out for one minute, make the procedure turn and see how it works out After I rattled the numbers around in my head for awhile I was pleased to calculate it'd work out fine

 

[RotorDude]

Yeah Dave, my first thought was if I was caught flatfooted and did this cold on the fly was;
slow 'er down to cross at 90 knots, immediately after crossing pull the power back and set up a 1000 fpm descent, fly out for one minute, make the procedure turn and see how it works out After I rattled the numbers around in my head for awhile I was pleased to calculate it'd work out fine

I would probably do the same under the circumstances, but as we all know, in single pilot operations a high rate of descent with no altitude alerter only requires a small distraction to result in an altitude bust, with potential non-fun consequences.
Which is why I'd ask for the GPS approach at that field, and anywhere else possible.

 

[peerlesscowboy]

I would probably do the same under the circumstances, but as we all know, in single pilot operations a high rate of descent with no altitude alerter only requires a small distraction to result in an altitude bust, with potential non-fun consequences.
Which is why I'd ask for the GPS approach at that field, and anywhere else possible.

Yes, that's why I'd hold that high descent rate only down to 2500' with a PT minimum of 2400', if I'm coming down at 1000 fpm I'm going thru' 100 feet every 6 seconds. A few seconds distraction and you can blow right thru' your target altitude, I want 100 feet extra to reduce the descent rate.

ps--with the target of 2500' (100' above min) I want to have my descent rate reduced to 500 fpm by the time I go thru 2500'

 

[midlifeflyer]

So that begs the question. Mark says they don't have to be done in a particular order, you say bad things can happen if you do them in the wrong order. The latter is what I would expect too, but which is correct?

I think the distinction is in how one uses them use them. I can see a problem occurring if one treats the Ts as a "do list" at a fix and "Talk" as the first step. But I treat it as a "briefing list" before a fix which means it's a series of things to consider doing.

But either way, is there really a significant difference among the primary tasks? The "traditional" 5 Ts are, in order,

• Turn – Turn to the Course Heading
• Time – Start the Time
• Twist – Tune the Radio (VOR etc) and/or Twist the CDI
• Throttle – Reduce the throttle; Go Down (descent) or Slow Down
• Talk – Talk to the ATC

On a VOR approach you on the 45° intercept to the FAC. Do you really have to wait to Twist the LOC to the inbound course until after you Turn to intercept it? Exactly how does that work? Can't speak for anyone else, but I personally much prefer to run them ahead of time and use "Twist" to double-check that I have already twisted the dial to the FAC and to do it then if I somehow managed to miss it earlier.

And when you make the initial 45° turn on the PT, does it really make a major difference if you take a quarter second (or even a full second) to hit the timer before you make the turn itself?

I'm a big anti-mnemonic guy and rant about them all the time. It's mostly because I've noticed that in most cases, the mnemonic becomes far more important than what it represents, which I believe is a hindrance to learning, not an aid.

If one runs the Ts before the event as a briefing of tasks to consider, I hope one has the sense to figure out the order that makes sense in the particular situation. yikes: Sometimes I even reduce throttle before turning! ) If not, I really don't think blind adherence to a bunch of tasks to be done only in that specific order as a substitute for pilot judgment will help that much in the long run.

[/rant]

BTW, when I use the Ts as a training aid, I use the traditional set. Just seen a lot of moronic arguments about whether Twist or Time should come before or after Turn with wonderful statements to support either. It doesn't matter.

 

[midlifeflyer]

Using my "standard" method (Cap'n Ron close your eyes) for 5 mile PTs I know ground speeds up to 120 kts will remain within the limit with the user-friendly 180/45° reversal and no more than one minute outbound. Conservatively adding up the time: 1 min out, 1 min dogleg, 1 min 180° turn, and 2 mins return to the fix gives me 5 mins to lose, say, 3500' or 700 fpm. Somebody trying to use Cap'n Ron's "non-standard" method given in post #2 would be way out of limits. (You can open 'em now Cap'n Ron.)

dtuuri

I don't know. That very practical advice sure sounds contrary to your comments in other threads about the form of hold entry needing to be exactly as specified in the AIM :wink2:

 

[poadeleted20]

Using my "standard" method (Cap'n Ron close your eyes) for 5 mile PTs I know ground speeds up to 120 kts will remain within the limit with the user-friendly 180/45° reversal and no more than one minute outbound. Conservatively adding up the time: 1 min out, 1 min dogleg, 1 min 180° turn, and 2 mins return to the fix gives me 5 mins to lose, say, 3500' or 700 fpm. Somebody trying to use Cap'n Ron's "non-standard" method given in post #2 would be way out of limits. (You can open 'em now Cap'n Ron.)

dtuuri

How would my method put you out of limits?

 

[poadeleted20]

On a VOR approach you on the 45° intercept to the FAC. Do you really have to wait to Twist the LOC to the inbound course until after you Turn to intercept it?

Not only don't you have to, but you don't want to, and it would be contrary to what we teach, which is to twist the inbound when you do the T's making the displacement turn off the outbound leg. We teach twisting the next course to be tracked as soon as you are no longer tracking the last course, not waiting until you Mae the turn to the intercept heading. Likewise, we teach twisting for the inbound course of a holding pattern when you roll out of the outbound turn, not waiting until you make the inbound turn.

 

[dtuuri]

I don't know. That very practical advice sure sounds contrary to your comments in other threads about the form of hold entry needing to be exactly as specified in the AIM :wink2:

Glad my post #23(?) was able to provide some grist for 'real' IFR pilots' discussion. Was trying to inspire 'would bees' like Melissa to immediately begin thinking that way right from the first lesson. After all, they ARE logging PIC time too, aren't they? :wink2: When you take responsibility for your own safety, the shortcuts we teach have much more meaning. I've done the math and shown it in my tutorials. I hope they take note.

As to the holding entries, I view them the same way--standard procedures you don't need to think about. Do it the way they fitted the protected airspace to and you're covered without being a test pilot.
EDIT: There are 31 different sizes of holding patterns. No way a pilot knows which was used. If they have done the math for the smallest sized pattern, then they should be able to show what the maximum groundspeed is that keeps them within it, like I've done for PTs.

I find it curious that Cap'n Ron teaches a 'standard' descent rate outbound of 500 fpm, but disparages those who teach a standard outbound time to stay within protected airspace. (He never answered my questions about ground speed limits in post #21(?) either. :wink2

dtuuri

 

[azure]

On a VOR approach you on the 45° intercept to the FAC. Do you really have to wait to Twist the LOC to the inbound course until after you Turn to intercept it? Exactly how does that work? Can't speak for anyone else, but I personally much prefer to run them ahead of time and use "Twist" to double-check that I have already twisted the dial to the FAC and to do it then if I somehow managed to miss it earlier.

Same here (except that I don't do the Ts, so I don't have a "Twist" step). But I was taught to set the OBS to the inbound course *at the latest* when outbound on the 45. With an HSI, twist to the inbound course (or the front course, in a LOC, LOC BC, or ILS approach) upon crossing the IAF outbound for the procedure turn.

If one runs the Ts before the event as a briefing of tasks to consider, I hope one has the sense to figure out the order that makes sense in the particular situation. yikes: Sometimes I even reduce throttle before turning! )

I pretty much always reduce throttle and add approach flaps before (a couple of minutes before) arriving at the IAF, or the holding fix. The only exception would be in case of a strong headwind. I rarely adjust the throttle while maneuvering unless for climb or descent.

If not, I really don't think blind adherence to a bunch of tasks to be done only in that specific order as a substitute for pilot judgment will help that much in the long run.

My understanding of the idea is that making certain sequences of tasks routine helps to manage the workload. But generally, I agree. Instrument flying is all about thinking, getting the needed information from the gauges and using it to control the airplane. There's no substitute for thinking one or more steps ahead, and if you're doing that, the proper sequence should follow from knowing the desired outcome.

 

[midlifeflyer]

Same here

Process-wise I think we do very much the same thing.