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Driver170

Circling to land.

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I'm finding i'm overshooting the centreline once i turn final, i believe i'm too close to the runway, but i don't know what else to correct for. I'm following my set of SOPs.

 

In a nutshell

 

1. L/R 45* for 20sec and (+/- wind component) my TWC is 7kts so i start the timer for 4 seconds.

 

2. Turn downwind once time is up

 

3. Abeam landing threshold, start timing. (3 sec/100ft +/- wind) eg 1200 agl = 36 sec and minus half my TWC which is 17kts this gives me a timing of 28 seconds abeam the threshold.

 

4. Turn base - When TIME OUT is noted proceed as follows:

 

 Keep the landing threshold and PAPI’s in sight

 Turn the MCP HDG to the runway heading

 Call for landing flaps

 Select MCP speed to V Fly

 Descend on the PAPI’s

 Complete the landing checklist

 Disengage the autopilot, and disengage the autothrottle at the same time

 

 

5. And Land.

 

 

But i'm still overshooting the centreline. I have even used AOB 30* and set landing flaps before the rollout on base. It seems like 20 seconds and TWC is to little a time.

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But i'm still overshooting the centreline. I have even used AOB 30* and set landing flaps before the rollout on base. It seems like 20 seconds and TWC is to little a time.

 

Fly a traffic pattern. Keep airport in sight. Done.

 

Don't overcomplicate it.

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Are you correcting appropriately for drift on the downwind leg (i.e. are you being blown tighter by a crosswind?). It might be worth looking at the flight track via either the FS map or by using some sort of software that will give you a graphical representation of the flight track overlaid on to Google Earth or whatever to see what shape your circuit is...

 

What speed/config are you in turning downwind/final? Obviously the timings will be based on maintaining a particular speed, otherwise you'll end up in a different place if you're faster or slower than whatever the timings were calculated with.

 

To be honest, it's almost impossible to reliably judge the final turn in FS because of the visual limitations of the sim, so I wouldn't beat yourself up too much.

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Fly a traffic pattern. Keep airport in sight. Done.

 

Don't overcomplicate it.

 

CTL thats what i'm doing. It all works out if i stick to 20sec but its that TWC that shortens my 45* left turn keeping me closer to the runway.

Are you correcting appropriately for drift on the downwind leg (i.e. are you being blown tighter by a crosswind?). It might be worth looking at the flight track via either the FS map or by using some sort of software that will give you a graphical representation of the flight track overlaid on to Google Earth or whatever to see what shape your circuit is...

 

What speed/config are you in turning downwind/final? Obviously the timings will be based on maintaining a particular speed, otherwise you'll end up in a different place if you're faster or slower than whatever the timings were calculated with.

 

To be honest, it's almost impossible to reliably judge the final turn in FS because of the visual limitations of the sim, so I wouldn't beat yourself up too much.

 

No correction for drift on downwind. I'll check that out and see what my flight path is.

 

Before turning 45* left from the instrument runway and 4nm from the threshold i set gear down, f15

 

I've gave myself 2 Choices – diverge slightly downwind and slow down around finals. being in the landing config as i roll out as there is not a lot of space to lose 1200ft 25 AOB and even tried 30* that should be enough!!!

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CTL thats what i'm doing. It all works out if i stick to 20sec but its that TWC that shortens my 45* left turn keeping me closer to the runway.

 

I know what you're doing.

 

What is the point of a CTL procedure? It's there to put you on the opposite end of the runway, or onto another runway. It doesn't need to be a crazy scientific and mathematical process. Maneuver to the other runway. Keep the airport in sight. Done.

 

What you're seeing are commonly used guidelines/techniques.

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Terrain around the airport and a straight in approach is a no go.

 

Nothing scientific here, its pretty basic procedures that pilots use for a CTL. Few minuses and pluses to get where you need to be.

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Vernon, the Nav Display includes a turn path predictor (looks like a dog's tail wagging) that gives an indication of the projected flight path for a given angle of bank.

 

Without getting fixated on this instrument, and using it with reference to the runway extended centreline, it can be used to give you an idea of whether your turn is going to roll you out on centreline or not.

 

Bottom line though: Circling to land is a visual maneuver, and the techniques you've outlined are designed as guides only. If you get too fixated on timing the maneuver rather than actually flying it, you will usually end up in a pickle!

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Extend outwards a little bit. You should have a ton of room. CTL require 2.7-3.3NM of clearance of obstacles depending on the MSL you are landing at for CAT C approaches.

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Vernon, the Nav Display includes a turn path predictor (looks like a dog's tail wagging) that gives an indication of the projected flight path for a given angle of bank.

 

Without getting fixated on this instrument, and using it with reference to the runway extended centreline, it can be used to give you an idea of whether your turn is going to roll you out on centreline or not.

 

I'm aware of that tip. Great tool yes, i use 20nm range gives you 2 or those white lines and then i adjust bank selector to get the trend on the threshold. Great tip!!!

Extend outwards a little bit. You should have a ton of room. CTL require 2.7-3.3NM of clearance of obstacles depending on the MSL you are landing at for CAT C approaches.

PANS OPS protected area for circle to land approaches is 4.2nm ring around both thresholds

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Nothing scientific here, its pretty basic procedures that pilots use for a CTL. Few minuses and pluses to get where you need to be.

 

Yes. That's what I've been saying this whole time. You were the one dragging math and various components into it. That would be suggestive of mathematical or scientific approaches to an otherwise simple concept. As I've been saying, and the others have chimed in:

 

Move airplane to line up with other runway.

Done.

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Yes. That's what I've been saying this whole time. You were the one dragging math and various components into it. That would be suggestive of mathematical or scientific approaches to an otherwise simple concept. As I've been saying, and the others have chimed in:

 

Move airplane to line up with other runway.

Done.

 

0

 

I follow this

 

8.19 Circle to Land Approach - SOP

 

Timing is started when steady on track or wings approximately level whichever is sooner. Both pilots will time the leg. PM selects PROG page 2 at this point. Wind effect must be factored into the duration of this leg by reducing/increasing the still air time of 20 seconds by an amount that is equal to half the TWC/HWC. TWC/HWC can be seen in the PROG page 2 in the FMC. HDG is used to ensure that the required track is maintained. At Time Out turn onto the downwind track using HDG to adjust for wind.

 

So you see? Timing is needed.

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So you see? Timing is needed.

 

No. It really isn't. If your SOP states it, then fine, do it, but don't make it more difficult than it needs to be otherwise. I know you really like the fact that you have a RW operator's SOP, but it's one of several hundred. Personally, I find it to be completely counter productive to my primary mission: keeping the field in sight (remember, the CTL is a VISUAL maneuver - if you lose the vis, you get to shoot that approach again) and putting the plane safely on the ground.

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No. It really isn't. If your SOP states it, then fine, do it, but don't make it more difficult than it needs to be otherwise. I know you really like the fact that you have a RW operator's SOP,

 

Its not about my SOPs. I've searched about and found on PPRUNE that every pilot uses that simple technique to get around the airfield. Of course its a visual manoeuvre and its the PM to keep an eye ball on the airfield environment or lights in sight throughout the approach. This approach is certainly a numbers game, as well as autopilot and manual flight!

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Its not about my SOPs. I've searched about and found on PPRUNE that every pilot uses that simple technique to get around the airfield. Of course its a visual manoeuvre and its the PM to keep an eye ball on the airfield environment or lights in sight throughout the approach. This approach is certainly a numbers game, as well as autopilot and manual flight!

 

No. Please stop making these wild assertions without having flown an aircraft enough to make them. The PF needs to have their eyes up and out. Why do you think the PNF calls speeds during the TO roll and on approach?

 

It's only a numbers game if you want it to be. If you want to make it complicated, go right ahead. If you'd like to worship everything that comes out of pprune, then that's fine, but you have to keep in mind that the site is also subject to a bunch of armchair pilots making half-cocked assumptions about flying. Meanwhile a bunch of them haven't actually flown at the level they're claiming to have flown. Sure, many are probably speaking from experience, but a good number of others are just bleating the same info because the other people said it.

 

Do yourself a favor: spent a day up at an airport FBO talking to the pilots there. I can guarantee you that you'll get better answers, particularly because none of them can hide behind a keyboard. I'm also relatively sure very few of them are going to give you a numbers-based rule of thumb for circling procedures.

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