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YorkiesWorld

Knowing the Right Altitude to Capture the Glideslope?

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Hi guys,

 

I'm learning to fly the PMDG 777-200 at the moment and I did a flight from EGCN (Doncaster Sheffield, UK) to LEIB (Ibiza, Spain).

 

I'm fine with the ground config and takeoff etc..., but I wanted to know how I find out the correct altitude I have to be at when I want to capture the Glideslope when trying to perform an ILS approach.

 

I usually set this to around 3500ft which works fine in the 737-800, however in the 777 this left me way too high, causing me to have to manually descend and land even though the Localiser was captured and Approach Mode switched on.

 

How do I find out the correct altitude I need to be at in order to capture both the Localiser and the Glideslope correctly? Would this be on the airport charts by any chance?

 

Cheers!

-YorkiesWorld

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You need to be below the glideslope in order to capture it. This varies depending on how far you are from the runway. That info will be on the charts. 

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Specifically it is found on the approach plates (charts). Not sure where to get those for UK airports, though.

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You're going to want to intercept the glide slope at the Final Approach Fix (FAF). This altitude varies and is dependent on a number of factors, and there are many excellent resources available on youtube/google that teach how to properly read approach charts. 

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You need to be below the glideslope in order to capture it. This varies depending on how far you are from the runway. That info will be on the charts. 

 

You're going to want to intercept the glide slope at the Final Approach Fix (FAF). This altitude varies and is dependent on a number of factors, and there are many excellent resources available on youtube/google that teach how to properly read approach charts. 

 

Thanks guys, so according to the charts for runway 06 below, am I right in reading the altitude for this as 2000 feet? Or am I looking at the wrong figure? It shows ILS and LOC as 2000?

 

7FLhDi9.png

 

-YorkiesWorld

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Hi guys,

 

I'm learning to fly the PMDG 777-200 at the moment and I did a flight from EGCN (Doncaster Sheffield, UK) to LEIB (Ibiza, Spain).

 

I'm fine with the ground config and takeoff etc..., but I wanted to know how I find out the correct altitude I have to be at when I want to capture the Glideslope when trying to perform an ILS approach.

 

I usually set this to around 3500ft which works fine in the 737-800, however in the 777 this left me way too high, causing me to have to manually descend and land even though the Localiser was captured and Approach Mode switched on.

 

How do I find out the correct altitude I need to be at in order to capture both the Localiser and the Glideslope correctly? Would this be on the airport charts by any chance?

 

Cheers!

-YorkiesWorld

just Google, came up with 2000' for rwy 06 and 2200 for r 24,

 

you need to see the approach for each rwy.

 

bob

 

I see you found it,

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Look at the sample approach plate. Inside the red circle there is a symbol for glideslop intercept altitude. It is not necessarily has to be FAF  

 

N0gxBcz.png

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The Maltese cross denotes the FAF on USA charts at least.

 

I'd say 2000 is the altitude you'd fly at... ATC would vector you outside the FAF and probably at 2000, if terrain and obstacles allow it

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The Maltese cross denotes the FAF on USA charts at least.

 

I'd say 2000 is the altitude you'd fly at... ATC would vector you outside the FAF and probably at 2000, if terrain and obstacles allow it

 

Its a lightning bolt that denote glideslope intercept 

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In your example SHAKE is the FAF and denoted by the Maltese cross (that is the official name). Maybe you're discussing something else?

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For a 3° GS which is the norm, When you follow the glide you descent 300 feet per nautical Milles. That means that "usually"you intercept the glide(Always by under) at 10NM and 3000 feet. Of course the altitude of interception can depend of airports but always in the relation of 300 feet/ NM for 3° GS! 

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Perhaps this can help -

 

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&sqi=2&ved=0CCIQFjABahUKEwjnnZewrZjJAhWSoogKHdDpAGA&url=http%3A%2F%2Fsunairexpress.com%2Fimages%2FHow_to_Read_Approach_Plates.pdf&usg=AFQjCNG2rFeRfaOOdJ28CGgm7HOIwXCiNQ&sig2=b96UWO_Wj5kMRw5aLHuyfw&bvm=bv.107763241,d.cGU

 

In reality you cannot just wander around the sky under instrument conditions trying to find a place to land. Either you are under the control of ATC or you are flying a published approach. IAC, when ATC hands you off to complete the approach, you will need the approach plate handy. Ideally, you will have made yourself familiar with the procedure BEFORE flying it.

 

Learn the symbols and notations - all the info you need is there.

 

Just a suggestion - learn to fly IFR in a small a/c before you jump into the tubes. I know we all want to jump right in and be an airline captain but just learning how to push a few buttons without understanding what you are doing won't help when you get into a situation you don't understand.

 

Of course, in P3D you have the reset button.

 

Vic

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In your example SHAKE is the FAF and denoted by the Maltese cross (that is the official name). Maybe you're discussing something else?

 

Glideslope intercept symbol (denoted as lightning) and FAF symbol (Maltese cross) are two different things. Does it make sense? 

 

sacils2.jpg

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Perhaps this can help -

 

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&sqi=2&ved=0CCIQFjABahUKEwjnnZewrZjJAhWSoogKHdDpAGA&url=http%3A%2F%2Fsunairexpress.com%2Fimages%2FHow_to_Read_Approach_Plates.pdf&usg=AFQjCNG2rFeRfaOOdJ28CGgm7HOIwXCiNQ&sig2=b96UWO_Wj5kMRw5aLHuyfw&bvm=bv.107763241,d.cGU

 

In reality you cannot just wander around the sky under instrument conditions trying to find a place to land. Either you are under the control of ATC or you are flying a published approach. IAC, when ATC hands you off to complete the approach, you will need the approach plate handy. Ideally, you will have made yourself familiar with the procedure BEFORE flying it.

 

Learn the symbols and notations - all the info you need is there.

 

Just a suggestion - learn to fly IFR in a small a/c before you jump into the tubes. I know we all want to jump right in and be an airline captain but just learning how to push a few buttons without understanding what you are doing won't help when you get into a situation you don't understand.

 

Of course, in P3D you have the reset button.

 

Vic

 

Another suggestion is to get a program like Pro ATX and you can practice STARs and SIDs. on every flight as well as ILS and RNAV and VOR approaches with ATC telling you where you need to be. 

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As a general, non-official, totally unrealistic rule of thumb that I tend to use when flying casually (offline) and when I don't have the appropriate charts: I aim to intercept the LOC at a distance of 8-10 NM and at altitude 2200-2500 ft above airport elevation assuming the surrounding terrain allows it.

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In reality you cannot just wander around the sky under instrument conditions trying to find a place to land. Either you are under the control of ATC or you are flying a published approach. 

 

Perhaps you mean published SID? ATC can't grant unpublished instrument approach unless it's an emergency ex. no gyro approach.

 

 Once I had an alternator failure and 20 minutes of battery life (estimated) in IMC. ATC squeezed me inside FAF to intercept ILS for the priority approach (kind of emergency but not in legal sense).

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Perhaps you mean published SID? ATC can't grant unpublished instrument approach unless it's an emergency ex. no gyro approach.

 

 Once I had an alternator failure and 20 minutes of battery life (estimated) in IMC. ATC squeezed me inside FAF to intercept ILS for the priority approach (kind of emergency but not in legal sense).

 

A SID is a departure procedure, not an approach procedure. 

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A SID is a departure procedure, not an approach procedure. 

 

Yes in this context I meant STAR. SID and STARS can't be excluded from the flight plan (if you are not  RNAV equipped). However, DP procedures are mandatory because some of them have "minimum required rate of climb" 

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Yes in this context I meant STAR. SID and STARS can't be excluded from the flight plan (if you are not  RNAV equipped). However, DP procedures are mandatory because some of them have "minimum required rate of climb" 

 

SID and STAR are given by ATC, you can request what you want but ultimately it's their call.

 

Also SD _flyer is correct about the Lightning bolt...I think someone owes an apology :P

 

The ILS glide slope is intended to be intercepted at the published glide slope intercept altitude. This point marks the PFAF and is depicted by the “lightning bolt” symbol on U.S. Government charts.

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SID and STAR are given by ATC, you can request what you want but ultimately it's their call.

 

 

 

If we are talking about real world. Not quite. Ultimate call is by pilot in command not ATC. ATC can't enforce pilot to make approach that his/her is not capable to do.  It also applies to SID and STARS

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If we are talking about real world. Not quite. Ultimate call is by pilot in command not ATC. ATC can't enforce pilot to make approach that his/her is not capable to do.  It also applies to SID and STARS

 

That is strange, you have many aircraft on a star coming into an airport like Atlanta, and some pilot can say he doesn't like that particular star and demands another one instead????   

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SID and STAR are given by ATC, you can request what you want but ultimately it's their call.

 

Also SD _flyer is correct about the Lightning bolt...I think someone owes an apology :P

 

The ILS glide slope is intended to be intercepted at the published glide slope intercept altitude. This point marks the PFAF and is depicted by the “lightning bolt” symbol on U.S. Government charts.

I don't owe anyone an apology

 

He apparently was discussing the altitude where you descend. The FAF is the Maltese cross. And also where you descend.

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That is strange, you have many aircraft on a star coming into an airport like Atlanta, and some pilot can say he doesn't like that particular star and demands another one instead????   

 

If your aircraft is not capable or adequately equipped than yes you can decline STAR/SID or indicate on your IFR flight plan prior the flight "no sid/star". I'm not talking about part 121 or part 135. They have their own set of rules and equipment requirements for type of operation.

 

I've been in and out international airports (part 91) and have never been assigned any  SID or STAR.

 

P.S. You can also enter class Bravo without working mode C transponder just  have to let ATC know in advance. 

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Shite - I am mistaken - not sure of this changed but the cross is only on non precision approaches. Lightning is for precision

 

Sorry!

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Here is a great table (link below) that may help some members participating in this thread.  In the USA the standard has been a 3° angle of descent from approximately 2,000 ft above ground level (AGL) and a final approach fix (FAF) located approximately 5 nm distant from the touchdown (TDZ) point.  These do often vary based on topography and other local issues such as ground based structures or noise abatement that may restrict the location of the FAF or the published approach altitude at the FAF.  If the FAF is closer to the airport than that, the approach altitude at the FAF will likely be lower, or the descent angle higher. The opposite would be true if the FAF is more distant for some reason.  

 

The rate of descent is based not only on the distance and published angle of descent, but is highly dependent on the approach speed.  As I believe most are aware, the approach speed varies considerably from one aircraft type and model to another.

 

To keep this chart from confusing anyone. please note that the first line under "GROUND SPEED (knots)" contains ground speeds from 30 knots (glider or blimp?) up to 180 knots (fighter jet?). Starting with the 2.0°  line, the remainder of the table expresses the rate of descent in feet per minute (FPM) that correlates to that angle of descent and ground speed.  An airliner approaching at 135 knots at a published 3.0° angle of descent will have a higher rate of descent (715 FPM) than a Beech Baron approaching at 105 knots (555 FPM). For our purposes the table could be distilled down to the lines and columns for 2.0° to  4.0° angles, and air speeds from 60 kts to 150 kts.

 

The almost now outdated paperback bound volumes of Instrument Approach Procedures (IAP) contained tables like this.  Now that it is easy to access digital approach plates on a one-by-one basis, key IAP elements like this get missed.

 

http://www.flightsimbooks.com/foi/app_b_2.php

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