Jump to content

Archived

This topic is now archived and is closed to further replies.

vertigho

A couple of basic'ish questions

Recommended Posts

Hey all, I'm relatively new to the world of flight and aviation, so my knowledge is fairly limited. I recently picked up FS9 and the iFly 737 addon, and while I'm making progress, I still have a long way to go.

 

I had a couple of questions pertaining to the descent procedure in general terms, and less specific to the iFly.

 

1.) How does one determine the transition level? I understand that in the US it's FL180. However I'm currently working on the tutorial flight for the iFly, which runs from YSSY to YMML. They give you the transition altitude early in the tutorial, but they do not specify the transition level for descent. How does one determine this?

 

2.) Upon reaching that transition level, one must reset their altimeter to whatever it is for that area. How does one determine what to set that altimeter to? I understand that the standard is 29.92, and that's what's given in the tutorial flight, but I'm attempting the tutorial with weather from Active Sky Evolution, so the altimeters won't be standard, I believe. Should I look at the current numbers for Melbourne, where I'm landing, or is there another way of obtaining this?

 

3.) The tutorial also references radio altitude and barometric altitude in order to set minimums, however it doesn't specify which to use, nor does it give you the needed value. It's my understanding that the radio altimeter is used for CAT II and CAT III landings, while the barometric altimeter is used for CAT I landings. How does one determine whether the runway they're landing on is CAT I, II, or III, and furthermore, how does one then set their minimums? (barometric altitude for CAT I, of course, and the radio altitude for CAT II and III.)

 

4.) Lastly, the tutorial makes reference to engaging VOR/LOC hold, but it doesn't specify when to engage it. I'm currently flying without traffic and ATC while I get familiarized with the aircraft, and I realize that approaches will vary when ATC is enabled... so that will be another thing to learn down the road. But for the time being, I simply want to get comfortable with the plane itself, and flying a plan (with SIDs and STARs) via the CDU. When should I engage the VOR/LOC hold switch?

 

Thanks in advance guys. As I said, I'm new to the aviation world so I'm learning as I go. Any and all help is appreciated.

 

Cheers. 

Share this post


Link to post
Share on other sites

1.) Transition Altitudes and Levels depend on where you fly - I would say that info is contained in charts, and IRL I gues you could also ask ATC when in doubt. For example, Europe has usually 3,000ft, in Australia I believe it's 10,000

 

2.) Altimeter is always set to 29.92inHg/1,013hPa above the Transition Altitude. That is simply to guarantee a sufficient vertical separation by standardizing the pressure at and above a certain altitude. If - due to the pressure - some flight levels are not available, those will simply not be assigned, e.g. if pressure is too low to have FL030 in Europe but would only allow for FL035, ATC would assign you FL040, FL050 and so on when climbing, When descending they will simply give you the correct altimeter setting.

 

3.) I am not at all sure about this, but I would say that the radio altimeter (if available) should be preferred in any situation, since it is less prone to errors due to small pressure differences. As far as I understand it, you could still fly a CAT I approach with the radio altimeter enabled, but you're not allowed to fly a CAT II or III approach with only a barometric one.

Again, the info about the available ILS categories can be found in the approach charts of the airport, and ATC would probably also specify what category you should use, unless it's obvious. Minimums would either be specified on the charts as well, or they are the same as the usual regulations, depending on the ILS categories.

 

4.) The use of the NAV/LOC hold depends entirely on the type of apporach you're making. For some you wouldn't engage it at all (RNAV, and purely visual approaches), for others (VOR/LOC/full ILS) you would. Typically you would engage it as soon as you're able to pick up the signal, provided that ATC allows you to navigate directly to that beacon. If you're on an ILS aproach, you would also engage the APP hold button as soon as the G/S is available.

 

I hope that the above is more or less correct, I'm still not completely familiar with all of the things, and lacking RW practice may cause some misunderstandings and errors. But in case I'm wrong, I am sure others will correct me.


Florian

Share this post


Link to post
Share on other sites

Thank you so much for the feedback!

 

I feel confident on questions #1 & #2. I will look up transition alt/lev for the particular region(s) I will be flying in, prior to flying in them. Simple enough. As for #2, I will use the altimeter setting given by ATC below transition alt/lev, or use the 'B' button if I'm not using ATC. Obviously will use STD above the transition point.

 

Still unsure on #3 and #4, though. I will do some more research on radio/barometric altimeter and setting the minimums. But if others could chime in, that'd be great. I want to know when to use radio or barometric, where to find that information, and where to find information regarding minimums. It sounds like I'll have to consult approach charts, but I have no idea where to look for those, and how to interpret the information provided on them. 

 

Forgive my naivety, but what precisely is an RNAV landing, and under what circumstances would it be used? As someone who will primarily be flying commercial jets, would ILS landings be the standard procedure most of the time? 

 

Sorry again for all the questions. I'm feeling a bit overwhelmed and in over my head but it's all very fun and exciting at the same time. 

 

**EDIT**

 

Based on the following video, about 3:45 in, the guy explains (in what seems to be fairly simple terms) the difference between CAT II and III landings. Would seem the minimums/decision height for CAT IIIs would be 0 or 50 feet, depending on the sub classification of the category. CAT II landings, meanwhile, have a minimums/decision height of 100 feet. From what I've read, CAT Is would have a decision height of 200 feet. Might be a bit oversimplified, but it seems to make enough sense to me, if I'm indeed understanding him correctly. So, with that in mind, I suppose I'll use the radio altimeter is almost all circumstances and adjust it between 200, 100, 50 or 0, depending on the runway in question. If others could chime in and confirm or correct my thinking that'd be great!

 

Here's the video I mentioned:

 

https://www.youtube.com/watch?v=I_lxOSC3cws

Share this post


Link to post
Share on other sites

While on youtube, check out the vids of AVSIM forum member and PMDG beta-tester Kyle Rodgers. He won't mind you flying the iFly version, as you use FS9!  B)

 

Cool! Will do! I've been watching mostly Frooglesim recently. I can't get enough of the guy. Love watching any of those type of videos, so I'll definitely check out Kyle's channel.

 

Will look some of his videos up right now, in fact! 

Share this post


Link to post
Share on other sites

Ok, this is very refreshing for a post made by "relatively new to the world of flight and aviation" guy. Very clear, precise and well shaped questions  To be honest I'm a little bit tired of "Tell me how to fly 737 " type of questions.

 

Anyway, to answer your questions:

​1.Civil authorities (caa) of every country decide what's transition altitude and transition level for their country (or airport) as part of airspace construction process. Then air traffic service agency enforce those standards set by authorities. CAA of every country release Aeronautical Information Publication (AIP) which contains all air laws and procedures for that airspace. AIP is usually in sync with global or regional organizations such as ICAO, EASA (Europe union). In AIP you can find textual description and graphical description of procedures, better know as "charts", and in charts you can find what is transition altitude and transition level.

Now, 3rd party companies such jeppesen, or lufthansa (lido)... take AIP of every country, reformat it and sell to pilots.

 

If you open set of charts for any airport you will notice transition altitude (TA) is usually fixed, and transition level (TL) is "byATC" which means ATC has procedure to determine what is transition level according to local pressure and to maintain vertical separation of 1000ft. For example if TA is 10000ft, TL can be FL110, 120 or 130 depending on what is local pressure. As you fly alone without any traffic, you can pick FL120 (2000ft above TA) as standard and use it.

 

2.Airports release current meteo informations at 30 minutes interval (or less if there is hazardous weather) , known as METAR, and weather forecast known as TAF. METAR contains QNH so you can read it and set your altimeter. You can read METAR and TAF for every airport at NOAA website or in activesky.

IRL ATC would provide you QNH information. Be aware that US uses altimeter settings in inHG format (29.92 standard), while rest of the world uses hPa (1013.25). You can change reading in aircraft on EFIS panel.

 

3. Look again at 1.) In those charts you can find almost anything related to airport operations. You take set of charts for airport you want to fly and if there's ILS CATII or III presented, you can fly that approaches. If there's no such a chart, you cannot fly that. Anyway, CATII and III are reserved for low visibility operations, so of weather is good you do not need that informations.

Landing minimums are also published in AIP, and depicted on approach charts. Those are published minimums but you can go with higher value if you feel unsafe, or IRL company can obtain permission to operate with lower minimums if they meet requirements. For simming purposes, published minimums are good enough. 

I'm not sure you should use radio minimums (height) for CAT I minimum because maybe there's some hill or something that would trigger a false call. Anyway, in clear weather that's not so important, but when you approach CAT I limits, than it makes sense.

 

To summarize, if weather is clear, it's always CAT I . If weather is below CAT I, than you look if there is CAT II/III approach published. If there isn't, though luck  :P

 

4. If you want to fly ILS, you arm VOR/LOC when you are at localizer interception course. Then, VOR/LOC would engage automatically depending on aircraft speed, interception angle, wind speed...

 

 

To conclude, I think you need to learn how to read charts, but more important, the true knowledge is not to hold everything in your head, but to learn where the information you need is stored. 


[color=#a9a9a9][size=1][size=4][img]http://forum.avsim.net/public/style_images/flags/rs.png[/img][/size] Lj. Prodanovic[/size][/color]

Share this post


Link to post
Share on other sites

Ah, great! Thank you so much guys -- you've been incredibly helpful.

 

One lingering question: how do I figure out where the localizer interception point is?

 

Also, from looking at this chart of KATL ILS 27L, I can figure out the category of the runway (top right corner. 27L is standard approach category 1) and I can determine the airport elevation, but outside of that I'm clueless. Where should I be looking for the minimums and other necessary information?

 

http://155.178.201.160/d-tpp/1404/00026I27LSAC1.PDF

Share this post


Link to post
Share on other sites

It's depicted on approach chart. If you fly with ATC (or online), ATC usually vectors you to interception course and then say "You are cleared for ILS XYZ, report established", and at that moment, you arm LOC.

 

Standard interception point is 8-12 nm from threshold captured with up to 45 degrees angle, under glideslope and in level flight; however ils is often preceded by procedure turns, base turns, holding patterns in lieu, race tracks, ATC vectors... In other words, every single airport is different, and that's why every airport has its own set of charts.

 

I suggest you to take cessna 172 (default one), pick an airport, print approach chart, analyze it and fly whole approach. C172 is slow enough to give you enough time to think, and the default c172 is simple enough to let you to keep focus at important navigation things rather than to manage systems. 


[color=#a9a9a9][size=1][size=4][img]http://forum.avsim.net/public/style_images/flags/rs.png[/img][/size] Lj. Prodanovic[/size][/color]

Share this post


Link to post
Share on other sites
Hey guys, I attempted a flight form KJFK to KATL today, and things went well in the sense that we landed safely, however some strange things happened while doing that landing. I've got a number of screencaps to show what happened. 

 

Upon hitting my decel point, the speed reference went from "FMC Speed" to a white-colored "ARM" indication. At that point the plane slowed from 240 knots to 217 knots, but it never continued to decelerate from there, leaving me scrambling to set the MCP along with moving the speedbrakes to flight detent as I approached the runway in order to slow me down. I managed to get my speed down to 185 knots upon flare, but it needed to be at 163 knots. Any idea why this happened?

 

Furthermore, as I said, everything came up on me very quickly and I think it may have been because I engaged VOR/LOC too late. Overall, I got the plane down safely, but some quirky things happened. If you guys could attempt to work through the screen caps and offer me feedback on what happened, that'd be absolutely fantastic. 

 

1el07l.jpg

 

2lub22x.jpg

 

1pjq6e.jpg

 

11s06lv.jpg

 

2qa8leb.jpg

Share this post


Link to post
Share on other sites

Sorry for the double post, but since a video probably helps a lot more than a handful of pictures with little context, here you guys go. Critique away.. please! I want to improve, and while I did a lot right (at least I think), I certainly screwed up somehow, as evidenced by the fact that the plane didn't continue to reduce speed towards VRef, which left me scrambling to slow the speed with the speedbrake right as approaching the runway. Also, due to all the commotion, I forgot to lower the landing gear and I was swerving on the runway, as I hadn't put my feet on the rudder pedals upon touchdown. Brain farts, no doubt. If there's anything else besides the obvious aforementioned error, please note it! I'm sure I made a mistake somewhere else as well. If possible, please tell me what I did wrong and how to correct it. 

 

https://www.youtube.com/watch?v=ibbCoa_kASM

Share this post


Link to post
Share on other sites

Wrong choice of autopilot mods in wrong time, and very slow time of reaction. Additionally, you do not know how to perform an ILS approach and relying on AP to do things you don't know. You are slave of AP, and that's wrong.

 

I don't even know where to start:

 

0.You should select VOR/LOC as soon as you turned to final, or even before that. You shouldn't arm VOR/LOC at 5nm from runway.

 

1.Flaps schedule:. When your airspeed is at green "*UP" dot, you should select FLAPS1 and command maneuvering speed for flaps1; When your airspeed is at green "*1" dot, you should select Flaps5, and command maneuvering speed for flaps5 and so on. If you selected flaps 1 at 217kt, AP would command lower speed.

When APP mode capture ILS, MCP speed window opens and leave you setting airspeed manually. 

 

2.You cannot just forget to extend landing gear. Why? Because 737 cannot descend and slow down in ILS if you do not select gear down and at least flaps 10.

 

 

I know it sounds harsh but you are not ready for this aircraft, go back to a cessna 172, learn to fly first. Become IFR proficient first, learn how to fly approaches. Practice at least 100 different approaches. :smile:


[color=#a9a9a9][size=1][size=4][img]http://forum.avsim.net/public/style_images/flags/rs.png[/img][/size] Lj. Prodanovic[/size][/color]

Share this post


Link to post
Share on other sites

Yeah, thanks for the constructive feedback... exactly what I needed.

 

Look, I realize I was in over my head. I made that clear. The last thing I need are particularly critical comments, which approach the point of being overly harsh. Nothing you said was wrong... I thoroughly botched the landing, but nonetheless, the tenor of your comment almost seemed to indicate that you were somehow offended by my landing, which I don't get.

 

I do appreciate what legitimate feedback you did give, and while I'm not the police of semantics, or who says what, or how they say it, I would encourage you to tread a bit lighter. You've been in my shoes before, and when I'm the one giving advice a couple years down the road, I can only hope my horse's saddle is a bit closer to the ground.

Share this post


Link to post
Share on other sites

Look, my previous post was not intended to criticize you, nor my intention is to glorify my knowledge in any way. Sometimes it's hard to pick up "the tone" of post just by reading it. Every word I've written was to help you. 


[color=#a9a9a9][size=1][size=4][img]http://forum.avsim.net/public/style_images/flags/rs.png[/img][/size] Lj. Prodanovic[/size][/color]

Share this post


Link to post
Share on other sites

Look, my previous post was not intended to criticize you, nor my intention is to glorify my knowledge in any way. Sometimes it's hard to pick up "the tone" of post just by reading it. Every word I've written was to help you. 

 

Water under the bridge. Apologies if I misinterpreted the tone of your post. 

Share this post


Link to post
Share on other sites

  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
  • Donation Goals

    AVSIM's 2020 Fundraising Goal

    Donate to our annual general fundraising goal. This donation keeps our doors open and providing you service 24 x 7 x 365. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. We reset this goal every new year for the following year's goal.


    50%
    $12,660.00 of $25,000.00 Donate Now
×
×
  • Create New...