Hi,

 

I bought Radar Contact today and I love it! I've been flying with fligtsim just over 5/6 months now and I want to make my simming more realistic now.

 

I don't fly irl however have an interest in real world avaition, I'm still a novice at flying and still learning most procedures. Usually at default ATC I fly at cruise until controller tells me to descend however on RC it gives me a descend and maintain 11,000 from FL350 and it's just impossible to do that and then I get criticised.

 

Am I missing something?

maybe, hard to say from the description you gave. first,are you flying in the US or outside? are you setting your altimeter to the local pressure after you pass through the transition altitude? don't be lazy and press the B key, it won't work reliably outside the US

 

second, what is your rate of descent, when you are told to start your descent? are you starting your descent shortly after getting the descent clearance? are you flying at 4x (don't. not even 2x).

 

lastly, is there a VOR at or near the arrival airport? that helps with the timing of the descent clearance.

 

if none of this helps, make a log, instructions pinned to the top of the forum. and make sure you click debug before loading your .pln

 

jd

Sorry that the explanation isn't clear, it's hard for me to explain when I'm quite a newbie at aviation.

 

Now I start my descent when I'm told to descend and maintain, I'm flying at normal speed. I ask for an altimeter check when I pass transition alt, I fly both in europe and the USA.

 

My usual rate of descent is -1800fpm however I have tried descending at -2600fpm using the speedbrake where necessary and still cannot get down in time.

 

The way I have set my flight plan up is with waypoints and none of the waypoints are VORs however I'm not 100% sure, it happens at KATL & KLAX however I haven't tested with others yet.

 

I'm about to fly KLAX - KATL and will send over a log of the flight once finished, however I do strongly feel as if it's me causing the problem and not Radar Contact.

It's Radar Contact. It rarely gives you descent instructions early enough to properly descend and get down to height in time.

 

I totally ditched built in ATC, whilst it is more than sufficient for VFR, it becomes pointless for IFR once you start wanting to do any vaguely realistic procedures.

Hi James thanks for the reply!

 

If Radar Contact rarely gives descent instructions early enough what can I do to get down in time, as I can't deviate from my altitude or I'm shouted at by ATC.

 

Also I've just touched down from KLAX at KATL and will send you the log now, here's how the descent went:

 

At FL350(cruise) toward dest I was told to 'descent and maintain FL270 which straight away I descended at -3000fpm with speedbrake.

 

At FL320 out of FL270 I get 'descend to 11,000 now please I need you down by 30 miles or less', in which I descent to 11,000 can't really go any quicker than 3,000fpm

 

At FL240 I'm told I've missed my crossing and to turn heading...

 

EDIT: I debugged the flight but have no .LOG folder in my radar contact install directory, I'll have to debug another flight.

Honesly i'm not sure why it's doing that, i don't know a huge amount about radar contact's inner workings but it's certainly not right. There's no way you should be expected to descend 22,000ft in 30 miles.

 

Radar Contact seems incredibly simplistic, i'm not surprised it struggles to work out a top of descent.

 

-2800fpm is not an abnormal descent profile, quite normal i would say, but it seems it is still too late in issuing the descent clearance...

I'm tempted to request lower cruising alt nearer to my destination but it just doesn't feel realistic enough.

If it has the option to do so, do it. Calculate your descent before you fly the flight and request clearance when needed. As a starting point, use 3x your altitude in miles as your T/D. For example at 30,000 feet, you would begin descending at 90 miles out.

RC gives me an earlier descent than the T/D calculated in my vertical profile every single time. Yes, RC descents me earlier than I want to, just like IRL. So your problem is completely new to me.

 

- Do you switch enroute frequencies as soon as you're told to do so? Or do you wait for, say, minutes? (Sounds like an odd question, right?)

- How fast is your plane (cruise speed)? It's not a Concorde or a sub-sonic plane? (Again, sorry for asking!)

- Can you give us the complete flight plan of a flight where this happens? Including all waypoints that are fed into RC?

 

Totally confused myself ...

RC uses the 3:1 rule of thumb to compute your top of descent to the crossing restriction at 12,000 or FL120 or 11,000 feet or FL110 depending on your arrival direction, not the airport surface altitude. That restriction is about 40 nm out from destination. Depending on your aircraft nav gear you may insert a fix or range ring. For example on a Boeing Smiths type FMC, open the fix page, set your ICAO airport code as the fix, and enter /40 for the distance, and the nav display will show a dotted circle as a range ring around you destination. If your FMC displays altitude trend arcs, they should terminate at or before crossing the range ring.

 

To meet altitude requirements you need to plan ahead and start slowing if necessary reducing to increase the available time to lose altitude. Another option is to know your terrain clearance and while still enroute ask for a lower altitude to reduce the amount of altitude to be lost in the descent phase.

 

For example when approaching LEPA from the west because of terrain or whatever, stepping down is fast so I know to request a lower enroute altitude of a few thousand feet before I get to the Spanish coast and slow the aircraft. There are some high mountains on the east coast on that route and descent must increase after you cross them. Get and look at the STAR charts available. This is especially important for rough terrain.

 

For FAA territories I use the INFO button for the destination ICAO at flightaware.com. Just click when the tabs open on IFR plates and download the full .pdf bundle so you will not have to revisit the site for different charts for that airport. Print out or just view the charts you need.

 

For Eurozone destinations I use Eurocontrol:

 

http://ead-website.ead-it.com/publicuser/public/pu/login.jsp

 

and get the free registration. After you log in you can sdelect Enter Application, then PAMS Light. A queryscreen opens. For the example I gave of LEPA coose Authority Spain (LE), then Civil, EN(glish), AIPP type Charts, Part AD, check Advanced, and you'll get a pop-up search box. In the document name field enter *LEPA*, then you'll get a list of all LEPA charts.

 

The rightmost column is the title such as AD 2 - LEPA - STAR RWY 24L/ 24R and to get the .pdf chart click on the second column LE_AD_2_LEPA_STAR_2_en.pdf which will open it in Acrobat reader. You can the save the file from there (for later recall) as a .pdf and/or print. In this example approaching from the west you would get down to 7,000 feet for moving around and then for the instrument procedure down to 4500 at the IAF points as directed by ATC.

 

In RC once you are assigned a runway and accepted the first vector you can request an IAP in which RC will no longer issue instructions and you can follow the chart or FMC guidance. Another choice preflight is to select the NOTAMS option on the controller page, in which case RC issues instructions as advisories during the later descent stages in which you can deviate and not get hounded by ATC although you still must meet the crossing restriction without deviation.

 

RC's computation of TOD allows a near constant idle descent to the crossing restriction and then stepped as necessary.

 

I flew from the west using these STARs with the PMDG B738 (emulating Air Berlin - LEPA is a hub) and did need speed brakes only after leaving the eastern coast to get down to 7,000 feet or altitude commanded by RC.

 

Now, things get very busy as you get near the coast and for me reducing cruise speed was a necessity to handle everything as well as requesting a lower altitude. I used NOTAMs to get over that rocky hump on the east coast. Do this in visual conditions on route from one of the distant Spanish airports in the central western section or from Portugal. Try FL350 and it will make good training

Olli reminded me of something important. When RC gives you a command first execute it promptly then ASAP ack it. If not promptly acked, the next command will be late as RC stalls until you ack a command. If you also do not ack a command before crossing a waypoint to get RC credit, you will not get credit for it so choose carefully when you ack.

Ronzie thanks very much for the detailed reply I'll definately try, I don't know whether it's the setup I'm using into why I'm not being cleared on RC however it happens on multiple flight plans, I usually just use FSX's high altitude airways and use those default waypoints.

 

I do switch frequencies as soon as I'm told and I'm just flying the B737-800 cruising at .78 mach at FL350.

 

I can't request descent early but I can 'request lower' so I might just request FL230 or FL200 and descent from there and see how I get on.

 

In terms of the 30 miles out, how do you calculate miles to nm, or does 30 miles mean 30nm?

 

Thanks guys!

(...)

 

Olli reminded me of something important. When RC gives you a command first execute it promptly then ASAP ack it. If not promptly acked, the next command will be late as RC stalls until you ack a command. If you also do not ack a command before crossing a waypoint to get RC credit, you will not get credit for it so choose carefully when you ack.

 

 

Yep: Could be something unimportant like a traffic advisory - if you don't 'Roger' you're going to loose distance for descent!

 

(...)

I do switch frequencies as soon as I'm told and I'm just flying the B737-800 cruising at .78 mach at FL350.

 

(...)

In terms of the 30 miles out, how do you calculate miles to nm, or does 30 miles mean 30nm?

 

Thanks guys!

 

Miles should be fine as nm.

 

In the general options, you tick 'jet' for the 738, not 'turbo prop' or 'prop', right?

 

Do you tick 'tune on contact' to speed up freq changes, too?

 

Do you answer immediately after the clearance given or do you wait for your answering options to display? Do the displayed answers come in late due to some system load, maybe?

An rc .log file is in your main RC folder. If you terminate FS and RC hangs where you have to use the task manager to close it you may not get the .log. file. Once you have STARTED RC the only way to get out of it correctly is to close it from menu choices or to ALT-TAB to it and click the QUIT button (now in place of the START button) so the log is saved.

 

BTW, 22,000 feet in 30 nm is less than 750 feet per nm, well within an aircraft's performance profile.

It's jet yes, auto ack is on however not auto tune I'll activate that next flight.

 

Ronzie it says I need to be down at 30 miles out of the airport but it doesn't give me clearance until I'm like 37/40 miles out.

 

It's probably something I'm doing so my next flight I'll monitor everything extremely carefully and see if it's something I'm doing. That's also why the .log didn't save but I'm going to do a few short legs and EGGP - EGAA and see if I can find the problem out.

 

 

BTW, 22,000 feet in 30 nm is less than 750 feet per nm, well within an aircraft's performance profile.

 

Doesn't that depend on the aircraft speed Ron? 750 feet per nm at 100kts might be easy but not perhaps at 280kts.

 

Assuming a speed of 250kts it takes around 7.2 minutes to travel 30 miles. So to descend 22,000ft in 7.2 minutes requires a descent rate of 3,022fpm. A far higher rate than is normal.

 

However, if the descent speed was 280kts it would only take 6.42 minutes requiring a descent rate of 3,426fpm almost certainly resulting in an overspeed situation.

 

Perhaps Deeb could provide his flightplan for a troublesome flight.

 

And to James Bennett let me assure you that RC does calculate the ToD point quite accurately and if anything starts you down earlier that your CDU may suggest.

 

The key to a proper rate of descent is to insert a waypoint in your plan 40 miles from the arrival airport with a mandatory altitude of either FL110, FL120 or the equivalent in feet for US flights. Most CDUs allow you to do that.