Hi Norman,Thanks for that excellent write-up. I hope it helps Andy with his approaches.

This has been brought up so many times. RC leaves you too high and/or too far from the LOC to capture more often than it should. This will occur in flat places like KATL, so the mountain terrain (MSA) has nothing to do with it. The ability to request the IAP isn't accomplished very well either since it mostly occurs too late in your approach. You might be happily on a STAR trying to head to an IAF when ATC tells you to turn and you have no choice to tell ATC that the instruction to turn is gonna mess up the flight completely. By the time you're given the choice to request your IAP, you are too high and so far off course that you are heading back in a different direction to capture the IAF. I've also had PD requests denied so that didn't fix the issue of not being able to descend correctly.RC has a lot of promise and offers a lot of great features, however, it isn't a very realistic simulation of real world ATC. Real world ATC will instruct planes to descend on time so they can meet waypoint restrictions. Real world ATC will allow you to continue on a STAR as long as it doesn't interfere with the flow and traffic permits. Real world ATC won't issue unrealistic headings or require modification to your flight plan via FMC just to make them happy. In the real world, if you are on a STAR, you are either allowed to continue that STAR to an IAF or FAF, all the while given correct instructions to descend on time so you aren't too high and struggling to slow down, or you are vectored off the STAR and entered into a specific pattern that ATC tells you to follow via new headings. Each of these methods are employed in a way that they don't interfere with pilot workload and provide a comfortable path, both vertically and horizontally, to the airport. In some cases, if traffic is an issue, Wx is a problem, or some other issue with ATC (e.g., poor execution of flow control) is occurring, then you might be required to descend later than is preferred, enter a hold, or follow some new headings until things settle down for the controller.Bottom line, real world ATC isn't perfect either and pilots do have to manage certain things on their own, such as PD clearances, STAR approaches when allowed, and transition to IAPs. However, ATC will nearly always allow the pilot to get down in time, in most cases not requiring excess drag from speedbrakes, gear, or flaps because this affects the flow heavily in major traffic regions, and while it does happen, it shouldn't be the norm. These problems could all be avoided if RC provided an interface for vertical descent and gave more latitude to the pilot. When you enter your flight plan, you should be able to enter altitude restrictions at each waypoint, so if you are on a STAR or have calculated your descent properly, then RC should instruct you to those altitudes within a reasonable time frame. If the math is too hard to adjust based on certain aircraft not slowing as easily (e.g., ground speed versus distance/3:1 calculations), and therefore requiring a few levelling off points to slow to 250 and subsequent flap extension speeds (e.g., 737NG), then a provision should be included that takes that into account. Either PD is always granted, unless traffic is a potential hazard, or an option to include shallow descent calculations is included in the setup screen. Real world ATC knows that a lot of jets require a level off or pitch up to slow down and meet lower speed limits. Even if the pilot is on a CDP or similar RNAV profile, he is still gonna be given time and clearance to pitch up for a few degrees along his vertical path to slow and still meet altitude requirements. Boeing doesn't want it's spoilers/speedbrakes extended very much for approaches. Pilots don't want to use spoilers anymore than is required, and in some aircraft they're nearly worthless for descent and slowing. Pilots, ATC, FAA/Gov, and airline companies don't want pilots dropping gear or flaps too early either, so this is a poor solution. The MSA and NOTAM programming could be all but dropped since it doesn't provide a realistic solution either. A vertical profile pattern that could be entered into the setup for preflight would eliminate any terrain concerns. Even a parameter to include certain waypoints for missed approach would help things. MSA should only be looked at as a last resort or for G/A and holding instructions. Also, the choice to use vectors, which is still a widely used practice, should work all the time. If your flight plan has a provision for "At or Above 2800" feet crossing the FAF, then using vectors should reference that altitude you specified and give you proper headings and descent clearances to meet that requirement comfortably. Whether you are using vectors to ILS in low RVR or visually land, it shouldn't matter, it should work. You should also be given a more realistic pattern, not 20 NM downwind before cleared to base leg. Having to request a short pattern is poor practice and increases the workload. If you want a longer pattern on vectors, then it should be a option to check in setup. You should always be able to override this setting, but to automatically force you downwind and base 20 NM out is wrong.I conclude that with the proper preflight setup options, an ATC program could realistically simulate real world flows. In all honesty, an application that read the Navigraph database would be an ultimate solution to flying real DPs and STARs or IAPs to transition. ATC would have complete knowledge of all DPs and STARs for the airports in the flight plan and be able to list them for the pilot to choose and follow. If the FMCs from PMDG, Level-D, and others can read this info, then an ATC program should be able to and thus easily instruct the pilot based on lat/lon and altitude.

Ive tried various methods for the approach.Total FMC descent control, but getting "drag required" or "cannot meet the descent profile" all the time.Tried a combination of the way i originally conducted my descents plus FMC below 10000ft.In all cases, it is still difficult to slow this aircraft down.Bottom line is for me anyway, because you cannot get an instrument approach from ATC until inside 40 miles, and ATC has you at either FL120 or FL110 at that mark, you cannot slow the aircraft down from 250kts to comfortably intercept the localiser without using speedbrakes or getting the gear out early to try and slow the aircraft down, which as Chris has mentioned in his post, is not what you want to do all the time.It will work if you slow the aircraft down to 210kts or less at the above mark and drag your &@($* all the way to the airport, however that is unrealistic. I use the same calculations as Chris (ground speed versus distance/3:1 calculations), and have never had a problem slowing down in any type of aircraft.The problem with this aircraft is by the time ATC hand you off to approach and you get to sort out an instrument approach, you are way too high to maintain 250kts. For a comfortable descent i would expect to be at 8000ft max to allow the nose to be pitched up to bleed off the airspeed.This from a Southwest 737 driver: "One accurate measure of drag is the 250kt descent out of 10,000' at idle. a lightly loaded -700 (with winglets) will come down at 1450 fpm and only 1250 fpm closer to max landing weight."And this is exactly the problem. From 10000ft at 250kts, you need more than that to get down without the use of speedbrakes.Its an aircraft problem, the 737ng as in real life can be a tiger to slow down. ATC needs to allow us to descend a lot earlier to achieve 250kts a lot closer to the airfield without the use of speedbrakes.

Hi Andy,You've raised my curiosity level sufficiently for me to want to fly one of your troublesome routes. Can you provide a plan (flight time < 1 hour would be appreciated) together with required altitudes for the STAR sector. I'll fly it in my PMDG737-800 with the only difference being that I'll be using Project Magenta Boeing Suite for autopilot control, not PMDG's but that should not substantially change anything.I'll need a cruise level and fuel to be loaded too please. But if you can fly this route with a 747 it sounds more like you have a problem with the aircraft than Radar Contact.

Ok Ray, sorry for the late reply but ive just flown back from work today.I will set up a plan and give you the details in the next few days.It will probably be Kalgoorlie to Perth (Western Australia) to meet the 1hour requirement.Or better still, is it possible to record the flight using FSRecorder and send it to you?

Hi Andy,Blimey, that's different to my usual flights! :( I don't know how big the recording would be so let me fly it first and I'll report back. Here's the route I'll use. KG J141 CUN J64 PHCan you suggest wind direction for runway assignments? A straight-in would be best as that requires lower aproach speeds. I'll cruise at FL340 in a PMDG737-800.

Ok Ray i conducted the flight, here's a synopsis.I flew the same route as you did, however i completed a self designed STAR, with the waypoints PEPPA, ONDEE, YUNGA, WOORA and HAIGH added after CUN, which leads you into an ILS for RWY 21 at Perth.RC4 descended me down to FL120 at 40 miles DME Perth (standard for any approach by RC4), by which you cannot request a further descent at this point, you must wait for RC4 to hand you off to approach. I maintained a speed of 250kts, which is the crux of my argument, that being you should be able to maintain 250kts a lot closer in to the airport.And here's where the problems start.I requested an instrument approach for RWY21 whereby i initiated a descent using FLCHG which will give me max rate of descent based on the speed i input into the MCDU, being 250kts.The descent was initiated at 36 miles 12000ft (right on the 3 times rule). This is where i believe the problem starts, because when i need to reduce from 250kts i obviously need to bring the nose up, further reducing the vertical rate of descent.At 25 miles i reduced the speed to 220kts, which i achieved at 20 miles at 8000ft. (3 times rule should have me at 24 miles, but you can see ive lost 4 miles).I further reduced the speed at 20 miles to 180kts and achieved that speed at 17 miles, 7500ft (3 times rule should have me at 22.5 miles, ive lost a further 1.5 miles).I finally reduced to my final approach speed, 150kts (VREF +10) at WOORA.I toggled the APP button for the ILS intercept just before reaching HAIGH, and by the time i intercepted I was so high that the Autopilot initiated a descent rate of 3000ft per minute to capture the glidescope, not what you want when your that close to the ground!My landing weight 141.7 and fuel 7800 on landing.So here's my question. How do you from FL120 at 40 miles (because RC4 wont let you desend any further until after this point) as in the case above, maintain 250kts until a lot closer to the airfield without the use of speedbrakes?From talking to and reading from what real 737-800 drivers have said, you should be able to do it, although i do know that it can be a pig to slow down. I am very interested to see how you go Ray, to see if im doing something massively wrong.Thanks,Andy

Hi Andy,I didn't get a chance to fly this route over the weekend but I'll make time this evening. I just wanted to comment on a couple of points.

RC4 descended me down to FL120 at 40 miles DME Perth (standard for any approach by RC4), by which you cannot request a further descent at this point, you must wait for RC4 to hand you off to approach. I maintained a speed of 250kts, which is the crux of my argument, that being you should be able to maintain 250kts a lot closer in to the airport.

Whilst you're above 10,000ft you can exceed 250kts. I see no reason why you couldn't be at 300kts at FL120 but you will need to manage your speed more carefully once descending. This comment sums it up really...

So here's my question. How do you from FL120 at 40 miles (because RC4 wont let you desend any further until after this point) as in the case above, maintain 250kts until a lot closer to the airfield without the use of speedbrakes?From talking to and reading from what real 737-800 drivers have said, you should be able to do it, although i do know that it can be a pig to slow down.

You can't have your cake and eat it! :( Either slow down without speedbrakes and be below the glideslope when you intercept the ILS or go for the fast descent with speedbrakes to put you at the same location and height. If real 737-800 pilots say speed control is difficult on descents you have to accept you can't do fast descents without speedbrakes.Anyway, let me fly it using your waypoints and I'll report back with my findings. The fact that you had a far-side approach (as indicated by FL120) suggests there is plenty of time to get down and still maintain a reasonable speed. But requesting a instrument approach is something I haven't done for a while - I usually leave it to RC.

Hi Andy,I didn't get a chance to fly this route over the weekend but I'll make time this evening. I just wanted to comment on a couple of points.Whilst you're above 10,000ft you can exceed 250kts. I see no reason why you couldn't be at 300kts at FL120 but you will need to manage your speed more carefully once descending. This comment sums it up really...You can't have your cake and eat it! :( Either slow down without speedbrakes and be below the glideslope when you intercept the ILS or go for the fast descent with speedbrakes to put you at the same location and height. If real 737-800 pilots say speed control is difficult on descents you have to accept you can't do fast descents without speedbrakes.Anyway, let me fly it using your waypoints and I'll report back with my findings. The fact that you had a far-side approach (as indicated by FL120) suggests there is plenty of time to get down and still maintain a reasonable speed. But requesting a instrument approach is something I haven't done for a while - I usually leave it to RC.

Hi Andy and Ray,The use of speed brakes as a means of slowing down a 737NG is only prohibited when flying at or above 300knts,unless some airline SOP dictates otherwise.The FAA in 2002 issued this directive following an incident when excessive vibration was felt in the elevator when deploying speedbrakes at high speeds.As with all of the comments posted on some forums sometimes a little check on the facts can produce the actual definative answer!Speedbrakes can be used to slow the NG series down!RegardsNorman Bowman

Hi Andy and Ray,The use of speed brakes as a means of slowing down a 737NG is only prohibited when flying at or above 300knts,unless some airline SOP dictates otherwise.The FAA in 2002 issued this directive following an incident when excessive vibration was felt in the elevator when deploying speedbrakes at high speeds.As with all of the comments posted on some forums sometimes a little check on the facts can produce the actual definative answer!Speedbrakes can be used to slow the NG series down!RegardsNorman Bowman

Thanks for the confirmation Norm. I'm sure it's quite acceptable to use them but not on every flight perhaps. I'm a little concerned by Andy's use of a "self-designated" STAR. I'd be interested to know the altitude constraints for each of his waypoints.I've had a look at YPPH STAR charts and the most appropriate for an approach from the NE appears to be JULIM THREE but the waypoints for that differ to the ones Andy supplied. JULIM is 36DME from YPPH and 23DME to WOORA. If he was at FL110 at JULIM I think he could get down to WOORA okay. By WOORA he should be down to 3000ft descending to 2500ft by HAIGH. If he's landing on 21 then it's a near-side approach and he should have been cleared down to FL110, not FL120. I wonder what the winds are. :(

Andy,I've had some time to look at the charts for YPPH and the thing that jumps out at me in your message is the fact that RC cleared you down to FL120. It only does that for a far-side approach suggesting the wind was from the north and 03 would be used by landing traffic.If you're requesting an instrument approach for a different runway to that used by landing traffic then you're left to your own devices by RC. You'll just be cleared down to 3000ft and after that it's down to you how you control speed etc. But I think you're doomed to failure if you expect to maintain 250kts during the descent. There just isn't the distance available to allow that.The fact that you've requested 21 suggests you're landing with a tail wind and will be using a near-side approach. For starters you need to throttle back to 210kts very soon after being cleared below 10,000ft in order to meet the altitude constraints for the ILS approach.But I'll fly this later today and save a flight around 50 miles out. That will allow me to change the wind direction and see how RC reacts.

Hi Andy,I flew your route earlier and encountered problems descending from FL120 having requested a IAP to 21. If you're going to request an IAP then RC leaves you alone and you're expected to control your descent and altitudes. But given you were at FL120 this suggests the winds were from the north and I confirmed this by setting the wind 020/6. So you shouldn't be landing on 21. You should be flying the approach for 03.I set QNH deliberately high at 1031Mb. The Transition Altitude at YPPH is 10,000ft in RC so once I was cleared to approach 21 and cleared down to 3000ft I had to set the altimeter to QNH of 1031. That together with the 1000ft difference in my altitude when contacting APP put me 1500ft higher than I wanted to be.So I set 3000ft for HAIGH and left the CDU and MCP to control the speed and descent. I couldn't keep the airspeed below 250kts despite using speedbrakes and although I reached 3000ft by HAIGH my airspeed was far too high. You had a different problem where your speed was okay but you were too high. I presume you set the altimeter to QNH on being cleared to 3000ft?It just isn't possible to fly this approach and stay within the speed constraints. To start with you should have requested an approach to 03 and then you would have had ample time to descend at 250kts until on the downwind leg when 230kts is the limit. You were too close for an approach to 21 without entering a hold to lose altitude.Try it again and set the winds from the south. RC will clear you down to FL110 but once you request an IAP you must reduce speed to 230kts max before starting down especially for near-side approaches such as this one. You just don't have the distance to go any faster and as you said earlier the 737-800 is a pig to slow down. I can certainly vouch for that!Hope that helps.