My first time flying a 737 ATC had me 2,000ft above the Glide-slope at the FAF(I know, technically its the FAF whe you intercept the GS at the assigned altitude). I assumed my descent rate was enough. So another day I decide to increase my descent rate next time I was beng vectored for final...this time I came within a couple hundered feet of slamming into the mountains for the SUNOL interection. I was at the instructed altitude, but I guess I got there too soon(I had to cross the hill-line to reach the ILS localizer. So I figure maybe ATC expects a certain descent rate to not come in too high for approach, but to also clear obstacles along your path that are near or above the given altitude instructed to descend to.Now because of varying speeds, I'd assume we would need this descent rate in Feet/NM instead of feet/min.

I find a descent rate of anything less than 800ft/min results in atc asking you to speed up your descent. I thought I heard somewhere that 1800ft/min was standard rate but that may be aircraft specific. In most cases, but certainly not all, fsatc starts you down too far out - especially with smaller aircraft. But this is clearly not the case for you in the larger aircraft. I usually descend at about 1000ft/min.Also, my understanding is that atc is unaware of terrain so your can't count on them not flying u into a mountain. Grab approach plates, request that approach, and you will then know exactly what alt you should be at during each phase of the approach. They are very fun to fly and can certainly keep u busy with atc comm and all.Hope this helps in some way.Adam

I aim for 3000' every 10Nm. If I am flying 737 at FL330, ATC starts my descent 100+ Nm out and I'll set my descent rate ate about 2300 fpm. Then I count on my fingers 3, 6, 9, 12, 15, 18, 21, 24, 27, and aim for FL270 at DME 90. (Adjust these numbers if the airport is 1000' or more above sea level)I'll probably still be high but then I try for FL240 at 80 DME. I decrease my descent rate as I slow down or if ATC vectors me for a circling approach; 1800 fpm at 300 KIAS, 1000 - 1200 fpm at 250 KIAS, etc. My goal now is to be at 6000' AGL when I am 20 miles from the runway threshold.R-

The descent rate is used by the sim is found in the aircraft.cfg for the aircraft you are flying. Under the autopilot section there is a figure for the default climb/descent rate. This figure along with your current speed are used. As you descend your speed over the ground changes so it is not always very accurate. If you maintain your current airspeed and use the default descent rate you might come out alright. The other factor is that MSFS does consider terrain height but only for the area right around your aircraft. This is why you will be instructed to descend into the mountain in front of you, or be cleared to a peculiarly low altitude only to be instructed to climb again upon or before reaching that altitude. My recommendation would be to use a IAF (initial approach fix) for your approach instead of the default vectors to final. When you are given approach instructions look over the options and select a different approach. It can be to the same runway or and adjacent runway if available and you will have options for vectors to final or using a "fix" (it will be a navaid or intersection). By doing this you will be directed to the IAF and told to descend to the altitude in the published approach for that "fix" in that approach plate. Upon reaching the "fix" you are then instructed to continue the approach and contact the tower (not exactly realistic but better than being instructed to fly into terrain!). Most approaches using the SUNOL intersection will have you cross at 5,000 feet, some as low as 4,200, then descend to 3,500 after passing. I would assume that you are landing at Oakland and not Hayward with that 737 ;).Hope this helps,Zane

ATC don't expect a set descent rate, they just expect you to be at the required altitude at the stated point and they expect you to get there by the shortest route, which is a constant 'glide' rate. For example, if you are outboud in the procedure from the hold and the base turn is 8nm from the hold 1500' lower than the hold at 220kts ground speed then you have to estimate the required descent rate so that you capture the localiser at the correct altitude. The fact that you must level out for the base turn can complicate matters. If you remeber that D=S*T (D=distance, S=speed and T=time) then T=D/S. 8nm/220kts is quite hard to figure out in your head so it is easier to think in nautical miles per minute than per hour which is just a case of 220/60 = 220/10/6 = 22/6 = approx 4nm per minute (never try and deal with fractions). 8nm/4nmpm = 2 minutes. 1500'/2 mins = 750fpm descent rate.All this can be worked out before you even arrive at the hold if you know the runway or procedure, your procedure speed and the wind.

Never had any serious problems with the descent rate. It takes some expiremtation to find the optimal rate for a given speed/aircraft.If you race down at 350kts expect to be too high -on the other hand with most GA props you need to fly with the airspeed close to the red line unless you want to do a cross country flight at 1500 feet until you reach the glideslope 30 minutes later :-roll

Yeah, but ATC had me descend down to 2500ft...the glide-slop intercept altitude for the ILS29. That just so happen to be the rough altitude of the East Bay hill line. I think I need to make a point of including the FAF fix to my flight plan, but in this case I was doing a "test" flight out of KOAK. I had no flight plan, just KOAK-KOAK so I was at the mercy of ATC the whole time.You guys have been a great help though, thanks! Keep them coming.

>>f you race down at 350kts expect to be too high ->>on the other hand with most GA props you need to fly with the airspeed >>close to the red line unless you want to do a cross country flight at >>1500 feet until you reach the glideslope 30 minutes later One thing to remember is that if you are endeavouring to make this relistic you are limited to 250kts below FL100. You also want to have the approach stabilised such that you are ready to select gear down as soon as the glideslope needle starts to budge.BTW, if you want to estimate the ILS glideslope descent rate (a 3 degree glideslope), just multiply your ground speed by 5. So a 100kt ground speed would be 500fpm and 140kts would be 700fpm.

I use FSNavigator to calculate a top of descent point. Then when I reach that point, if ATC hasn't started my descent yet, I just request a lower cruise altitude. So when ATC does get around to the descent, I am already on my way down. For example say I am cruising at FL350, I just request an altitude 10,000ft lower. So then the ATC is only handling my descent from FL250 which usually gives me enough time to slow down. If it gets too annoying, I just switch to a VFR flight plan, and handle everything about the approach myself. (actually I usually end up doing this as I want to fly a star)

The question that springs to my mind is what was earlier ATC like in FS. It must have been pretty fearsome as this one leaves a huge amount to be desired. I haven't yet had a sensible approach offered into Juneau with default wind(the sim,not me) and trying to get to Salzburg, which I posted somewhere by mistake as Strasbourg, I went M.A. when about 5000ft above the runway! and then was directed into the landscape, which is something I can do quite well enough on my own without any help from ATC. It's a great shame as it's all part of the sim to be directed into an airport in bad weather and so on and instead of sticking a few bridges about the landscape MS could have addressed these problems that are so annoying.

To make it easy for myself (because many times I ended up to high too close to the runway resulting in a missed approach) I approach as follows when flying various jets in my hanger:Anywhere above 15,000ft my decent rate is 2700FPM.15,000 to 10,000 I descend at 2100FPM10,000 to touchdown will have me at 1800FPM depending on the situation. Some jets (FeelThere's ERJ for one) have a problem with overspeeding if the decent rate is too steep... A rule of thumb for me with FS2k4's ATC is to try and be ahead of them. You don't want them asking you to expedite your decent and if you

FS2k2 was the only other version of Flight Simulator to have default ATC built into the program... ATC in Flight Simulator is a farley new technology. FS2k6 should bring some nice new surprises and improvements...

The descent profile I use is based on the "3 nmi per 1000 feet" rule for calculating the start of descent. It so happens that a slope of 3 nmi per 1000 feet is very close to 3 degrees.As mentioned earlier, you can maintain a 3 degree glideslope with a descent rate equal to 5.3 times the ground speed (rounding to 5 is precise enough). With a ground speed of 500 knots, that gives a descent rate of 2500 feet/min. Some aircraft will increase airspeed (KIAS) when the descent rate is as high as 2500. I try to anticipate the ATC command to descend by slowing the aircraft before they begin directing me.All of the above are just guidelines. They usually work well for me when flying the big jets. Regards,JerryH

One thing I'm hoping they'll do is to use published approaches, and stick to them. Currently they have a program that reads airport diagrams and that is how they made all default airports- the buildings are in the same positions and sizes as on the diagrams. It would be nice if they got jeppesen to give them the 'raw' data for all the approaches and automatically created them all. Too many approaches are way to difficult for MS ATC to just 'wing it'. If they could read in crossing altitudes and minimums and intersections from the plates, and use that, we'd see an enormous jump in the reliability of the approaches. Maybe I'm wrong, because there is the option to use published approaches, but still usually fly you into terrain in mountainous areas. If they followed real approaches, and published minimums, the FAA has already figured all that stuff out.

Your problem comes from unrealistic expectations that airliners doescend all the way from cruise to ILS intercept in one swoop. Nothing can be further from reality. They descend in steps so there is plenty of time to reach desired altitude/fixes. No particular descent rate is expected unless it is very slow and controller gest anxious you are falling behind. Obviously there are bugs in ATC in MSFS and we have to cope with them (or fly on VATSIM).(also from Oakland)Michael J.WinXP-Home SP2,AMD64 3500+,Abit AV8,Radeon X800Pro,36GB Raptor,1GB PC3200,Audigy 2