Something seems amiss.....

[kingnorris]

Ok: I've done these approaches the same way since FS9. On long flights, I speed up the sim after acknowledging a handoff but NOT contacting the controller until I'm about 170 NM from my destination, then I return to normal speed, re-establish contact with controllers, and await descent instructions.

 

Never had issues until recently. Now, I get talked down from say, 36,000 feet. Told to descend and maintain say, 20,000 feet, then 15,000 feet, etc. All ok, until.....

 

"You are 15 miles from the airport. Descend and maintain 2,300 until established on the localizer. Blah blah blah". Problem is, I'm still around 15,000 feet, and have to descend so rapidly that my speed exceeds 300 knots. Because of this, I cannot get established on the localizer. And if I'm cleared for a visual, I WILL overshoot the runway!! Also, if I click on the APP button, it turns me AWAY from the runway and also descends almost to the point of crashing me into the ground. I've never had this issue before; it always gave me plenty of time for descent, and I was always lined up for landing.

 

Only things different is, I upgraded my GEX to a newer version (not the most recent release). I fly using the sim's real weather, updated every 15 minutes.

 

This is happening with any aircraft, default or addon. Any airport as well.

 

I tried coming out of faster sim rate further away from my destination, but that didn't help. I don't get initial descent instructions until I'm about 120 NM from the airport. I have to descend so rapidly I end up slewing to the proper altitude. Something doesn't seem right with this, does it??

[bgets]

I used to do the same thing. Still do but don't use accelerated time. When ATC gives you the command to descend and maintain a certain altitude at what rate and speed do you set for your descent? I usually use between 18 to 1900 fpm and around mach .54 until below 18,000 ft. and switch to indicated air speed at about 235 kts to avoid busting the 250 knot limit below 10,000 ft. Then just keep descending each time ATC tell me to. Sounds like you are missing a command from ATC to descend from 15,000 to a lower altitude that is higher than 2300.

Bob G.

[kingnorris]

I used to do the same thing. Still do but don't use accelerated time. When ATC gives you the command to descend and maintain a certain altitude at what rate and speed do you set for your descent? I usually use between 18 to 1900 fpm and around mach .54 until below 18,000 ft. and switch to indicated air speed at about 235 kts to avoid busting the 250 knot limit below 10,000 ft. Then just keep descending each time ATC tell me to. Sounds like you are missing a command from ATC to descend from 15,000 to a lower altitude that is higher than 2300.

Bob G.

I usually set rate of descent around 2500 FPM. Seems high I know, but I feel I need to descend rapidly to "catch up" with ATC.

[mrzippy]

I got into the habit when flying over a longer distance at altitudes of 35,000 feet or higher, I initialize my own descents starting at about 150 miles out. I try to be at 20,000 or so by the time ATC wants to start giving their descent orders. It will save you headaches and diving for the deck in those situations.

[kingnorris]

I got into the habit when flying over a longer distance at altitudes of 35,000 feet or higher, I initialize my own descents starting at about 150 miles out. I try to be at 20,000 or so by the time ATC wants to start giving their descent orders. It will save you headaches and diving for the deck in those situations.

 

I've never had to do that before, but I'll try. So I guess you ignore ATC when they say "you are _______ feet below your assigned altitude. Climb and maintain ______ feet"?

[mrzippy]

I've never had to do that before, but I'll try. So I guess you ignore ATC when they say "you are _______ feet below your assigned altitude. Climb and maintain ______ feet"?

 

As long as you request the lower altitude from ATC, which you can do any time before they give you your approach to the airport, there is no annoying ATC to bug you.

[kingnorris]

As long as you request the lower altitude from ATC, which you can do any time before they give you your approach to the airport, there is no annoying ATC to bug you.

 

Ok thanks. Will give that a try.

[baddadnv]

Hi,

 

Slow down.......Use Your Spoilers.

 

You're reaching Your destination to quickly. You can try 180 KIAS from about FL180 AGL. Of coarse this will require Spoiler use, and appropriate flap settings.

 

Then speed up the process as You see fit.

 

Randy Burton

[il88pp]

ATC messages reach you with a delay if you have lots of aircraft traffic.

 

Also if settings high, if much more weather, or new high detailed addons installed. All details need to be processed by the processor, to put them on the screen.

 

-- message is sent and should reach you at that time -- delay, many other atc messages also sent, maybe computer 'catching up with where you are after accellerated time use' , anyway, delay -- messages reaches you several minutes too late. --

Or it does not reach you at all.

 

Once you start the descent to late, it all goes wrong.You are already close once reaching 23.000. The Atc message to descend further is not generated untill you reach that last target altitude of 23.000.

It does not get generated right away even then. Plus it may again reach you with a little delay again as well. causing more and more trouble.

 

I don't use accelerated time at all, but I can think of three solutions.

>>After coming out of accelerated time, pause the flight. Then go dring coffy with some nice buiscuits for 15 mins. It may help the sim to get everything lined up. And your pc gets time to wipe the sweat of it's brow too.

(You probably never realised, but accelerated time causes a lot of extra load on the CPU and videocard. The scenery has to fly by the window faster, requiring more computations a minute.)

(When I used it in the past, I often got weird white flashes, and sometimes vertical black tears through the screen. Ok, that videocard was dying already, but it only really died a hundred deaths using the accelerted time! And not just once.)

 

>>Option two, descend at slower Airspeed.

Remember, descending fast (high vertical gradiënt, many meters down for each mile flown), is all about flying slowly.

The indicator in the cockpit (V/S) shows you the vertical speed in feet per MINUTE.

Lets say you descend at 800 feet per minute.

That's 800 feet down for every minute flown.

If in that minute you fly 2 miles forward, you have descended 800 feet in two miles.

But if you fly slower, and you fly only one mile forward in that minute, you will have descended 800 feet in one mile.

In two miles you have descended 1600 feet. Nice.

 

So fly slower. You will be at the assigned altitude at a point further away from the field, and ATC will have some more wiggle room to get you down in time.

 

>>Third: Use less AI, and lower your settings. Defrag the HDD. Basic stuff.

 

il

[kingnorris]

Hi,

 

Slow down.......Use Your Spoilers.

 

You're reaching Your destination to quickly. You can try 180 KIAS from about FL180 AGL. Of coarse this will require Spoiler use, and appropriate flap settings.

 

Then speed up the process as You see fit.

 

Randy Burton

 

Hey Randy! Where've you been??

 

Anyway thanks for the advice. Just find it odd that my method which has always worked before suddenly isn't. Thought my FSX may have gotten fudged up or something.

[kingnorris]

ATC messages reach you with a delay if you have lots of aircraft traffic.

 

Also if settings high, if much more weather, or new high detailed addons installed. All details need to be processed by the processor, to put them on the screen.

 

-- message is sent and should reach you at that time -- delay, many other atc messages also sent, maybe computer 'catching up with where you are after accellerated time use' , anyway, delay -- messages reaches you several minutes too late. --

Or it does not reach you at all.

 

Once you start the descent to late, it all goes wrong.You are already close once reaching 23.000. The Atc message to descend further is not generated untill you reach that last target altitude of 23.000.

It does not get generated right away even then. Plus it may again reach you with a little delay again as well. causing more and more trouble.

 

I don't use accelerated time at all, but I can think of three solutions.

>>After coming out of accelerated time, pause the flight. Then go dring coffy with some nice buiscuits for 15 mins. It may help the sim to get everything lined up. And your pc gets time to wipe the sweat of it's brow too.

(You probably never realised, but accelerated time causes a lot of extra load on the CPU and videocard. The scenery has to fly by the window faster, requiring more computations a minute.)

(When I used it in the past, I often got weird white flashes, and sometimes vertical black tears through the screen. Ok, that videocard was dying already, but it only really died a hundred deaths using the accelerted time! And not just once.)

 

>>Option two, descend at slower Airspeed.

Remember, descending fast (high vertical gradiënt, many meters down for each mile flown), is all about flying slowly.

The indicator in the cockpit (V/S) shows you the vertical speed in feet per MINUTE.

Lets say you descend at 800 feet per minute.

That's 800 feet down for every minute flown.

If in that minute you fly 2 miles forward, you have descended 800 feet in two miles.

But if you fly slower, and you fly only one mile forward in that minute, you will have descended 800 feet in one mile.

In two miles you have descended 1600 feet. Nice.

 

So fly slower. You will be at the assigned altitude at a point further away from the field, and ATC will have some more wiggle room to get you down in time.

 

>>Third: Use less AI, and lower your settings. Defrag the HDD. Basic stuff.

 

il

 

Great tips there. Yeah I found it weird that ATC would start my decent already 120 NM out. Then I get a rapid fire of instructions: turn L/R heading, descend and maintain, turn L/R heading again, climb, descend......you get the idea. Ending with the final approach instructions. ("But I'm still descending to 3,000 from 15,000 feet!! Give me a break here!!")

 

What I think I'll try first is a quick hop, keeping all communications going and at normal rate to see if that helps.

[il88pp]

sounds like delay.

[MBKHOU]

I usually set rate of descent around 2500 FPM. Seems high I know, but I feel I need to descend rapidly to "catch up" with ATC.

 

That should be fine unless the distance to cover is shorter than it should be.

I've always used the altx3 rule for making a WAG about TOD. IE: FL360=108 miles.

120 miles from the airport at FL360 should be plenty. And about the distance I would

normally expect. That seems fine, and should be doable with room to spare if descending

at 2500 fpm, even if you hold mach cruise until the merge to IAS, and then hold a hot

IAS down to 10,000.. IE: say 290-300 knots..

If I use VS to descend, I usually use 2200 when I first start the descent. I'll only start

to shallow up as I'm nearing 10,000 and need to slow down.

With the 737, the TOD is calculated by the FMC, and can be flown VNAV, but being

as I go by ATC's TOD, I usually switch to MCP ALT and SPD before the FMC TOD.

Sometimes I do get cut short and the distance is shorter than what you really need.

Maybe 1-2 flights out of 10.. In that case, I just do whatever I need to do to get

down quicker. But the other 8 or so out of 10, it works out OK. As long as I get my

altx3 TOD distance, I'm good to go without having to do anything really special in

the descent to get down quicker. I don't use the speed brakes too much. Only when

I have no choice. Most flights I never touch the handle except to arm for landing deploy.

But 1-2 flights out of 10, I gotta make some rumble noise with the boards.. :pilot:

 

BTW, you can also use altx3 during the descent to see how things are working

out, and if you need to modify the descent.. IE: if I were descending from Fl360,

at FL300, I know I want to be about 90 miles out. More than that, I'm good.

Less.. I need to tweak the descent rate and get down a bit quicker, and maybe

slow down a bit. FL250=75 miles.. FL200=60 miles.. etc.. You get the picture.

[il88pp]

What I think mrzippy meant:

reestablish contact. Then request "decrease cruise altitude by 7000ft" or slightly more.

You will get cleared for that. Descend as instructed and await approach instructions.

[darryl737]

What I do is once I get my initial descent instruction I wind the AT right back to 210knts and descend at 18, I find that for me seems to be the sweet spot that the aircraft will slowly slow while maintaining a good decent rate. I find that 9 times out of 10 I am will and truly at the right altitude before I get further descent instructions. Its a time on distance thing. I find that ATC will start to get behind if you reach a certain point on your approach to fast or if you have intercepted a VOR to fast and to high you start getting the insane messages expecting you to lose bucket loads of altitude over a short distance and before you know it your flying a combat approach and landing.

[HoggyDog]

What I do is once I get my initial descent instruction I wind the AT right back to 210knts and descend at 18, I find that for me seems to be the sweet spot that the aircraft will slowly slow while maintaining a good decent rate.

 

I've been flying the default B738 a lot, and of course Darryl's "sweet spot" of -1800 fpm will vary a bit by airplane. I use -1500 for normal descents because in the B738 that allows me to descend and decelerate gradually at the same time without using speed brakes. If I don't want to decelerate yet (for example, descending from FL360 to FL200, I wouldn't need or want to decelerate so I leave the AT set at cruise airspeed) and set the same VS as Darryl said: -1800 in the default B738.

 

Slow down.......Use Your Spoilers.

 

I avoid using the speed brakes ("spoilers") in FSX unless there's no other choice because they cause a severe nose-up pitch change that the AP does not compensate for. This behavior seems unrealistic and it screws up my descent plan as well by abruptly leveling or even climbing the airplane- the pitch up is that severe. Also, if you can avoid the late ATC descent clearance in the first place, slowing down from cruise airspeed is neither required nor even desirable until you are cleared below 10,000 feet.

 

My preference is to eliminate the problem altogether by avoiding the late descent clearance in the first place. The rule of '3x altitude' (mentioned above in this thread) to plan TOD is a good rule of thumb as a fallback in case ATC doesn't start you down in plenty of time for a normal, cruise-speed descent to arrive at least 25 miles out at final approach altitude, but I've never gotten a sim-acceleration-caused late descent clearance from FSX ATC even with WoAI cramming airplanes all over the place. Just remember, when using that rule of thumb, subtract final approach altitude from your pre-descent altitude to keep your TOD as realistic as possible. If you don't know what your final approach altitude will be because you left your Jepps in your other suit :p add 2,000 feet to the airport elevation as a reasonable SWAG.

 

Example:

Cruising altitude = FL360 ("36,000 feet" for this calculation)

Destination airport elevation = 3,000 feet MSL

Estimated final approach altitude = 3,000 + 2,000 = 5,000 MSL

Estimated total altitude to lose in descent = 36,000 - 5,000 = 31,000

Estimated TOD = 31 x 3 = 93 nautical miles from the airport.

 

The truth of the above calculation can be shown like this: to descend 31,000 feet at 1500 fpm will take 20.66667 minutes. At my cruise speed of 300 KIAS, I will have a ground speed of 400 knots or so... but that ground speed will be decreasing as I descend because my TAS (True airspeed) will decrease as I descend while I hold 300 KIAS. 400 knots is 6.66667 NM per minute, but I eventually must decelerate to 250 KIAS below 10,000 feet, and that is only 4.16667 NM per minute. So my average speed throughout the entire descent can be estimated at about 5 NM per minute. Since it's going to take me about 21 minutes to descend at 1500 fpm, I can estimate my distance traveled in the descent as 21 x 5 = 105 NM. However, ATC is not going to allow me to just fly direct to the airport, AND I am going to use 1,800 fpm for most of the descent, which means the descent will actually only take 17.2222 minutes... so the 12-mile difference above pretty much vanishes and can easily be compensated for if it becomes an issue at the end. In this example, to be safe, I would SWAG my TOD at 100 NM, and request lower if ATC didn't ring me up with descent clearance by then. I am the PIC, not the controllers.

 

When I want to accelerate the Sim Rate, the first thing I do is save the flight in case doo-doo occurs. I have 3 "rotating" temp save slots named 1, 2 and 3, and those 3 slots are always at the top of my Saves list so they're quick and easy to find and use. That way I always have a fallback in case today is the day Aliens Attack. :D

 

I use a maximum of 8x time acceleration, which is . This allows the autopilot to stay active and handle the navigation, speed and altitude. If you exceed 8x, the AP will disconnect and you will come out of accelerated time at Mach 7 with the wings ripping off, 3,000 feet off altitude and 100 NM off course. ATC will yell at you for this on your way down to the scene of your crash. :p 8x acceleration means that it takes only 7.5 minutes real time for one hour to pass in-sim. To me, that seems plenty fast for most situations.

 

While accelerated, I keep a finger "armed" to stab the Pause key (or ) if ATC calls me. You have to pause the sim (or revert to 1x acceleration) quickly when your ATC window pops open, because ATC will only call 3 times before throwing you to the wolves (cancelling your IFR flight plan) and since you have accelerated the sim rate, those 3 calls will come and go in just a few seconds of real time.

 

Once you have paused the sim, hit to return to real time, unpause the sim, handle whatever it is that ATC is pestering you about, save your flight in a Temp Save slot then lather, rinse, repeat.

 

Using this method, I have never had ATC issue me a late descent clearance, nor have I ever missed a call from them and come back to reality to find I am no longer on an IFR flight plan. The drawback is, you can't go to the "reading room" while your accelerated sim flies you across the North Atlantic because you need to be there to handle incoming ATC calls. However, if you DO happen to wander off while your sim is accelerated, at least you have your temp saves in case you come back and realize that you have missed some calls and you are now flying for a new employer: FUBAR Airlines. :pilot:

[kingnorris]

Hoggydogg, I go up to 16x speed. Autopilot is still engaged.

 

Also, to avoid missing ATC in the sped up rate, before I accelerate time I acknowledge the next controller, but I don't contact them. This way they'll never bug me while I in accelerated mode.

 

Anyway, thanks for all the tips. I'll try each. This is why I'm not a real pilot; my procedures are garbage compared to the real world, lol!!! But isn't that why some of us sim?

[mabe5454]

What aircraft, what airport? Madeira for instance doesn't like fast approaches to RW5, better be in some flaps and slow already when within 25 miles from touchdown.

 

Cheers,

[kingnorris]

What aircraft, what airport? Madeira for instance doesn't like fast approaches to RW5, better be in some flaps and slow already when within 25 miles from touchdown.

 

Cheers,

 

Any, any.

[MBKHOU]

I avoid using the speed brakes ("spoilers") in FSX unless there's no other choice because they cause a severe nose-up pitch change that the AP does not compensate for. This behavior seems unrealistic and it screws up my descent plan as well by abruptly leveling or even climbing the airplane- the pitch up is that severe. :pilot:

 

I don't notice too much of that with the NGX. Certainly not strong enough to overpower

the A/P. I'd have to test when flying by hand to see how much is noticed there, but

even hand flying I don't think the pitch up is too awful much.

The main reason I try not to use the speed brakes is largely because I view avoiding

them as a bit of a game. With a normal flight and path, one should not need them, and

if one has to use them, they will have wasted some fuel vs flying the path without them.

It's like pouring energy down the toilet, which I don't like doing that unless no choice.

But sometimes you really have no choice when dealing with the sometimes ornery FSX

ATC buoys. :(

[kingnorris]

Resolved. I WAS going too fast. Now what I do, as unorthodox as it may be, is upon starting descent, I hit the flaps one notch, then reduce my speed to around 240-250 knots. Each time I get a new descent altitude, I keep hitting the flaps one notch at a time and keep my speed around 240 knots. Once below 10,000 feet, I reduce speed to around 180 knots. So far, this is working just fine. Now, I'm just awaiting final approach instructions while maintaining my slow speed and flaps almost all the way down. On final, gear down, flaps down, speed (depending on aircraft of course, but I mainly fly the QW 757) around 165 knots. So now a big difference than "chasing" ATC and their rapid instructions.

 

Thanks all for the help!