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Guest monsterzero_jr

How to estimate rate of descent for visual approach?

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I've gotten pretty good at automatic ILS approaches but if tower directs me to a visual runway I have problems estimating the descent rate so I don't undershoot or overshoot the threshold. I fly CaptainSim's Legendary 727. Is there any rule of thumb to estimate the rate? Runways have approach lights (red and white) but I'm not very successful using them as a guide.Now, the automatic pilot in the 727 has a pitch dial that is very good and allows for very precise control of the pitch angle; I can raise and lower the nose 1 degree at a time.

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Five nm from the rwy threshold, establish and maintain ~700 fpm descent. This is about a 3

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If you are using VASI, keep the red and white lights balance. (e.g. 2 red lights and 2 white lights)..Just keep the descent rate at around -700 to -800 fpm40-50 feet (Radar altimeter) above runway,m start flaring to make the rate 0 to -500 fpm.cheers.

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Okay.....Good advice, but what happens if he gets on the back side of the power curve while attempting such? How does one deal with that?That subject rarely, if ever, comes up in FS.As one who often flies real approaches without visual or other approach slope guidance (many airports have runways without it), I might suggest parking the 727, and doing this for a while in something like the default Cessna 182 so you get an idea of how things should look while on approach. That's right, how to "eyeball" it.Yes, 700 FPM is fine, but speed is also critical in both a 727 or a small Cessna. You have to manage speed, power and descent rate and have to understand how to do such. It's a balancing act.With swept wing jets you especially need to determine the appropriate Vref, or approach speed. Approach speed is critical. If you do not have the approach speed nailed for your weight, it doesn't matter what descent rate you are trying to achieve as it will become a bad deal all around.Regards,http://www.dreamfleet2000.com/gfx/images/F...R_FORUM_LOU.jpg

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An important tip is to keep the runway at the same point in your windsheild. If it is sliding toward your panel you will overshoot, if it is heading for the overhead you will undershoot.Also reducing speed while mantaining the same VSI results in a steeper aproach, while increasing speed shallows it out. That being said, it is best to keep a stable aproach speed aproprite for type.Best Regards, Donald T.:-wave

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Another bug-a-boo when hand flying approaches in the smaller planes like the Cessna-172, 152 and similar Piper A/C is the difficulty trimming. It is so much easier to do in the real ones.Now, the problem I have in hand flying approaches is that of lining up with the runway on final. I find it hard to establish visually what the runway should look like when flying down the extended center line.--RogerI

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If the runway you are landing on has an ILS, dial in the frequency and course and use the glideslope for vertical guidance. Pilots commonly use this technique as a backup for visual approaches. If not, use the VASI/PAPI or pick some "piano keys" in the touchdown zone to aim at. Keep them in the center of the windscreen, it takes practice. If you aim at just the runway touchdown zone itself and not a group of "piano keys" on it, you are more likely to land long and/ or float. Thats no good.

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HelloThe procedure I follow in order to make a proper descent is the following.1) I divide my flight level by 3 in order to find at what distance from the airport I should start my descent. For example if you fly at 30000 ft your flight level is 300. Divided by 3 =100. So you should start descending 100 miles away from the airport.2) After that you must find your ground speed. A rough estimate is to add 2% of speed for every 1000 ft of altitude. For example if your speed indicator points at 200 knots and you fly at 30000 ft. >>> 1.6*200=320. Your ground speed is 320 knots.3) For all this to work you must maintain a 3 degree descent. This means that you must have about 500ft/min descent rate for every 100 Knots of ground speed. For the above example you should maintain 3.2*500=1600 ft/min.Be aware. If you keep a steady IAS your ground speed will decrease as you descent so you will have to recalculate your rate of descent.So as long as you know how far away you are from your destination you can make a proper descent.Hope this helps.Cheers.

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Hello,Figures and instruments (FPM, DME, VASI PAPI...) will help your approach, no doubt, however the best way to master it is to do it a lot. Just practice, do it with the autopilot (down to 1000FT) and manually.Once you're confident put some nasty weather in it and start all over again. You'll see, it's a whole other ballgame.Happy landings

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>If the runway you are landing on has an ILS, dial in the>frequency and course and use the glideslope for vertical>guidance. Pilots commonly use this technique as a backup for>visual approaches. I do this whenever I start flying a new aircraft much.Flying the ILS and GlideSlope manually helps me fix a mental image of what a good approach/ descent looks like in that aircraft, and learn the aircraft characteristics, how it sinks, how it recovers, does it pickup speed on final, or lose speed, throttle settings, etc.I got to fly in the jump seat for some of the company pilot's early flights when we got the Gulfstream 200, and they did basically the same thing - though of course with simulator training and their experience they are a heck of a lot better in the real world than I will ever be in FS.

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The formula to work out your decent rate is as followsFPM = (Glide Path x Ground speed x 100) / 60example for a 3 degree angle and approach speed of 120(3 x 120 x 100) / 60 = 600 fpm

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I've made some progress on the issue. First of all, I looked up airplane documentation and found a table with final approach speeds (Vref + 5) for a given landing weight of the plane. It turns out I had been approaching at too low a speed resulting in a nose-up attitude and excessive sink rates. Now with the plane approaching at correct speeds it's a lot easier.You know, if real life transport aviation is so freaking complicated it takes much of the magic of flying out of it. I am glad there are volunteers to do that for a living in the airlines. I'm a real life sailplane flyer and a registered nurse by occupation. Flying sailplanes is 99% fun and 1% procedures.

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Backing up with the ILS is a good idea, if the runway has one. My first ever approach in the ATR flying passengers was a pure visual. I use the same technique I used in every plane i've flown. Pick a spot where I want to land and keep that spot in the same place in the windshield. Don't left it slide up or down. Your problems are not uncommon at all, especially in the real world. Visual approaches are one of the biggest training issues on IOE.

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Well, as has been mentioned a typical rate of decent for an airliner is 3 degs. However to calculate it there are all sorts of weird and wonderful sums....fine if your capable but during the heat of a tricky visual with callouts happening checklists to be done..flap selections..gear...etc can be hard to calculate..so I just do half the ground speed plus 50feet eg.. 160knots divide by 2 80kts add a 0 ive or take 50feet gives 800 - 850 ish, that'll work just try that. Works with any groundspeed as that is the key when flying a 3degree glide. 120kts = 600 - 650fpm140kts = 700 - 750fpm160kts = 800 - 850fpmI use this method and I've been flying the 737 for 5 years...REAL WORLD! I've not messed up yet!Just another thought to add to the mix

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