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MarkRey

Heavies Glideslope/Visual approach

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hi allhope I'm in the right forumAs a pilot that did 30+ hours towards his PPL, I can fly and land light aircraft no problem. Even Seneca V no problem, although seem to need more height on the approach, and always above glideslope, using visual cues to arrive and approach for the landing. Isn't that how we all fly!!!More so with the larger aircraft, If I try to approach from 4-5Nm out from 2-2500ft QFE, I undershoot the runway, if I were to try and correct this, I.e. pull back I loose sight of the field/runway.I am aware that in the Panel config file I can set the view angle (VIEW_FORWARD_DIR=9.0, 0.0, 0.0). Obviously the Heavies have a greater rate of sink, due to payload. I hear a lot of talk about how airliners control speed via the elevators and rate of descent with thottles. If I have this wrong, what I am trying to say is the different principles involved between light aircraft and airliners.From my experience in flying, which must be a basic principle, that Elevator/Throttle movements are linked together. If I push down on the yoke, I reduce power. I remember a RAF instructor trying to explain to a Student in a Hunting Jet Provost, to get him solo, that he should image that his right and left hands were connected by string, when moving the stick backwards or forwards. This created a opposite movement in the throttles, this I aways throught was the best example, and an essential ingredient to understand. However, this does not help me much now.My main problem seems to be having to greater nose up attitude, to reduce descent, naturaly I would need to maintain Airspeed with increased power, but then can't see the runway on the approach, which as a Cessna pilot I must have, Ha Ha Ha!!!!Is the only answer not to fly Boeings or airbus's!!!There must be another way other than 3500ft/3nm finals in order to maintain Visual Metrological Conditions on approach, in fine weather.Hope some expert pilots can put me out of my misery, either with view config files or with controling rate of descent, via throttles, whilst maintaining VMC on runway.Any thoughts would be appreciatedCome on you Jet Jockies (B727, Bac 1-11, eye ball Mark 1, types)Regards Dave

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Dave,If you would volunteer more info about which aircraft you are flying, aircraft weight, flap setting(s) you are using, airspeed you are flying, and technique you are trying, I will be glad to offer some advice.From what you have said though, you are starting at too high an altitude for your distance from the runway to begin with. But there are other issues I can address if you will supply more information as requested above.Best Regards,Tim SandersB-727,B-747,DC-8, Falcon 20&10

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Hi UOK2Fly,I'm no Jet Jockey so I have the same problem. I've solved it by assigning one of the toggle switches on my Ch Yoke to raise and lower the pilot's view. So, as I approach the runway, I (in effect) raise myself in the seat and can see the runway. Use the Kneepad (F10), look under View, and find the key or keys to press which raise and lower your point of view. I don't have FS open now or I'd be able to tell you. Works great.Regards, John

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Will have to try the key assignment suggestion, I just usually press "W" making most of the panel dissapear except for the analog guages. I can see the runway no problem then.Matt

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Hi Guys, thanks for the replies.It seems that my problem is seeing the runway when I am in a high pitch attitude. I have configured my yoke so I can adjust my height view point (Shift_Bkspace/Shift_Enter)Tim, I'll get back to you with some data for flying the Dreamfleet 737.It seems that the heavier aircraft which, rightly have a greater sink rate, need a greater degree of pitch attitude, hence my problem, but surely given the attitude that most aircraft adopt in the approach they still maintain visual contact.Is this just a FSMS problem or a Aviation/Pilot knowledge thing.Thanks to all again, I guess i'll just keep plugging away!!!Regards Dave

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Dave: I don't understand what you mean by heavies having a higher sink rate.With jets if hyou get into a very high sink rate and yank the yoke back all you are going to do is change the attitude of the aircraft but at least for awhile the sink rate is still going to be there.Inertia.........Sink rate is controlled by you, regardless of the size of the aircraft.I have lot of RW jet time and the old tale about what controls airspeed has been going on forever.Old Captain going for flight check with FAA.FAA: What controls airspeed?Captain: ThrottlesFAA: WRONG, Everyone knows it is the elevators.They taxi onto the runway.The Captain starts pumping the yoke back and forth, back and forth.FAA: What are you doing?captain: Just trying to get up enough airspeed to fly this thing.

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Another reason for a 'nose up' attitude on approach, is flying with too much fuel. The extra weight caused by too much fuel requires a nose up attitude to keep a sensible airspeed (more drag to reduce speed). If you do not believe me, fly using autopilot set to 3000ft in a B737 with autopilot at 220 knots with a full fuel load. Note the attitude of the aircraft on the Flight Director. Then reduce the fuel load (using the drop down aircraft settings) to 20% in the wing tanks and 0% in the centre. Do this and then watch the aircraft level off on the attitude indicator.Regards Nitram UK

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Come on Gramps; give us some clues is it flying by numbersFrom my RW flying days in the 'humble' C152 my instructor was always telling me to put the hedge on the end of the spinner to arrive on the numbers.In FSMS, I seem to pefer to have access height, rather than not enough and end up temping fate with stretching the glide. As you say, it is up to you the pilot to make it happen. I think this is a classic situation, knowing something is required and actually doing it, are what makes the diference.I just want to maintain the glideslope and see where I am going, which I think a few posts have helped me with.Thought there was a difference in controling airspeed/Vsi, between light and heavier aircraft. Myself, always thought these were interlinked, what goes up must come dowm. If you want to climb and maintain a particular airspeed you need power. Likewise, if you want to descend and not let your speed run away from you, you throttle back and even use flaps to keep your speed under control. Either way, if you alter one you will need to adjust the other. Weight=lift thrust=Drag equation.Obviously the inertia comes from the weight, and jet engines have lag and spool up times, as opposed to light piston aircraft types, not to mention lack of slipstream effect over control surfaces.Why do the Heavies seem to have this high pitch attitude on approach, when the use of flaps is said to improve vision on the descent? Obviously were using flap to get our airspeed down without inducing the stall. In lighter aircraft, I think I have always reduced power to push forward on the column, to lose height and not increase airspeed, with obvious use of flap and therefore, I have never had a problem seeing where I was going because of the attitude of the aircraft for that very reason!!!This doesn't translate to heavier aircraft, I think.Hope some body can understand me, I'm not without knowledge, just a little confused may be, philosophy between aircraft's. Regards Dave

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Dave:I am a jet jockey. I've been flying the 747s in the MS sims for about 4 years and can land them and all heavies anywhere in any weather. The trick is to be set up for final approach by the time you hit the outer marker about 6 to 7 nm away from touchdown. To do this, by the time you hit the OM you should be at flaps 20 and have gear down and be doing no more than IAS 160, with fuel remaining of around 30,000lbs (about 8% tanks). From there on down, slow to 150, throw out flaps 25, and then slow further to around IAS 145-148. You can land the 744 at flaps 25 or flaps 30; if 30, slow down another 3 to 5 knots. The pitch-up angle of the 744 should not exceed 2.5 degrees on final approach. If you have flaps 30 and are approaching slightly fast, around 150-152, your attitude may be flat which is fine since it enhances your visibility of the runway. If your IAS is too low on final, your nose will rise and visibility ahead over the panels will be hindered. It's fine balance between thrust, lift, vertical descent speed, and visibility; and it takes pratice, practice, practice, practice, and more practice.For visual approaches, I use the VASI or PAPI systems which are incredibly well modelled in FS2002 and are visible from miles out in good weather. I can descend "on the money" with these systems all the way down to flare over the threshhold.You can land quite well in the 2D cockpit views or the 3D virtual cockpit view. The virtual cockpit view gives you much better visibility of scenery and runway and lighting however and is therefore preferable. Hit SHIFT+Enter to raise your seat a tad for final approach if you wish. I normally don't do so because it's not really necessary but it's nice to have as an option.For landing, retard the thrust gently to idle no higher than 50'AGL in the 744, 30' AGL in the 777, and at around 20' AGL in smaller jets like the 737. Pull back on the yoke a tad and land nose high, but not to exceed 5 degrees if possible. 4 degrees is perfect in the 744.Hope this helps.Post again, I'll try to clarify if need be.JS

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Note:Do your approaches assuming a standard slope of 3 degrees. At this angle, you will descend at 320 vertical feet per nautical mile (actually, from cruise level to ground assuming no holding pattern). If the OM is 7NM out, therefore, your altitude at that stage will be about 2200 feet. If your approach speed is IAS 145 to 155, your vertical descent speed will be around 700 to 800 feet per minute. The rule of thumb to calculate the required vertical speed for a 3 degree slope is True Air Speed x 5. So if your TAS is 160 by 1500 feet AGL, your required rate of vertical descent is 160x5=800 feet per minute.You want to aim to put the a/c down on the ground at no more than minus 200 fpm and if possible minus 50 fpm which really takes a lot of practice so don't feel bad if it doesn't work out that way for the first 68 landings !JS

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uh Dave...(timidly sticks his hand up)?By no means a jet jockey here and you've already gotten some great advice but in addition I find the default zoom level of 1.0 completely unusable - VIEW_FORWARD_ZOOM of about 0.6 - 0.7 etc along with VIEW_FORWARD_DIRECTION=1.0 etc has done wonders for me in the air as well as in keeping the runway in sight on finals with the heavies.Regards,Mark

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Hi Dave,Believe it or not, sink rate required has basically nothing to do with the "size/weight of an aircraft, though weight plays a part because it determines the approach speed for a given flap configuration. The airspeed, or more directly the groundspeed, has a direct impact on sink rate required however...As someone else has said, most ILS approaches are 3 degree profiles, which is considered a standard descent profile as well (in any jet aircraft, the pilot is expected to approach the runway on a 3 degree profile or greater even when doing a visual approach.)There are several "elbow formulaes" but the most useful is the one that works for ANY descent angle, and that is GS(Miles per minute)X angle(degrees)=descent rate (Feet per minute), or simply 150kts=2.5nm/min.2.5x3=750fpm. That formula can be used for ANY descent angle required, and it is easy to do in your head.Now if you are flying a typical ILS, it gets even simpler, groundspeed/2=fpmx10 (140knots div by 2=70, add a zero..presto! 700 fpm. Easy!As for the large jets, many do indeed approach with higher pitch attitude than what you were used to in the Cessna, but typically when onspeed, most Boeing aircraft approach at about 2-3 degrees nose up, but this is perfectly manageable if you are on the correct approach speed for the required sink rate (fpm). Even with 2.5 nose up, which was typical in the 747-200 that I used to fly for a living, the runway was perfectly visible during the approach 8^)I currently teach, evaluate and check in the simulator for the Falcon 20 and the Falcon 10, and the -20 approaches with 4 degrees nose up, even higher than the typical Boeing aircraft! Still not a problem!The key to success is proper airspeed for weight and configuration (flaps setting), and being "on the profile", which simply means being at the right altitude for your distance from touchdown...The Dreamfleet 737 has a reasonably decent Flight Model for a FS aircraft, so provided the forward view is properly set, you should have no reason not to be able to succeed with practice.Try the following.1) Ascertain the correct approach Vref for the flap setting and weight of the aircraft (it's important to know exactly what you weigh).2) Make sure that you use the recommended landing flap setting for the above Vref, if you don't select the flaps (or forget), you will definitely have a problem with pitch on final.3) Select a Runway at your favorite airport with an ILS approach, and try to get an ILS approach chart if you don't have one. 4) Read the chart carefully, and determine what altitude to cross the final approach fix (quite often depicted with an NDB BEACON (compass locator by another name).5) Ideally, try flying the ILS approach using the A/P first, but make sure the the aircraft is properly stabilized BEFORE crossing the final fix, at a speed slightly above the final approach speed recommended in the manual. The most important aspect, regardless of the "technique" that anyone sells you on, is to be stabilized early, airspeed and descent rate rock solid! Importantly, select landing flaps when crossing the final fix (NDB if available), do not wait until short final, the approach speed depends on this flap setting!6) Watch carefully how the A/P flies the approach AFTER it is stable.Note the pitch attitude with the airspeed stabilized, the vertical speed stabilized, and on Glideslope of course. This is a model for how you need to be looking when you hand fly it!7) Finally, The published Vref is a MINIMUM speed in a jet aircraft. Most Boeing aircraft are recommended to be flown at Vref plus 5 knots, or Vref plus wind adds(that's another story for later). So, fly the approach at Vref+5, or +10, but no faster, at least for training. At and below Vref, the aircraft becomes difficult to fly, and drag increases greatly as you get slower than the published Vref speed (1.3xstall speed), so try not to go there!8) Even if you don't want to fly ILS approaches, but want to hand fly the approach visually, watching the A/P do the approach is excellent training, and necessary to see where the pitch, power, and airspeed belong for a normal descent to a landing in a jet.Finally, as Gramps alluded to, the question of pitch vs power controls vertical speed has been around very long, and a lot of people like to argue over it. The fact is, jet airplanes respond very differently than propellor driven aircraft, and pitch is ABSOLUTELY important as the primary initial input for controlling rate of descent! Push up the power, and at least at first, the aircraft just goes faster! It's a poor method for controlling altitude in a jet, and creates sloppy flying habits. Aerodynamic arguements are one thing, aircraft control in flight is completely another 8^)Take care, I hope some of this is helpful!Best Regards,Tim

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Many thanks to all, for their honest opinions and advice.Flying out EGBB(Bham UK) ILS/R33 glideslope commences at 2000 Agl/5.1 Nm. So I have good data at hand, as one of you said, Practise, Practise, practise and finally practise!!!I tried to observe the Autopilot, and have problems with the aircraft (Df737) capturing the glideslope, captured the localiser on Nav selection, no prob's, but App selection only appears to recapture Loc. (3000ft QFE, 10+ NM out in AltHold, Autothrottle/Ias selected, Second radio tuned to localiser, for Autoland Capability.)whilst knowing the importantance of weight, V1 Vr V2 and Landing Vref, tables seem impossible to get hold of. sometimes I just want to do curcuit and bumps or thumps, so using FMC to calculate Vref's isn't an option. This is where excellent products, like Df737 and PIC767 fail to finish the job. I recall tables for a B757 addon for 'FLY' did I swear!!!To sum up, mark put it well I think, I have had some excellent advise and Technical input from those that know. Just wish it came as easy as the old Cessna did, still guess that took practise!Thanks again, watch this space, for progress!!!!!!!!1Dave NewtownMid WalesUk

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Dave:Don't be discouraged; it takes much time and patience to get it right. In fact, it took me ages and much study and much questioning.Regarding approach data, a good rule of thumb for any mid to large size jet is to ensure that the pitch angle of the a/c does not exceed a maximum of 5 degrees at any phase during the approach to landing. So, if you slow down and dump flaps and find your nose is rising quickly and/or above 5 degrees, add power; do NOT pull up on the elevators at such a time or else you will (a) lose airspeed even quicker and (:( lose your vertical glidepath guidance, and © possibly be setting yourself up for an irrecoverable stall close to the ground.The issue of power vs. pitch is forever discussed and nobody ever fully agrees with anybody else on this, it seems. But it goes something like this for approach and landings:Add power=more speed=more lift=climbLess power-less speed=less lift=descendUse the elevators to make fine adjustments to pitch and to control speed to some extent as a result on the approach. If you are coming in too fast and too high, reduce thrust first to slow down and then "sink" back into the right glidepath. Do not just push the nose down first of all or else you will gain more speed and become unbalanced in this critical phase of the flight. Approach is a careful control act in which you literally "sink".Hope this helps!JS

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