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Guest ted320

landing the 744F

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Guest ted320

Hey GuysI really hope someone can help me out with this.My flight instructor taught me to land a Cessna by controlling speed with pitch and rate of decent with power... I'm confused, does the same principle work with the 747?I've been performing touch and go's for the past couple of days in the 400F and I cannot consistently perform a good touchdown.I either hit the runway too fast or float a few thousand feet down the runway. I find with flaps 30 the plane is very unresponsive.Also my speed and rate of decent are all over the place during the approach - any tips on controlling it would help.TED320

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Guest 744nut

Hi Ted,In the 74X you have to deal with the "cushion effect". You have to fly the AC "into the tarmac" otherwise the ac keeps on floating on the thick air cushion ;-)Hope this helpsTon

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Guest Jacob Lee

I noticed that when I put flaps at 25 for landing those problems described go away. Have you tried that?

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I am no ATP, but I believe the consensus among big iron pilots (including the 2 or 3 I talk to) is that the throttle/thrust response in, say, a 744 is too slow to allow you to effective control ROD with power alone. Instead, they control ROD with pitch and speed with power. That said, my personal technique for good landings is, once in a stabilized approach, between the 100 and 50 feet radio callout I will begin to shallow the descent slightly and start to retard the throttles. Between the 50 and 30 foot radio callouts smoothly bring the throttles to idle. At the same time I begin to pitch for the flare. For me this requires a fairly hefty pull. At this point I am making an effort to mentally de-emphasize the sight picture (always feels too high) and concentrate on the intervals between the 30,20,10 radio callouts, after you do this a bit you will get a good sense of how your rate of descent is changing. My goal is to arrive at the 10 feet radio callout with the throttles at idle and very little sink. At the 10 feet callout I relax the backpressure on the yoke slightly and she drops right on. Unfortunately, I haven't had lots of time to fly the Queen, so this is probably not the most "correct" method, but I will remedy that before long. As for establishing a stable approach, I would suggest either letting the autopilot do it via the ILS, then disconnect and "feel it out", or to do it all manually. I would NOT recommend hand flying with the autothrottle engaged since it is generally lags little bit "behind" your pitch inputs and this leads to larger oscillations in ROD. Hope that all makes sense, and sorry if I'm telling you a bunch of stuff you already know as I see you are a PPL.regards,Ryan

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Forget everything what Cessna flight instructors may have told you. This is a different thing: Higher weight and approach speed = higher momentum = more stability on the approach. Control ROD with combined adjustments on pitch and power and keep in mind that demanded thrust output is delayed. Therefore, use pitch only for short-term corrections.As for the landing technique, it is important to focus primarily on aural callouts (this is true for both simulation and reality). Just fly the aircraft down the glideslope until you hear the "FOURTY" callout. Then:- 40: Begin to retard throttles- 30: Pull back on the stick slightly to reduce your rate of descent. Approx 5

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Actually, I've noticed that from the 2d panel perspective if you pull up the a/c will fly away because of the pitch you are already in during the flare.I use the same technique as well, autoflight until about 300-200' at VRef+5, then retard at about 50' radio alt, however I notice that from the panel perspective it looks like you're looking straight down at the ground, so the natural instinct is to pull up for the flare, but you are already in it. If you pull up more even after retarding the aircraft will start to fly again because even at VRef or VRef - 10 you still have enough airspeeed to fly.That's one of the weird things I've noticed with both the 37 and 47.It's something you have to get used to.

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Ton-The pitch vs. power argument is one that will go in in aviation until the last airplane flies... and probably for some time after that. (Especially if there is a forum involved....hehehehe)When flying a transport category airplane, especially something as large as the 747, you really aren't as concered with pitch vs power. What you ARE concerned about is drag configuration, and flying by the numbers.When flying your touch and goes- if you find that you are making a lot of adjustments to your throttle- then you are doing it all wrong. :-)Try this exercise and see if it helps:I recommend doing this on autopilot the first time- then do it again adjusting the throttles yourself... then fly the whole thing by hand.Line yourself up to an ILS about 25nm from the runway, about 6,000 AGL and bring the power to idle so that you slow rapidly toward 240KIAS. As you approach 250KIAS, smoothly pring the power back up until you are stable at 240 knots. You can use the green "prediction arrow" to help you adjust power as needed to capture 240 knots precisely.I recommend putting the airplane in HDG SEL and ALT hold at this point- just so you can concentrate on the demo.Level Flight, 240KIAS, CLEAN, you should see about 75% of N1 is needed to maintain speed.Now select FLAPS 1, and move your speed bug to the flaps 1 indicator (appx 215 knots). You will notice that Level Flight, 215KIAS, FLAPS1 you should see about 76% of N1.Now select FLAPS 5 and move your speed bug to the flaps 5 indicator (appx 190 knots). You will notice that Level Flight, 190KIAS, FLAPS 5 you shuld need about 78% of N1.Are you noticing a pattern here? To slow the airplane from 240knots to 190 knots- you barely had to reduce power- IF AT ALL while adding drag via the flaps. And with each successive increase in flaps- you wound up with a VERY SMALL increase in power in level flight.In other words- no need to slam the throttles around- it's all about finesse. :-)Now- do the same for FLAPS 10, which in Level Flight, FLAPS 10 (appx 180 knots) should give you about 78% as well....At some point here, arm APP mode- so that the airplane will capture the approach path. Then, when you are capturing the glide slope, select Gear down/FLAPS 20.This is the part that may amaze you, so pay close attention!At FLAPS 20/GEAR DOWN on a 3 degree approach path, you should need 73% to maintain 150 knots.... Select your REF speed (appx 133?) and flaps 25/30 and what do you notice about the power setting?That's right.... barely moves at all. :-)So- the moral of the story is that from 240 knots until touchdown- you should only need to select power settings of between 73% and 78% N1!!!!If you control your power setting carefully- and you give the airplane enough time to bleed energy- you'll find that your landings improve dramatically....FWIW: The mark of a pilot who is truly comfortable with his airplane- is if you can make the absolute minimum power changes needed from the beginning of the approach until touchdown. :-)Hope this little lesson helps!

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Guest cargo747

>Hi Ted,>>In the 74X you have to deal with the "cushion effect". You>have to fly the AC "into the tarmac" otherwise the ac keeps on>floating on the thick air cushion ;-)>>Hope this helps>>TonHi Ton,well, i hope you refer to the 74Y (as the 74X is the 747-200 Freighter ;-) )Cheers,Norbert - CLX001CEO Virtual Cargoluxwww.virtualcargolux.org914.png

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Guest 744nut

Hi Norbert,OK! for me the X is a designator to show that it is effect happens on the complete series :-)TonPS I am on my to PAFA...so assume we meet later on the day ;-)

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Thanks for pointing this out, Captain Randazzo! I don't know why it never dawned on me that it might be useful to find some power settings for reference... Flying "by the numbers" certainly makes it easier to manage speed and energy during the approach phase. For anyone who might be interested, here are the results of some test flights I did earlier today. Note that these figures are based on ISA conditions (standard atmosphere) with no winds, A/P + A/T engaged. I've chosen 3000 feet as a sensible altitude for these tests. The table should be more or less self explanatory. Power settings are of course shown as N1-percentage.This data allows a number of interesting conclusions. For example, note that on the 747, there are only very small thrust changes required (from 65 - 80% N1) to maintain an optimal speed based on flap setting.For additional comparison, I've included data for the 767 (1/2 the weight of a 747) and 737NG (1/4 the weight of a 747) as well.*** SPEED VS. POWER CHART (3000ft, ISA WX) ***Boeing 747-400 (PMDG)General Electrics CF6-80 C2B1FZFW 222.000 KGsGW 250.000 KGs (~ 85% MLW)Vref 142 ktsLevel Flight --------------------------350 kts 72 %300 kts 67 %250 kts 65 %Level Flight --------------------------Ref + 80 F 0 65 %Ref + 60 F 1 65 %Ref + 40 F 5 68 %Ref + 20 F 10 70 %Ref + 10 F 20 72 %Ref + 10 F 20 + G 77 %ILS Glideslope ------------------------Ref + 10 F 20 + G 63 %Ref + 10 F 25 + G 65 %Ref + 5 F 30 + G 66 %Boeing 767-300ER (Lvl D)General Electrics CF6-80 C2B6ZFW 111.000 KGsGW 125.000 KGs (~ 85% MLW)Vref 135 ktsLevel Flight --------------------------350 kts 77 %300 kts 67 %250 kts 58 %Level Flight --------------------------Ref + 80 F 0 51 %Ref + 60 F 1 54 %Ref + 40 F 5 57 %Ref + 20 F 15 61 %Ref + 10 F 20 62 %Ref + 10 F 20 + G 70 %ILS Glideslope ------------------------Ref + 10 F 20 + G 47 %Ref + 10 F 25 + G 52 %Ref + 5 F 30 + G 53 %Boeing 737-800 (PMDG)CFM 56-7B24ZFW 55.000 KGsGW 58.000 KGs (~ 85% MLW)Vref 140 ktsLevel Flight --------------------------350 kts 74 %300 kts 69 %250 kts 62 %Level Flight --------------------------Ref + 70 F 0 44 %Ref + 50 F 1 44 %Ref + 30 F 5 58 %Ref + 20 F 10 61 %Ref + 20 F 15 64 %Ref + 20 F 15 + G 72 %ILS Glideslope ------------------------Ref + 20 F 15 + G 58 %Ref + 10 F 25 + G 62 %Ref + 5 F 30 + G 63 %

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