Speeds

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Hi everyone,

ATC often requests planes to follow different types of speeds (ie. best forward speed, slowest practical speed…etc.)

Could anyone please tell what all these speeds refer to and which speed I have to maintain for each (I am in a 777)?

Thanks!

2

Slowest practical speed is that you can land safely without staling aircraft. Best Forward speed is that you can land safely without overshooting runway or crashing.

Speed depending on the Load/Weight of the aircraft plus weather condition. Don’t worry about weather😀

ATC only ask you to do this because you either approaching airport too fast or too slow.

Typical landing speed.

B737-400 Vref (Flaps 30, Gear down)
147 KIAS (136,400 lbs)
144 KIAS (132,000 lbs)

B747-400 Vref (Gear down)
188 KIAS (880,000 lbs, Flaps 25)
181 KIAS (880,000 lbs, Flaps 30)
134 KIAS (450,000 lbs, Flaps 25)
125 KIAS (450,000 lbs, Flaps 30)

B777-300 Vref (Flaps 30, Gear down)
157 KIAS (580,000 lbs)
But I found most 777 pilot prefer flaps25, don’t ask me why.

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3

When you’re told to maintain best forward speed it means someone is coming in behind you, FAST! You need to pull everything in and go as fast as you can, then drop your gear, flaps, spoilers, etc. at the last possible moment.

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Not really Sean, when this is said below for example 2000 feet and slats/flaps and gear are out forgot it. The traffic behind that is coming in way to fast can get a go around. No need for traffic that is perfectly stablized as the rules in the air say the faster traffic behind has to adjust.

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5

Depends on your gross weight.

This is for the B772 (weight is in lbs):

image
image2048×1536 248 KB

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Thanks to everyone!

I generally land in “Normal”. My tanks contains 56788kg of fuel, I have got 179 pax which represents 13813kg. My total cargo weight is 8142kg. My GW is 78743kg.
1kg = 2.20462262lbs
So 2.20462262 x 78743 = 173 598 lbs

I can’t see 173598 in your table Laurens…
I always land in Conf Full (ie. Flaps 30°) at 167kts + Trim 20°.
I generally don’t have any problem to land, to turn (ie. I still have lift)…Etc. I find that I am at a good speed.

I take-off around Vr = 150kts with thrust at 90-95% (flaps 15). I try to not cross N1 100% for engine performance. My average CRZ ALT is 12 000ft (FL120). I enter 250kts (245kts when there is tailwind) in the SPD window, to not exceed 250kts below FL100. I retract flaps 15° at 230kts. I maintain 250kts - Flaps 5° till FL100. I then accelerate to 320kts after FL100 and climb towards FL120

During landing, I ask ATC to clear me to descend at 3000ft. When I request to descend, I enter 240kts in my SPD window (to not cross 250kts below FL100). I then trim my plane at 60-70 and descend at VS -1500ft/min till 3000ft. At 240kts, I extend flaps to 5°.

Finally, when at 3000ft (I always try to look at the carts to figure out at which altitude I should intercept LOC and GS), I reduce directly to 167kts - Flaps 30°.
When I intercept ILS, I descend at VS - 700ft/min (sometimes -800ft/min).

I am always surprised when ATC asks to me maintain another speed (few days ago, ATC requested me to accelerate at 260kts at 3000ft!)

Please help! :smile:
I really want to listen to ATC and follow their requests.

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7

Which controller asked you to do it? Approach? Maybe he missed your altitude😀😀 if you go that fast at 3000ft soon you’ll have more violation then XP. If you are flying by charts and following SID/STAR then you fly with professionals in advanced server.

8

What is the MLW for the 772?

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MLW
777-200 = 445,000 lb/201,840 kg

777-200ER = 470,000 lb/213,180 kg

MTOW
777-200 = 545,000 lb/247,200 kg

777-200ER = 656,000 lb/297,550 kg

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10

For the 777-200ER:
In the app it’s indicated 470.000 lbs
In real world it’s 460.000 lbs

For all my aircrafts I have set a typical landing weight, to avoid too fast inbounds.

11

You can adjust your weight manually (it will then remain your preset weight for all further flights with that aircraft).

I suggest you 410.000 lbs (185.972 kg), rotation will be at 126 knots with Flaps 5, or 121 knots with flaps 15.

Please send me a PM for further specifications.

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Thanks a lot to everyone!

Laurens, I will send you a PM shortly! :wink:

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@Swang007…your example has me in stitches here(falling off chair)…amazing discription…but i think @Aernout has a valid point…and why mess with landing controls(gear + flaps + throttles)…so speedy gonzales behind you can have a perfect landing,whilst you risk over-shooting and ballooning and screwing up a good approach. I’m not laughing at you,i just think my mind is very animated in trying to picture all this…but i get where you’re coming from…hehe

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