Hello! 

 

Please look at this screen shot.  These are the speeds that the MFD displayed for me for approach and landing.

 

 

I don't understand what they mean.  I know what Vref means for example but none of these say Vref.

 

I know what V2 means on takeoff, but what does it mean on landing?

 

Sp please, what do these speeds mean, and perhaps more importantly, at what point in the approach and landing should an aircraft be at these speeds (I'm having a hard time with landing speeds obviously lol)

please?  the reason there is confusion is because two different tutorial included with the aircraft say two different things,

The V speeds V1 VR V2 are there if you need to do a missed approach/go-around and have already touched down. The AP is the approach speed that you use for landing approach.

The V speeds V1 VR V2 are there if you need to do a missed approach/go-around and have already touched down. The AP is the approach speed that you use for landing approach.

So the AP speed (the one in green) is the speed that I need to be at when my wheels touch down?

Yes, the AP speed is your VAPP speed, the speed you should approach at (usually VREF+5kts component).    So in this instance, you'd cross the threshold at 146*, and as you start retarding power, would touchdown at around 141kts.

 

*Incidentally, 146 is a very high VAPP speed for the ERJ.    Were you very heavy for landing (eg.. still a lot of fuel on board?).

I typically see a VAPP of around 125 with the ERJ, touching down at around 120kts).

If you haven't seen this site, some additional info. Look at the patterns. I agree with the other poster. I generally target 130 kts on approach.

 

 

 

 

 

 

http://www.smartcockpit.com/plane/EMBRAER/EMBRAER-135-145.html

Yes, the AP speed is your VAPP speed, the speed you should approach at (usually VREF+5kts component).    So in this instance, you'd cross the threshold at 146*, and as you start retarding power, would touchdown at around 141kts.

 

*Incidentally, 146 is a very high VAPP speed for the ERJ.    Were you very heavy for landing (eg.. still a lot of fuel on board?).

 

I typically see a VAPP of around 125 with the ERJ, touching down at around 120kts).

I had all 50 seats filled and about 800 pounds of cargo.  I was flying the erj-145 xr.  I put 60 mins in the reserve fuel section of the perf init.

 

This does raise the question though.  When I order the flight computer to compute landing speeds, does it do so based on the weight of the aircraft at that very second?  Or does it calculate based on the FMC's prediction of weight at landing?

 

The reason I ask is because I have been calculating speeds at the top of descent.  Maybe I'd get more accurate numbers if  waited until I intercepted the localizer?

 

Oh and thank you so much for the help, AGAIN Craig, you are one of the most helpful people I've met in this community!

The fuel you burn on descent shouldn't make a lot of difference to the total weight of the aircraft and thence landing speed.

I had all 50 seats filled and about 800 pounds of cargo.  I was flying the erj-145 xr.  I put 60 mins in the reserve fuel section of the perf init.

 

This does raise the question though.  When I order the flight computer to compute landing speeds, does it do so based on the weight of the aircraft at that very second?  Or does it calculate based on the FMC's prediction of weight at landing?

 

The reason I ask is because I have been calculating speeds at the top of descent.  Maybe I'd get more accurate numbers if  waited until I intercepted the localizer?

 

Oh and thank you so much for the help, AGAIN Craig, you are one of the most helpful people I've met in this community!

 

You're welcome, thanks for the kind words :smile:

 

As @yellowjack said, the descent burn would probably only make 1 or 2 knots difference in the calculation.    I tend to compute the speeds just after the top of descent.   Ah, I never realized you were flying the 'XR' ; that makes more sense, and the 146 VAPP speed sounds about right at those weights.  It sounds like you're doing everything right.   As someone else said above, the FMC will compute V1, VR and V2 speeds at this phase, but they aren't relevant except in the case of a Go-Around, when they become very relevant :smile:

Got it!  Thanks!  The Aircraft should be easier to control at that speed, but that runway is coming up REALLY fast compared to my old J41 lol.

 

Oh one more thing, is it normal for jet engines to have a slower response to throttle inputs than turboprops?  it seems like it takes longer from applying power to getting increased speed than on props.

 

Thanks Craig and John both!

In theory, jets and geared turbo props (like the J41's Garretts) would have about the same responsiveness to power changes.   Free-spinning turbo-props like the Pratt & Whitney PT-6 would have slightly slower responsiveness.

It will also depend on what else is happening with the aircraft though, for how that translates to speed - for example, in the ERJ, power increases just after increasing flaps will lead to quite a delayed speed increase, as the flaps are pretty efficient on the ERJ, and the little Rolls Royce AE3007s on the ERJ have quite a (relatively) long airframe to push forward against them.

 

after doing a bunch more short hops, I got to say, whats working better for is flying the green APR speed until about 500 AGL, then slowing to white V2 until over thershold, then cutting the power, which seems to put my wheels down at exactly Vr BLUE speed.

 

I mean I believe you guys don't get me wrong, but flying APR speed all the way to the threshold was causing me to land at a pretty rapid FPM.

 

Maybe I just don't have the skills to land that fast lol,