greg765 wrote on Jul 14^th, 2010 at 2:25pm:

Thanks for your answer Tim :) Yes, I am using navigraph data for my approaches.(Airac 1007, the last one) ------------- Questions : 1/So when I arrive on the T/D (STAR already selected), I've seen on the video that I must set the altitude of the next WP in the glareshield. Is it really necessary ? Because at this time, I am still in VNAV and LNAV, so I shouldn't need it, no ? Why do I have to enter the altitude of each WP ? Wouldn't it be better to directly enter an altitude of around 2500ft for the loc intercept ? 2/Must I tune the frequency of the ILS manually when approaching, or is it automatic ? 3/How do I know when the LOC/GLIDE are intercepted by my plane ? ------------- So, if I understand what you said (I'm French and bad in English so I want to be sure to understand well), when approaching the runway, to intercept the ILS (LOC first),I must : reduce my speed to Vref+30 (with spd button on the glareshield, is that correct ?), set flaps around 15,and have an altitude of 2500ft(Altitude hold of 2500 in the Glareshield, is that correct ?).Then, I must push on LOC and the plane will automatically align with the runway.Then, flying towards the runway, I must push on "Appr" button, the plane should capture the glide path of ILS, and all I have is slow down to Vref+5, set flaps in landing configuration (as given in FMC), lower the gear, arm spoilers and that's all.Is that it ? Am I wrong somewhere ? Thanks for your answers , that's nice  :)

Setting the next altitude on the MCP provides a "hard floor" if you want to make sure you don't blow through altitude constraints.  But your autopilot should descend properly and respect altitude constaints of the STAR, so it is not absolutely necessary.  I usually dial down to 10,000 feet because that is where a lot is going to happen and I wouldn't want to miss it.  

After that, if you want to be sure you don't blow through altitude constratins, you can add the safety measure of putting the next one into your MCP, although the autopilot should handle them properly.

The ILS should tune automatically.  I go to the nav radio page and select it, then put it back in the line so that it is displayed bigger.  Just make sure it is correctly displaying in the windows on your console: frequency and course.

There are a couple of ways you will know when you intercept the localizer and the glide slope.  The most obvious is that your airplane will turn by itself, and start to lose altitude by itself.  You will also see -- I think -- LOC and G/S display in green in your PFD once captured.

Reduce your speed to VREF 30 + 40 knots, not VREF + 30.  VREF 30 is the speed you should be going at 30 flaps, which may or may not be your VREF.  That value is found on the very handy approach page.  (You enter your flaps and speed in the vacant line, btw.)

The biggest "gotcha" with glide slope is not intercepting from below.  If you are above the glide slope you have little chance of interceptping it.

Let me know if you nail your next instrument approach.