Flying The GS
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Flying The GS
What's the best method to correct the glideslope (being high or low, or even staying right on it) during an ILS Approach? Some people say pitch for the GS other say power...
Re: Flying The GS
Calculate your required vertical speed and adjust the power to control your descent.
Think about it, if you are on the slope and alter your pitch, you will not be on that slope for much longer.
If you are a bit high, you don't want to destabilize your approach with large pitch changes, just fine power adjustments.
Think about it, if you are on the slope and alter your pitch, you will not be on that slope for much longer.
If you are a bit high, you don't want to destabilize your approach with large pitch changes, just fine power adjustments.
Re: Flying The GS
Take your ground speed in knots times that 5 and will give your required vertical speed( on a 3 degree average GS)
Ex:
100 knots times 5= 500 feet a min descent rate.
Adjust power to keep both stable and it will fly it self.
Andy
Ex:
100 knots times 5= 500 feet a min descent rate.
Adjust power to keep both stable and it will fly it self.
Andy
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172_Captain
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Re: Flying The GS
I use the half ground speed, add 0 technique. Example of flying 120 knots, 120/2 = 60, add a zero on the end you get 600 FPM.
Re: Flying The GS
Ground speed x 5, or x 10 / 2, or (groundspeed/2) x 10 is a good estimate for required vertical speed. But to answer the original question: use power/gear to establish the required descent rate, but use pitch to correct for minor deviations. For major deviations, your selected power setting is probably not working, so you'll have to change it.
Simple?
Simple?
Re: Flying The GS
On a tangentially related note, if you want to get really good at following the ILS, try doing one in a 172 at full throttle. Everything happens a lot faster at 150 kts, and if you can get good at managing that (with pitch alone), then flying an ILS at 90 kts will seem like a joke. I might, however advise against trying to land off of a full throttle ILS...
Re: Flying The GS
Assuming your're on speed, power is the correct way to fly the glide slope, it's also easier. Trim the plane off so it wants to fly at the approach speed, adjusting power will then change your rate of descent but maintain your speed and keep you in trim.
If, however, you're not on the correct speed, then using pitch may be appropriate. For example, if you're slow and getting high, you've likely let your pitch increase and by pushing forward you'll regain the speed and the glide slope. Correspondingly, if you're fast and low, pitching up will allow you to use the extra airspeed to get back on glide slope.
You can use pitch alone but you're going to change your airspeed as you pitch up and down, changing the amount of lift the wing produces, changing your ground speed (and thus the required descent rate to maintain the glide slope) further creating other deviations. You could practice this for a scenario like a stuck throttle and use pitch alone. But, it's actually harder to fly this way. Power is more technically correct and actually easier.
If, however, you're not on the correct speed, then using pitch may be appropriate. For example, if you're slow and getting high, you've likely let your pitch increase and by pushing forward you'll regain the speed and the glide slope. Correspondingly, if you're fast and low, pitching up will allow you to use the extra airspeed to get back on glide slope.
You can use pitch alone but you're going to change your airspeed as you pitch up and down, changing the amount of lift the wing produces, changing your ground speed (and thus the required descent rate to maintain the glide slope) further creating other deviations. You could practice this for a scenario like a stuck throttle and use pitch alone. But, it's actually harder to fly this way. Power is more technically correct and actually easier.
