Pitch and Power on the ILS

[cforst513]

when shooting ILS approaches, just to be safe, do you guys usually fly it down above the glideslope a bit? i've asked this before regarding PAPI's and VASI's, but how about ILS's? or since it's a 'precision approach', you don't have to add in that extra saftey factor?

 

[taters]

As stated by an examiner that I did most of my rides with:

"When people say pitch for airspeed, power for altitude, I tell them on takeoff not use any power, just give me some pitch. If your theory is correct, then pitching us down the runway should give us all the airspeed we need for takeoff!"

I got a kick out of that.

This guy wants to fly for g-0 jets,,,,,,scab

 

[minitour]

when shooting ILS approaches, just to be safe, do you guys usually fly it down above the glideslope a bit? i've asked this before regarding PAPI's and VASI's, but how about ILS's? or since it's a 'precision approach', you don't have to add in that extra saftey factor?

Center it up if possible...


-mini

 

[WMUchickenhawk]

With a glideslope, the FAA has already built in the fudge-factor for you. Just keep it centerd, but higher IS better than lower.

As for our approaches, We have been taught to put flaps to 10 in either in the base leg if being vectored (or close to it) or on the full procedure once the procedure turn inbound is completed, maintaining 90 knots. At glide slope intecept throttle back to 1700 rpm to 1900 rpm to maintain 90 KIAS down it, then at DH throttle back to decresae airspeed to 85 and dump in flaps to 30, or if prefereable leave them at 10, its your option.
They are pretty picky about having 10 degrees in before the FAF.

 

[Lead Sled]

Center it up if possible...

OK, I'm going to both agree and disagree. Flying it centered is the way to go PROVIDED that you're not following something large enough to create a wake turbulence issue for you. For example, lets say you're sliding down the ILS in a light jet and you're following something like a B777. I'm going to want to be a dot high to keep out of his wake. If I'm going to do it in a small jet, you really ought to seriously condiser doing it in your trusty 172. I'm also going to make sure I land down the runway a bit. Remember, when you're dealing with truly low minimum approaches you're also frequently dealing with fog and when you're dealing fog you don't have a lot of wind - those pesky wingtip vortices can hang around for a while. The key to flying IFR is being aware of the big picture - situational awareness if you please.
'Sled

 

[Pedro]

OK, I'm going to both agree and disagree. Flying it centered is the way to go PROVIDED that you're not following something large enough to create a wake turbulence issue for you. For example, lets say you're sliding down the ILS in a light jet and you're following something like a B777. I'm going to want to be a dot high to keep out of his wake. If I'm going to do it in a small jet, you really ought to seriously condiser doing it in your trusty 172. I'm also going to make sure I land down the runway a bit. Remember, when you're dealing with truly low minimum approaches you're also frequently dealing with fog and when you're dealing fog you don't have a lot of wind - those pesky wingtip vortices can hang around for a while. The key to flying IFR is being aware of the big picture - situational awareness if you please.
'Sled

Everytime I'm behind a 757 or anything larger I fly one dot above, I hate riding the wake...

 

[Bernoulli]

Perhaps many of us use two different techniques because we are only looking at one side of the coin. When you think about trying to hold the glide slope, we often only think of two situations (above GS or Below GS)... when in reality there are four situations, each of which should be controled differently regarding pitch and power.

1. below glide slope and fast (pitch for glide slope and leave power alone)
2. Below glide slope and slow (Use power to get back on glide slope and get airspeed back up by holding pitch the same)
3. Above glide slope and fast (Reduce power to get glide slope and get speed back to approach speed while holding pitch the same.
4. Above glide slope and slow (pitch for glide slope by increasing pitch down a bit and leave power on approach power setting.

Of course every approach will not be the same due to the velocity of the winds and therefore tweeking both pitch and power is required.

 

[Lead Sled]

Perhaps many of us use two different techniques because we are only looking at one side of the coin. When you think about trying to hold the glide slope, we often only think of two situations (above GS or Below GS)... when in reality there are four situations, each of which should be controled differently regarding pitch and power.

1. below glide slope and fast (pitch for glide slope and leave power alone)
2. Below glide slope and slow (Use power to get back on glide slope and get airspeed back up by holding pitch the same)
3. Above glide slope and fast (Reduce power to get glide slope and get speed back to approach speed while holding pitch the same.
4. Above glide slope and slow (pitch for glide slope by increasing pitch down a bit and leave power on approach power setting.

Of course every approach will not be the same due to the velocity of the winds and therefore tweeking both pitch and power is required.

It seems to me that you're still making it way too difficult - 4 scenarios for Pete's sake! Keep it simple. Pitch for glide slope, power for airspeed. Everything thing else resolves itself without a bunch of mental analysis and it works just fine in every airplane you're likely ever going to fly from a Cessna 150 to a B747.

'Sled

 

[NYCPilot]

According to the FAA Instrument Handbook, the proper technique for flying the ILS is to pitch for glideslope and use power for controlling airspeed. This has been the technique I've used and it seems to work pretty well. It also seems more intuitive when making the corrections. Pitching for the glideslope needle seems more visually logical as well as adjusting power with the throttle to regulate the airspeed.

I also think that you will find that the corrections can be made more quickly and more accurately. The ability to pitch for the glideslope gives you more control as to the rate of pitch movement that allows you to get back on the GS.

Although pitch and power must both be manipulated in order to remain on speed and on the GS, it is much easier to think in terms of using pitch for the GS and power for the airspeed.

 

[Foxcow]

According to the FAA Instrument Handbook, the proper technique for flying the ILS is to pitch for glideslope and use power for controlling airspeed. This has been the technique I've used and it seems to work pretty well. It also seems more intuitive when making the corrections. Pitching for the glideslope needle seems more visually logical as well as adjusting power with the throttle to regulate the airspeed.

I also think that you will find that the corrections can be made more quickly and more accurately. The ability to pitch for the glideslope gives you more control as to the rate of pitch movement that allows you to get back on the GS.

Although pitch and power must both be manipulated in order to remain on speed and on the GS, it is much easier to think in terms of using pitch for the GS and power for the airspeed.

What page is that on?

 

[Tarzan]

Don't worry. There's one for the other side also. Pull the power to idle while in the air pull the yoke all the way back and and show me how you pitch up to gain alitiude.

I have no problem pulling back on the yoke with the thrust levers at idle and gaining altitude. When I did stalls, the thrust levers went to idle and when you get Flaps 9, you had to give foward pressure to keep from climbing. Must have been a thrust thing huh?

Pretty lame attempt at the proverbial "flip side of the coin."

 

[A Squared]

Pretty lame attempt at the proverbial "flip side of the coin."

yes, precisely the same lameness quotient as pretending that an airplane on the ground is a relvant comparision to one in flight.

 

[Tarzan]

I'm not the one who made the quote but at least his was amusing. Yours was not. And if you're going to start using big words to try and impress us, capitalize, Tool.

 

[A Squared]

Yours was not.

mine? you obviously aren't too terribly observant. not real surprised. just speculating, but i think perhaps the reason you think one is breathtakingly original and an downright knee-slapper and the other is soooo *lame* as to require comment is that one agrees with your somehat narrow and dogmatic view of things and the other doesn't. the fact that *neither* actually sheds any relevant light on the discussion is completely lost on you. incidentally, both pointless arguments have been around about as long as the pitch/power debate, which is to say about as long as airplanes have been around.

 

[Tarzan]

You're still a tool.

 

[Fury220]

Gettin' hot in here...

 

[Pedro]

mine? you obviously aren't too terribly observant. not real surprised. just speculating, but i think perhaps the reason you think one is breathtakingly original and an downright knee-slapper and the other is soooo *lame* as to require comment is that one agrees with your somehat narrow and dogmatic view of things and the other doesn't. the fact that *neither* actually sheds any relevant light on the discussion is completely lost on you. incidentally, both pointless arguments have been around about as long as the pitch/power debate, which is to say about as long as airplanes have been around.

I think you lost him at speculating...

 

[A Squared]

You're still a tool.

ummmm, yeah. snappy rejoinder there, sport

I think you lost him at speculating...

Apparently.

 

[NYCPilot]

What page is that on?

FAA Instrument Flying Handbook
[FAA-H-8083-15]

P. 7-33

"The heaviest demand on pilot technique occurs during descent from the OM to the MM, when you maintain the localizer course, adjust pitch attitude to maintain the proper rate of descent, and adjust power to maintain proper airspeed."

i.e., Pitch for your glideslope or descent rate, depending on the glideslope angle, say 3 degrees, and maintain the proper speed, say 90 knots by adjusting your power.

.

 

[Lead Sled]

FAA Instrument Flying Handbook
[FAA-H-8083-15]

P. 7-33

"The heaviest demand on pilot technique occurs during descent from the OM to the MM, when you maintain the localizer course, adjust pitch attitude to maintain the proper rate of descent, and adjust power to maintain proper airspeed."

i.e., Pitch for your glideslope or descent rate, depending on the glideslope angle, say 3 degrees, and maintain the proper speed, say 90 knots by adjusting your power.

FWIW, you'll also find almost the exact same quote in the most recent edition of the U.S. Air Force's instrument flying manual.

'Sled

 

[NYCPilot]

Using the power to control your glideslope is a less precise method. By pitching for my glideslope, I feel more in control of the oscillations of when to start and stop or freeze my pitch to hold the needle. Just the same, I feel I have more precise control when I use power to regulate my airspeed. It all seems much more intuitive and easier to control by using this method.

Pitch for GS
Power for AS

Although they are normally used together, it is much easier to think of the corrections in these terms.

 

[PeanuckleCRJ]

With brand new students I would do the power for descent path and pitch for airspeed method. By the time it's time to do an ILS, they understand the flying characteristics of the airplane better.


Never ever fly an ILS using power to control glideslope and pitch to maintain airspeed. That's a quick way to lose it. Doesn't matter if you're in a Cherokee or 747....

 

[WMUchickenhawk]

With brand new students I would do the power for descent path and pitch for airspeed method. By the time it's time to do an ILS, they understand the flying characteristics of the airplane better.


Never ever fly an ILS using power to control glideslope and pitch to maintain airspeed. That's a quick way to lose it. Doesn't matter if you're in a Cherokee or 747....

I always used the power for glidepath and pith for airspeed, and although it worked it seemed to be a lot more adjustment that i wanted in a stable approach. On my most recent ILS the other day i tried the way you suggested. I was within 2-3 knots of airspeed, and 1 dot pretty much the whole way down. Even if it isnt SOP here, I think I may try it more. If it results in a better, more stable approach, who can argue with it.

Pitching for airspeed seems to work best when there are limited power options, such as takeoff.

Just the .02$ of an instrument student. Later on I may find that the other way is better suited for whatever I fly.

 

[Foxcow]

Never ever fly an ILS using power to control glideslope and pitch to maintain airspeed. That's a quick way to lose it. Doesn't matter if you're in a Cherokee or 747....

I guess it depends on the person. I was initially taught to pitch for the glideslope and power for airspeed but chasing needles.

In my experience, if you are established inbound already at a given airspeed (100kts for arguments sake), the easiest thing to do is bring the power back a few hundred rpm once you pass the FAF. For the type of aircraft that I have flown thus far, it has never failed. The only time that I have had to pitch for my glideslope was when I was really low and in dager of going full scale.

 

[Huggyu2]

I currently fly 2 different aircraft. In one, it is primarily pitch=glidepath, power=airspeed. In the other, you set the power for the glidepath, and adjust speed with pitch. Why? Because the throttlle is difficult to set and reset/fine tune, and it leads to folks overcontrolling the throttle. Adjusting this aircraft's speed by a few knots is much more precise if you use pitch. Glidepath change is negligible, and you avoid a "power PIO" for lack of a better term.
Obviously, I'm referring to actions once you're basically stable on final. And yes, I know it ultimately is a combo of both.

 

[nosehair]

the easiest thing to do is bring the power back a few hundred rpm once you pass the FAF. For the type of aircraft that I have flown thus far, it has never failed. The only time that I have had to pitch for my glideslope was when I was really low and in dager of going full scale.

...ahh, it's that last line "when I was really low and in danger of going full scale"...that gives it away. You said you tried *pitch to the G/s - power to speed* at first but were chasing the needles. Well, that means you just need more practice and perhaps a better x-check tecnique, but as you say "it's easier to just pull back the power a certain RPM and ride it down". Yeah, that works most times in relatively smooth (training) air, but you will come closer to losing it, as you indicate "when I was really low and in danger.."
A real instrument approach in severe up/down drafts such as are associated with "bad weather" causes sudden dramatic reversals in up/down velocity and when you are rapidly sinking and your first control reaction is "increase throttle", in that instant, you are INCREASING your rate of descent. Your nose (thrust) is still pointed DOWN. You should first initiate PITCH Up as you are increasing throttle. And sometimes (many times) the airspeed has increased also as a result of the wind shear and throttle is NOT DESIRED, so...well, you get the picture.

​

 

[Pedro]

I guess it depends on the person. I was initially taught to pitch for the glideslope and power for airspeed but chasing needles.

In my experience, if you are established inbound already at a given airspeed (100kts for arguments sake), the easiest thing to do is bring the power back a few hundred rpm once you pass the FAF. For the type of aircraft that I have flown thus far, it has never failed. The only time that I have had to pitch for my glideslope was when I was really low and in dager of going full scale.

This is a different situation here. Given that an airplane is stable, if you are properly trimmed doing 100 kts straight and level, when you pull the power back a few rpms, the nose will come down to maintain 100 kts. If you remember when you were in groundschool, they probably told you that attitude plus power equals performance. For any given airplane, there is a power setting that will maintain a desired speed on a 3 degree glidepath. So I agree that just reducing the power would eb a good way to capture the glideslope. But once you are on it and have to make corrections, pitch for flight path, and power for airspeed.

 

[NYCPilot]

I think there is even mention on one of the FAA written tests that ifyou're on GS and fast, to ADJUST THE POWER to bring the airspeed back.