Descending under IF

[Obes]

Morning all.

A question arose the other day while a group of instructors were discussing IF training with students. I have always been taught that when descending under IF, whether in the approach or just normal descending, the way that you control your speed and ROD is opposite to the way you do in VF flying. In other words, we all teach the students when approaching under VFR to land, that the ROD is controlled with the throttle, and speed with the a/c attitude, right? Well, i was taught that in IF, the ROD is controlled now with the attitude, and the speed with the power (throttle).
I think this was taught because during an ILS approach, to keep the glideslope, its easier to flying the gs with attitude and speed with power setting.

My fellow instructors thought i was mad and that under IF the same rule applies as under VFR, ie. ROD controlled with power, speed with attitude.

Am i mad? Should i give up and agree with them? Have any of you heard the method i am talking about?

Thanks in advance.

[mad_jock]

It works both ways and both ways are a valid method of skinning the cat depending what you are doing.

Its also linked to type as well. Not that I have flown one but I would imagine that if you go from cruise power to flight idle on a turbo piston you are going to shag it. Do the same thing on a TP and you just go down like a brick with no ill effects.

[RTN11]

Here we go again...

Ultimately, it will always be a combination of the two in a powered aircraft. If you are high, you can't just stuff the nose down and expect that to fix it, you will also have to make a power adjustment or the speed will increase.

The methods you have described above are a way of breaking it down to make it easier to learn. Once you have mastered it, you will find you make small attitude and power adjustments without even thinking about it, simply using the energy available to you to keep a constant approach at the correct speed.

Generally speaking, it is easier when flying a 3 degree ILS to set a sensible power setting at the start which you anticipate will work, then follow the ILS indication with the attitude of the aircraft. Also, when you move onto larger aircraft the speed will take longer to change if you need to speed up or slow down, so having in your mind that you need to get the speed right first will certainly help when applied to larger aircraft in the future.

[Obes]

'here we go again'? Has this been discussed here before? apologies if it has!

That all makes sense. Thanks. I think i just wanted to make sure im not going to train students with the incorrect method. But i understand all of the stuff you have mentioned. Just glad both are valid.

[RTN11]

Only kidding :}

I was mainly referring to this thread

http://www.pprune.org/private-flying/484771-attitude-speed-control-power-pitch.html

Which became more and more hilarious with every page...:D

This type of topic probably comes up about once a month, but the search function isn't always brilliant at finding such topics.