Precision approach speeds w/FP prop

As a new instrument pilot, I am trying to develop routines that will serve me well. Most of my approaches in training were low approaches without many landings (probably a flaw to avoid for others - I should have been doing T&G's occasionally). I have a 6A with a FP prop. I flew most of my approaches around 95-100 Kias and liked the stability afforded at this speed. I have no problem slowing down to flap speed on the non-precision approaches. However, the ILS and LPV's are different.

The other day I did a practice LPV to test my new 430W. I decided to do a T&G and at 250' I tried to slow down an add flaps. That wasn't going to happen without leveling off for a bit or slipping it (probably don't want to do that with 200/1 ). During my training, I just planned to land long without flaps on the ILS', as most have longer runways and wouldn't be an issue. Now that I have Waas and LPV's, I could be shooting approaches to 250' on shorter runways. I admittedly haven't gone out yet to figure out what I can realistically do to lose speed in this situation. That is the plan for this weekend.

I have read quite a few posts here about slowing down and adding flaps once the runway is made. However, I suspect most of these folks have CS props. I like the stability of the faster approaches, but I need a plan for when I expect to pop out at 200 or 300'. I am wondering what others with FP props do. I am thinking that I will need to slow down to 80 Kias and add flaps when I intercept the GS when I am expecting a low ceiling.

Thanks in advance for sharing your experience here.

Larry

lr172 said:

I am thinking that I will need to slow down to 80 Kias and add flaps when I intercept the GS when I am expecting a low ceiling.

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I don't know what your approach speed with flaps so that makes a difference. In my airplane with a FP prop I set 10 degrees of flaps at 85KIAS before the FAF. Then use power to stay on the glideslope all the way down. I do this on all approaches so I know how it is supposed to act without having different settings. Lessens the chance that I make a mistake.

If I break out early I can add flaps if needed. If I don't break out til mins I can land it without changing configuration. If I have to go around I don't have too much flaps to be a major concern.

YMMV

I fly the -9A st 90 knots so that flap speed is only 3 knots away. I have no problems slowing to flap speed, then full flaps, then 70, all at about 500'. That's what I do. On the other hand, you want to get everything taken care of before the glideslope gets real sensitive farther down.

Go see what works for you. Try a 70 knot approach and get good at it, even if you don't like it, just because. Be able to do everything because some day it might come in handy, regardless of what you prefer.

Ed

85-90kts

on approach. I'm with Galin on this. get 'er slowed down prior to the FAF and put 10 degrees flaps in. makes for a very comfortable approach with plenty of stability - I like the feel of the plane better than the same speed with no flaps in approach mode. also lessens the workload when you do break out on short final - just add flaps reduce power and land, no worries.

Speeds

I fly 120 knots until a mile from the final fix then slow to 110 and add 10 degrees of flap. As it slows down to full flap speed, 88 knots, I add full flaps and add power at about 500 feet for 70 knots to minimums. RV 8 fixed pitch.

+1 for Ed.

I agree with Ed, in that a safety pilot and a lot of different practices will get you ready most arrivals. Don't be afraid of 70Kts. or above to flap speed. And if you are landing on an ILS runway and stay on the slope you should have plenty of runway with even no flaps. Try it with the blinders off. It is just a longer roll out, but not much even at 80Kts. You can put the speed breaks out after you touch down.
Yours, R.E.A. III #80888

P.S. If you have an "A" you can also keep as much pressure pulling the stick back as will just keep you on the ground until you get just under flight speed, then keep it all the way back. This to will slow you down faster than you may think.

Ed_Wischmeyer said:

. I have no problems slowing to flap speed, then full flaps, then 70, all at about 500'.
Ed

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Do you do all of this at 500 AGL while on the GS? Or is this after you break out of the clouds and setting up visually?

Larry

look out above

the nice thing about already having slowed is, well, you're already slowed.

one of my early IFR flights in the RV involved a 120 kt no flap descent on the glide slope to a cloud deck at 6 or 700'. figuring 120 kts wouldn't work too well on landing in my -6, I went power to idle and pulled the nose up a little to bleed some speed.... yep, right back into the clouds. probably a dozen ways that scenario could go bad. the missed worked out okay, and was good practice, but I wouldn't want to do that at 300-400'. with a fixed pitch prop you really have to plan ahead for airspeed reduction.

Thanks for the ideas and suggestions here. I'll go practice some LPV approaches, in VFR, at 95-100 MPH, with and without 10* of flaps. I'll try taking that all the way to the runway, as well as trying to add more flaps.

Larry

Key word: Be stabilized

172: in every type of aircraft and approaches the key word is to be stabilized...

You don't wanna start lowering flaps or gears ( as the case may be ) below 1000' AGL.

In the Airline world ( at least mine ) IFR is to be stable by a 1000' AGL, VFR 500' AGL...This means to be on speed with flaps (if required) & gears down...

If unstable....Go Around & try again...

It also depends where you're landing at...O'Hare will be different than your local airport..
Landing at major airport it is a good idea to tell the approach controller at what speed you plan on flying your approach so that he can plan accordinly with the guy behind you..(I do this in Paris as they will always sequenced us behind a A-319 or an AVRO 146 who's flying the approach at 120 kts while we're at 160 with everything down..

Good luck and keep on flying IFR, Best way to learn the system..

Bruno

lr172 said:

Thanks for the ideas and suggestions here. I'll go practice some LPV approaches, in VFR, at 95-100 MPH, with and without 10* of flaps. I'll try taking that all the way to the runway, as well as trying to add more flaps.

Larry

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Larry, you might try all the way down to 200 ft then adapt to landing mode as if you are on ILS/GPS approach to minimums. The hardest part for me was always the adaptation on breakout to visual and landing. If you always plan to go to minimums then it becomes a standard practice. There are a lot of ways to do things but accelerations/decelerations configuration changes all have an affect on the human senses. Short final in the soup does not seem like a good time to challenge the brain with additional processing if it can be avoided. Maybe it's just me.

I do my deceleration on the glideslope and under the hood. I've been based at airports with airline traffic where 90 knot approaches just won't cut it. It's easier to do a constant speed approach, but...

When I had my old RV-4, I would fly the ILS (solo, VMC) at 140 knots and at the marker, pull up steeply to flap speed and to the parallel runway, slip like mad and do a wheel landing. If I did it perfectly, I could make the first runoff. If I only did it extremely well, I would watch the first taxiway creep past...

One of the things I like about the RVs is that they are especially fun to fly with high skill levels and precision...

Ed

As a new instrument pilot for a precision approach to minimums I would slow to an approach speed of 90-100 knts IAS and 10* flap within 5 miles of the IAF.

Get level, trim and stabilized to where pitch=airspeed and throttle=altitude. Just prior to intercepting the glideslope/FAF do your landing checklist (BCGumps) and pull the power to follow the glideslope keeping your speed (pitch) stabilized.

An easy formulation to follow a 3 degree glideslope is (Groundspeed/2 with a zero on the end) is your Feet per minute required to follow the glide slope. So a 90 knt ground speed is 90/2=45 with a zero on the end is 450 fpm on the VSI. A 150 knt ground speed is 150/2=75 with a zero on the end is 750 fpm on the VSI.

When you breakout at minimums with the required visibility and the runway environment in sight pull power to idle and add flaps and you will have no problem touching down on the 1000' markers if you are stabilized on airspeed, glideslope and lateral nav.

I initially had trouble slowing down my fixed pitch RV7 as well, especially in IMC. If conditions are 800ish overcast I'll fly the approach at 120knts and no flaps. If it's the approach is going to be 200-300 minimums I want to be established at 90 knots and 10* flaps by the FAF. My wife had to use the facilities on a recent flight and I was hitting the IAF at 200 knots groundspeed but I also had 4000 OVC. Practice, Practice and Practice!

I did three approaches tonight without the hood (no safetly pilots available). I did the approaches around 95 MPH. I found it very easy to pull the throttle and add 30* of flaps at 250'. I didn't notice any meaningful change to my attitude or glidepath. However, as Bill mentioned, I never seem to land as well as normal when I've been under the hood for an hour. I'll have to try this in those conditions and see how it works out.

Either way, I didn't find the handling that much different than what I am used to. I believe that I will make 95 MPH my SOP for precision approaches. I did two without flaps and one approach with 10*. I didn't notice any real differnce, but I wasn't being very critical and was a bit distracted having to spot my own traffic. I will play with this a bit more in the future. I'll also try the approaches with 30* of flaps. However, I was having no troubles slowing down to 80 MPH on short final and with 10* of flaps, I am pretty comfortable I could land on any 4000' runway and probably won't find many shorter than that with an LPV or ILS.

Thanks again for sharing your experiences.

Larry