ILS Speed?

Target 100 kts

I use 100 kts as my target speed for all instrument approaches including ILS. If the glide slope is out and it becomes a localizer approach I use the 100 kt time for the missed approach point. I accept whatever varriations are necessary to stay on altitude. RV-6A

Bob Axsom

100 kts works well for me and my RV9.

120kts. for me. 7a

ILS Speed

120 Knots for me also, aircraft is more stable.
In fact for instrument practice I climb, cruise and descend at 120 Kt and then aircraft is always in trim for autopilot engagement/disengagement (ADI 11 Trutrak). For an experiment on 5000 + foot long ILS runway I flew 140 kts to 200 feet on glideslope, did a bunch of side-slipping but no problem getting down and stopped.

Which Prop? CS vs Fixed

You guys who use 120 kts - which prop? I wonder if I could get slowed down that well with my Catto - doubt it.

I have been practicing with 110kts and no flaps. It seems easy enough to slow down and put in some flaps at DH. This leave me in a good position to go missed and climb out without too much fuss. The speed works well especially when it is a bumpy ride down and/or the plane is heavy. When getting below 100kts it is a little too sluggish for my tastes. I also like the the engine running no less than 12" MAP for the long ride down.

I tried several speeds, but 120K seems to be the most stable for me. Like George said, I use the 120K for climb, decent, and approach. I would probably prefer 100K, but my plane just feels more solid at 120K.

hevansrv7a said:

You guys who use 120 kts - which prop? I wonder if I could get slowed down that well with my Catto - doubt it.

Click to expand...

I have a fixed pitch Sensenich on my 6 and I also like 100 to 120 knots for practice (I primarily use the elevator for glideslope and let the speed vary). It has a more stable feeling to me. If I land after one of these approaches it takes a long runway to get slowed down enough to land and that big speed transition down low isn't something I would want to do if conditions were actually low. Under those conditions I would use a lower speed.

I don't like using flaps because you have to fly so slow to stay under flap speed, using my method.

With a constant speed the slowing down part would be much easier.

Why not normal speed on final

OK maybe I don't get this but why not shoot for your normal approach speed. It seems unsafe to me to fly down to 200' then try to dump the flaps and get on speed for the approach. I would think 500' as an on-speed fully configured altitude would be a good target, then when you break out of the weather you only need to transition to landing. I fly airplanes for a living and am not flying my RV yet, but my time in a Cessna doing IFR this is how I flew them. Faster to the FAF is fine but once descending the goal should be on speed fully configured (maybe leave a notch of flaps if you like). I can't believe go around performance on the RV is a problem. Do I have this wrong? I plan to build my RV to do IFR flying on occasion since the weather where I live dictates this, I am just curious if this is the recommended way to fly approaches in the GA world. Thanks for the discussion

100 Kts in my 9A

I use 100kts no-flaps in my airplane, but I have lower approach speeds than the 7A.

I use that speed because I have good control authority, good margin above stall, and because I can use the throttle to stay on the glide slope.

Problem is, unless the runway is very long, an approach to near ILS minimums is out of the question. At that speed it will take forever to stop flying

In my view, this is a real downside of slippery fixed gear airplanes.

I used 120kts in my last Mooney with gear-down flaps up on the glide slope. It was draggy enough that getting slowed down to land from minimums was not a problem.

I've experimented a little with some flaps-down approaches, but haven't worked out the details yet

120kts. on an ILS with an RV. You guys must all fly G-IVs for your day jobs. Anyone try to fly with approach flaps extended inside the marker? I suspect that I'll waste 2000-3000 feet of pavement if I come in over the middle marker with 100 kts or more in my 9A (flap extension 78 kts.). I'll try it this weekend and let you know.
Terry

Transition

terrykohler said:

120kts. on an ILS with an RV. You guys must all fly G-IVs for your day jobs. Anyone try to fly with approach flaps extended inside the marker? I suspect that I'll waste 2000-3000 feet of pavement if I come in over the middle marker with 100 kts or more in my 9A (flap extension 78 kts.). I'll try it this weekend and let you know.
Terry

Click to expand...

I have been watching this discussion on approach speeds. First, the lad in the G-IV may have a fairly high calculated approach speed and will be configuring at or before the marker and holding the speed from there. Trying to reconfigure (in the case of an RV adding flaps) and slowing to a reasonable approach speed after breaking out of the weather can be a real sucker move. Going fast down the ILS then breaking out, trying to slow and adding flaps can cause an increase in altitude and, in the worst case, put you back into the clouds. In airliners we configured so that when the runway was in sight all you had to do was pull a little power off and land. It all depends on what is going to happen when you break out. If the weather is 1000 and 3 underneath, go for it, you have time to slow. Same if you know that your are going to face a circling approach once out of the clouds. But if you find yourself facing a 200 and 1/2 situation, slow down and take your time.

John Clark ATP, CFI
RV8 N18U "Sunshine"
KSBA

Agree, but

John Clark said:

I have been watching this discussion on approach speeds. First, the lad in the G-IV may have a fairly high calculated approach speed and will be configuring at or before the marker and holding the speed from there. Trying to reconfigure (in the case of an RV adding flaps) and slowing to a reasonable approach speed after breaking out of the weather can be a real sucker move. Going fast down the ILS then breaking out, trying to slow and adding flaps can cause an increase in altitude and, in the worst case, put you back into the clouds. In airliners we configured so that when the runway was in sight all you had to do was pull a little power off and land. It all depends on what is going to happen when you break out. If the weather is 1000 and 3 underneath, go for it, you have time to slow. Same if you know that your are going to face a circling approach once out of the clouds. But if you find yourself facing a 200 and 1/2 situation, slow down and take your time.

John Clark ATP, CFI
RV8 N18U "Sunshine"
KSBA

Click to expand...

Here's the problem, at least with the 9.

I like to have about 10kt margin in whatever configuration I'm in on the ILS. That way I can set the power for the nominal case, then use pitch to address the rest. For my last airplane (M20J) 120kts allowed >10 kt margin below gear down. Had no problem using pitch for fluctuations on the glide slope.

In the 9A, allowing a 10kts margin with flaps puts you at 69kts. Besides the angst a 69kt approach brings from ATC, I don't know if I am willing to fly a whole ILS at 69 kts. For one, there is the issue of being low, slow, and draggy a long ways from the airport. If the motor coughs????

I have yet to master the technique of staying solid on the glide slope while deploying flaps - in any airplane. I think I may just need to master that skill. I know its possible because the autopilot in my Mooney was able to do it.

I've also thought about just deploying flaps for the whole approach and keeping the nominal airspeed at 80 kts (or 90?). That caries other risks that someone may be able to comment on. My assumption is that the flap speed is related to load factor with full flaps, but I really don't know.

This is something I've wrestled with as obviously other have as well. Probably its not as mush of an issue with CS prop.

Well, I tried 110..

Today I tried one on KDET's runway 15 at 110 kts. In all cases I'm talking no flaps while on the needles because the first 20 degrees of flap calls for a max speed of 95 kts. The runway is about 5000'. I did a good one, so the position at DH was correct. I did not deploy flaps but I managed to land it and make the turnoff to my hangar (Taxiway Golf) which is pretty much at the end. I did not use much braking and thus had two more options - flaps and brakes - available. I think 120 would have been pushing the margins a bit, but with more headwind even that would be OK. Fixed pitch, too. Of course, if you come in high as I did earlier this week in practice, then getting down and stopped could be pretty tricky.

Guys who fly jets do come in faster, but they also can land at higher speeds, use thrust reversers, etc.

Thanks for all the advice. It has been very helpful.

Steve:
John Clark's post addresses a correct ILS in that the approach should be stabilized inside the outer marker. Trying to make massive speed and trim corrections near the bottom is a recipe for disaster. With the 9, you're flying an aircraft that stalls near 43 kts. and has a best glide in the area of 75 kts. If you're flying with a FP propeller, try setting the RPM near 1500 as you're getting vectored or turning procedure turn inbound. Approach flaps at outer marker and RPM at 1300 to 1500 as you capture the GS. You shouldn't have to touch anything other than the stick until you break out or call missed. Go to full flaps only on short final with the landing environment appropriately identified. With a slower approach speed, there's no reason you shouldn't be able to keep the needles within +/- one dot in any direction. For a non-precision approach, you can use the same power/RPM setting, and should roll approach flaps near your PT. Just an FYI, I flew a T210 for many years on a weekly basis throughout the midwest. NEVER flew an approach in IMC above 100kts, even though I had the capability to drop full flaps, gear, and go to max RPM to slow me down. Not a bad idea to practice evey instrument approach as if you're going to ultimately miss. That way, when the real thing comes (once or twice a year), you're ready, relaxed, and focused.
Terry

Be prepared...

terrykohler said:

Not a bad idea to practice evey instrument approach as if you're going to ultimately miss. That way, when the real thing comes (once or twice a year), you're ready, relaxed, and focused.
Terry

Click to expand...

Terry speaks the truth. Assume that every approach is going to end up in a miss. Be prepared and know what to do and where to go. Takes the pressure off. I used to tell newbie first officers that my goal was to only be surprised if I saw the runway.

John Clark ATP, CFI
RV8 N18U "Sunshine"
KSBA

Then 100 should work for me

hevansrv7a said:

Today I tried one on KDET's runway 15 at 110 kts. In all cases I'm talking no flaps while on the needles because the first 20 degrees of flap calls for a max speed of 95 kts. The runway is about 5000'. I did a good one, so the position at DH was correct. I did not deploy flaps but I managed to land it and make the turnoff to my hangar (Taxiway Golf) which is pretty much at the end. I did not use much braking and thus had two more options - flaps and brakes - available. I think 120 would have been pushing the margins a bit, but with more headwind even that would be OK. Fixed pitch, too. Of course, if you come in high as I did earlier this week in practice, then getting down and stopped could be pretty tricky.

Guys who fly jets do come in faster, but they also can land at higher speeds, use thrust reversers, etc.

Thanks for all the advice. It has been very helpful.

Click to expand...

I need to go try 100 kts down to DH and check my landing distance. Even if I need 90, that's better than cranking in flaps.

The man asked what "speed"

I didn't think this was intended to be a method thread. When I travel in my RV I try to go with the flow and at Winston-Salem I was 160 kts in front of a falcon with a harassing controller in the mix. If I can accomodate the situation I will. I am not so stuck on perfect identical approaches every time because I don't have to. If the ceiling is at the minimum and I have low fuel, I'm tired, it's getting dark soon, etc. I may put the flaps down in troll mode and work very hard to be right on the money to successfully complete the approach. An RV flys sidways very well when you need to slow down for landing after a fast approach. I target 100 kts as one of the parameters I monitor during a serious approach but it is a variable. You don't have to fly an RV like a bus and I don't.

Bob Axsom

Interesting. This thread started with "I'd appreciate some feedback from those who are experienced". While forums such as this are a wonderful tool for those seeking information, it's important to keep in mind that when you ask a question, it's hard to be certain of the qualifications or experience level of those of us that respond. Most imortant to remember is that in many cases, what you're getting are (free) opinions. You may or may not want to use these as a starting point, but if the question is important to you, get some professional advice. If you want to do some reading, try looking at the practical test standards for commercial and ATP ratings and see if you can meet these with the technique you're using. In the end, there's no requirement to do it the same every time - that only becomes important if you're objective is consistent results.
Terry

I used to do "slow" normal approaches on ILS but after a few times with the controllers asking to "keep my speed up" something occurred to me. First, most airports with an ILS have a length of at least 5000 feet. Second, even if you cross the numbers at 110 knots, stopping the descent, chopping the power and flattening the prop can easily get your speed down to landing with 3, 4 or more THOUSAND feet of runway remaining.

I flew an AngelFlight mission last week in my C177RG to Boston Logan and landed in between a 767 and a Glufstream. Coming in at 120 knots, I still had to taxi quite a way to make the mid runway turn-off. I do NOT see any good reason to use a "slow", "normal" approach speed on an ILS. A VOR or RNAV approach to a 3000 foot strip is a different matter entirely.

It's worth more than I paid!

terrykohler said:

Interesting. This thread started with "I'd appreciate some feedback from those who are experienced". While forums such as this are a wonderful tool for those seeking information, it's important to keep in mind that when you ask a question, it's hard to be certain of the qualifications or experience level of those of us that respond. Most imortant to remember is that in many cases, what you're getting are (free) opinions. You may or may not want to use these as a starting point, but if the question is important to you, get some professional advice. If you want to do some reading, try looking at the practical test standards for commercial and ATP ratings and see if you can meet these with the technique you're using. In the end, there's no requirement to do it the same every time - that only becomes important if you're objective is consistent results.
Terry

Click to expand...

Well, Bob Axom was right - I was only asking about airspeed on the ILS inside the OM. I asked in the context of working with a CFII on my IPC, but he's not an RV guy. I got more and I'm grateful. It's a tradition on this forum and it's usually a good thing. Many of those who offered opinions also offered information on their experience and that lends a lot of credibility. As I see it, to get the "right" answer you have to know the criteria for success. I had not thought about it before but now I'll take a stab at it. Further comments welcome!

1. Meet the test standards, of course, for my level (private/instrument SEL).
   
2. The speed should be low enough for a safe landing even if I'm high with a strip of 5,000' and no headwind and no flaps. Slipping allowed. No flaps because they might not work or work fast enough.
   
3. The speed should be high enough that a quick change from going downhill to going "missed" can be started before the power comes on.
4. The speed should be high enough for good control in bumpy conditions and even wind shear.
5. The speed should be high enough to keep me out of trouble with controllers at busy airports. I trained for IFR at KDTW many years ago so I have a gut feel for this.
6. The speed should not be too high for my skill level to keep the bars crossed in the center.
   
7. The speed should be high enough that the engine will keep warm enough and un-fouled enough to respond well to a "missed". Fixed pitch prop.
   
8. It's desirable but not necessary to "get it over with", not taking any longer than necessary for the other criteria.
   
9. A personal choice: I have tried it both ways and for the RV I prefer to set the throttle and leave it, using the stick to "chase" the needles. This is because the RV is so powerful and thus sensitive to throttle inputs. It's also because I like to use the HITS feature of the GRT EFIS and that's easiest with just the stick chasing the smallest box with the path marker. The speed must be appropriate for this, too.
10. And finally, I agree with Terry and others that I should be able to vary it when circumstances make it wise to do so. Consistency is good but cannot be the over-riding value.

So what do you think?