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Old 10-30-2017, 12:18 PM
AAflyer's Avatar
AAflyer AAflyer is offline
Join Date: May 2009
Location: Belle Mead, New Jersey
Posts: 291
Default Instrument approach speeds/configs for -8

I've started practicing non-precision approaches in my -8, using my Dynon SkyView and autopilot, but am guessing at speeds, flap settings and use of a/s hold vs. v/s while descending on final to MDA.
Does anyone have a proven set of procedures (techniques) that will help me establish a safe & efficient routine during an approach?
Bruce Windom
QB RV-8 N148BW
First Flight: Oct '16
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Catto 3-blade, with black carbon spinner.
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Old 10-30-2017, 10:15 PM
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steve murray steve murray is offline
Join Date: Jan 2005
Location: Flat Rock, North Carolina
Posts: 266

I use 2200 RPM and 17 inches manifold pressure for straight and level and 12 inches manifold pressure for 500 ft./m descent. This is with zero flaps and gives me about 120 mph for the approach My thought is if I decide to land I can slow down and add flaps as necessary. If I need to go amissed I don't need to mess with flaps, but do need to adjust the trim once I at full power.

I am flying behind a Subaru engine with three bladed iMT prop, your power iand rpm. settings may very

RV8 Flying since 2007
RV10 in construction (Finish Kit)
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Old 10-31-2017, 04:32 AM
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rzbill rzbill is offline
Join Date: Nov 2005
Location: Asheville, NC
Posts: 2,550

Since an RV will easily fly at 90 kts, why not use that since it is a standardized approach speed for low precision approach times written on the plates. With vertical guidance of high precision approaches, speed is your choice.
Bill Pendergrass
ME/AE '82
RV-7A: Flying since April 15, 2012. 750hrs
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Last edited by rzbill : 11-01-2017 at 08:35 AM.
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Old 10-31-2017, 08:35 AM
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humptybump humptybump is offline
Join Date: Feb 2011
Location: Eastern Shore of Virginia
Posts: 3,087

Within reason, your instrument approach speed is a personal choice.

You have more time to adjust and stabilize if you are at 90kts vs 130kts.

You will want a speed that is easy to transition to land.

You will want to find the correct setting for your aircraft to achieve your desired approach speed *and* you will want to know the adjustments to establish different decent rates.

Find a practice area, pick a speed, and record engine settings for level, 300fpm, 500fpm, and 700fpm decent. Repeat several times to get consistent settings. On a different day, pick a different practice area and verify your engine settings.

There's no hard and fast rule. You may even decide to change your preferred speed in the fixture. Just go out and find the new engine settings.
- Glen, ESVA
RV-8 FP IFR | Track my RV-8 | 53VG
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Old 11-01-2017, 07:48 AM
jonweisw jonweisw is offline
Join Date: Mar 2005
Posts: 97

Agree with the above - you should go out and find what works for you, but it doesn't hurt to have a point to start from..

I fly my approaches at 100kts. As soon as I am given vectors or I am 5 or so from the final approach course, I pull back to 16" at my cruise RPM (2350). Sometimes I will slow down even earlier if the controller sounds busy and I want to make sure that they give me a comfortable turn to intercept. Similarly, if I am flying a transition, I try to be at those settings before I arrive at the first transition fix. This usually gives me 120 kts.

Once I intercept, I pull back to 12" and run my prelanding checklist, which includes a 'full forward' prop. At straight and level (for me at least) this gives me 100 kts. Once I cross the FAF or I intercept the GS, I add a notch of flaps, which keeps me stabilized at 100kts on the way down. I find that at the bottom at that speed, it is a very comfortable transition to a landing configuration, which for me is a cross-the-fence speed of 75kts.

I suspect everyone will be a little different, but that's how I do it.. Hope this helps.

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Old 11-01-2017, 09:40 AM
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jjconstant jjconstant is offline
Join Date: Dec 2006
Location: Oakland CA
Posts: 770

I am just doing my training and am doing it in my 7A. Currently using approach speeds of 90kts with 10 degrees of flaps, 2300 rpm. 13" of manifold pressure keeps me level and 10" gives me 500fpm decent with 2 aboard and lots of fuel.
All Best

Jeremy Constant
RV7A "Stella Luna" ECI IO-360 WW200RV Pmags 360hrs
VAF 2019 paid plus some for those who can't
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