Instrument Approach Speeds

[Ironflight]

I am finally getting ready to start thinking about filing IFR in the -8, and have been working through approach procedures in VFR conditions, just to make sure that the EFIS doesn't surprise me in the clouds. Quick question for those who've been flying their -8's in the clouds - what do you find to be a comfortable ball-park approach speed?

Paul

 

[gmcjetpilot]

ball park speeds

comfortable ball-park approach speed?

Paul

I flew my RV-4 IFR/IMC. I don't know what you mean by "ball park" means. I will tell you my strategy with my dash 4.

I found 90kts clean requires too low power (MAP). 90kts is also a tad too hot for the flaps, so I flew 120 mph clean as a base line. (This will not work with low mins and short runways, since slowing is a pain.)

However situations needing a steaper final descent gradiant, to get down faster, I would use partial flaps and fly 90-95mph (80kts). Besides steep descent gradient and non-precision approaches I would use flaps for tail winds, short runways or low visibility (to get to lower category).

As far as the RV-8, I have no idea and the constant speed prop will help. Good lucky, sorry if that does not help. I guess my advice is fly the approach at differnt speeds and find what is the comfortable configuration and speed is for you. I found flying fast has advantages, but let ATC know the speed you are going to fly. You don't want to embarrass the jet an catch them on final.

Regardless, I would pick a spacific speed or speeds (high and low speed) for consistency and especially timed approaches.

George

 

[Vyking]

Inst apch numbs

Acft: RV-7A w/ constant speed prop flying at density altitudes 7,000'+ on even cool days.

RPM 2,300, MAP to ~11.5" to slow to 80-85 kts.
Approaching GS or FAF, flaps half (10-15 clicks of nose up trim) and MAP to 14.0" if I need to maintain altitude. I've tried full flaps but didn't like large trim changes required when going from 40 to 0 degrees flaps on missed. To me, it's potentially disorienting. Once trimmed in smooth air (I find that finding smooth air is difficult), 10" gives -500fpm and 8.5" gives -750fpm at ~80 kts w/ 20-deg flaps. If I decide at DA or VDP to land from the approach, full flaps and holding power slows me nicely to ~65kts by TH.

John Nystrom

 

[dan]

Flap speed

I fly my approaches at 100 KIAS. That roughly corresponds with the speed at which (on my RV-7) I can start dropping the first 20 degrees of flaps. That speed is actually 110 mph, so I'm flying my approach about 5 mph faster than that. When I get to the FAF I reduce the throttle and start dropping flaps for final approach.

I would love to fly approaches faster than that, but slowing up at the bottom of a downhill line is all but impossible without doing a pitch gyration, which I don't want to do in or just below the clouds, in fog, etc. So I'm pretty conservative about staying right there at a speed that is as fast as possible without being too far away from flap deployment speed.

Hope this makes sense. I don't have a lot of IFR time in my RV-7, but that's my 2 cents since you asked!

 

[Bob Axsom]

100 kts but you asked for "8" inputs

Roughly 100 kts in my RV-6A. I never use flaps on an approach unless it is one of those minimum days that probably is not going to give me a real pleasant option if I don't make it on the first attempt. Then I let everything hang out and troll for a hole.

Bob Axsom

 

[Ironflight]

Good inputs guys!

I was thinking that 100 knots feels about right to me - but I like to fly approaches fast. The Constant Speed prop allows me to throw out the anchor if I have to. But I agree, if things are really low, I can always slow the thing down and give myself a little more time.

I probably made a mistake when I was doing my initial avionics checks in Phase 1 testing - I'd be doing performance stuff up at 8K, then dive down onto the ILS at about 160 knots (no traffice of course - VFR),and it felt really good. Of course, I didn't land out of that!

By the way, the "Highway in the Sky" display on the GRT EFIS makes the ILS effortless - it should probably banned as cheating....

Paul