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RV-9A - Slow Down, or Drop Altitude, Not both

pmccoy

Well Known Member
I had an interesting flight this week. Flew one of my normal routes between Chino, CA and Big Bear Lake, CA. On the way home I was direct to Chino on flight following to go through the maze of Southern California airspace. After take off from Big Bear, it's normally a 22 minute flight with a nice 300 to 400 ft per minute decent the entire way. This particular flight seemed to have lots of traffic call outs from ATC. I was on an altitude hold at 6,500, then another at 4,500. As I was getting closer to Chino the altitude hold was not being released. I saw a couple of planes pass about 1,000ft below my path. When I was 7 miles out, I was still at 4,500 on hold. Time to slow way down. I know I can slow down the RV-9A pretty quickly, but I can't slow it down and loose a bunch of altitude at the same time. This is not a surprise to anyone, but I had to be thinking about it if I wanted to nail the upcoming landing. When ATC released me for my final VFR decent into Chino, I was 5 miles out and had already slowed to 75-80 knots with flaps out. The issues was I now had to drop almost 4,000ft in the last five miles on final. No problem since I had slowed down first. Pulled the rest of the power and floated down with full flaps at 65-70 knots. Put her down just at the end of the runway, after having one of my slowest final approaches on record. If your flying a one of the short wing RV's with a constant speed prop, you might read this and wonder what's up. I did my transition training in a 7A and was amazed at how fast we could drop altitude with the power out. With my fixed pitch prop and larger wing, the 9A flies great. I really love it. Sometimes you just have to keep your head in the game and make sure you are doing the appropriate planning as ATC modifies you normal approach.
 
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Pete, you could have stalled and ridden the stall down to your desired altitude. Give that some practice and see how it works for you. It is a nice trick to have in your back pocket.

BTW, I was doing my approaches today at 55 kts with full flaps.
 
My 9A doesn't sink much in a slip. But, I am probably used to a full flap C182 slip that is aggressive and effective. The 9 just sinks a bit more... than without the cross control. Or, is it just me...?
 
I've slipped my 9A a bit. It does work but is nowhere like my old Aeronca Sedan was but I didn't expect it to be.

One thing that I did from before my first flight was to set the idle pretty low. Yea, getting down can take a little planning but it's not as difficult as I expected. I'd have to say that overall, I really don't have many issues getting down or slowing down. I even was asked to perform a short approach at my home airport which I complied with. I went full flaps on downwind and slipped it all the way around. It was kind of fun.
 
Bill-

Pete, you could have stalled and ridden the stall down to your desired altitude. Give that some practice and see how it works for you. It is a nice trick to have in your back pocket.

BTW, I was doing my approaches today at 55 kts with full flaps.

I have to admit I would have never thought to try this. It's an interesting idea. Sounds like I should head out to my favorite practice area over the Mojave desert and try some extended stalls. It will be interesting to see how quickly I can drop out of some unwanted altitude. These will have to be solo. My wife would have a cow if I tried a stall descent with her in the plane. Thanks for the idea.
 
For some of us "less bold" pilots, a full slip to scrub off that altitude would be w-a-y preferable. :D I've been able to use a full slip quite successfully from altitude, though I admit never from 4000'. That's a bunch!

I hear ya on that "longest, slowest approach". It's amazing how we get used to cruising at 140 - 160 kts. The slow stuff in the pattern seems a whole lot slower now than it did when I flew 172s. :)
 
I have to admit I would have never thought to try this. It's an interesting idea. Sounds like I should head out to my favorite practice area over the Mojave desert and try some extended stalls. It will be interesting to see how quickly I can drop out of some unwanted altitude. These will have to be solo. My wife would have a cow if I tried a stall descent with her in the plane. Thanks for the idea.

Most planes I've flown can be kept very stable during a stalled descent as long as you have a light touch on the rudder. If you're high, it feels like normal flight except for the unwinding altimeter. Unless she's unconfortable with a gentle initial stall, the actual stalled descent won't seem very adventurous.

I shot this in the Pitts at idle power and full aft stick. 32 seconds from 3,000' to 1,500' - 2,800 FPM. Very stable and tame.

http://www.youtube.com/watch?v=mLZG2lU0WrQ&list=UUm9cBvavbT4j6vReBu9H8Qg
 
...I have to admit I would have never thought to try this...

I have flown the ragged edge of a stall right down to within 75 feet of the runway threshold in a -9A many times. It seems to halt all forward motion and comes down like an elevator.

IIRC, this technique was a spitited discussion on this forum some time ago and many people essentially said I was insane/reckless for suggesting such a move, but I've done it, and it works fine.

As Bill says, its a fine skill to have in your "toolbox".
 
I think this thread is going to motivate some of us to head for altitude and try out some things....
And, I am going to check that idle setting again.
 
I fly a 9a and an HR-II. This is quite a difference in flight characteristics, for sure.

The 9A slips fine, but most folks don't put full rudder in during the slip. With full rudder, the elevator lightens up a whole lot, so you need practice.

This is preferable to a stall-buffet descent because of the increased visibility and the ability to keep it slipping right down until flare.

The other technique is the overhead break. Fly initial, perform the break at idle power and 60 degree bank to downwind, dial in the slip and keep it in until short final. Unfortunately, this manoeuvre is not advisable at most airports.

Also, don't fly at best glide speed in the circuit.... you want to be faster or slower than this at idle power in order to bleed energy. Otherwise the only advice I can give is to build a Rocket.
 
I routinely put my 9 into an aggressive slip to lose altitude (full rudder deflection is really necessary) and it works well right down to crossing the threshold if necessary. Doesn't sink like the shorter wing RVs but is definitely a useful way to lose altitude.
 
I routinely put my 9 into an aggressive slip to lose altitude (full rudder deflection is really necessary) and it works well right down to crossing the threshold if necessary. Doesn't sink like the shorter wing RVs but is definitely a useful way to lose altitude.
Agree completely. :)
 
I do slip the 9A often, I have just never tried to loose 4,000' of altitude in a slip before. Most of my slips are to correct a few hundred feet on final. Looks like something else to go out and try in the practice area.

This is really cool. I have an excuse to go fly. Love it.
 
I have really enjoyed learning the flight characteristics of the RV-9. I find it is all about speed. From the slip, approach and landing, speed is the most important thing. Some of my approaches have been fast and I just could not seem to get it down. Pull the stick back to 70-80 kts and the thing sinks. Same with a slip. It seems natural to slip @ 90-100 kts but it keeps flying. Pull it back to 80 kts and it sinks nicely. Full rudder of coarse. The 9 wing is so long it is still out there in clean air during a mild slip.
 
I've only been flying my -9A for about 5 hours now and I don't find it difficult to slow down or get down at all. Certainly not as I was anticipating from reading posts here. Sure it glides better than other Vans series, especially those outfitted with constant speed props, but its really no different than a Skyhawk or Warrior. (just a bit smoother, easier, better control harmony, oh and a heck of a lot faster.)

Tried a slip at altitude yesterday, after reading this thread, was surprised how hard you have to step on the rudder. I guess im just used to it swinging so freely in the garage all this time pretending.
 
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....This is preferable to a stall-buffet descent because of the increased visibility and the ability to keep it slipping right down until flare...

Though I've ridden the -9A down thousands of feet with full aft stick, the airplane shaking like a wet dog the whole way, I'm not suggesting going quite that far as a matter of course. It would be uncomfortable for any passengers, just like a prolonged slip is uncomfortable for passengers. However, if you can tease the airplane right to the edge of the stall, it remains glass smooth, yet still comes down like an express elevator.

Visability over the nose is somewhat limited however, so your point is quite valid there.
 
So, full slip in a 9 at 80 kt, what kind of decent rate do you guys get?

Tim

80KIAS is too fast. You'll get about 6-700fpm or so. Slow to 65KIAS with full flaps and you will see about 900. By comparison in a 172 you can easily bury the needle at over 1500.
 
Of course the other option is to cancel advisories squawk 1200 and maintain the 500 fpm decent.

Without traffic would make me a little nervous.
Love our 330/696.
 
Of course the other option is to cancel advisories squawk 1200 and maintain the 500 fpm decent.

Without traffic would make me a little nervous.
Love our 330/696.

This thread and the concept of "ATC control" while in VFR flight following has me curious? Is this becoming routine? I would had thought that just learning of traffic then descending at your discretion would have been perfectly legal, and knowing traffic, safe.

What am I missing here?

I have been reading Stick & Rudder lately and it discusses this near stall descent as a proper procedure under needed circumstances. Great discussion!
 
You can see from the L/D chart, that you need to slow to near stall to really see your Total Drag increase over time/distance. I wonder if Bill's method produces more rate of descent than a slow, full slip. Give's me a reason to go fly! I suspect that it does.

23keooo.jpg
 
Of course the other option is to cancel advisories squawk 1200 and maintain the 500 fpm decent.

Without traffic would make me a little nervous.
Love our 330/696.

I also love getting TIS traffic displays on my panel mounted 696. Cancelling flight following wasn't a real option, as ATC was guiding me through Class-C airspace for Ontario. If I cancel with ATC, I would have needed to be on with Ontario Tower for the transition through Charlie.

My flying is done out of a Class Delta airport, surrounded by a Ontario and Class Charlie. Yes, I am on Flight Following on 98% of all my flights in SoCal. Lots of airspace and other planes to deal with. I am often given altitude holds both going up and coming down, as well as vectors to avoid incoming jets landing at Ontario. It's just part of flying in a big city.
 
I believe if I had a -9, I'd have to seriously consider speed brakes. Seems like a fun tool for the tool bag.
 
This thread and the concept of "ATC control" while in VFR flight following has me curious? Is this becoming routine? I would had thought that just learning of traffic then descending at your discretion would have been perfectly legal, and knowing traffic, safe.

What am I missing here?
Once you are assigned an altitude and/or heading ... that's what you have to follow up until told to resume own navigation.

When directed to maintain 4000 one could always say unable and see where that goes.
 
Cancelling flight following wasn't a real option, as ATC was guiding me through Class-C airspace for Ontario. If I cancel with ATC, I would have needed to be on with Ontario Tower for the transition through Charlie.
or avoid the C ... But in your case than may be a little more difficult.

If we don't go over the Bravo we avoid Burbank to the west and fly the special transition.

About 1/3 of the time we can get a clearance just past LAX to decend through the Bravo onto Oceanside.
 
My 2 cents:

In general, I would not recommend using a slip or near stall profile for a prolonged descent. Both maneuvers present limitations in visibility and in the event of a traffic conflict you are not in a very maneuverable state.

Also, depending on which tank you are feeding from, a prolonged slip may uncover a fuel pickup.

At any rate, turn on your boost pump during your idle descent before entering any of these maneuvers.

Also shock cooling is a possibility during these maneuvers.

My preference would be to execute a 360 or S-turns as necessary to lose altitude.

Good point on the unporting of the fuel pickup. It's my SOP to select the opposite fuel tank as the pattern direction in anticipation of the slip.

We '9 drivers are such complainers. My airplane flies to fast and glides too well!...waaaah
 
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Good point on the unporting of the fuel pickup. It's my SOP to select the same fuel tank as the pattern direction in anticipation of the slip.

Say you're making left traffic - wouldn't you want to select the right tank? The fuel pickup being near the wing root, in a left bank the fuel in the left tank will be forced away from the pickup. Fuel in the right tank would be most available.

Now in a slip, couldn't you choose which direction to slip based on the tank you have already selected for the traffic pattern?

Am I thinking about this wrong?
 
Say you're making left traffic - wouldn't you want to select the right tank? The fuel pickup being near the wing root, in a left bank the fuel in the left tank will be forced away from the pickup. Fuel in the right tank would be most available.

Now in a slip, couldn't you choose which direction to slip based on the tank you have already selected for the traffic pattern?

Am I thinking about this wrong?
I am sure Vern will supply his comments to your questions but having experienced an engine cut off due to fuel unporting in a slip on final I don't think you are thinking about it wrong. I have always been taught that one should slip with the nose pointed into the wind. I have always assumed that the reason for this rule of thumb was that once you released the controls the prevailing wind would 'push' the nose back into appropriate alignment for the direction of flight. Now having learned this, I have to admit that almost all of my slips are to the left with the left wing down. I tend to slip in this manner because I sit in the left seat and by slipping in this manner I have a perfect birds eye view of what is in front of me and below me. Comparing that attitude to that of a right slip where I have to look across the cockpit out the right side of the cockpit to see, it just feels more comfortable slipping to the left.

Since I tend to slip to the left and since I have had the heart stopping experience of having the engine quit on me during such a slip while on the left fuel tank, I now make a point to have the right fuel tank selected before approaching the runway.
 
I have always been taught that one should slip with the nose pointed into the wind. I have always assumed that the reason for this rule of thumb was that once you released the controls the prevailing wind would 'push' the nose back into appropriate alignment for the direction of flight.

Geothermal wind does not "push" on the airplane and it makes no difference which way you point the nose during a slip. I've even heard people claim that slipping with the nose into the wind will reduce your groundspeed. All of it is nonsense. A proper slip has no impact on your ground track. The only difference between slipping with the nose toward or away from the wind is in the heading correction you must make before touchdown. If you slip with the nose into the wind, then you will be making a more significant heading transition into a slip in the opposite direction to align the airplane with the runway. Slip with the nose away from the prevailing wind direction, and you are very close to the alignment needed for touchdown.
 
I am sure Vern will supply his comments to your questions but having experienced an engine cut off due to fuel unporting in a slip on final I don't think you are thinking about it wrong. I have always been taught that one should slip with the nose pointed into the wind. I have always assumed that the reason for this rule of thumb was that once you released the controls the prevailing wind would 'push' the nose back into appropriate alignment for the direction of flight. Now having learned this, I have to admit that almost all of my slips are to the left with the left wing down. I tend to slip in this manner because I sit in the left seat and by slipping in this manner I have a perfect birds eye view of what is in front of me and below me. Comparing that attitude to that of a right slip where I have to look across the cockpit out the right side of the cockpit to see, it just feels more comfortable slipping to the left.

Since I tend to slip to the left and since I have had the heart stopping experience of having the engine quit on me during such a slip while on the left fuel tank, I now make a point to have the right fuel tank selected before approaching the runway.

My bad, i mean't opposite. Original post corrected.
 
I have a 9A with a CS prop and rather than waiting to slow to say 60 kts with full flap and idle power to lose height I just slow to max flap speed ( 78 kts ), idle power, full flaps and point the nose down to maintain max flap speed.

I have not done accurate testing but today in turbulent conditions I was getting about 1,100 fpm sink at 60 kts and about 1,700 fpm at 78 kts. The advantage is that I can start descending sooner rather than waiting for the speed to slow to 60 kts. Once at the desired height the speed bleeds off quickly when the high descent rate is checked. As I said I have not done accurate testing but it sure feels to be a quicker way of losing height rather than waiting to slow to 60 kts.

The CS prop would help. I find I have to point the nose well down to maintain 78 kts.

Fin
9A
Australia
 
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It's been a while since I've been in a -9, but 60 knots is still pretty fast - you really need to be right on the edge of a stall to get the L/D working in your favor. The descent rate goes up quite fast for every knot you slow down beyond 60.

And I think it should be pointed out that this technique really only has value if you are not only high, but running out of room between you and the runway. In other words, it's a fairly extreme form of stretching time. I'd never consider this as a routine action.
 
Saturday my son and I flew over to KGMU for BBQ the local EAA chapter was providing.

ATC kept me high and fast until very close to the runway. As soon as I got to flap speed out went all the flaps, 60 kts, and a full deflection slip from 1000' AGL to the threshold.

The -9 was coming down at between 500 and 700 FPM. I did see 800 FPM for a second but the AS was going up and I was trying to hold 60 kts in the slip.
 
This is a great thread, you did an engine out landing from 4000' agl, 5 miles out, full flaps, and nailed the end of the runway. Great job. I did two of these over New Richmond WI while transitional training two weeks ago. We were over the runway at 4500' agl and Tom Berge said pull the power all the way out and land between the two taxi ways on the runway. I was told to circle on down using 30 degree bank at 70 miles per/hour. With no flaps in the RV7A I could get 6 turns by staying right over the runway. On my last turn I added 1/2 flaps and then full flaps on final to a normal landing. What a plane! Just starting my phase one in my RV9A.:)

Jim
 
The 9 would be a good airplane to put a Precise Flight speed brake on. With a FP prop its hard to kill altitude. I did a few test flights of a wood prop fixed pitch 9 and had to go to idle on downwind entry. But the larger wing down low hurts speed.
 
Losing alt in the 9's

I heard that a certain 9A owner from your area has been known to top off his fuel at Big Bear.... shut off the motor after clearing the terrain and glide all the way down to Redlands.
Then his buddies look at remaining fuel and scratch their heads to see how he gets such good mileage. He will remain nameless to protect the guilty.
I did a high and close approach yesterday in my 9A and kept pushing the trim switch while looking over my shoulder at the flaps (which were not responding)
A real brain fart if I ever experienced one. I was amazed how well the flaps worked when I pushed the correct rocker switch... duh...
 
I heard that a certain 9A owner from your area has been known to top off his fuel at Big Bear.... shut off the motor after clearing the terrain and glide all the way down to Redlands.

That very same RV owner, who likes to glide home from Big Bear fuel stops, gave me one of his hats the last time I saw him refueling in Big Bear. Turns out Big Bear is my primary weekend destination. I have a cabin out on the edge of the forest, which is a great place to relax after a week in the big city. My yellow and white RV9A can be seen parked on the ramp most weekends.
 
Holy smokes Bob, I looked at the Precise Flight speed brakes and they are $$$
I think it would be about as costly as putting a CS prop on!

The 9 would be a good airplane to put a Precise Flight speed brake on. With a FP prop its hard to kill altitude. I did a few test flights of a wood prop fixed pitch 9 and had to go to idle on downwind entry. But the larger wing down low hurts speed.
 
Peter... I find Big Bear to be one of the more dangerous stops I make. This summer I gained about 8 pounds over three months. The free cookies at Big Bear near the big screen weather TV are my downfall. Must work on will power.
Have been trying some harder, more aggressive slips in my 9A. Sure takes a big leg push with all that rudder real estate.
 
Pete, you could have stalled and ridden the stall down to your desired altitude. Give that some practice and see how it works for you. It is a nice trick to have in your back pocket..

I know this is an old thread that I am resurrecting here but I tried this procedure today while practicing some stalls. I found that the 9 will buffet its way down pretty nicely but I just happened to look over my shoulder and was shocked to see my horizontal stabilizer flapping pretty aggressively in the buffets. Not being comfortable with that much movement I exited the stall immediately and I don't think I will try that again.

Has anybody else looked over their shoulder while attempting this procedure?
 
360

I have had a similar problem in my -10, and I found that rather than doing the high-rate descent which takes it's toll on the ears and makes the PAX uncomfortable, I just ask for a 360 to lose the extra altitude. If I can't get that I'll do a go-around and enter the downwind to fly the pattern. It's just never that important to get it down the first time. The stabilized approach is always preferred.

-Marc
 
Spin

Or maybe just spin it to the desired altitude?

Pete, you could have stalled and ridden the stall down to your desired altitude. Give that some practice and see how it works for you. It is a nice trick to have in your back pocket.

BTW, I was doing my approaches today at 55 kts with full flaps.
 
Why not do an overhead approach? Or maybe practice an emergency circle to land and try to nail it with power off.
 
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