Saturday, September 30, 2006

I got it.

The weather was spectacular. The seasons have changed here and morning temps have been cool in the low 50's. The visibility was a little less today, but still better then 10 miles.

Objectives: Landings

I got out to the airport a little early, in time to preflight before my instructor arrived. Many of the staff and instructors were on a "Fly Away" down to Florida, followed by a Caribbean cruise. So it was quiet when I went into the office to get the dispatch kit. By the time my instructor came back the plane was ready to go. Information Xray, and again we decided to save some time by staying in the pattern.

During the taxi down to the run up area for 27, my instructor asked if we should start with 3 pointers and ease into the Wheel Landings. No, I had been thinking about this all week and was "chompin' at the bit" to try Wheel Landings again. Takeoff was normal, and performance was great in the cool air. No traffic for distractions, I concentrated on speed and rate of descent. My gaze transistioned from the cockpit down to the far end of the runway and I waited. Patience. Squeak, and I gently but deliberately pushed the nose to the take off attitude. Beautiful. It was at least a 9 on the pretty landing scale.

But was it a fluke? Back around again, speed dead on, nice rate of descent and bingo...two in a row. This time I got a small jounce, but corrected it nicely for extra pretty points (9.5). One more time around and I know I have learned how do this. (I realized I no longer had a 'death grip' on the stick, but used the gentle touch of three fingers with my thumb to finesse it onto the deck.)

The next one we were asked to fly a close pattern for traffic. Too fast and too high led to the expected result, a go around. I felt good and decided to see if I remembered how to do the 3 pointer. Slower speed (below 70) and put the stick in my gut when the mains touched. (maybe an 8). I'm ready for the check out ride next week, and told the instructor the next one would be a full stop.

Another full stall with just a bit of jounce (6.5) but I taxied off on Bravo 4! It usually takes two more exits before I'm slow enough to get off the runway. (Change that to a 7)

Obviously a Great day!

8KCAB
Time = 0.7

Saturday, September 23, 2006

Wheels

I called McCollum ATIS to find out what the conditions were at the field. Information 'Juliet' said the clouds were broken 1100' and broken at 1800' with light a variable winds. I looked out the front door to see low dark gray clouds with little patches of blue peeking through. I called the club and asked if it was good enough for the Decathlon to do some T&Gs, and my instructor said 'it was getting better'. I took that as a yes.

Objectives of this flight: Wheel Landings.

When I got to the airport the plane had already been fueled. As I approached I noticed an access panel missing under each wing. I never saw that one before. (Maybe this was a 'catch the dumb student' preflight trick?) Nope when my instructor came out he noticed the same thing. Seems that the owner had been out playing and popped them doing some aerobatics. No big deal, and not a hazard to flight, the rest of the preflight, and ground procedures were normal. We decided to stay in the pattern for the workout.

The winds were picking up a bit as we finished the runup, to a fairly good left crosswind. Good, I need the practice. Takeoff was normal, as was the pattern work. My 'arm chair' flying had convinced me that I was trying to do it all wrong last week. I was really trying to make the Wheel Landing like a full stall. Nope, can't do it. They are DIFFERENT! The Wheel Landing is more like a very, very low pass. It should almost be a surprise when the mains touch. The key word here is PATIENCE. The airplane will land when it wants to, you just can't force it. So, in my mind the sequence is to set up on the proper approach speed (75), with power on to minimize the rate of descent. Get into the 'belly of the flare' and wait. It worked! (well, kinda sorta.) The touch down was good (squeak), but I failed to coordinate the nose attitude. Jounce!

The other thing about a wheel landing is the Pilot Induced Oscillation (PIO). See, the airplane is flying slow( just a bit above stall), and you are trying to pin the wheels on the deck. If they come off the ground because you didn't nail the nose position and you still try to pin them down...well, it gets ugly fast. Porpoise is an understatement. I got some good practice exercising the 'go around'.

Progress was made on each pass, and one was actually very good. I learned a lot! During this work the winds continued to increase, and at one point the tower called 20 KTS. (That's a lot for a taildragger, especially since it was still coming off my left side.) I see the picture now, just a few more circuits should do it.

The final full stop was planned as a full stall (3 pointer) and I executed it well. A great way to end the day.

8KCAB
Time = 1.0

Friday, September 15, 2006

Introduction to Wheel Landings

Last time I mentioned that there were two options when landing a taildragger; 3 point (full stall) landings and wheel landings. I got a taste of 3 pointers last week, and while not perfected I'm getting comfortable with them.

Wheel landings are a bit different. My preparation for this flight included spending some time on the internet:

In a wheel landing, the airplane is flown onto the runway under power, instead of stalling it on without power, and the two mainwheels touch down first. Once that's done, power is taken out while the airplane is held down on the runway. This is done by keeping the wings at a very low, or perfectly flat, angle-of-attack (AOA) in order to not develop lift: the tail of the airplane is kept off the runway to flatten the AOA until speed bleeds off below that needed for flight.

I also listened to two good Podcasts from Aero-news.net. Part One stressed the differences in taildraggers due to aerodynamic forces and discussed the work needed for a tailwheel endorsement. Part Two talked about landings.

Another good source I found stated:

The key difference between the three-point landing and the wheel landing is sink rate. Successful wheel landings require minimum sink rate. If the airplane at all settles, falls, or sinks toward the runway in the last few feet, a wheel landing will be difficult or impossible. And if the pilot flinches and applies back elevator as the main wheels touch down, the airplane will rebound into the air. At this point, the pilot needs to react quickly and efficiently--either convert the landing to a three-pointer or add power and execute a go-around. The wheel landing occurs at a higher ground speed than a three-point landing. Consequently, wheel landings tend to use up more of the available runway. It's also easier to instigate a pilot-induced-oscillation (PIO) during a wheel landing.

So, my prep work completed, I was ready to try this stuff out.

The weather was just beautiful. Excellent visibility, with small little puffy white clouds meant it would be a good day to fly.

Objectives of this flight; Landings

I got to the airport a little early, in time to see another student doing some T&Gs in the Decathlon. I sat on the picnic bench enjoying the weather and watching the show. When they were done the other instructor recommended to refuel with about 5 gallons on each side. I did the preflight and checked to be sure the fuel caps were on tight. My instructor arrived and we discussed going to Cartersville, but opted for home field. The winds were light and variable, the runway changed from 9 to 27 when I called for ATIS. The run up and takeoff went well.

The rest of the flight was spent driving around the pattern, giving me the experience and sight picture to fly the airplane into the landing. One was particularly good, with mains squeaking as the touched, but I was too slow to pin the tail down. (It went from a '10' to a '5' real quick.)

I never really got the picture with wheel landings. My approach was good, speed control good, but when I got into the flare I tended to push the nose down BEFORE the mains were on the ground. Not good.

So again, I have the concepts...Ideas about what I need to do, but haven't developed the techniques yet to execute the maneuver. Other airplanes allow you to 'pad' your speed just a bit. 5 Knots is not critical in them, but an additional 5 knots in a taildragger is going to cause a 'jounce' every time. It is a matter of precision. As the instructor said; "after a day like this, you can't wait to come back for more." Its hard work, but it puts a smile on my face just thinking about it. I can hardly wait until next week.

8KCAB
Time = 1.9

Saturday, September 09, 2006

3 Points

Conventional Gear airplanes provide the option of using two landing techniques. The first is a full stall, or 3 point landing. The airplane is flown close to the ground at ever slower speed until it stalls and settles to the ground. The second, called Wheel Landings are flown a bit differently and just might be discussed next week.

There was nothing special about the weather today. Possibly a scattered layer at 5000, but mostly haze with visibility about 5 miles. Nothing that would keep us on the ground.

Objective of the flight: 3 Point Landings.

I got to the airport a little early for my flight. The owner of the aircraft had the bucket and hose out washing it down. (He warned me not to smash any bugs.) He finished as my instructor arrived and we completed the preflight. Ground procedures were normal (once I remembered to plug in my headset).

The takeoff; this one was actually pretty good. My 'arm chair' flying at home had uncovered a major error with my scan. At the most critical time (raising the tail) I wasn't looking far enough down the runway. I was able to correct this and had pretty good control. Not wanting to allow any drift, I "snatched it" off the ground instead of letting the airplane accelerate and fly off.

We departed to the north to practice some stalls. The nice thing about this airplane is that it really stalls. No mushy, slushy bubbling along, it just sounds the horn breaks clean. I like that. Power on and power off both act pretty much the same.

OK, back to the pattern. I picked up my bearings quicker, but was having a slight problem picking up tower calls. I don't like that. I'll check my batteries to see if I can boost the volume a bit. Traffic was called as base, but was really downwind for runway 9. It turned my pattern into a long straight in. My "arm chair flying" had also uncovered a flaw here. I was flying into the flare too fast. So I really concentrated on speed control as I got into the landing position. It worked well, not great but acceptable. The instructor rode the controls pretty closely and I liked that. That immediate feedback of where the stick should be coupled with the visual cues for nose attitude really gave me the sense of where the plane should be.

The next takeoff went well. I felt very comfortable with the controls and let the airplane fly this time. It felt better. Again traffic pushed us a bit deep on final but it really wasn't a problem. I lined up a bit left but made my corrections. Got on speed and descended to my spot. This was nice. No help from the instructor, this one was mine. And it worked well.

The next takeoff also went well. I'm OK with takeoffs now. Nose position probably needs a bit more fine tuning, but rudder control is no longer a problem. This time the approach was short for traffic, and I carried a bit more speed then I would have liked. A small 'jounce' but under control. I'm learning. The primary objective was met...I had fun.

We flew 70.4 miles, climbed to 5738 feet and reached 133 mph over the ground.

8KCAB
Time = 1.2

Sunday, September 03, 2006

Conventional Flying

There was a time when the third wheel was located on the back of the airplane. When they started putting it up front it was considered unconventional, tricycle gear. Since it was so much easier to control the airplane on the ground (including take-offs and landings) the tricycle configuration became standard and conventional gear went the way of the manual transmission. So, like sports cars, conventional gear is found on really fun airplanes.

My preparation for this transition included two books: Conventional Gear, Flying a Taildragger by David Robson, and The Complete Taildragger Pilot by Harvey S. Plourde. I think Harvey's book is superior by providing more analysis of the aerodynamics, especially what causes the 'jounce'. I also studied the Pilots Operating Handbook for the Decathlon and took the written test required by the Flying Club.

The weather was iffy. Ernesto had just passed through to the east of us and some of its remnants were stirring up the air. Bases were anywhere from 1200 broken to 1700 overcast, and nearby Dobbins AFB (KMGE) was reporting variable ceiling height (CIG). No showers and an occasional hole with blue sky peeking through kept me optimistic during my short drive to the airport. Due to some scheduling changes, my flight had fortunately been pushed back to noon, and when I arrived my instructor was still out on another (instrument training) flight.

Objectives of this flight: Introduction to conventional flying.

My log book says my last flight in a taildragger was 1.5 hours solo in an Aeronca 7Ac up in Slatington (69N) during the fall of 1970. My instructor at that time had limited me to full stall (3 point) landings, and I don't remember the limits on crosswind component. FAR 61.31 (i) (2) says that I'm grand-fathered in for my tailwheel endorsement, but 36 years seems to be just a bit long between flights for me to be safe. I wasn't sure that this was 'like riding a bicycle', so I scheduled plenty of time to get checked out. Note: the Decathlon is a fully aerobatic aircraft. However I didn't think it wise to put my already overloaded frame though 3.5 g pull ups. Just too many pounds and too many years since I did that the last time. I'll forego the aerobatics for now.

My instructor arrived and we introduced ourselves, talked about experiences, etc, and what I wanted to get out of this training. I mentioned spin training, soft field operations and just getting back to basics. Preflight and ground ops were straight forward. This airplane has a constant speed prop (which I haven't played with before) but otherwise the cockpit is pretty basic. Taxiing is not unlike the Tiger, just a bit slower and the need to anticipate corrections sooner. I got through the runup with a few embarrassments, but overall not too bad.

Ah the takeoff. All of the studying told me what would happen. My mental rehearsals warned me what might happen. Even so, the darn airplane went heading for the weeds on the left of side of the runway as soon as I lifted the tail. (Torque, P-factor, winds...Whatever, the airplane goes left and pushing the rudder full right is NOT the correct response.) Just plain ugly.

Once airborne (thankfully) we headed north to a practice area over the lake. Unfortunately the clouds were too low to allow any stalls. So I just got familiar with the controls, slow flight, etc. Sitting on the aircraft centerline and flying a stick instead of a yoke...Is FUN! I'm falling in love again.

Well, let's go try some landings. First, where is the airport? No GPS, low clouds, can't see Mt Kennesaw, where the heck am I? My instructor pointed out the bridge that marks about 9.5 miles northwest of the field and slowly I got my bearings. ATIS remained the same and I was cleared for a right downwind. My spacing was good, speed was good, altitude a little sloppy (-200), but I was comfortable. Nice line up on final, good rate of descent to my spot, everything was good. I got into my flare a bit high, held it off and...'jounce'. The third landing was pretty good. (I could only log one of them though.) We took the next taxiway and went back for more.

OK, so what is the 'jounce'? When you land a tricycle gear plane, the mains touch and you lower the nose. The angle of attack (AOA) is reduced, reducing lift. In a taildragger, after the mains touch you lower the tail, increasing the AOA and therefore the lift and up you go...jounce.

The next iterations were similar, showing some slight improvement. Lets just say that I'm getting the picture but it is not yet fully developed. So, was this a successful flight? This is FUN stuff! Humility is good for the soul, so that part of me is very healthy right now, and I still have a smile on my face.

We went 73.3 miles, climbed to 2647 feet and reached 135 mph over the ground.

8KCAB
Time = 1.3

* Note: Olathe did a great job with the 96c. Overnight air got it back quickly and I'm happy with the results.