25 March 2012

Friday Soaring, Weekend Washout

I got to the airport extra early on Friday to assemble the Cirrus. The wings must be aligned just right before the wing spar pin--the only thing that holds the wings together--will slide into place. That usually requires a few rounds of adjustment to the wing dolly followed by pushing and pulling on the wing roots, all while uttering gentle persuasions. I've heard the assembly process compared to foreplay; I guess I can see a vague similarity there.

Elapsed time from opening the hangar door to finishing taping the wings was about 35 minutes, my fastest single-handed assembly to date. With practice, I'll get that (safely) down to 15-20 minutes like the grizzled vets in the club. I still managed to get white lithium grease on my clothes despite taking extra care. So it goes.

I took her up for a sled ride after some of the morning haze had burned off. My takeoff was better than the prior two, but I still found myself hunting in pitch while the Cirrus accelerated in ground effect on tow. I will get smoother with practice. I flew a slightly lower and tighter pattern for landing, but it required full dive brakes from the base leg all the way to touchdown. I'm going to try flying at roughly 600 feet AGL abeam the touchdown point next time; that should permit a tight, half-spoiler approach in this ship.

The Grob 103 was available, so I took that up in the afternoon. I hadn't flown it since last summer, and I really noticed how much easier it is to fly the takeoff and tow in that heavy trainer compared to the Cirrus and the 1-36 that I usually rent. The lift was mostly to the south and east of the airport, near Linden VOR and over the city of Front Royal. A slowly moving rain cell appeared to the southwest. The sight of distant shafts of rain from an aerial vantage point is always impressive. I circled around until getting called down to help on the ground  and got a decent 50 minute flight out of the deal.

I'm glad I went flying on Friday. Glider operations were cancelled Saturday and today due to weather. My aerobatics lesson was cancelled as well.

13 March 2012

The Immelmann

After several botched attempts, the Immelmann seemed to make sense to me. Enter a little faster than the loop and maintain a steady pull until reaching an inverted slow-flight attitude. Push a bit to stop the loop, unload the wings, then apply full left aileron to get it rolling.

Sounds simple, but it went off the rails on the first few attempts: I'd keep some forward elevator in when initiating the roll, then overcompensate (to be really sure the wings were unloaded) and gracelessly whip the stick over to ensure full aileron extension. After a few more tries, I'd roll out upright in a slow-flight attitude at slightly under 60 mph indicated.

I had an epiphany flying the slow roll: I needed to scoop the nose up higher and push a little more over the top. Once I got the pitch attitude high enough, I was able to perform a few passable examples. It will click next lesson. And the half cuban is close. I predict that it will click next time, too.

That was hour 3 of aerobatic training. It is clear that I over-think the maneuvers. My flying skill, already in short supply, approaches zero when I consciously think through the control inputs. I'll get there, though. This training has been the most fun I've had in an airplane by far. I'm grateful that the instructor is so patient.

The landing was better than the last, but I had a tiny bit of a side load at touchdown. I need to be more aggressive in making adjustments to the sideslip as the crosswind changes.

Next lesson: the Hammerhead.

Nothing written on this blog should be considered training or advice. Do not attempt to teach yourself aerobatics. Find a competent instructor and an aircraft suitably stressed for the task.

11 March 2012

First Flight in the Schempp-Hirth Open Cirrus

Having met the pilot in command (PIC) minimums to fly the club's Open Cirrus sailplane, I'd wanted to get checked out in it for the past couple of months. After watching several Cirri compete in The Sun Ship Game--a film that everyone should see--I set a goal to fly it this season. The weather was right yesterday and the instructor on duty took the time to ensure that I had assembled it properly, provided some much-appreciated insight into her flight characteristics, then gave me the requisite logbook endorsements.

With a book maximum L/D of 44:1 (for comparison, a Cessna 172's glide ratio is at best about 9:1), the Cirrus is the highest performing glider that I can rent from the club. It is a classic aircraft, Shempp-Hirth's first glass glider (read the original review from the July 1967 issue of Soaring, page 18, if you're curious). It has a retractable landing gear and a center of gravity (CG) tow hook, neither of which I had experience flying. I'd also never flown an aircraft with an Experimental category airworthiness certificate as pilot-in-command.

The Cirrus is flown in a more reclined position than I am accustomed, and it was clearly designed for someone taller than me. The pilot sits in a canvas sling that can be adjusted via the roller at the top. With the sling ratcheted tight and rudder pedals adjusted full rearward, I can just barely get full rudder extension. I was warned that the landing gear requires some finesse to retract, so I strapped in and practiced actuating it several times before taking the glider off of the fuselage dolly. It took several tries before I could get it to reliably lock in the retracted position.

I had anticipated the glider's desire to pitch-up on takeoff, but when the ship was ready to fly, it really wanted to fly. I needed a much bigger push than expected to keep from ballooning above the tow plane. After talking to a club member who watched the takeoff (you get used to the ever-present audience in a glider operation), the resulting pitch oscillation didn't look as dramatic as it felt. And the Cirrus is a bit more slippery than anything I've flown before; even a slight pitch change would cause it to speed up and slacken the tow rope. Once off tow, I raised the gear and got it to lock on the first try. It was much easier to operate in the air than on the ground.

The Cirrus flies beautifully; it is quiet and graceful. It climbed in weak thermals even better than the Schweizer 1-36 that I thought was unbeatable on a weak thermal day. At the minimum sink speed of 39 knots in reasonably still air, I had to tap the altimeter to make sure it wasn't stuck. At the maximum glide speed of 46 knots, I was still compelled to tap the altimeter in disbelief. The performance is a noticeable step above anything I'd flown before.

I lucked into a thermal that punched through the inversion that capped off the lift and it carried the glider to about 5,300 feet MSL. After fooling around for a little more than an hour, I decided to land because I had forgotten water and wanted to be sharp for the first landing. I circled lazily in the predictable sink northwest of the airport to get down, and extended the landing gear at about 2,000 feet AGL to make sure that I could get it locked. I checked the gear at least 5 more times before committing to landing.

The windsock didn't tell the whole story and the quartering tailwind for runway 28 was stronger aloft than I had anticipated. The wind had slackened and reversed around noon. It is an ordeal for the glider operation to change runway ends, but we will do that if a tailwind becomes unacceptable. These wind conditions were tolerable, and I usually prefer to land with a bit of a tailwind than to land against traffic.

As I watched my aim point on final approach begin to slide beneath the nose with the dive brakes completely extended, I took a moment to see how well the Cirrus slipped (I wasn't prepared to use the European dive-bomb-with-airbrakes technique on this flight). I resigned to landing a bit long and focused on getting it straight and on the runway centerline. I was pretty happy with the touchdown, but I couldn't get it stopped until 100 feet beyond the usual midfield taxiway intersection. That bummed me out until I watched someone do the exact same thing a few minutes later.

Disassembly took about four times longer than it should. It is one thing to watch and help someone do it, but quite another to do it yourself for the first time. I wanted to be sure that nothing got dinged in the process and solicited help.

06 March 2012

Aerobatic Lesson 2: Loops, Slow Rolls, and Half Cuban 8's

I'm surprised the instructor didn't get sick during Sunday's lesson with all of the side slipping that went on while I tried to get the inverted-to-knife-edge part of the slow roll down. I'd feed in way too much top rudder then release some of the aileron in the process. And my timing was way off. He said he'd get a good blast of cold air during those moments to add to the tail wagging. He sits behind the center of gravity, so that feeling caused by poor coordination is more pronounced. I felt a touch nauseous once we were back on the ground, no doubt due to that ham-handed display of airmanship.

Though I am currently butchering the maneuvers, it is so much fun. I look forward to each lesson all week long. The instructor is awesome. If everyone had the opportunity to fly aerobatics, there would be no drug problem in this country.

And it isn't all bad: my loops were more round with mostly the right amount float over the top. I need to start getting the elevator back in a bit quicker on the way down, though. I felt more accustomed to the strange attitudes this time. Yeah, that last half of the slow roll needs work, but I'm going to chair fly them this week and it will click next time.

I learned the half cuban eight, which is 5/8 of a loop followed by a half roll from inverted on a 45 degree down line. This maneuver teaches proper recovery from a nose-low inverted attitude. The roll on the line requires more subtle elevator input than the level slow roll and just a slight bit of rudder. Smooth and subtle on the controls, I am not; I'd put in way too much of both and not enough aileron. I need to focus more on the visual reference to hold the line rather than thinking about what I should be doing. It will click next lesson. I'll get it.   

I'm not going to describe the landing. Not my best.   

05 March 2012

Petersburg (W99) Wave Camp

I spent last week at Grant County Airport (W99) in Petersburg, West Virginia for Wave Camp. I was fortunate to get instruction and some experience soaring in mountain wave lift as well as the opportunity to fly in winds and turbulence outside my comfort zone. Last Thursday afternoon, we managed to climb to almost 23,000 feet MSL in the club's ASK-21 sailplane.

The aerotows through rotor turbulence were the roughest I've experienced in my brief soaring career. The character of the turbulence changed from day to day: on Saturday, we plowed into bumps with significant g-loads (peak +3.8 and -3.5g if I believe the g-meter), while on Thursday the jolts packed less punch (maybe +/- 2.5g) but they were constant and had more rolling moment as the towpilot flew up the valley in an attempt to escape the massive sink. We were flying in a washing machine. I have never seen a towplane jerk around like that. Slack line was unavoidable and control inputs to the stops were frequently required. It was good to see just how strong these gliders are.

Once we entered the laminar wave lift, the ride was perfectly smooth and quiet. The wave steadily carried the ship up though 18,000 feet and we reset our altimeters to 29.92 inHg as we entered Class A airspace. I fished my cell phone from my pocket and used XCSoar to ensure that the sailplane remained within the window defined in the waiver with Washington Center. The view was like that from a seat on an airliner. The ridges below lost some of their significance; the terrain appeared more model-like than real.

The lift was 500 ft/min at times, and in a few minutes we approached the top of the window at 23,000 feet. Still in about 2 knots of lift, only airspace limitations kept us from climbing further. Just below the ceiling I pulled the air brakes, maintaining a descent of 800-1000 feet/minute. Descending any faster would risk thermally shocking the cold-soaked glider as the air temperature warms at about 2 degrees Celsius every thousand feet.

This was my first time breathing oxygen in the cockpit. The club's Mountain High distribution system began dispensing puffs into the mask at a pressure altitude of 11,000 feet and worked flawlessly.

Solar heating in the cockpit kept me comfortable with just a few layers on. I didn't need my hat or gloves. My feet, however, were beginning to go numb by the end of the flight despite wearing insulated boots, two pairs of socks, and toe warmers.

I would never have attempted a flight like this without a skilled instructor in the back seat. My policy is not to list names on this blog, but I am grateful for the soaring knowledge that was shared with me all week.

I camped north of the runway, sleeping in my car. Though the temperature was in the twenties a few nights, I was comfortable. The pavilion (far left in the photo) had heated restrooms, hot water, and electricity. That's luxury camping to me.    

This was the first gathering of glider pilots that I've attended. There was lots of camaraderie and I learned something from everyone. What a great week!