R.B. Aviation

January 17, 2016 -- Cold and lower visibility operations with ground reference and wind correction manuevers


     During this flight, we maneuvered around 4M7 and the city of Russellville, circling the bypass both clockwise and counterclockwise at 2500 ft, then returning to the airport for two full-stop landings – all with the added challenge of a 12-14 knot crosswind component. I tuned the radio scanner at my house to 122.7 mHz before I left, and, prior to getting the airplane, the instructor and I discussed the student-built Stratux ADS-B receiver and the effects of the cold wind on our flight.

     That frigid and windy weather produced several challenges to our flight. The 172’s carbureted engine was difficult to start, needing priming, several seconds of cranking, and eventually leaning during flight. The low temperatures likely also contributed to certain plastic items becoming brittle, while the north (330) wind drove the wind chill temperatures down as it brought in rather ominous gray clouds.

     Once the instructor managed to get the engine started, we taxied down the taxiway to the end of runway 24, checking the windsock along the way and making radio calls as necessary. During the pre-takeoff checklist at the hold-short line, the instructor taught me a visual flow, similar to the pattern of Catholic blessings: start with the top (main six) instruments; move down to the left to check the circuit breakers, switches, and engine instruments; move to the right to examine the radio stack (on, correct frequencies, etc.); and end at bottom center with the fuel selector and elevator trim. I used the landing lights for takeoff and landing, and left the navigation, anticollision, and strobe lights on for the flight.

     Takeoff was fairly normal, though a crab angle needed to be held to keep the airplane tracking straight down the runway. The aircraft seemed to climb better than it does in summer, and, as we climbed to pattern altitude (1700 ft MSL), I turned off the landing lights. Once at pattern altitude, I turned transitioned to a climbing turn towards Walmart at 2500 ft MSL. The building was difficult to see until I started looking for the familiar massive parking lot, as the instructor pointed out West 9th street and other landmarks on the ground. I then began to circle the bypass girding the city, staying on the inside and adjusting the wind correction angle so as to maintain a consistent distance from the road. As I flew the pattern, the instructor had me change direction and follow both sides so as to better understand how to continually correct for drift, and to develop a better sense of direction in relation to local landmarks like downtown Russellville.

     As I flew the hold, the instructor connected his Foreflight-equipped iPad to the Stratux ADS-B receiver. Evidently, it was able to connect to a tower and receive weather data from another town, though no traffic appeared. This was probably due to the fact that there was only one SDR in use at the time with the Raspberry Pi board. Either way, it was interesting to compare the performance of the instructor’s Stratus and my home-brewed device.

     The pattern around the town involved continual adjustments so as to avoid sliding off course. We flew over Russellville High School, and, after we sighted the 1200 ft MSL radio tower across from Walmart, I noted my house on the ground.  I was told to maintain 2500 ft MSL, but I varied in altitude as much as 100 ft, depending on how much I was looking at the ground. Midway through this ground reference maneuver, I turned us to the right, flew to either side of the bypass in two circuits, then turned around over the southern end of town and flew the counterclockwise. I saw more landmarks each time, and gradually recognized the sprawling, road-spoked land below that I had seen in maps of the city, as well as on very similar missions in flight simulators. We turned back to the airfield after confirming operation of the Stratux, and the instructor realized that we had been transmitting on the wrong frequency for some time. This was quickly corrected.

     I was told to find a road that ran southwest, as this would most likely be Franklin road or at the least parallel to it. By this time, the weather was deteriorating to the point where gray sky, gray ground, and gray roads became slightly difficult to distinguish. I actually followed Nashville road (running south) instead of Franklin road, but the instructor pointed out the airfield to me, and I turned towards it. I had visual contact, lost it, then found the runway again – I then decided not to take my eyes off of it. Had I not found the airport, I would have turned and flown back over Russellville, then got out my map and tried again.

     I called downwind using the call sign “Cessna Skyhawk”, and began reducing power. I used a few degrees of flaps to slow down, though because we were going to have to enter a substantial slip in order to make a straight approach. After I had turned the base and final legs, I made the appropriate radio calls, reducing power and descending in a slipping approach using the landing lights. The aircraft touched down on runway 24, and I began breaking to slow the airplane to a slow roll. Once this was accomplished, I taxied to the right of the runway, used full left rudder deflection, and tapped the left break to bring the airplane around. As we rolled onto the taxiway, I announced on the aircraft’s radio that “Cessna Skyhawk is clear of the runway, returning for takeoff, remaining in pattern. Russellville traffic.” As I did this, I managed to skid the airplane slightly because we was going too fast and making a sharp turn. The instructor promptly told me not to do this.

     Because it was parallel to the runway, the taxiway was also experiencing a 12-14 knot crosswind component. I held the yoke into the wind but did not find elevator useful at the angle; as we approached the threshold for runway 24, the instructor had me taxi out to the side of the taxiway so as to make a sharper turn into the wind for the before takeoff checklist. This consisted of confirming operation of the flight controls, “Blessing” the airplane’s instruments, and observing current weather and traffic conditions. After calling “Russellville traffic, Cessna Skyhawk taxiing onto runway 24, remain in pattern. Russellville traffic”, I turned onto the runway and immediately began to apply full throttle and right rudder. When the airspeed was alive and the engine instruments were within limits, I rotated and crabbed to the right. The goal was to climb out straight over the runway at a pitch attitude at which the top of the nose is level with the horizon, and I quickly learned that, in gusty conditions, crosswind correction is a continual process, not a fixed angle like it typically is in cross-country flight.

     I made the turn to crosswind at approximately 500 ft AGL, and was told to call the CTAF when you are on the leg – not as you are turning it. We climbed to 1000 ft AGL, though I began turning downwind earlier than usual because of the wind. I had to hold the airplane at a crab angle for a ground track straight to the runway, though this angle was less than was necessary for takeoff, as the airspeed was higher. At his point in the pattern, the instructor pulled the throttle out to simulate an engine failure.

     The first priority during an engine failure is to immediately establish the appropriate glide airspeed and attitude.  In this case, I was close to 4M7’s runway but 1000 ft above it, so I had to be careful in judging the approach so as to require as few adjustments as possible – a difficult proposition in high winds. The process is made easier by a turn, and so I continued to descend, but without flaps (they reduce the airplane’s overall lift-to-drag ratio and Cessna 172s aren’t supposed to slip with flaps extended). I did not realize it at first, but the airplane began to drift because the crab angle was insufficient for lower airspeeds. The instructor pointed this out to me, so I corrected to stay within range of the airport. After a gliding turn to left base, I made the appropriate radio call and began to judge the touchdown. Skids on the turn to final are dangerously close to spins, so I avoided the danger by making a shallow turn onto an imaginary line extending from the runway. The instructor helped me continually adjust for the gusting crosswind as the aircraft touched down on the right and then the left wheels. As we slowed down, I lowered the left wing but continued to hold the flight controls into the wind, ensuring that the aircraft was not blown off of the runway. I taxied us back to the ramp, at which point the instructor took the flight controls in order to safely park in front of the corporate hangar. We put the airplane back, waved to Steve Dillahay as he left, then went inside for debriefing.

     Inside the airport terminal, we discussed my performance and mistakes – namely, skidding the airplane around on the ground and failing to continually adjust correction angles. These problems mostly had to do with paying attention; a considerable portion of flight training addresses the multitasking involved with flying, speaking on the radio, navigating, taking notes, and more, all at the same time. The instructor informed me that the Stratux appeared to function and that we would fly again on “a warmer day in February”.