I read with interest Colleen Mondor’s “Moose Stalls” piece in the May issue. As a pilot who avoids both scouting for moose and low-altitude turns, I wonder if there’s another factor. At low altitude, a pilot likely subconsciously perceives the greater relative motion of the aircraft over the ground as greater airspeed, perhaps leading the pilot to think she/he has a greater cushion above stall speed than actual. This, coupled with a ham-handed turn, complete with crossed controls while trying to keep a spot on the ground in sight, adds up to trouble.
Drake Hokanson – La Crosse, Wis.
PS: Aviation Safety is the first thing I read each month among several aviation and other magazines. Thanks for the important good work.
Good point, Drake, and thanks for the kudos!
CIRCLING TECHNIQUE
It was delightful to see Ryan Motte’s thorough article on the circling approach (“The Lost Art Of Circling,” June 2021). It contained everything except the actual technique of flying such an approach.
A couple of decades ago, a guy who began his career flying DC-3s into small airports in the Midwest with North Central Airlines taught me a foolproof technique: In this, assume that the cloud bases are right at the minimum altitude and that it’s night, and there’s some breeze—the most challenging situation.
1: Fly the approach, establish visual contact with the airport, choose the landing runway and establish downwind to the optimum runway at the minimum circling altitude (usually in a left-hand pattern).
2: When abreast of the touchdown point, note the time and heading.
Stay on the gauges at a constant altitude—this is important, as craning our neck around to keep the airport and runway in sight can cause disorientation (vertigo) and, due to the “hand-follows-gaze” phenomenon, may disrupt coordinated flight unconsciously. It’s not necessary to keep the airport constantly in view because, as my friend says, it’s not going to go anywhere. Meanwhile:
3: Fly the current downwind heading for 20-30 seconds (depending on aircraft speed) to stay within the altitude-protected circle as depicted on the approach plate.
4: Begin a standard-rate turn, on the gauges, until within 45 degrees of the landing runway.
5: Then come off the gauges, re-establish visual contact with the runway, and adjust direction, speed and configuration for final approach.
6: If the ceiling decreases and visual contact with the ground is lost, fly the miss for the approach, which may require a turn not depicted on the plate (which presumes a straight-in approach), in order to fly the designated course for the miss.
This technique is easy for the fatigued pilot, remains within the safe limits established by the survey and approach designer, and brings one very close to the runway centerline.
Best wishes,
Daniel L Johnson – Via email
Thanks, Daniel. We’ll schedule an article exploring circling technique in greater detail for a future issue.
PITCH TRIM RUNWAY
Pitch trim runaway (Accident Probe, June 2021) is one of those scenarios that has always made me a bit uneasy. My old T182T had a manual pitch trim wheel and electric trim. My Pipistrel Virus SW and Lancair ES-P do not. They also lack the dual contact trim switch of the 182. I’ve accepted that pitch trim runaway is a moderate risk. I’ve often thought it would be a good idea to try flying both airplanes up to their full trim stops in landing and go-around flight envelopes just to better understand what I would face if it happened. Never did that.
A few weeks back, I retrieved my Lancair ES-P back from a G3X avionics upgrade including an autopilot upgrade. The plane had been down seven months, but I had been flying regularly in the Pipistrel. I considered grabbing my CFI for the short return flight but did not.
I spent about 1.5 hours going over the aircraft. I found a few small squawks which were quickly fixed. I noted trim tab positions during my walk-around and when I powered up the plane, tweaked trims a small amount to center on the G3X. After a few high-speed taxi runs and another brief inspection, I was ready for my test flight. I planned to circle to 2500 feet agl above the airport and, if everything looked good, head back to my home airport about 10 nm away. Shortly after takeoff in my initial climb, I dialed in some nose-up trim to steepen my climb angle. Nothing was happening. I let the trim switch go, and then pulled on it again. Not relieving control pressure. Kept pulling on the trim and it just got worse. At about 250 feet agl, first time in-type in seven months, I realized I had a bit of a problem.
I figured I had runaway trim and I knew that it was already way too late to be reaching over and trying to pull a fuse (which would have increased my chance for loss of control by about 10x). The plane was controllable. Although two hands on the side stick was more comfortable than one, I could fly the plane with one hand. I decided to do as normal a pattern as I could. Fortunately, there was no other traffic in the pattern. Getting into a descent and slowing relieved some stick pressure, and I was able to get the plane on the runway without any additional drama.
I learned a few things here. First, pay very close attention to trim and autopilot function and particularly direction, after any wiring work to those items. Think about how the control and trim surfaces work (elevator trim surfaces move opposite of control surface directions, stabilator trim moves with it). Although an autopilot commanding a roll in the wrong direction would be alarming, we have a control stick to override it (we did that in our preflight checklist) and the disconnect is just below my thumb.
In my case, the avionics guy wired pitch and rudder trim backward (up was down, left was right). So when I though I was commanding pitch up, I kept commanding pitch down. During preflight, I adjusted trim to the center position on the new G3X but I did not pay attention to which way I was moving the switches.
Second, at least with the planes I have flown, pitch trim moves fast enough that you are not likely to be able to pull the trim fuse much before full trim is commanded. If you have a manual control wheel, it’s definitely worth doing once the aircraft is stable. Not something to rush or worth jeopardizing control of the airplane to stop from going too far.
Third, practice flying with full trim in each axis, at a safe altitude and with a CFI. Way better to know what you are getting into if an emergency were to unfold.
Al Youngwerth – Via email
