Wednesday, June 25, 2014

Voices in the Ether

We are in a karmic retribution phase here in Central Ohio, at least when it comes to nice flying weather. I would have to be churlish indeed to cast aspersions at the season that gifted us with such nice weather only a week and a half ago, but, well, it is what it is. The weather, while not completely impossible to deal with, has been uncharacteristically muggy and uncomfortable. Or at least it has seemed that way every time I have had the opportunity to fly, those events having been admittedly curtailed to a large degree by the fluctuating moods and energy levels I am prone to during the seemingly interminable work week.

It having been at least two weeks if not longer since Jeff's last "lesson," an opportunity arose for a short flight Sunday morning. The mission was to deliver a pillow (well, not just A pillow, but THE pillow) to Co-pilot Egg, who had forgotten to take it with her on her semi-weekly trip back to her at-school home in Lancaster.

It truly was a short flight - it's only a fifteen minuet flight - but it would still be of some utility to Jeff who, having not flown for awhile, would benefit from a refresher in standard practices. This need was proven by the relative difficulty he had in getting his seatbelts fastened.  While that sounds like a trivial thing to get tangled up over, it really isn't, at least until you have done it a few hundred times and run across every little thing that you can get wrong. The most common error, and the one that Jeff tripped over, is to not lay out the shoulder straps before climbing into the plane to ensure that they don't get crossed over left-to-right. If that happens, and it is terribly easy to do once you're sitting in the plane and have limited rotational flexibility, everything will seem normal except for the fact that the slotted ends of the should straps will not fit correctly into the lab of the left belt strap.

Engine start and taxi went well enough and we were soon climbing into a clear morning sky, with a great contrast between the June green flora and the cerulean morning sky. The downtown Columbus skyline, such as it is, stood out quite well. As I am confident in Jeff's ability to climb us out and turn us on course, I was able to grab my camera to get a great morning shot.  Alas, I had failed to retrieve the memory card from my PC - there would be no pictures today, at least not of any higher quality than that available from my cell phone.  The moment was long past before I could retrieve and ready said phone, so... no picture.

I had Jeff route us around the Class D airspace around Rickenbacker even though we probably could have climbed to a high enough altitude to just go over it in order to give us a little more flying time. He would need a few minutes to regain his straight and level mojo, but once he seemed comfortable again I wanted to start moving away from that kind of simple flying and into the more advanced maneuvering stuff that comprises the majority of the airwork in the training regimen. I had introduced him to the subject of stalls early in our flying, my thought being that he will have learned about them in his training videos and that some people get nervous and obsess about them. Having ridden through a couple, I thought, it would be less stressful for him when it came time for him to perform them himself. The precursor to stalls, though, is slow flight.

Slow flight is a flight mode in which the plane is slowed to just above stall speed and the student has to maintain both that slow speed and the target altitude. At speeds that close to the actual stall, the primary control for maintaining altitude becomes the throttle. Having heard the analogy of the throttle being similar to the gas pedal in a car enough times, it is possible that the student will always equate the throttle with being the thing to use to manage airspeed.  The actuality is that it is a little more complicated than that. While many texts insist that the elevator controls airspeed and the throttle controls altitude (which is starkly counter-intuitive to people used to thinking in only two dimensions), that too is not entirely correct and is an over-simplification. The reality is that there is a sliding scale of contribution of both controls to both flight aspects. In slow flight, the slider is very close to the "throttle = altitude, elevator = airspeed" school of thought, but still not entirely. In any event, slow flight teaches the student how to safely manage the flight of an airplane that is at or near a boundary condition, that condition in this case being an aerodynamic stall.

At the risk of (further) boring you, here is a description lifted from the FAA guide:
The maintenance of lift and control of an airplane in
flight requires a certain minimum airspeed. This
critical airspeed depends on certain factors, such as
gross weight, load factors, and existing density altitude.
The minimum speed below which further controlled
flight is impossible is called the stalling speed. An
important feature of pilot training is the development
of the ability to estimate the margin of safety above the
stalling speed. Also, the ability to determine the
characteristic responses of any airplane at different
airspeeds is of great importance to the pilot. The
student pilot, therefore, must develop this awareness in
order to safely avoid stalls and to operate an airplane
correctly and safely at slow airspeeds. 
Slow flight could be thought of, by some, as a speed
that is less than cruise. In pilot training and testing,
however, slow flight is broken down into two distinct
elements: (1) the establishment, maintenance of, and
maneuvering of the airplane at airspeeds and in
configurations appropriate to takeoffs, climbs,
descents, landing approaches and go-arounds, and, (2)
maneuvering at the slowest airspeed at which the
airplane is capable of maintaining controlled flight
without indications of a stall—usually 3 to 5 knots
above stalling speed. 
Maneuvering during slow flight demonstrates the flight
characteristics and degree of controllability of an
airplane at less than cruise speeds. The ability to
determine the characteristic control responses at the
lower airspeeds appropriate to takeoffs, departures,
and landing approaches is a critical factor in
stall awareness. 
As airspeed decreases, control effectiveness decreases
disproportionately. For instance, there may be a certain
loss of effectiveness when the airspeed is reduced from
30 to 20 m.p.h. above the stalling speed, but there will
normally be a much greater loss as the airspeed is
further reduced to 10 m.p.h. above stalling. The
objective of maneuvering during slow flight is to
develop the pilot’s sense of feel and ability to use the
controls correctly, and to improve proficiency in
performing maneuvers that require slow airspeeds.
Maneuvering during slow flight should be performed
using both instrument indications and outside visual
reference. Slow flight should be practiced from straight
glides, straight-and-level flight, and from medium
banked gliding and level flight turns. Slow flight at
approach speeds should include slowing the airplane
smoothly and promptly from cruising to approach
speeds without changes in altitude or heading, and
determining and using appropriate power and trim
settings. Slow flight at approach speed should also
include configuration changes, such as landing gear
and flaps, while maintaining heading and altitude. 

This maneuver demonstrates the flight characteristics
and degree of controllability of the airplane at its
minimum flying speed. By definition, the term “flight
at minimum controllable airspeed” means a speed at
which any further increase in angle of attack or load
factor, or reduction in power will cause an immediate
stall. Instruction in flight at minimum controllable
airspeed should be introduced at reduced power
settings, with the airspeed sufficiently above the stall to
permit maneuvering, but close enough to the stall to
sense the characteristics of flight at very low
airspeed—which are sloppy controls, ragged response
to control inputs, and difficulty maintaining altitude.
Maneuvering at minimum controllable airspeed should
be performed using both instrument indications and
outside visual reference. It is important that pilots form
the habit of frequent reference to the flight instruments,
especially the airspeed indicator, while flying at very
low airspeeds. However, a “feel” for the airplane at
very low airspeeds must be developed to avoid
inadvertent stalls and to operate the airplane
with precision.
In you didn't read all of that, the FAA also points out that learning to fly at slower than normal speeds is also a requisite for learning to takeoff and land the airplane.

We spend about five minutes at it. The short span was because 1) I really just wanted to introduce Jeff to the concept so he could reflect on it prior to our next flight, 2) I don't like doing it in the RV-12 because a small (but not indiscernible) amount of exhaust creeps into the cockpit, and 3) we had an appointment with Co-pilot Egg.

With the radio tuned to the destination Unicom, I could tell that our arrival would be to a relatively busy airport. I narrate what I learn from listening to the chatter in the hopes that Jeff will start to learn how to build a mental picture of what's going on at the destination long before we get there, one of my pet peeves being arrivals that barge into the pattern with no clue as to the current situation and then simply demand "an advisory" to make up for their own shortfall. We had already consulted the automated weather observation and learned that the winds were light out of the east. That indicated a landing on runway 10, but by monitoring the Unicom we learned that there was a helicopter flying right traffic touch and goes to runway 28, apparently willing to accept a slight downwind on landing. I guess I would be fine with that too if my touchdown speed was the same as theirs, which is to say zero knots.

Another arrival, this one a Cessna, also was setting up for a 28 arrival, possibly due to having to work his way around the helicopter. There were also jump planes jumping up and down to drop parachutists into the mix. I keyed the mic and reported our position as seven miles west, inbound for left traffic, runway 28.  A brief pause, then something unusual came back in reply:

"Experimental two eight four delta golf?"

I replied back in confirmation of that being our tail number.

"Hi Daddy!"

Ah, so our appointment would be on time. I replied back with a quick "Hi, Egg."

 the Cessna had landed by the time we, but the helicopter was still parked on the runway.  He finally flew off as we made our turn from left base to final.  The wind was definitely noticeable on our tail as we came down the final approach, but not too much to really matter. The landing was fine and we were able to make the midfield turnoff.  Egg met us at the plane.

Egg had been talking to the local airport mavens and had learned of a small museum on the airport premises. We decided to take a look, and having loaded up into her tiny little car, would also head into town for brunch. The museum was nearly as small as her car, but what was lacking in quantity was offset by variety. I would share some pictures, but the cell phone only manage to capture two before some unreported malfunction caused all of the others to just be black rectangles.  It was a bad day for photo-journalism.

This is a Folland Gnat Mk 1:

Jeff had expressed an interest in buying a kayak, so despite knowing that it would cause a flood of puerile jokes from Egg, I suggested that we follow up our brunch with a visit at the nearby Dick's Sporting Goods. After that, it was back to the airport for the short flight back to Bolton.

Monitoring the tower frequency, it seemed that there two Cessnas in the pattern doing touch and goes, and that the active runway had changed from our calm-air departure on runway 4 to a six knot wind favoring runway 22. Coming from the east, I had figured on being given either a midfield left downwind for 22 as the least likely possibility, and a left base entry for 22 as the most likely. What I failed to consider was that our diversion to the south to get around Rickenbacker would actually put us southeast of the airport, where an entry into the left downwind would be the most expedient course. Having misreported our position, we were given the expected entry into the left base, but we were in actuality far south of a location from which that would easily work. I took over the controls and headed north while still well outside of the tower's area of concern.

Knowing we were going to be trying to fit into the pattern soon, he directed one of the touch and goes to make right traffic, thus clearing a path for us to follow the other Cessna, he being already at midfield left downwind. The tower was going to be expecting us to fit in between the two Cessnas. To make that match work, I needed to get in place quickly, so I stoked the furnace back up to full steam. It all turned out fine; we followed the first Cessna, the second was instructed to extend his left downwind until the tower cleared him to turn base, and I made an expeditious approach by keeping our speed up well into the base leg, then landing precisely far enough down the runway to allow for a very efficient clearing of the runway at the first usable taxiway.  It ended up being somewhat more efficient than the tower had expected - there was a pretty big gap between our clearing the runway and the second Cessna landing.

Still, it was a very good example of monitoring the airwaves, determining how events are likely to turn out, and the utility of being able to manage the approach and touchdown point to suit the current needs.

That said, it was not a good example of accuracy in position reporting.

No comments:

Post a Comment