IFR Diary, Day 6: Thursday, Sept 2
Party Hats All Around
The first few minutes of today's ground instruction consisted of a
review of the previous Friday's brief session on basics
aerodynamics. "What does trim establish?" he asked, cutting to the
chase. "Airspeed," I said mockingly, recalling his histrionics on
Friday when I had answered "attitude."
On that Friday he had lectured pragmatically, "Look, I don't want to
debate this. For purposes of flying an approach, you need to
remember only one fact: when an airplane is trimmed for a given
airspeed, it will try to maintain that airspeed when the power
setting changes." He paused to allow me to digest his last
statement, but did not invite a response. "This behavior means that
you don't have to worry about the airspeed during the descent.
Better, it means that you can adjust your rate of descent entirely
with small power changes." I decided that I sort of knew this
already, but had never thought of it quite like that. "So at the
final approach fix, you should be trimmed for your approach
airspeed, then reduce power to begin descent. After that, whatever
you do, don't touch up the trim."
On our first flights, we had calibrated the Tiger. The most
important calibration is the "approach configuration," the
power/flap combination that produces 90 knots in straight and level
flight. On the Tiger, this is one-third flaps and about 2000 RPM.
Reducing to about 1850 rpm produces a descent of about 475 feet per
minute, just right for the ILS. A setting of 1400 rpm gives a
descent rate of about 1500 feet per minute, a rate suitable for the
step-downs in a majority of non-precision approaches. For reasons
that were not clear until later, we also calibrated the Tiger for an
approach configuration of 130 knots.
Now, back to today's story. "OK. Now that you've flown a few ILSs
and are comfortable with the pace of action, I want to discuss the
most critical time on an ILS approach: the first thirty seconds
after glide-slope intercept. Let's assume that you're flapped and
trimmed for approach speed and are flying straight and level. The
glide slope begins to come in and you...what?" Charles has a way of
turning declarative sentences into interrogative ones by
unexpectedly replacing the final word with a relative pronoun. This
pedagogical technique is a little disconcerting at first, but with
practice I learned to tell when he was expecting an answer and when
he was asking a rhetorical question.
Without a moment's hesitation I answered, "When the needle centers,
I reduce to descent power and push the nose over three degrees." He
rejoined, "On most GA aircraft it is not necessary to push the nose
over, just let the airplane reach its descent rate in its own good
time."
"In most planes, if you're in approach configuration, pulling the
power at or a half-dot before glide slope intercept will get you
into the slot just above the slide slope. It's psychologically more
comfortable to be a dot or so above the glide slope than below it.
This takes the pressure off...there's a natural tendency to over-
control a bit as soon as you drop below glide slope."
"There's another reason for using this technique--you sort of plan
to stay a bit high so you can ignore the glide slope for a few
seconds. Have you noticed that you lose heading in the first few
seconds after starting down?" I nodded affirmatively. "Why do you
suppose this is?" I shrugged stupidly. He could see that I was
getting a bit bored with his Socrates act. He gave it one more try,
"Well, here's a clue: you always lose the heading to the left.
Why?"
I knew the answer. "Because when the nose drops, the plane yaws
slightly to the right. P-factor." Excellent," said Charles. I was
a little exasperated. "Come on, Charles, I'm barely able to keep
the plane heading in the right direction and you're trying to get me
to compensate for a half a ball of yaw?"
He laughed. "There's more to this than you think. Part of IFR flying
is knowing which things are most important at any given time. For
example, the three most important things on an approach are heading,
heading, and heading. Well, your heading is at greatest risk just
as you pull power and start down. My solution? Pull back to descent
power, then forget about it for five seconds or so while you nail
the wings absolutely level and keep the ball centered. This allows
you to get the heading stabilized before the localizer starts
getting sensitive. You should also do this when you enter a cloud
layer and your heading is at risk because of the buffeting."
This was the second time I had been instructed to abandon my scan
and concentrate on binding several operations into a single atomic
act. He could see this was troubling. "I know that after being told
to keep your scan going, you're finding it creepy to be told to
suspend it, even for a few seconds." He had this uncanny way of
being just an answer ahead of my question.
"One of the reasons you get overloaded is that you assign an equal
importance to all tasks. But you know that it's not true. If you
learn what things are most important when, you'll always be focusing
most of your mental capacity on the things most affecting the
outcome of the approach."
"The gottcha is that you've got to have common aviation sense. I'm
telling you that you can ignore descent rate for the first few
seconds on the glide slope in order to establish a rock-solid
heading reference. The laws of physics tell you that your airplane
is going to be in the ballpark. But you must have sense enough not
to ignore both heading and descent rate for 20 seconds while you,
say, set up a VOR for the missed approach. I don't expect you to
make these decisions today or even next week, but as you gain some
experience, I want you to know that it's OK to prioritize--but use
your head."
I nodded. "Let's go fly," said Charles. We launched at about
8:15.
Before leaving home, I had used DUATS to file a flight plan to
Sonoma County Airport in Santa Rosa Ca, about a 45 minute flight.
Santa Rosa is in the Sonoma Valley, one valley over from the Napa
Valley. Today we got there just before the stratus burned off. ATIS
was calling ceilings of 400 feet, but departing pilots were
reporting breaks in the overcast a few miles north.
Cleared for the ILS RWY 32, at glide slope I pulled power to 1850
and then concentrated on heading and centering the ball. Sure
enough, I had half a ball to the left. I stepped on the ball and
noticed that even in that short time I had drifted a few degrees
off. I made an atomic tracking turn to 321 degrees, and rechecked
wings level. The outer marker went off. I glanced at the VSI which
showed only about 350 ft per minute, then to the tachometer, which
had crept back up to 1900 rpm. I set it back 1850. Only now did I
check the glide slope. Sure enough--I'm not quite two dots above
it.
Just out of curiosity, I decided to check my timer to see how long
all this had taken. Damn! I'd forgotten to start the timer again.
No need to panic--the MAP is at the middle marker. I started the
timer. Better late than never. I estimated I was 20 seconds inside
the marker, dead on course and with the descent rate under control.
This was going well.
At about one minute out the needles were both inside the doughnut. I
had never been this far ahead of the airplane. At 450 feet a change
in the light in the cockpit told me that we had broken out. I
started cheering, giving myself emotional high-fives, celebrating
like a teen-ager. "All right!"
Getting to look up and see the runway is the payoff, the orgasm. At
about 50 feet from DH, I queried excitedly, "Charles, can I look?"
Silence. The Middle Marker went off. "Charles?" Silence. By the
time reality put its foot down, I was 50 feet below DH.
MISSED APPROACH! ALL HANDS ON DECK! I got the Tiger climbing, got
the turn established, talked to tower, and, just as I got things
under control again, we bumped into what remained of the clouds.
"Now tell Center that we want the VOR/DME 14," Charles said. This
is a terminal approach--the transmitter is on the field. Center
quickly vectored me around for the approach. Now things went to hell
in a hand basket. Because of conflicting IFR traffic, the
controller vectored me very close to the final approach fix and kept
me 500 feet high. To compensate, I started down at very fast rate. I
was behind from the moment I was cleared, and stayed behind until a
pegged needle forced me to initiate a premature missed approach.
Along the way, I busted altitude on both step-down fixes.
I didn't know what had hit me. After I was correctly on my way to
the hold-after-missed, Charles asked, "Do you know why you fell so
far behind?" I nodded no. "Well, there are two reasons. First, you
still had on your party hat well into the VOR approach. You never
did get completely setup for the approach."
Party hat. Jeeze, what a mean bastard. A guy ought to be allowed to
celebrate his first really good approach. A rite of passage, that.
I thought this stuff, but didn't say it.
Charles started in a firm, but not unkind voice. "If you hadn't
been so busy patting yourself on the back and looking to me for
praise, you might also have noticed on your DME that the 5-knot
head wind you had landing on runway 32 is now a 15-knot tail wind on
14. The stratus is gone and now the wind is up." Let's land and
talk about this. We circled to land, shut down the engine in the
run-up area, and debriefed.
Aside from never really getting on course, death in the VOR approach
had also taken the form of busting the altitudes. In trying to get
down fast, I would shoot through them. Charles offered, "What are
the three most important things on an approach?" I recited heading,
heading, and heading. "Well, you didn't fly it that way. Your
heading slipped because you what?" The statement was a rhetorical
question. "Because you became preoccupied with distance. With the
power back as far as you had it, you had almost a full ball of yaw,
which you repeatedly allowed to drag you off heading. As we got
closer to the VOR and it got more sensitive, you started chasing
needles."
"Now," he began more cheerfully, "You had three balls in the air--
heading, altitude, and distance--and you were treating them with
equal importance." I wondered if our conversation this morning about
priorities and common sense had been a setup for this.
"Let me simplify the altitude step-down problem: while stepping
down, monitor the DG and the altimeter, and ignore the DME." I
should have seen this coming. "When the altimeter gets to the
desired altitude, just level off. When you're certain that you're
not going to bust the altitude, then, and only then, look at the
DME. Just ask yourself, 'Can I descend further?' If the answer is
yes, start on down; if no, just wait."
He got his wide-eyed, self-satisfied look. "Don't make this a mental
exercise." But I had to protest. "But if I'm already at the step-
down fix, leveling off will just put me behind for the next one."
It seemed like an intelligent observation when I said it. "So what?
The time penalty for leveling off is small--maybe 10-seconds. In
real life you needn't worry about being behind the step-down fixes
until you reach the MAP anyway. Unless you're WAY behind, chances
are you'll break out, and it won't matter; just be ready to land. If
you don't break out, you'll just have to try the approach again. The
second time around, you'll have to get down faster, reduce your
ground-speed, or both. Keep in mind, though, that your troubles
began when you didn't notice the 15-knot difference between your
ground speed and air speed. If you had slowed to 75-knots air
speed, you wouldn't have had to dive for the altitudes." He then
grinned mischievously at me and said, "If you hadn't pegged the
heading."
Out of Santa Rosa we flew a SID whose transition (legend has it) is
over Charles Schultz's house. The name of the intersection is SNUPY.
We then headed North for Lampson, a rural airport set in a caldera-
like valley near a beautiful lake with the unimaginative name, Clear
Lake. Its only feeder route is a radial off the Mendocino VOR 18
miles to the West.
On the way to the Mendocino VOR, Charles asked Oakland Center, "Sir,
we'd like the NDB at Lampson. And when we get to the VOR, would you
please make up a realistic-sounding hold for my student. We'll stay
in VFR conditions all the way." The controller sounded a bit shocked
at being thus invited out to play, but then agreed.
At about 5 miles out, the controller gave me a pedestrian hold
requiring a direct entry. Once in it, Charles asked, "What's the
maximum holding speed for a propeller aircraft?" I usually don't
clutter my mind with facts like this, but for some reason I
remembered the answer. "I think it's 175 knots, why?"
"Slow down to 65 or 70 knots. Why work yourself to death?" I
throttled back and settled in at 70. "Now, how far can an airplane
fly at 175 knots in one minute." Teaching electronics has made me
quick at guestimational arithmetic, so I replied instantly "A little
less than three miles." He acted surprised at my speed, "Excellent.
So ask the controller for three mile legs." I complied. Without
hesitation the controller came back, "Three-mile legs approved.
Five mile legs also approved."
"Now this becomes a much simpler ball game, doesn't it? This means
that you can ignore time and just fly distance. The controller
doesn't care how long a leg takes--he just wants you within
protected airspace."
He paused, then asked, "If you didn't have DME, what would you do?"
I replied, "I'd still have to fly time, but my inbound time would
be the time required to fly five miles at 70 knots...four minutes
and change." I detected a grin in his voice when he said, "OK. Tell
Center we're ready for Lampson."
At the NDB approach at Lampson, I was again guilty of not studying
the approach plate, which contained lots of new things on it: the
initial approach fix is defined by the VOR radial and a bearing from
the NDB, and the approach requires a procedure turn. It is a
terminal approach, the NDB is the MAP. Plain and simple, I blew
this one.
We landed, debriefed over lunch, kicked some tires at a near-by
Mooney store, then Charles said, "Let's finish up at Stockton. Out
of here, fly the departure procedure and see if you can get us a pop-
up IFR clearance to Stockton."
I contacted Oakland Center and requested IFR to Stockton, confessing
sheepishly that we had not pre-filed. The controller seemed very
annoyed. Charles said, "Uh oh, you're in trouble now. You just
asked him to put down his doughnut. Popping up for an approach is
one thing, getting an enroute clearance is another."
The Center came back, "Grumman 74613 unable IFR to Stockton at this
time." It was not the same voice that earlier had cooperated by
issuing the surprise hold.
"Beg," Charles told me. I couldn't believe my ears, "Do what?"
"Beg. Try to cut a deal with him. First try sympathy--tell him this
is a training flight. If that doesn't work, tell him you'll accept
VFR-on-top."
"Charles!" I sounded like a mortified school girl.
Things got worse. "If he won't buy that, call him again in three
minutes with the same request. He'll either tell you not to call
back for a long time, or he'll cave in. If he stiffs you, go to
work on the controller in the next sector."
"Hey, I know this is humiliating, but sometimes you gotta do what
you gotta do to get a clearance. There's nothing in the regs
against begging and nagging--just don't lie and don't fake an
emergency or urgency situation. Besides", he said with obvious
pleasure, "on a clear day like today there ain't much traffic in
this sector, and he ain't got nothin' better to do."
I was a bit scandalized. But what the hell. Using my most ingenuous
'gee-whiz, Mister Controller" tone, I told him that I needed this
clearance for 'important' training. He acquiesced, and judging from
the clearance he gave me, he figured if it was so important, it
ought also to be educational. I expected a clearance comprising
maybe two VOR-directs. Instead I got six Victor airways with
several altitude changes.
He was right--it was good training. And I flew it well, maintaining
altitude and heading, and making all the airways. After an NDB and
ILS at Stockton, and a VOR at nearby Tracy, we headed back to
Hayward.
This the fifth day was the longest and most grueling day I would
spend. It had cuffed me around as usual, but more important, it had
tossed me a crumb or two from the table of success. I enjoyed the
taste.
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