ASOS AND AWOS

ASOS AND AWOS
Technology has brought an enormous increase in the amount of information—especially weather information—at a pilot's fingertips. During the preflight briefing, you can study conditions at multiple reporting points, thanks to automated surface observation systems (ASOSs) and automated weather observation systems (AWOSs) at many airports. And those same systems are there to help you plan your arrival at many destinations. Include monitoring the station's report on your list of arrival duties before you contact the tower or request an airport advisory at nontowered airports.

"Each ASOS is equipped to transmit weather via voice or computer through telephone or on VHF radio frequencies," Use the Safety Advisor to learn the different service levels of the various ASOS installations—and consider the circumstances under which the information provided is susceptible to inaccuracy or error. You'll also see an explanation of the differences between ASOS and AWOS installations. ASOS is more sophisticated, uses more computer processing, and has better quality control. Note that if a component of an ASOS's weather reporting capabilities is not operating, a code to that effect will appear in its published METAR. For instance, the code TSNO indicates that thunderstorm information is not available—definitely worth knowing during your preflight briefing.

Want to start watching weather trends at a possible destination, or just curious about what's happening at your home airport? Visit this FAA's ASOS Web page to check conditions.

With ASOS information so easily obtainable in a preflight weather briefing by telephone or computer, and from the air by radio, there's no reason not to acquire the most timely reports, then update as you near your destination [see your VFR aeronautical chart, AOPA's Airport Directory, or the Airport/Facility Directory for the correct frequency].

SHARING YOUR AIRSPACE

You have learned the correct method for safely entering the traffic pattern at nontowered airports, and you've studied right-of-way rules that keep different categories of aircraft safely separate. (See the May 2, 2003, "Training Tips" on right-of-way rules.) Now you're ready to put these concepts to the test as you endeavor to operate safely in the presence of other airport users.

After you check airport publications for your destinations' radio frequencies, runway lengths and bearings, and facilities, be sure to look up what other kinds of air traffic might be present. "To airplane pilots, the ways of helicopters, gliders, and balloons seem mysterious. Knowing how they come and go helps you to coordinate your departures and arrivals with theirs. Being familiar with their operation is comforting when you scan for traffic because you know where to look for them.

Towplanes and gliders may use only the runway that is closest to the glider operation's base; you may need to use another because of reported surface winds. Large airplanes may use only the longer runways and fly a higher traffic pattern. Parachute jumping could be under way; what frequency is used to advise local aircraft about "jumpers away"? Helicopter pilots are responsible for avoiding the flow of fixed-wing aircraft, but keep an eye out for them in the pattern and while taxiing. Instrument approaches flown for practice by pilots training for the instrument rating could be in progress. These aircraft train with different arrival routes than aircraft making routine arrivals under visual flight rules. Ask your instructor to describe instrument training that could be in progress and what to listen for on the common traffic advisory frequency (CTAF). If there is a floatplane base on an adjacent body of water such as a river or lake, visualize its traffic pattern. Does the seaplane base use the same CTAF as the airport?

Experience will make these other kinds of aviation activity more familiar. Meanwhile, do your research and ask questions to fill in the gaps.

FLAPS: WHEN AND WHY

Most student pilots train in aircraft equipped with flaps. In the traffic pattern, the flaps are typically deployed gradually, starting abeam the runway numbers and ending with full deployment on final approach. Many students ask: Why not deploy the flaps all at once?

"Large flap deflections at one single point in the landing pattern produce large lift changes that require significant pitch and power changes in order to maintain airspeed and descent angle. Consequently, the deflection of flaps at certain points in the landing pattern has definite advantages. Incremental deflection of flaps on downwind, base leg, and final approach allow smaller adjustment of pitch and power compared to extension of full flaps all at one time," explains Chapter 8 of the Airplane Flying Handbook.

"When teaching landings in a Cessna or Piper training aircraft, I have the student use one notch of flaps and trim when abeam the numbers. From here, the remaining flaps are used to adjust the aircraft's descent to the touchdown point. If the pattern is a normal-sized pattern (the turn from base to final will be slightly more than a quarter-mile from the runway), and the headwinds on final are light, the second notch of flaps will be applied when they are needed to keep from landing long. This typically occurs just before turning from base to final. The third and last notch of flaps is applied when the landing is assured."

But don't let that comfortable routine make you complacent. Unusual winds, extending your downwind leg for spacing, or getting instructions from the tower to "make short approach" may call for other techniques (and don't forget to perform some no-flap landings).

During dual sessions of airwork, it will help if you spend some time practicing holding heading and altitude at approach airspeeds while changing flap configurations—full flaps, no flaps, and everything in between—to learn the aircraft's responses and the power-pitch inputs required. With some practice, you'll be ready for whatever kind of landing is called for next!

WHAT'S THE CEILING?

WHAT'S THE CEILING?
When it comes time for you to fly solo, your instructor will note limiting weather conditions for your flights in your logbook. One limit likely will be the lowest ceiling under which you are permitted to solo. Another may be a minimum visibility value. [See the Jan. 27, 2006, Training Tip "Solo Limitations."]

Not all cloud cover represents a ceiling. It depends on how much of the sky is visible. The definitions used to describe sky cover carry inferences as to whether a ceiling exists. "A ceiling, for aviation purposes, is the lowest layer of clouds reported as being broken or overcast, or the vertical visibility into an obscuration like fog or haze. Clouds are reported as broken when five-eighths to seven-eighths of the sky is covered with clouds. Overcast means the entire sky is covered with clouds," explains chapter 10, page 17 of the Pilot's Handbook of Aeronautical Knowledge.

You'll find current sky conditions in aviation routine weather reports (METARs) and many automated observations. Sky cover reported as less than broken (few clouds, or scattered layers) does not constitute a ceiling. See the table of contractions on chapter 11, page 6 of the handbook for sky cover, represented in eighths (octas) of the sky from horizon to horizon, for each description.

Why octas? "Students frequently ask why sky cover and obscurations are reported in octas rather than tenths. The four cardinal points of the compass (N, E, W, S) and the four intercardinal points (NE, NW, SE, SW) divide the compass into eight sectors. Cloud cover and obscurations are easy to evaluate if you observe the conditions that exist in each of the eight sectors and base your report on how many sectors that condition occupies. Sky cover is also an element in pilot reports (pireps).

On nonflying days, practice estimating sky cover and comparing your conclusions with aviation weather reports. Also check out the AOPA Air Safety Foundation's online course "Weather Wise: Ceilings and Visibility" to further sharpen your skills.

HEAVY AIRCRAFT

A sample question from the private pilot knowledge test question bank asks: "When departing behind a heavy aircraft, the pilot should avoid wake turbulence by maneuvering the aircraft

A) below and downwind from the heavy aircraft.

B) above and upwind from the heavy aircraft.

C) below and upwind from the heavy aircraft.

When clearing you for takeoff or landing, the tower controller may add to your clearance the phrase "Caution wake turbulence" from the preceding arrival or departure. Although it may seem obvious to the pilot of a single-engine trainer that the preceding aircraft is heavy, the use of the term has special significance, as explained in Chapter 7 of the Aeronautical Information Manual (AIM): "For purposes of Wake Turbulence Separation Minima, ATC classifies aircraft as Heavy, Large, and Small as follows: Heavy—Aircraft capable of takeoff weights of more than 255,000 pounds whether or not they are operating at this weight during a particular phase of flight. Large—Aircraft of more than 41,000 pounds maximum certificated takeoff weight, up to 255,000 pounds. Small—Aircraft of 41,000 pounds or less maximum certificated takeoff weight."

Considering those definitions, the AIM describes aircraft separation requirements: "Because of the possible effects of wake turbulence, controllers are required to apply no less than specified minimum separation for aircraft operating behind a heavy jet and, in certain instances, behind large nonheavy aircraft (i.e., B757 aircraft)," as Elizabeth A. Tennyson explains in the AOPA Flight Training May 2001 column "Aviation Speak: Heavy."

If you find yourself facing wake turbulence on departure, you may choose to ask the tower to approve an early turn (upwind of the wake's probable drift track) when altitude permits after takeoff. Make this request when you contact the tower for your takeoff clearance. Don't wait until you are airborne, when traffic concerns or frequency congestion can delay approval.

Stay alert to hearing the word heavy on the ATC frequency!

"Pilot or Operator?"

"Pilot or Operator?"

It's my latest obsession. Pilots using GPS and using it wrong. I've been on a mission for the last few newsletters to try to give reasons on how to use GPS correctly and not let it become your only form of navigation. So here's my latest installment and it's one that I think drives the point home.

When you think about using a GPS in a car that same logic doesn't carry through to an airplane. For example, if you set the address wrong you'll just go to the wrong place and probably nothing else will happen. Maybe the database isn't 100 percent correct and you take a turn to a dead end. Again, probably nothing bad will happen. You set where you want to go in the GPS and you "allow" it to take you there. You can eliminate all sense of direction if you want and just follow the voice commands from the GPS. You are an operator of the GPS and really you don't need to know anything else about how it works or the errors it may have or really much of anything else. If the GPS makes a mistake, or you do, the consequences aren't that bad. It's a time penalty and that's about it. So you can truly just be an operator of the GPS and get by just fine.

GPS in aircraft are different than GPS in your car. The consequences of making an error using the GPS are higher and because the GPS is not just going to an address, gas station or following a single road etc. there are many more choices of flight plan routes to consider. The car only has a few choices, we have many more.

Terrain, what to do if the engine fails over this area or that, weather, choice of airports for fuel stops etc. are all extra things to consider when we use an airplane GPS that don't exist when we use the car GPS. It's important to be a pilot first and a GPS Operator second. We must use our judgement when selecting routes, airports etc. without just letting the GPS do it for us. Why? Because in an airplane you don't want to be just an operator because the consequences are too high. When we allow the GPS to tell us where we are and where we are going we become operators and we are no longer pilots.

So how do we fix this? Well to start we challenge ourselves to know where we are first then let the GPS confirm that we are in fact there. We ALWAYS use a different form of navigation other than GPS to back up data that the GPS is giving to us. We begin thinking that the sky is one big canvas that we can navigate in any way we choose and not as a series of IFR airways and intersection to intersection flight planned GPS routes or VP this or that. When we begin using the GPS as a pilot first we allow ourselves to consider all possibilities and not just the pink line. IFR Flying is a slightly different story as there may only be GPS data available.

So in summary, learn to tell the GPS where you are, then affirm the GPS is where you know it to be. A last thought is that GPS can be a powerful tool to help you navigate to a nearest airport in case of trouble or to take a more direct route.

Use the GPS as an aid in navigation and it will be yet another powerful tool for you to select to use as a pilot, not one you MUST use. This simple approach will help take you from an Operator to a Pilot.

CLOUD TOPS

When you call for a preflight weather briefing, information about the height of cloud bases and the extent of cloud cover helps you make your go/no-go decision.

What about cloud tops? Flying above cloud layers is not routine for student pilots—and the federal aviation regulations prohibit it "when the flight cannot be made with visual reference to the surface." Yet many pilots hoping for a complete weather picture ask how to find information about cloud tops.

"But that's precisely the problem. For all the meteorological advances in recent decades, apparently very little effort has been put into technologies that could help us in this regard. So for the near future, anyway, we're left to rely on just a few sources of information about tops," including area forecasts, radar summary charts, satellite imagery, atmospheric soundings, and pilot reports (pireps).

An area forecast (FA) is the most familiar of these resources. Cloud top information found in the fourth section of an FA is general. That's because the FA "gives a picture of clouds, general weather conditions, and visual meteorological conditions (VMC) expected over a large area encompassing several states," explains Chapter 10 of the Pilot's Handbook of Aeronautical Knowledge.

Pireps help, but Horne offered this reminder: "Pireps promise the most accuracy, but please check the dates and times of any pireps. It's not unusual for pireps to be a day old, yet still be posted. The problem with pireps is that most pilots never make them, so we are deprived of good cloud-top information by some of the best weather observers in the world."

Why is flying VFR above clouds discouraged for the inexperienced pilot? One risk is becoming trapped above a scattered or broken cloud cover that unexpectedly closes up to solid overcast. But even when breaks remain, pilots have encountered spatial disorientation and lost control during descent, as documented in this accident analysis. Steering well clear of all clouds remains the best bet.

'MAINTAIN VFR'

Two recent Training Tips discussed cloud cover ("What's the ceiling?" and "Cloud Tops"). Those clouds in the distance off your wing tip must be given wide berth, too. One day you might receive a clearance to enter or depart controlled airspace accompanied by the cautionary instruction, "Maintain VFR at all times." Why did the controller say that?

The caution was meant to remind you that you, as the pilot, should never let a radar vector or other instruction get you in trouble. "In many cases, particularly at radar facilities, the people on the ground have little idea of the flight conditions beyond what has been relayed by pilots," wrote Bruce Landsberg, executive director of the AOPA Air Safety Foundation, in the safety article "Just say 'unable.'" This isn't a concern only for instrument pilots trying to comply with instructions while avoiding turbulence or icy clouds. "A similar situation involving benign clouds can develop with a VFR pilot operating in Class B or C airspace. Pilots not on an IFR flight plan are expected to maintain VFR—period. If an assigned heading or altitude is going to put the airplane too close to a cloud, then advise the controller that you are 'unable to maintain VFR' and suggest an alternative heading or altitude."

Some experience flying nearer than is comfortable to clouds, in the company of your instructor, will eliminate any skepticism you may have about the importance of this responsibility. Horne argues that gradual exposure to poorer weather conditions should be included in any comprehensive flight training. "I've always been an advocate for flight instructors taking primary students on flights in marginal VFR weather—both in the traffic pattern and away from it. This way, the student can see what a 1,000-foot ceiling and three-statute-mile visibility (the VFR weather minimums at airports with controlled airspace designated to the surface) looks like. The same goes for flights at altitude, flying in three-mile visibilities and trying to keep the prescribed distance from clouds. The student quickly learns that three miles isn't much visibility at all."

Even when there's no controller reminding you to maintain VFR, remember those wise words. They'll keep you safe!

'POSITIVE' CONTROL

Most pilots spend most of their flying time operating in controlled airspace. But for the different classes of controlled airspace, there are varying degrees of control. The largest swath of controlled airspace isn't controlled beyond your obligation to observe weather requirements for VFR flight within its boundaries.

The basic differences can be summed up in the term "positive control." As defined in the Pilot/Controller Glossary of the Aeronautical Information Manual, positive control "means control of all air traffic, within designated airspace, by air traffic control."

Class A airspace, starting at 18,000 feet, is an example. Entry requires a clearance under instrument flight rules from ATC. Before airspace was classified by letters, Class A airspace was known as the positive control area. Pilots operate under positive control in Class B airspace, surrounding the busiest airports. You may not enter Class B airspace without a specific clearance from ATC. "Class B airspace provides for positive control of both VFR and IFR traffic.

Class C airspace, surface-based and centered on a towered airport with radar service, requires that communications be established, but specific clearance into the airspace is not required. In Class D airspace, centered on an airport with an operating control tower, there is also a requirement to establish two-way communications. The airspace reverts to Class E when the tower is not operating [Class G if weather information is not available].

In the vast reaches of Class E airspace a pilot may fly with no ATC interaction—provided the appropriate weather requirements for VFR flight are satisfied. However, it is recommended that pilots make use of radar flight following when and where it is available. And nowadays it is prudent to check notams for temporary flight restrictions along any route.

Positive control can require different procedures for different kinds of flights in airspace such as the Washington Air Defense Identification Zone (ADIZ).

CLIMBING, COOLING, CLEARING

CLIMBING, COOLING, CLEARING
What's the description of a well-executed climb to altitude after takeoff? Setting up the aircraft at the airspeed that delivers the desired rate of climb (V_x or V_y) is the first goal. Trimming the aircraft to maintain the climb airspeed comes next. But is that all there is to it?

Not exactly. In a climb to cruise altitude, collision avoidance and the efficient management of your aircraft's engine also demand attention. The designated pilot examiner who will conduct your flight at checkride time will want to see that you have the big picture in mind.

When climbing after takeoff, especially during warm weather, monitor your oil-temperature gauge for any signs of engine overheating. The design of an air-cooled engine (the type installed in most general aviation aircraft) "is less effective during ground operations, takeoffs, go-arounds, and other periods of high-power, low-airspeed operations," explains Chapter 5 of the Pilot's Handbook of Aeronautical Knowledge. The solution: "High engine temperatures can be decreased by increasing the airspeed and/or decreasing the power."

If the pilot's operating handbook for your trainer calls for full-power climbs, lower the nose and climb at a higher airspeed, once safely above obstructions. You should also consider leaning the fuel-air mixture.

Collision risks are elevated during climb because the nose-up climb attitude of the aircraft curtails forward visibility. In an extended climb, lower the nose at regular intervals and scan the airspace ahead. Accompany these clearing maneuvers by performing gentle, coordinated banks left and right so you can scan zones obscured by the wings. Also remember blind spots created by a high glareshield or other aircraft design features, as discussed in the AOPA Air Safety Foundation's Collision Avoidance Safety Advisor.

Clearly, there's more to a good climb than just holding the correct airspeed!