First of all, METAR as an abbreviation is vague at best. Different sources will tell you this comes from METeorological Aerodrome Report, Meteorological Terminal Aviation Routine Weather Report, Meteorological Terminal Air Report, or Meteorological Airfield Report. Let’s stick with aviation routine weather report and get straight into the decrypting.

Here’s an example of a routine METAR report for a station location:

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Each METAR contains specific information in sequential order. Let’s go through each bit of the standard formatted coding.

1. METARs begin with the type of report (shown in red).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR]

You will see two types of METAR reports. The routine METAR report, transmitted at a regular time interval, or the aviation selected SPECI, a special report that can be given at any time to update the METAR for rapidly changing weather conditions, aircraft mishaps, or other critical information.

2. Next is the station identifier. A four-letter code as established by the International Civil Aviation Organization (ICAO).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

In the 48 contiguous states, a unique three-letter identifier is preceded by the letter “K.” For example, Gregg County Airport in Longview, Texas, is identified by the letters “KGGG,” with K as the country designation and GGG as the airport identifier. In other regions of the world, including Alaska and Hawaii, the first two letters of the four-letter ICAO identifier indicate the region, country, or state. Alaska identifiers always begin with the letters “PA,” and Hawaii identifiers always begin with the letters “PH.” Station identifiers can be found on various websites, such as the Aviation Weather Center or  NOAA’s METAR Observation Station Identifiers.

3. The third grouping is the date and time of the report. Depicted in a six-digit group (161753Z). The first two digits are the date. The last four digits are the time of the METAR/SPECI, which is always given in coordinated universal time (UTC). A “Z” is appended to the end of the time to denote the time is given in Zulu time (UTC) as opposed to local time. This METAR was issued on the 16th at 1753 Zulu.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

4. The modifier denotes whether the METAR/SPECI came from an automated source or if the report was corrected.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

If the notation “AUTO” is listed in the METAR/SPECI, the report came from an automated source. It also lists “AO1” (for no precipitation discriminator) or “AO2” (with precipitation discriminator) in the “Remarks” section to indicate the type of precipitation sensors employed at the automated station. When the modifier “COR” is used, it identifies a corrected report sent out to replace an earlier report that contained an error. If this example had been corrected, the word AUTO would be replaced with COR.

5. The wind is reported with five digits (14021) unless the speed is greater than 99 knots, in which case the wind is reported with six digits. The first three digits indicate the direction the true wind is blowing from in tens of degrees. If the wind is variable, it is reported as “VRB.” The last two digits indicate the speed of the wind in knots (KT) unless the wind is greater than 99 knots, in which case it is indicated by three digits. If the winds are gusting, the letter “G” follows the wind speed. After the letter “G,” the peak gust recorded is provided (G26KT). If the wind direction varies more than 60° and the wind speed is greater than six knots, a separate group of numbers, separated by a “V,” will indicate the extremes of the wind directions.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Without gusts, this METAR would include only 14021KT.

6. The prevailing visibility is reported in statute miles as denoted by the letters “SM.” It is reported in both miles and fractions of miles (¾ SM).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

The runway visual range (RVR) may be reported following the prevailing visibility. RVR is the distance a pilot can see down the runway in a moving aircraft. When RVR is reported, it is shown with an R, then the runway number followed by a slash (/), then the visual range in feet. For example, when the RVR is reported as R17L/1400FT, it translates to a visual range of 1,400 feet on runway 17 left.

7. Now we get to the weather. It can be broken down into two different categories: the qualifiers (+TSRA) and the weather phenomenon (BR).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

First, the qualifiers of intensity, proximity, and the descriptor of the weather are given. The intensity may be light (–), moderate ( ), or heavy (+). Proximity only depicts weather phenomena that are in the airport vicinity. The notation “VC” indicates a specific weather phenomenon is in the vicinity of 5–10 miles from the airport. Descriptors are used to describe certain types of precipitation and obscurations. Weather phenomena may be reported as being precipitation, obscurations, or other phenomena, such as squalls or funnel clouds. Descriptions of weather phenomena, when they begin or end, and hailstone size are also listed in the “Remarks” sections of the report. The coding for qualifier and weather phenomena are shown in this chart. The weather groups are constructed by considering columns 1–5 in this table sequence: intensity, followed by descriptor, followed by weather phenomena.

The notation +TSRA BR is “heavy thunderstorms and rain with mist.” Another example, “heavy rain showers” is coded as +SHRA.

8. Next we have the sky condition. This is always reported in the sequence: amount, height, and type or indefinite ceiling/height (vertical visibility).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

The heights of the cloud bases are reported with a three-digit number in hundreds of feet AGL. Clouds above 12,000 feet are not detected or reported by an automated station. The types of clouds, specifically towering cumulus (TCU) or cumulonimbus (CB) clouds, are reported with their height. The amount of cloud coverage and obscuring phenomena is described using fractions, then reported based on the amount of sky coverage in eighths of the sky from horizon to horizon.

Less than 1/8 is abbreviated as Sky Clear, Clear, or Few; 1/8–2/8 as Few; 3/8–4/8, Scattered; 5/8–7/8, Broken; and 8/8, Overcast. For aviation purposes, the ceiling is the lowest broken or overcast layer, or vertical visibility into an obscuration.

9. The air temperature and dew point are always given in degrees Celsius (C).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Temperatures below 0 °C are preceded by the letter “M” to indicate minus.

10. The altimeter setting is reported as inches of mercury (inHg) in a four-digit number group.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

It is always preceded by the letter “A.” Rising or falling pressure may also be denoted in the “Remarks” sections as “PRESRR” (rising) or “PRESFR” (falling).

11. Lastly, we have the remarks section, which always begins with the letters “RMK.”

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Comments may or may not appear in this section of the METAR. The information contained in this section may include wind data, variable visibility, beginning and ending times of phenomenon, pressure information, and various other information deemed necessary. An example of a remark regarding weather phenomenon that does not fit in any other category would be: OCNL LTGICCG. This translates as occasional lightning in the clouds and from cloud to ground. Automated stations also use the remarks section to indicate the equipment needs maintenance.

Our sample METAR would be read as follows:

Routine METAR for Gregg County Airport for the 16th day of the month at 1753 zulu from an automated source. Winds are 140 at 21 knots gusting to 26 knots. Visibility is ¾ statute mile. Thunderstorms with heavy rain and mist. Ceiling is broken at 800 feet, overcast at 1,200 feet with cumulonimbus clouds. Temperature 18 °C and dew point 17 °C. Barometric pressure is 29.70 inHg and falling rapidly.

A few more examples:

To find more examples and learn even more about weather events that can affect flying, check out the Aviation Weather Handbook, available at asa2fly.com.

The post METAR Deciphered first appeared on Learn To Fly.

The overwhelming majority of owners operate in a responsible and safe manner, however there are those select few who choose to either push the boundaries or just ignore the rules all together. Whether or not owners are ignoring rules because they choose not to follow them or because they simply do not know the rules varies. If you ask me, I think it’s a little bit of both.

It’s important as a drone operator to understand that these rules or regulations are in place to prevent mid-air collisions between manned aircraft and unmanned aircraft. Such a collision has the likelihood of resulting in a catastrophic crash and loss of life.

The University of Dayton Research Institute recently conducted testing to determine the outcome of a small unmanned aircraft system colliding with the wing of a small single engine general aviation aircraft. The below video shows the result of a DJI Phantom 2 Quadcopter impacting the wing of a Mooney M20 aircraft at a combined impact speed of 238 miles per hour.

You can see the result is devastating to both aircraft involved.

Fortunately to date there have been very few collisions reported between unmanned and manned aircraft. One such incident took place over Canada in 2017 when a drone collided with a passenger plane coming in for landing at an altitude of 1,500 feet. This is the first known incident involving a collision between a passenger plane and a drone. Another incident took place over New York when a drone collided with an Army Helicopter monitoring the United Nations General Assembly. The drone had been operating out of line-of-sight and within a Temporary Flight Restriction (TFR). The incident resulted in substantial damage to the helicopters rotor blade but was able to make a safe landing (the helicopter, not the drone).

In the case of the drone versus Army helicopter, the National Transportation Safety Board (NTSB) investigated and was able to find the owner and operator of the drone. During an interview with the operator he was asked if he understood the rules pertaining to drone operations. The owner stated he knew to stay below 400 feet and out of class B airspace, however did not know about further airspace restrictions like TFRs.

The NTSB found the probable cause of the crash to be “the failure of the drone pilot to see and avoid the helicopter due to his intentional flight beyond visual line of sight. Contributing to the incident was the drone pilot’s incomplete knowledge of the regulations and safe operating practices.”

This incident is a great example of a pilot both pushing the boundaries and not being 100% familiar with the rules.

If you don’t want to find yourself in a situation like the one above, become familiar with the National Airspace System and Regulations surrounding drone operations. This will make you a safer, more competent drone operator. There are several books and programs available in the marketplace to help you learn this knowledge. One I would like to recommend is ASA Virtual Test Prep for Remote Pilots. This is a compressive ground school containing five-hours worth of on screen instruction covering regulations, the National Airspace System, weather, preflight considerations, and flight operations. The videos are available as individual lessons or as a set. Check them out!

Virtual Test Prep Remote Pilot Set

Virtual Test Prep Remote Pilot Individual Lessons

The post CFI Brief: Drone vs. Aircraft at 238 MPH! first appeared on Learn To Fly.

I’ve been building and tinkering with drones for the last couple years and flying them recreationally. I wanted to get into aerial photography and figured I’d eventually sell prints or try to monetize it, so it made sense to get a remote pilot’s license. Based on what I read online, it’s better to be safe and get the license than not. I didn’t have any prior piloting experience so I was starting with zero knowledge and this was all new to me.

Approach
Given I was starting from scratch and self-guiding myself through this process, I wanted to understand the test style (it’s also been over 10 years since I last took a test in college). I downloaded “Prepware Remote Pilot” and went through 10-15 random test questions to get a feel for the style of questions (I think I missed 90% of all these).

Next, I read through ASA’s Remote Pilot Test Prep as my main studying resource. It’s main appeal was the short chapter text and the easily consumable writing style. I read through the content in less than a week and took my first full test through the Prepware Remote Pilot app. I ended up getting 73%.

I looked through all my missed questions and reviewed the correct answers with the explanation blurb. Through reviewing the questions, I noticed a trend that I was missing most questions in a few sections (Weather–TAF/METAR and Sectional Charts), so I doubled down studying in those areas and spent a few days really diving into those sections to make sure I understood the content. I repeated the test in the app and increased my score to the high 80s so I felt comfortable taking the actual FAA test. I would recommend taking practice tests until you feel comfortable and achieve a high score.

Result
I scored an 82% on the final test and passed on my first attempt.

Tips

• Schedule a test date in advance to force yourself to study.
• Use the app, since your phone is always with you. It’s easy to run through a handful of questions randomly throughout the day (especially since you’d probably just be surfing facebook anyway).
• Check the updated test questions on the ASA website (they’re free) prior to taking the test.
• Notice the trends in certain areas, so you can spend your time studying other areas. For example, the Remote Pilot in Command is responsible for almost everything, so questions asking “who’s in charge when…” are easy to answer. Focus on studying what’s new to you.
• Eat something ahead of time.
• Once you’ve answered all the questions on the test, go back through and look it over before submitting.

The post Preparing for and Passing Your FAA Remote Pilot Knowledge Test first appeared on Learn To Fly.

The BasicMed privileges apply to persons exercising student, recreational, and private pilot privileges when acting as pilot in command (PIC). It also applies to persons exercising flight instructor privileges when acting as PIC. You cannot use BasicMed privileges to fly as a safety pilot, except when that pilot is acting as PIC. Pilots operating under BasicMed must hold a current and valid U.S. driver’s license and comply with all medical requirements or restrictions associated with that license. Applicants operating under BasicMed regulations must also complete the comprehensive medical examination checklist (CMEC) in collaboration with a physical examination by a state-licensed physician. Your physical must be completed within the last 48 months and the CMEC completed within the last 24 months. When operating under BasicMed, pilots are limited to:

1. Fly with no more than five passengers.
2. Fly an aircraft with a maximum certificated takeoff weight of no more than 6,000 lbs.
3. Fly an aircraft that is authorized to carry no more than 6 occupants.
4. Flights within the United States, at an indicated airspeed of 250 knots or less, and at an altitude at or below 18,000 feet mean sea level (MSL).
5. You may not fly for compensation or hire.

If operating beyond these limitations, pilots must obtain an FAA Medical Certificate.

In addition to 14 CFR Part 68, Advisory Circular No. 68-1: Alternative Pilot Physical Examination and Education Requirements is a great resource for pilots wishing to exercise BasicMed privileges. This advisory circular describes how pilots can exercise student, recreational, and private pilot privileges in certain small aircraft without holding a current medical certificate. It outlines the required medical education course, medical requirements, and aircraft and operating restrictions that pilots must meet to act as PIC for most 14 CFR Part 91 operations.

As a private pilot, commercial pilot, and flight instructor it is important that you become familiar with BasicMed, as the FAA is now asking questions on knowledge exam’s pertaining to this topic. Below are a few sample knowledge test questions that you could encounter.

 1. To operate under BasicMed the pilot in command must have completed a physical examination by a state-licensed physician within the preceding
A—48 months.
B—24 months.
C—12 months.

2.  For private pilot operations under BasicMed, the pilot in command is allowed to fly with no more then
A—6 passengers.
B—5 passengers.
C—5 occupants.

3. To maintain BasicMed privileges you are required to complete the CMEC every
A—48 months.
B—24 months.
C—12 months.

.

.

.

.

ANSWERS

1. Correct answer is A. BasicMed regulations require you to complete the CMEC every 24 months while a physical examination by a state-licensed physician must be completed every 48 months.

2. Correct answer is B. As PIC during private pilot operations under BasicMed, the aircraft is restricted to fly with no more than 5 passengers and authorized to carry no more than 6 total occupants. Answer (A) is incorrect because 6 passengers plus the PIC would equal 7 total occupants. Answer (C) is incorrect because BasicMed allows for aircraft authorized to carry no more than 6 total occupants.

3. Correct answer is B. BasicMed regulations require you to complete the comprehensive medical exanimation checklist (CMEC) every 24 months while a physical examination by a state-licensed physician must be completed every 48 months.

Further information can be found through the FAA at the following link: https://www.faa.gov/licenses_certificates/airmen_certification/basic_med/.

The post CFI Brief: BasicMed added to FAA Knowledge Exams first appeared on Learn To Fly.

June 6, 2018, at 1430 Central Time, to attend follow the below link.
https://attendee.gotowebinar.com/register/5931592944032783874

Private Pilot- Airplane (FAA-S-ACS-6B)
Instrument Rating- Airplane (FAA-S-ACS-8B)
Commercial Pilot- Airplane (FAA-S-ACS-7A)
Remote Pilot- sUAS (FAA-S-ACS-10A)

In addition to the updated Airman Certification Standards, the FAA has also released four new Knowledge Testing Supplements that will go into effect at all testing centers on June 11^th. Until then, current testing supplements are in effect. If you plan on taking a knowledge test for one of the below certificates or ratings on or after June 11^th, you will want to become familiar with these new supplements.

• Airman Knowledge Testing Supplement for Sport Pilot, Recreational Pilot, Remote Pilot, and Private Pilot (FAA-CT-8080-2H).
• Airman Knowledge Testing Supplement for Commercial Pilot (FAA-CT-8080-1E).
• Airman Knowledge Testing Supplement for Flight Instructor, Ground Instructor, and Sport Pilot Instructor (FAA-CT-8080-5H).
• Airman Knowledge Testing Supplement for Aviation Maintenance Technician – General, Airframe, and Powerplant; and Parachute Rigger (FAA-CT-8080-4G).

Stay tuned for the June Test Roll, and updates to the knowledge test question databases coming soon.

The post CFI Brief: Updates to ACS and NEW Testing Supplements first appeared on Learn To Fly.

Mach number is the ratio of the true airspeed to the speed of sound (TAS ÷ Speed of Sound). For example, an aircraft cruising at Mach .80 is flying at 80% of the speed of sound. The speed of sound is Mach 1.0. When in high-speed flight we refer to our airspeed in mach rather than true airspeeds or indicated airspeeds. At any airspeeds above Mach 1 you would be breaking the sound barrier.

A large increase in drag occurs when the air flow around the aircraft exceeds the speed of sound (Mach 1.0). Because lift is generated by accelerating air across the upper surface of the wing, local air flow velocities will reach sonic speeds while the aircraft Mach number is still considerably below the speed of sound. With respect to Mach cruise control, flight speeds can be divided into three regimes—subsonic, transonic and supersonic. The subsonic regime can be considered to occur at aircraft Mach numbers where all the local air flow is less than the speed of sound. The transonic range is where some but not all the local air flow velocities are Mach 1.0 or above. In supersonic flight, all the air flow around the aircraft exceeds Mach 1.0. The exact Mach numbers will vary with each aircraft type but as a very rough rule of thumb the subsonic regime occurs below Mach .75, the transonic regime between Mach .75 and Mach 1.20, and the supersonic regime over Mach 1.20.

A limiting speed for a subsonic transport aircraft is its critical Mach number (MCRIT). That is the speed at which airflow over the wing first reaches, but does not exceed, the speed of sound. At MCRIT there may be sonic but no supersonic flow.

When an airplane exceeds its critical Mach number, a shock wave forms on the wing surface that can cause a phenomenon known as shock stall. If this shock stall occurs symmetrically at the wing roots, the loss of lift and loss of downwash on the tail will cause the aircraft to pitch down or “tuck under.” This tendency is further aggravated in sweptwing aircraft because the center of pressure moves aft as the wing roots shock stall. If the wing tips of a sweptwing airplane shock stall first, the wing’s center of pressure would move inward and forward causing a pitch up motion. See the Figure below.

The less airflow is accelerated across the wing, the higher the critical Mach number (i.e., the maximum flow velocity is closer to the aircraft’s Mach number). Two ways of increasing MCRIT in jet transport designs are to give the wing a lower camber and increase wing sweep. A thin airfoil section (lower camber) causes less airflow acceleration. The sweptwing design has the effect of creating a thin airfoil section by inducing a spanwise flow, thus increasing the effective chord length. See the Figure below.

Although a sweptwing design gives an airplane a higher critical Mach number (and therefore a higher maximum cruise speed), it results in some undesirable flight characteristics. One of these is a reduced maximum coefficient of lift. This requires that sweptwing airplanes extensively employ high lift devices, such as slats and slotted flaps, to get acceptably low takeoff and landing speeds. The purpose of high lift devices such as flaps, slats and slots is to increase lift at low airspeeds and to delay stall to a higher angle of attack.

Another disadvantage of the sweptwing design is the tendency, at low airspeeds, for the wing tips to stall first. This results in loss of aileron control early in the stall, and in very little aerodynamic buffet on the tail surfaces.

The post CFI Brief: Mach Number first appeared on Learn To Fly.

When an airplane flies at subsonic speeds, the air ahead is “warned” of the airplane’s coming by a pressure change transmitted ahead of the airplane at the speed of sound. Because of this warning, the air begins to move aside before the airplane arrives and is prepared to let it pass easily. When the airplane’s speed reaches the speed of sound, the pressure change can no longer warn the air ahead because the airplane is keeping up with its own pressure waves. Rather, the air particles pile up in front of the airplane causing a sharp decrease in the flow velocity directly in front of the airplane with a corresponding increase in air pressure and density.

As the airplane’s speed increases beyond the speed of sound, the pressure and density of the compressed air ahead of it increase, the area of compression extending some distance ahead of the airplane. At some point in the airstream, the air particles are completely undisturbed, having had no advanced warning of the airplane’s approach, and in the next instant the same air particles are forced to undergo sudden and drastic changes in temperature, pressure, density, and velocity. The boundary between the undisturbed air and the region of compressed air is called a shock or “compression” wave. This same type of wave is formed whenever a supersonic airstream is slowed to subsonic without a change in direction, such as when the airstream is accelerated to sonic speed over the cambered portion of a wing, and then decelerated to subsonic speed as the area of maximum camber is passed. A shock wave forms as a boundary between the supersonic and subsonic ranges.

Whenever a shock wave forms perpendicular to the airflow, it is termed a “normal” shock wave, and the flow immediately behind the wave is subsonic. A supersonic airstream passing through a normal shock wave experiences these changes:

• The airstream is slowed to subsonic.
• The airflow immediately behind the shock wave does not change direction.
• The static pressure and density of the airstream behind the wave is greatly increased.
• The energy of the airstream (indicated by total pressure—dynamic plus static) is greatly reduced.

Shock wave formation causes an increase in drag. One of the principal effects of a shock wave is the formation of a dense high pressure region immediately behind the wave. The instability of the high pressure region, and the fact that part of the velocity energy of the airstream is converted to heat as it flows through the wave, is a contributing factor in the drag increase, but the drag resulting from airflow separation is much greater. If the shock wave is strong, the boundary layer may not have sufficient kinetic energy to withstand airflow separation. The drag incurred in the transonic region due to shock wave formation and airflow separation is known as “wave drag.” When speed exceeds the critical Mach number by about 10 percent, wave drag increases sharply. A considerable increase in thrust (power) is required to increase flight speed beyond this point into the supersonic range where, depending on the airfoil shape and the AOA, the boundary layer may reattach.

Normal shock waves form on the wing’s upper surface and form an additional area of supersonic flow and a normal shock wave on the lower surface. As flight speed approaches the speed of sound, the areas of supersonic flow enlarge and the shock waves move nearer the trailing edge.

Associated with “drag rise” are buffet (known as Mach buffet), trim, and stability changes and a decrease in control force effectiveness. The loss of lift due to airflow separation results in a loss of downwash and a change in the position of the center pressure on the wing. Airflow separation produces a turbulent wake behind the wing, which causes the tail surfaces to buffet (vibrate). The nose-up and nose-down pitch control provided by the horizontal tail is dependent on the downwash behind the wing. Thus, an increase in downwash decreases the horizontal tail’s pitch control effectiveness since it effectively increases the AOA that the tail surface is seeing. Movement of the wing center of pressure (CP) affects the wing pitching moment. If the CP moves aft, a diving moment referred to as “Mach tuck” or “tuck under” is produced, and if it moves forward, a nose-up moment is produced. This is the primary reason for the development of the T-tail configuration on many turbine-powered aircraft, which places the horizontal stabilizer as far as practical from the turbulence of the wings.

The post Aerodynamics: Shock Waves first appeared on Learn To Fly.

Most aircraft are equipped with either a 14- or a 28-volt direct current (DC) electrical system. A basic aircraft electrical system consists of the following components:

• Alternator/generator
• Battery
• Master/battery switch
• Alternator/generator switch
• Bus bar, fuses, and circuit breakers
• Voltage regulator
• Ammeter/loadmeter
• Associated electrical wiring

Engine-driven alternators or generators supply electric current to the electrical system. They also maintain a sufficient electrical charge in the battery. Electrical energy stored in a battery provides a source of electrical power for starting the engine and a limited supply of electrical power for use in the event the alternator or generator fails. Most DC generators do not produce a sufficient amount of electrical current at low engine rpm to operate the entire electrical system. During operations at low engine rpm, the electrical needs must be drawn from the battery, which can quickly be depleted.

Alternators have several advantages over generators. Alternators produce sufficient current to operate the entire electrical system, even at slower engine speeds, by producing alternating current (AC), which is converted to DC. The electrical output of an alternator is more constant throughout a wide range of engine speeds.

Some aircraft have receptacles to which an external ground power unit (GPU) may be connected to provide electrical energy for starting. These are very useful, especially during cold weather starting. Follow the manufacturer’s recommendations for engine starting using a GPU. The electrical system is turned on or off with a master switch. Turning the master switch to the ON position provides electrical energy to all the electrical equipment circuits except the ignition system. Equipment that commonly uses the electrical system for its source of energy includes:

• Position lights
• Anticollision lights
• Landing lights
• Taxi lights
• Interior cabin lights
• Instrument lights
• Radio equipment
• Turn indicator
• Fuel gauges
• Electric fuel pump
• Stall warning system
• Pitot heat
• Starting motor

Many aircraft are equipped with a battery switch that controls the electrical power to the aircraft in a manner similar to the master switch. In addition, an alternator switch is installed that permits the pilot to exclude the alternator from the electrical system in the event of alternator failure.

With the alternator half of the switch in the OFF position, the entire electrical load is placed on the battery. All nonessential electrical equipment should be turned off to conserve battery power.

A bus bar is used as a terminal in the aircraft electrical system to connect the main electrical system to the equipment using electricity as a source of power. This simplifies the wiring system and provides a common point from which voltage can be distributed throughout the system.

Fuses or circuit breakers are used in the electrical system to protect the circuits and equipment from electrical overload. Spare fuses of the proper amperage limit should be carried in the aircraft to replace defective or blown fuses. Circuit breakers have the same function as a fuse but can be manually reset, rather than replaced, if an overload condition occurs in the electrical system. Placards at the fuse or circuit breaker panel identify the circuit by name and show the amperage limit. An ammeter is used to monitor the performance of the aircraft electrical system. The ammeter shows if the alternator/generator is producing an adequate supply of electrical power. It also indicates whether or not the battery is receiving an electrical charge.

Ammeters are designed with the zero point in the center of the face and a negative or positive indication on either side. When the pointer of the ammeter is on the plus side, it shows the charging rate of the battery. A minus indication means more current is being drawn from the battery than is being replaced. A full-scale minus deflection indicates a malfunction of the alternator/generator. A full-scale positive deflection indicates a malfunction of the regulator. In either case, consult the AFM/POH for appropriate action to be taken.

Not all aircraft are equipped with an ammeter. Some have a warning light that, when lighted, indicates a discharge in the system as a generator/alternator malfunction. Refer to the AFM/POH for appropriate action to be taken.

Another electrical monitoring indicator is a loadmeter. This type of gauge has a scale beginning with zero and shows the load being placed on the alternator/generator. The loadmeter reflects the total percentage of the load placed on the generating capacity of the electrical system by the electrical accessories and battery. When all electrical components are turned off, it reflects only the amount of charging current demanded by the battery.

A voltage regulator controls the rate of charge to the battery by stabilizing the generator or alternator electrical output. The generator/alternator voltage output should be higher than the battery voltage. For example, a 12-volt battery would be fed by a generator/alternator system of approximately 14 volts. The difference in voltage keeps the battery charged.

The post Aircraft Systems: Electrical System first appeared on Learn To Fly.

This notice outlines a change in policy regarding testing applicants for a commercial pilot or flight instructor certificate, regardless whether the training was received under Title 14 of the Code of Federal Regulations (14 CFR) part 61 or 141. Specifically, it outlines the policy which no longer requires applicants for a commercial pilot certificate with an airplane single-engine rating to provide a complex or turbine-powered airplane for the associated practical test and no longer requires applicants for a flight instructor certificate with an airplane single-engine rating to provide a complex airplane for the practical test.

It is important to note this policy change does not affect the training and experience requirements as outlined in 14 CFR Parts 61 or 141. Applicants working towards a Commercial or Flight Instructor Certificate will still be required to obtain flight time and training in a complex airplane.

Part of the reasoning behind this change is that training providers have noted a concern regarding the availability of complex airplanes, adding to the complexity of scheduling checkrides. In addition, many of these aircraft are older models and require much higher maintenance cost to meet airworthiness standards. The FAA recognizes these flight school concerns and understands it might be cost-prohibitive and difficult to schedule applicant testing in a complex airplane.

Removing the requirements for a complex airplane to be used during the practical test will in turn reduce the overall cost of the practical test and allow applicants to utilize more cost effective and readily available aircraft.

Please note the corresponding changes to the Commercial Pilot ACS (FAA-S-ACS-7) and Flight Instructor PTS (FAA-S-8081-6D) as outlined below.

FAA-S-ACS-7
Change 3

• Revised the “Equipment Requirements & Limitations” section in Appendix 7: Aircraft, Equipment, and Operational Requirements & Limitations.

Note: This change will also affect the wording in some of the Task, Skill elements. To see all change 3 revisions please refer to the complete document by following the link below.

https://www.faa.gov/training_testing/testing/acs/media/commercial_airplane_acs.pdf

FAA-S-8081-6D
Change 6

• Removed the complex airplane requirement from practical tests for an airplane single-engine instructor rating and made corresponding changes to Task elements and the following sections in the Introduction:

• “Aircraft and Equipment Required for the Practical Test”
• “Renewal or Reinstatement of a Flight Instructor Certificate”

An update will be available shortly for the ASA Commercial Pilot ACS and Flight Instructor PTS publications. To stay informed of all updates please follow the link below.

http://www.asa2fly.com/FAA-Test-Standards-W24C162.aspx

The post CFI Brief: Complex Airplane, No Longer Required on Checkride first appeared on Learn To Fly.

Maintenance for sUAS includes scheduled and unscheduled overhaul, repair, inspection, modification, replacement, and system software upgrades for the unmanned aircraft itself and all components necessary for flight.

Manufacturers may recommend a maintenance or replacement schedule for the unmanned aircraft and system components based on time-in-service limits and other factors. Follow all manufacturer maintenance recommendations to achieve the longest and safest service life of the sUAS. If the sUAS or component manufacturer does not provide scheduled maintenance instructions, it is recommended that you establish your own scheduled maintenance protocol. For example:

• Document any repair, modification, overhaul, or replacement of a system component resulting from normal flight operations.
• Record the time-in-service for that component at the time of the maintenance procedure.
• Assess these records over time to establish a reliable maintenance schedule for the sUAS and its components.

During the course of a preflight inspection, you may discover that an sUAS component requires some form of maintenance outside of the scheduled maintenance period. For example, an sUAS component may require servicing (such as lubrication), repair, modification, overhaul, or replacement as a result of normal or abnormal flight operations. Or, the sUAS manufacturer or component manufacturer may require an unscheduled system software update to correct a problem. In the event such a condition is found, do not conduct flight operations until the discrepancy is corrected.

In some instances, the sUAS or component manufacturer may require certain maintenance tasks be performed by the manufacturer or by a person or facility specified by the manufacturer; maintenance should be performed in accordance with the manufacturer’s instructions. However, if you decide not to use the manufacturer or the personnel recommended by the manufacturer and you are unable to perform the required maintenance yourself, you should:

• Solicit the expertise of maintenance personnel familiar with the specific sUAS and its components.
• Consider using certificated maintenance providers, such as repair stations, holders of mechanic and repairman certificates, and persons working under the supervision of a mechanic or repairman.

If you or the maintenance personnel are unable to repair, modify, or overhaul an sUAS or component back to its safe operational specification, then it is advisable to replace the sUAS or component with one that is in a condition for safe operation. Complete all required maintenance before each flight—preferably in accordance with the manufacturer’s instructions or, in lieu of that, within known industry best practices.

Careful recordkeeping can be highly beneficial for sUAS owners and operators. For example, recordkeeping provides essential safety support for commercial operators who may experience rapidly accumulated flight operational hours/cycles. Consider maintaining a hardcopy and/or electronic logbook of all periodic inspections, maintenance, preventative maintenance, repairs, and alterations performed on the sUAS. See the figure below. Such records should include all components of the sUAS, including the:

• Small unmanned aircraft itself;
• Control station;
• Launch and recovery equipment;
• Data link equipment;
• Payload; and
• Any other components required to safely operate the sUAS.

You can find a UAS Operators Log here.

The post CFI Brief: sUAS Maintenance & Inspection first appeared on Learn To Fly.