Question: I acquired my private pilot certificate in my own airplane a few years back. I sold the airplane, so now I need to rent in order to stay current. My friends who rent on a regular basis are warning me to check the maintenance books of the aircraft before I fly them. I have never rented an airplane before. What should I be looking for?

Answer: You should check the maintenance logbooks to make sure the aircraft is legal to fly. Start with the required inspections. They can be found under FAR 91.409, 91.411, 91.413, and 91.207. Many pilots learn the acronym A AV1ATE to recall the required inspections—with the “1” replacing the “I”:

Airworthiness Directives

Airworthiness directives (ADs) are the items that are aircraft make and model specific—for example, the seat rail AD for certain Cessna aircraft—and must be done at specific time intervals. These come from the FAA, and often aircraft owners dedicate a logbook to ADs only. Other times compliance with the ADs can be found in the logbook entries for other required inspections. Read those entries carefully.

• READ MORE: Do I Need Renter’s Insurance?

Annual Inspection

As the name implies, these are completed every 12 calendar months. The annual inspection must be performed and signed off on by an airframe and powerplant mechanic with an inspection authorization (AP/IA).

Calendar months is a fancy way of saying “to the end of the month.” So let’s say the aircraft’s annual was completed and signed off on September 23, 2022. The next annual is due October 1, 2023.

Annual inspections can be very involved and take several days, weeks, or even months, depending on what issues are found (if any) and the availability of parts if something needs to be replaced.

VOR Receiver

“V” is short for VOR receiver, which must be checked within the preceding 30 days for an IFR flight, per FAR 91.171. Note that IFR is specifically called out. If you are flying VFR, having a VOR past its check deadline is not a grounding issue.

It is unlikely the VOR check will be in the aircraft maintenance logs, as many owners have a log or other record in the aircraft to record it. Look for that as well, noting the date the check was completed, the place (such as over an established VOR airway), bearing error (if any), and the signature of the person who conducted the VOR check.

100-Hour Inspection

The “I” in AVIATE is actually a “1” for “100-hour”. If the aircraft is used for compensation or hire, it is required to have a 100-hour inspection, per FAR 91.409(b). It can be confusing if the airplane belongs to a flying club, or if the instructor (if required) is not employed by the club or FBO. According to AOPA, if a customer rents the aircraft from a club or school, but the club or school doesn’t supply the instructor, the aircraft does not require a 100-hour inspection. The phrase “for hire” refers to the person, not the aircraft itself. Be advised that the annual inspection can replace a 100-hour, but the 100-hour, which is usually much less intense than the annual, cannot replace the annual.

• READ MORE: Is the Shift in Tornado Alley Related to Climate Change?

Altimeter

The third “A” stands for altimeter, which is part of the pitot-static system—because it is the pitot-static system that is required to be inspected and tested every 24 calendar months if the aircraft will be flying in controlled airspace under IFR rules. The check should include the aircraft’s static system, altimeter, and automatic altitude-reporting (Mode C) system.

Transponder

“T” is for transponder, which must be inspected every 24 calendar months.

Emergency Locator Transmitter

“E” is for the Emergency Locator Transmitter, or ELT, which must be inspected within 12 calendar months.

Each inspection must be signed off on by the AP who performed them, and in addition to their name, their certificate number must be recorded.

Progressive Maintenance

Some of the busier flight schools/FBOs use a progressive inspection to minimize the downtime of their aircraft. Progressive inspections allow for more frequent inspection phases, but they focus on one section of the aircraft at a time—for example, the airframe might be checked every 40 hours, the pitot-static system every 40 hours and so forth.

For a list of things that are checked during the annual and 100-hour inspections, refer to FAR 43, Appendix D.

When going through the maintenance logs, note if there have been any modifications to the aircraft (such as installation of vortex generators) and be sure the accompanying 337 form is there as well. 

You will also want to check the weight and balance sheet of the aircraft. One is required to be in the aircraft for it to be airworthy—make sure it matches what is in the aircraft maintenance logs.

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Question: I have just started flight training, and the flight school is telling me that I need to carry insurance to fly their airplanes. If I am flying their airplanes, shouldn’t I be covered under the school’s insurance policy? Flight training is expensive enough without this. Do I really need to have insurance?

Answer: If you have assets to protect like a home, car, bank account, etc., then insurance is a good idea. Many student pilots and private pilots fly without it because they don’t know it is available or think they are covered under the flight school’s policy. 

• READ MORE: Is the Shift in Tornado Alley Related to Climate Change?

You are, to an extent. However, if there is an accident or incident that results in the loss of a revenue-generating aircraft, the flight school will go after you for any losses not covered by the school’s insurance.

For example, if a hard landing damages the landing gear and wing of a Piper Arrow, you might be on the hook for the loss of revenue while the aircraft is in for repairs. So let’s say the aircraft rents for $160 an hour, and the school can show the aircraft usually flies six hours a day. It will take a week to make repairs. Now you do the math. The school may sue you to get that money. If this happens, you will be very happy to have insurance.

• READ MORE: Is a Handheld Radio Required for Flying?

It is a good idea to shop around for aviation insurance to get the right coverage for the flying you do. For example, there are policies written for renter pilots, instructor pilots, pilots who fly experimental aircraft, and even for drones.

Keep in mind there are often discounts for pilots who consistently add to their skills and proficiency through FAA-recognized safety programs, such as the FAASTeam or courses offered through the Aircraft Owners and Pilots Association (AOPA). A commitment to safety speaks volumes to the people who write these policies.

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Question: It seems there have been more significant severe weather events that include tornadoes happening in the Deep South, especially in Louisiana, Mississippi, and Alabama rather than in the traditional location of Tornado Alley. Is this driven by climate change?  

Answer: The short answer is yes. Tornado Alley has had a bad reputation over the last couple of decades, however. Although there has never been an official designation of where Tornado Alley is located, it is the area that is roughly approximated by the central and southern Plains from Nebraska to north-central Texas. 

There has been some debate that Tornado Alley has been shifting to the east over the last couple of decades. But it is more likely that Tornado Alley isn’t shifting but rather expanding to the east. 

From year to year, there may be a stark contrast in where severe weather strikes, especially thunderstorms that produce tornadoes. That is, there may be two or three years in a row where significant tornado events are focused more in Tornado Alley and other years where they are focused in the Ozarks, mid-South, and Tennessee Valley. This year-to-year variation happens for a variety of reasons, but climate change will continue to expand where supercell-type thunderstorms develop and produce significant and destructive tornadoes.  

• READ MORE: Is a Handheld Radio Required for Flying?

Scientists are studying how anthropogenic climate change (ACC) is affecting the location of severe weather. This climate change originating from human activity is causing a change in the location of where many supercell thunderstorms originate. 

Supercells are storms that are distinguished from ordinary pulse-type convection by its deep, long-lived mesocyclone, which has a rotating midlevel vortex with a diameter between 1 and 5 miles and a vertical depth of at least 6,000 to 10,000 feet. While many supercells are individually separate and distinct, others may be embedded within larger complexes of thunderstorms or what are called mesoscale convective systems. Relatively rare, some supercell thunderstorms can persist for four or more hours.

The greatest concern is that as the trend in tornado environments from supercell-type convection expands to the east this will undoubtedly increase the exposure and vulnerability of people in these areas. In other words, with socioeconomic vulnerabilities projected to rise in the Ozarks, mid-South, and Tennessee Valley, the likelihood of more impactful tornado events in these regions is certain for the remaining decades of the twenty-first century.

The best approach is to remain weather aware and to pay close attention to the Storm Prediction Center (SPC) convective outlooks. These include a one-, two-, and three-day categorical outlook of severe weather along with a forecast discussion.

In addition, the SPC issues a probabilistic forecast for severe weather specifically for the potential of tornadoes, strong straight-line winds, and large hail. While some of these probabilities can look quite low, don’t be fooled. 

• READ MORE: Can You Select a DPE for Your Check Ride?

According to the SPC, “If you have a 15 percent probability for tornadoes, this means you have a 15 percent chance of a tornado occurring within 25 miles of your location. This may seem like a low number, but a tornado is very uncommon at any one location. Normally, your chances of getting hit by a tornado or other severe weather are small, purely based on statistical average. Let’s say you have a 1 percent statistical (climatology) history of tornadoes within 25 miles on this day, which still is large. Having a 15 percent probability means 15 times the normal odds of a tornado nearby, meaning it should be taken seriously.”

Once severe convection is likely, the SPC will issue a severe thunderstorm or tornado watch for heightened public awareness. Once tornadoes are seen by trained storm spotters or are indicated by the Nexrad Doppler weather radar, tornado warnings are issued for you to seek immediate cover. 

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Question: What does a pilot require to remain current in an aircraft requiring a type rating?

Answer: The answer to this question can appear to be complicated unless you enjoy reading FAA regulations for personal amusement.

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FAR 61.58 states: “Except as otherwise provided in this section, to serve as pilot in command of an aircraft that is type certificated for more than one required pilot flight crew member or is turbojet powered, a person must—

1) Within the preceding 12 calendar months complete a pilot-in–command proficiency check in an aircraft that is type certificated…”

• READ MORE: Is a Handheld Radio Required for Flying?

The regulation goes on to say that the proficiency check may be conducted by a “person authorized by the Administrator, to include aeronautical knowledge areas, areas of operations and tasks required for a type rating in an aircraft that is type certificated.”

Or “…a check or test may be accomplished in a flight simulator under Part 142…”

As an owner-operator of a Cessna Citation CJ1, this basically means a yearly check ride, the so-called “sixty-one/fifty-eight.” This can be conducted in the airplane or in an approved flight simulator. A number of training centers qualify for the Cessna Citation series. Slots for proficiency checks typically last three days and may be hard to find as demand for general aviation turbojet flights has increased since the COVID pandemic, and pilots are finding new jobs on new equipment or with the airlines. The cost for a single pilot 61.58 for a CJ1 is $6,500 to $8,000. Heavier, more complex airplanes are more expensive

• READ MORE: How Often Do Airliners Go Around?

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This column was originally published in the February 2023 Issue 934 of FLYING.

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Question: I am a student pilot learning to fly at a towered airport. I see lots of other pilots taking handheld radios with them in the airplane. My instructor carries one in his flight bag, for example. I thought the airplane already had a radio installed—why do so many pilots carry a handheld? Are they required?

Answer: Remember the phrase “aviate, navigate, communicate”? It reminds us that communicating—that is, using the radio—is the last priority in the aircraft. That being said, if an airplane has a working VHF comm radio installed, a handheld radio is a backup device—not a requirement. Pilots, especially those who fly in airspace where radio communication is required (Class A, B, C, and D), often carry handheld radios in their flight bag just in case they have a problem with the aircraft’s electrical system, and/or the radio fails. 

Pilots who fly aircraft without electrical systems, such as Piper J-3 Cubs, often use handheld radios because the ability to hear as well as see traffic can increase safety. Instructors often have a handheld radio so that when they solo their learners, they can keep an ear on them in the traffic pattern. Student pilots may also find a handheld radio helpful when they are learning radio communications, as they can use it to listen to the unicom or tower frequency while studying or hanging out at the airport.

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Question: How often do airliners go around, and what’s the usual reason?

Answer: Go-arounds aren’t terribly common under Part 121 commercial operations, and most airline pilots go a year or more between wave-offs. The most frequent cause is a lack of separation between landing traffic at busy airports, usually when air traffic control mistakenly vectors a heavier, faster aircraft behind a lighter, slower one. Unstabilized approaches are another common reason, either the result of being “slam-dunked” by ATC or simply misjudging a visual approach.

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• READ MORE: What Do Pilots Need to Know About Temperature Inversions?

It’s quite rare to go missed on account of poor weather, since Part 121 requires reported visibility to be above minimums before starting an approach. Because go-arounds are both uncommon and easy to botch, they are practiced frequently during recurrent simulator training, and it is now common to review go-around procedures during the approach briefing.

• READ MORE: Can a CFI Applicant Teach Ground School?

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This article was originally published in the December 2022/January 2023 Issue 933 of FLYING.

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Question: As a skier in Virginia and West Virginia, we are frequently impacted by inversions at the mountain-top height. What do pilots need to know about temperature inversions? I have yet to find a good discussion of them.

Answer: Before we can discuss temperature inversions, we need to explore the more generic concept of atmospheric lapse rates. A lapse rate is simply the change in temperature over a given change in altitude. 

Pilots are taught during their primary training that the standard lapse rate is 2 degrees Celsius for every 1,000-foot gain in altitude. That means, on an average day, the atmosphere “cools” at this rate. In other words, the higher you ascend in the troposphere, the colder it gets. We refer to this as a “positive” lapse rate. 

If you open your Pilot Operating Handbook (POH) you will likely see tables that are based on the departure from the standard. These tables can be used to determine how your airplane may perform when the conditions are not standard, which is often the case throughout most of the year.

• READ MORE: Can a CFI Applicant Teach Ground School?

While you can calculate a lapse rate over the entire vertical extent of the troposphere, it’s usually something that is referenced more often in shallow layers of the atmosphere. In some cases, the lapse rate may be what meteorologists call isothermal. That is, the temperature remains the same through a shallow layer of the atmosphere. In some cases, the temperature may actually increase with increasing altitude. That’s called a negative lapse rate, or more commonly, a temperature inversion. A negative lapse rate adds stability that ultimately inhibits vertical mixing.

Inversions are actually quite common in the lower troposphere. They are created by several different atmospheric processes. One of the most common is called a nocturnal inversion. In the overnight hours with clear skies and calm or light winds near the surface, radiative cooling can produce a very pronounced and often shallow temperature inversion hugging the surface. Essentially after sunset, the ground radiates the heat it absorbed during the daytime hours toward outer space in the form of long-wave radiation. This sets the stage for significant cooling at the ground level to produce a surface-based nocturnal temperature inversion.

Such inversions can set the stage for what is referred to as a radiation-fog event, often called ground fog, and non-convective low-level wind shear (LLWS). Radiation fog routinely develops in various regions of the U.S. and Canada throughout the year and can be some of the densest fog you will ever encounter. When a nocturnal temperature inversion is coupled with a favorable hydrolapse and little or no turbulent mixing exists in the potential fog layer, radiation fog is usually the result. A favorable hydrolapse is when the dewpoint temperature increases with increasing altitude. It is common for it to lower the ceiling and/or visibility into the very low instrument flight rules (VLIFR) flight category.

• READ MORE: Can You Select a DPE for Your Check Ride?

Nocturnal temperature inversions also create an environment favorable for what meteorologists refer to as non-convective low-level wind shear (LLWS). This is a forecast you may see in a TAF such as WS020/09045KT. It also is an advisory issued by meteorologists at the Aviation Weather Center (AWC) as a Graphical AIRMET (G-AIRMET).

First and foremost, this is not low-level wind shear associated with deep, moist convection or thunderstorms, hence the term non-convective LLWS. The extreme stability courtesy of the surface-based temperature inversion eliminates vertical mixing and promotes a laminar flow immediately above the surface. This allows the flow of air a few hundred feet above the ground to be insulated and decouple from surface friction, allowing the wind immediately above the surface to freely accelerate and create a low-level jet maximum.

In the early morning hours, when the sky is generally clear and the surface winds are light, a surface-based inversion sets up once the sun sets due to the radiative cooling mentioned earlier. The inversion deepens in the overnight hours, and the wind just above the surface freely accelerates to produce a low-level jet maximum within the first 2,000 feet of the surface. The wind at the surface can be calm, but the air at 2,000 feet AGL may be screaming along at 50+ knots. This would seem like a classic scenario for clear air turbulence. In fact, the air is often glassy smooth in this layer due to the extreme stability courtesy of the surface-based inversion.  

Temperature inversions just above the mountain ridges create the opportunity for what meteorologists call gravity waves. A mountain wave is the most common form of a gravity wave in the atmosphere. As somewhat unstable air near the surface is forced into this layer of stable air, it expands and becomes cooler and denser than the surrounding air, thanks to the inversion aloft. This causes the air to sink back down on the lee side of the mountain range. 

As the air subsides, it compresses, and the temperature increases as it descends back down into the unstable air below the ridgelines which allows this air to ascend once again. This creates that up-and-down oscillation of air downwind of the mountain range. Flying into these waves can be felt as an upwash or downwash, causing the airplane to increase or decrease altitude, respectively.    

Frontal inversions are common in association with warm fronts. Essentially, the cold, dense air just north of the warm front settles in, and the warm air to the south of the warm front rides up and over that cold, dense air. This creates a surface-based temperature inversion that has a greater depth than what you usually see with a nocturnal inversion. 

In the winter, this kind of frontal inversion is often a key element in producing a freezing rain scenario. Skiers in the Appalachian Mountains can be in the warm air aloft, making for a cold rain event, while at the base of the mountain, it can be near or slightly below freezing with accumulating ice. Either way, this makes for a horrible skiing experience.

Lastly, radiative cooling and a nocturnal temperature inversion can also wreak havoc on ground-based Doppler weather radars, causing an unwelcomed phenomenon called anomalous propagation (AP). AP can occur whenever there is a strong temperature inversion near the surface.

The sidelobe of the radar beam is bent down or ducted back toward the earth, causing it to strike objects on the surface farther in the distance. The reflected energy follows the same path back to the radar, where it is received and interpreted as a reflectivity value. This nocturnal inversion created a large area of AP with intense reflectivity that is indicative of deep, moist convection. Even though the returns depicted on this radar image from the Indianapolis NEXRAD Doppler radar look very real, most of them are due to AP. There were a few cells on the northwest side of Indianapolis, shown in the white oval, that are actual areas of real precipitation validated using satellite imagery.

• READ MORE: What Impact Does Time Change Have on Aviation?

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The post What Do Pilots Need to Know About Temperature Inversions? appeared first on FLYING Magazine.

Question: I am a commercial pilot student, and I plan to roll right into the CFI rating to get my hours for the airlines. My CFI suggested I get a jump on the CFI training by sitting in on a private pilot ground school so I can learn how to be a teacher. The ground instructor is a CFI with lots of experience. I was surprised when the ground instructor asked me to teach the weight and balance lesson next week. I immediately reported it to the chief instructor because I’m not an instructor, therefore it’s illegal. The chief CFI said it wasn’t illegal because the ground instructor was still in charge of the class and will be there overseeing the lesson. It sounds fishy to me. I don’t really want to be a CFI; I’m just using it to build hours, so I don’t want to mess things up with the FAA by doing something illegal.

Answer: Teaching a lesson under the guidance of an experienced CFI is how most instructor candidates learn how to teach. You were given an opportunity to develop and exercise those skills. 

• READ MORE: Can You Select a DPE for Your Check Ride?

The weight and balance lesson isn’t so much aviation but basic math. The chief CFI was correct that the ground instructor is still in charge of the class. However, if you really don’t want to be a CFI, please consider finding another way to build your hours, since poor attitudes lead to poor instruction given.

• READ MORE: What Impact Does Time Change Have on Aviation?

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Question: I am about to be signed off for my private pilot check ride, and I am looking for a designated pilot examiner (DPE). I understand that the check ride endorsement is only good for 60 days. The owner of the flight school says they only use a particular DPE, but he’s so busy I’ll have to wait two months for a check ride. A friend suggested I go out of state to find a DPE, but the CFI I have been working with says the endorsement is only good in the state where I have been training. Do I have to wait for the school DPE or can I find someone else? I really don’t want to have to repeat all that training.

Answer: You can find someone else. Most flight schools do have favorite DPEs and not-so-favorite DPEs, and there are DPEs who chose not to work with particular flight schools for various reasons, but usually, DPEs are not assigned to flight schools.

The FAA has a list of available DPEs qualified to do the check ride in your area. That information can be found here.

• READ MORE: What Impact Does Time Change Have on Aviation?

Once the endorsement for the check ride is in your logbook, you have 60 days to get the ride done, or else a CFI needs to give you an additional three hours of training in preparation for the check ride—the lapse of the 60 days does not mean you have to repeat all the training.

The statement that the check ride endorsement is only good in the state you have been training is inaccurate. As the FAA is a federal agency, the endorsement is good in any state. Good luck on your check ride!

• READ MORE: How Do New Flight Students Obtain Credentials?

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Question: My workplace is struggling with the switch to daylight saving time and I’m wondering, what impact does losing an hour in the spring and gaining an hour in the fall have on aviation? I heard there are some states in the U.S. that don’t observe daylight saving time—doesn’t that mess things up for air travel?

Answer: The aviation world uses Zulu time, which is derived from the Prime Meridian running through Greenwich, England. Instead of having to convert to local time or local time adjusted for daylight saving time, pilots use Zulu time—adjusting to local time after they land.

Meridians are imaginary lines that run north and south, or longitudinally, stretching from the North to South poles. The Prime Meridian is the zero line, from which measurements are made in degrees east (E) and west (W) to 180 degrees. This is where time zones begin.

• READ MORE: How Do New Flight Students Obtain Credentials?

It takes one day, defined as 24 hours, for Earth to make a complete 360-degree rotation. Doing the math, 360 divided by 24 establishes that Earth rotates 15 degrees per hour as the sun moves across the sky from east to west. Time zones mostly fall within these 15-degree intervals. 

In the U.S., there are six time zones: Eastern (roughly 75 degrees from the Prime Meridian), Central (90 degrees), Mountain (105 degrees), Pacific (120 degrees), Alaskan (135 degrees), and Hawaii-Aleutian (165 degrees).

When it is noon in Eastern Standard Time, it is 11 a.m. Central Standard Time, 10 a.m. Mountain Standard Time and 9 a.m. Pacific Standard Time, etc.

That’s an awful lot of mental math—especially when you are traversing multiple time zones several times a day, so the aviation community uses Zulu time, with “Zulu” referencing the zero or Prime Meridian. This is also referred to as universal coordinated time (or UTC). Pilots convert to local time in the U.S. by using subtraction.

To convert Zulu to local time in the continental U.S.:

• Eastern Standard Time: Zulu time – 5 hours
• Central Standard Time: Zulu time – 6 hours
• Mountain Standard Time: Zulu time – 7 hours
• Pacific Standard Time : Zulu time – 8 hours

During daylight saving time, add 1 hour to the subtraction times.

Daylight saving time was first adopted in the U.S. during World War I. It created darker mornings and longer daylight hours used for war work. In 1974 it was adopted during the energy crisis for the same reason—starting “the day” earlier in theory gave you more daylight to work with.

In the U.S., daylight saving time runs from the second Sunday in March to the first Sunday in November.

• READ MORE: Why Is Area Forecast Discussion Important for Preflight Planning?

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Question: I have just started flight training. I was told that I need to get a TSA endorsement and then a student pilot certificate. That seems like an awful lot of work before I have even touched an airplane—how am I supposed to do this?

Answer: Provided you are a U.S. citizen, the TSA endorsement will be issued by your flight instructor after he or she verifies your citizenship using either an unexpired passport or a combination of your driver’s license or state ID card and a birth certificate. If you are a foreign national, the TSA endorsement is a little more complicated. The endorsement goes in your logbook.

(For foreign nationals, details can be found at the Flight Training Security Program.)

To apply for your student pilot certificate, you need to fill out an online application using the FAA’s Integrated Airman Certification and Rating Application (IACRA) form.

IACRA is the FAA’s web-based certification/rating application. It requires the user to come up with a username (email addresses are popular) and a password. Keep it clean, as the person who administers your check ride may not share your sense of humor.

• READ MORE: Why Is Area Forecast Discussion Important for Preflight Planning?

Once you have accessed the system, with the help of your instructor, you will fill in the boxes as required. It is your typical online application, asking for name, address, and place of birth. There is a box that asks for your social security number, and there is an option for “Do not use.” As identity theft has grown over the past decade, many pilot applicants opt for “Do not use.”

You will be issued a Federal Tracking Number (FTN) that you need to record and keep in a safe place. You will need it for check rides.

You can fill out part of the application yourself, but it is often easiest to do this with your instructor next to you, because the CFI has to verify your driver’s license number and that you are English proficient.

Note where it says “carrying of passengers prohibited”—as a student pilot, you are not permitted to take anyone with you in the aircraft. When you are flying with your instructor he or she is not a passenger, but the pilot in command, and you are riding with them as you receive dual instruction.

IACRA is an e-sign document. Once that is completed and submitted to the FAA, you can print out a temporary certificate. You should receive a plastic student pilot certificate in the mail in a few weeks.

• READ MORE: How Is an Engine Failure Handled on a Boeing 777?

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Question: I am a relatively new pilot. I recently read about something called a forecast discussion that could be useful for preflight planning. Can you tell me more about this and how I can access it online?

Answer: Since I introduced the area forecast discussions (AFDs) to the general aviation community a couple of decades ago, this has become a common resource for pilots to review before making operational decisions as it relates to weather. Just to clear up any initial confusion, the area forecast discussion is not a discussion describing the legacy aviation area forecast (FA) that was retired back in October 2017. The AFD is written by forecasters located at each of the local weather forecast offices (WFOs) scattered throughout the U.S. The same forecaster at the WFO that issues the terminal aerodrome forecast (TAFs) for their county warning area (CWA) is also responsible, in part, for issuing the corresponding AFD. The CWA defines the geographic “area” they are discussing. Shown below are the boundaries of the CWAs for the U.S. and its territories. 

The AFD is not a two-way conversation. However, it is a vehicle that the forecaster can use to document the technical reasoning behind the forecast they just issued. In other words, it’s a way for a pilot to know what the forecaster is thinking about the current trends in the forecast. Most important, this is the method the forecaster can use to quantify their uncertainty. It allows them to let the reader know what could go wrong or describe alternate scenarios. I’ve read dozens of errant terminal forecasts over the years; however, there have been very few forecast discussions that didn’t somehow confront the potential of a busted forecast before it happened. I tell all of my one-on-one online students that if you are not reading the AFDs and only looking at the TAFs, you are potentially missing out on half the forecast guidance. 

Each AFD has two primary parts of interest to pilots. The first consists of a synoptic overview and a review of the forecast weather over the next few days for the CWA. The good news is AFDs are written in plain English. The bad news is a lot of jargon is used in this part of the discussion. This is because the AFD is designed as a forecaster-to-forecaster memorandum, so it might be quite technical at times. Be prepared for dozens of terms that may be unfamiliar. For example, here’s a small excerpt from a past discussion outlining the long-term forecast. 

.LONG TERM /MONDAY THROUGH THURSDAY/…

Mid-level ridging will take place across the local area Monday into Monday evening. Mid-level transitions to a zonal pattern thereafter through Tuesday and then more SW Tuesday night through midweek with shortwave approaching. Mid-level ridging shown in forecast models thereafter through Thursday.

If you are a bit perplexed after reading an AFD, the National Weather Service glossary may help unravel some of the mystery. 

The second part is the aviation section, where the forecaster will discuss pertinent information about the TAFs they issue for their CWA. This section is generally written so that it is easily understood by any certificated pilot or other stakeholder in aviation (e.g., air traffic controller). How much information they put into this section often depends on the specific WFO, the current weather, and the individual meteorologist writing the discussion. In some cases, a forecaster can pack a lot of information into that aviation section, and some will offer few details.

For example, in the aviation section below issued by the Greenville-Spartanburg WFO in Greer, South Carolina, it’s clear that thunderstorms are expected across the area, but it’s not certain if they will impact the Charlotte Douglas International Airport (KCLT) terminal area. So, the forecaster is adding a placeholder for showers in the vicinity (VCSH) in the KCLT TAF to cover the convective threat. In most cases, the AFD may also provide an aviation outlook beyond the typical 24- or 30-hour forecast period. 

.AVIATION /16Z TUESDAY THROUGH SATURDAY/…

At KCLT…Little change from 06 UTC package as a west wind less than 8 kts under mostly clear skies will continue thru mid-morning. Expect increasing WSW winds with low amplitude gust potential by midday and perhaps periods of VFR ceilings thru the afternoon. Scattered showers and perhaps at tstm…are expected across the NC Piedmont from the afternoon until early evening and will carry VCSH for now to cover that threat. Deep convective activity will diminish by mid-evening when a wind shift to NW is expected.

There are several ways to view the latest AFDs. A few heavyweight apps provide access to the full AFD, including my progressive web app, EZWxBrief. By the way, you may see the AFD referred to as the “TAF Discussion,” or more simply, “Forecast Discussion,” leaving out the word “area.” You can also visit the National Weather Service and enter the city and state or airport identifier of interest in the location field at the top-left of the main webpage and click Go. This will send you to the local WFO’s page, where you will look for a map that says, “Click a location below for detailed forecast,” similar to the one below. 

That will take you to the correct page where you’ll find a link to the forecast discussion below the map, located further down the page on the right side. By visiting this forecast discussion link you’ll also be able to view previous versions of the AFD issued by this WFO.

However, don’t just skip to the Aviation section. Read the synopsis and then focus on the part of the discussion that is pertinent to your proposed departure time. The Aviation section only may be viewed at the Aviation Weather Center (AWC). Selecting the CWA here on the map searches the latest AFD and pulls out only the text associated with the aviation section (if any). 

Here’s my suggestion: Before you spend any time sifting through the TAFs along your route or at your departure and destination airports, take a few minutes to peruse the AFDs to get a good overview of the weather before examining the “fine print” that represents the TAFs. In some instances, your final decision might actually hinge on the forecaster’s comments in the AFD. 

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QUESTION: I am learning to fly in a place where there are lots of bald eagles around. I’ve seen a few in the air and I worry about hitting them. What happens if I hit an eagle? The guys at the airport told me you go to prison and lose your pilot certificate—is this true?

Answer: No, you do not lose your certificate or go to prison for an accidental midair with a bald eagle—or any other bird. 

• READ MORE: Decoding the Weather

You should, however, report the incident to the state fish and game department. They will want to know the place, date, and time of the incident, because one of the things they do is track animal migration patterns. 

If the animal encounter happens when you are in the traffic pattern, report it to the airport manager. Part of their job is keeping track of wildlife on the airport, and a sudden increase in a certain type of animal, such as deer or elk, could mean there is a hole in the fence, which would impact the airport’s security.

• READ MORE: Wildlife Is a Growing Threat to GA Pilots in the Summer

Do you have a question about aviation that’s been bugging you? Ask us anything you’ve ever wanted to know about aviation. Our experts in general aviation, flight training, aircraft, avionics, and more may attempt to answer your question in a future article.

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QUESTION: Let’s face it, technology has advanced in the last decade or two, so why do we have to know how to read all that goofy textual weather?

Answer: There’s a great divide in our aviation community that’s been going on for decades with no end in sight. That is, why are we in the 21st century and still decoding the cryptic language of surface observations, terminal aerodrome forecasts (TAFs), and pilot weather reports (PIREPs), just to name a few? After all, they coded these reports or forecasts more than a half-century ago because of the limited bandwidth in the days of 1,200 baud rates, right? Well, yes and no. There’s no harm blaming this on these data limitations, especially if it makes you feel better, but that’s not the real reason they were coded in the first place. And no, the coded form wasn’t preserved over the years as a hazing ritual for student pilots.

The primary goal of the coded form was to allow forecasters, observers, or other stakeholders in the aviation or weather industry to key in observations and forecasts quickly. One could argue otherwise, but it wasn’t as much about the consumers of this data or the bandwidth of the teletype connection used as it was about the data entry time and opportunity to make mistakes. 

Typing more characters likely means a greater chance to make a mistake or two. Multiply that by thousands of observations (or forecasts) every hour, and that adds up to a lot of potential mistakes.   

Now that we’re in the 21st century, is there any reason to keep the coded form around? Certainly. For the same reasons as before? Not exactly. 

Although the code today is different than what you see above, automated systems are programmed to generate the text. You may use some heavyweight apps and other web applications to ingest that coded text and translate it into something a little more readable. Sometimes the translation is near perfect, and sometimes it is not. This often depends on the translator’s assumptions—and hundreds of them are out there. Even if the automated system follows the exact standard, exceptional cases pop up from time to time which may cause a poor translation…sometimes really poor.

For example, in this coded surface observation, the remarks include FZRANO:

KPVU 011356Z 15005KT 10SM CLR M14/M19 A3018 RMK AO2 SLP281 T11441194 FZRANO

The Federal Meteorological Handbook No 1 under 12.7.2 (j) Station Status Indicators states, “…when automated stations are equipped with a freezing rain sensor and that sensor is not operating, the remark FZRANO shall be coded.”

Therefore, this just indicates the freezing rain sensor at KPVU is not operational. However, some translators (including the one at aviationweather.gov) will often pick up on this as a freezing rain event (FZRA) which gets added to the translated observation present weather as “freezing rain” when in fact, there isn’t any current precipitation observed, freezing rain or otherwise–the sky is clear.

Most heavyweight apps that aviators use today have a feature to translate the coded version into plain English. If that floats your boat, then so be it. If you are more like me and enjoy the compressed version or tabular form, then there’s no reason the coded text should be abolished or minimized in any way as “outdated.” Let’s face it, translators make poor translations. It could be owing to a flawed assumption or software design, or malformed coded text from the source. All of these occur regularly. That’s the underlying issue.

For example, look at the translation below. This is from the WxWorx XM satellite weather broadcast, which translated +TSRA into a “heavy thunderstorm” instead of a thunderstorm with heavy rain. In fact, WxWorx translated TSRA to “moderate thunderstorm,” and -TSRA was translated to “light thunderstorm”—as if there’s such a thing as a “light” thunderstorm.

KCLE 102323Z 36015G22KT 1/4SM +TSRA FG SCT007 BKN021CB OVC033 23/22 A2981 RMK AO2

Perhaps today there’s a better approach; why not have the automated systems generate the observation or forecast in a plain English fashion? First, that would require the software of all of these automated systems worldwide to be modified to generate plain English text. 

Then, of course, the applications that consume this data would need to be modified to ingest the new form of text. Easy to say but costly to implement. But it could be done. For example:

• MODERATE RAIN vs. RA
• LIGHT SNOW vs. -SN
• Moderate rain and thunderstorm vs. TSRA (if you don’t like caps)
• WIND 250 DEGREES AT 10 KNOTS AND NO GUSTS vs. 25010KT
• VISIBILITY 5 STATUTE MILES vs. 5SM
• OVERCAST 2,500 FEET ABOVE GROUND LEVEL vs. OVC025
• INDEFINITE CEILING 300 FEET ABOVE GROUND LEVEL vs. VV003.

I am all in for plain English as long as the coded version is preserved or it gets translated correctly back into coded form. But that places us right back into the same issue of poor translations or mismatches between plain English and coded forms. So, the problem isn’t completely solved, but at least we’ll get to argue about a different issue.

The post Decoding the Weather appeared first on FLYING Magazine.

QUESTION: How is an engine failure handled on a Boeing 777?

Answer: Considering that a Boeing 777-300 with GE 90-115 engines has a thrust rating of 115,000 pounds per side, the resulting asymmetric thrust from a failure is a force to be reckoned with. Granted, 3,000 psi of hydraulic pressure to the rudder and an electronic flight control system helps a lot. But there’s a bit more to it.

• READ MORE: When Is It OK To Use Pitot Heat?

Like any twin-engine airplane, the reaction of a 777 pilot should be to recite the iconic verbiage of, “Dead foot, dead engine,” and then apply foot pressure to the appropriate rudder pedal.

At low speed during the takeoff phase, a lot of foot pressure would be required if it weren’t for the 777’s bonus system of TAC (Thrust Asymmetry Compensation). After sensing differential engine thrust of greater than 10 percent, the TAC applies enough rudder pressure to keep the airplane from rolling while allowing the pilot to sense the correct input, adding just enough of his own pressure

• READ MORE: Am I Allowed To Review the Aircraft Logbooks Before I Rent?

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Question: I am a student pilot and I just completed my first solo cross-country flight. The temperature and dewpoint at the surface were identical and at altitude the temperature was below freezing. I fly a carburetor equipped Cessna 172 in the midwest and it is winter, so I used the carburetor heat a lot while at an altitude of 3,500 feet. There was haze and clouds forming (visible moisture) so I activated the pitot heat as well because I was worried about ice forming on the airplane, especially the pitot tube. We talk a lot about the use of carb heat in training but not so much about pitot heat—when should that be activated? I went through the POH for the 1971 Cessna and didn’t find any guidance.

Answer: The activation of pitot heat is predicated on the occurrence of “possible icing conditions.” You mention the temperature was below freezing at altitude and there were clouds forming which indicates moisture, so the potential for icing existed. 

Pitot heat, per the Pilot’s Handbook of Aeronautical Knowledge is an anti-icing device, not a deicing, so the prudent thing to do is to activate the pitot heat when in flight and there is the potential for icing to happen. Caveat: the electrically heated pitot tube gets warm very quickly, but the airflow passing over the pitot tube during flight keeps the electrical element from overheating. On the ground, the airflow over the pitot tube is not sufficient to prevent this, therefore the pitot heat should be turned off after landing. 

As far as ice forming on the airplane, I have seen frost form on the wings where the fuel tanks are. It doesn’t matter if it is a high wing or low wing—that fuel is cold and frost can form on the wing in flight.

• READ MORE: Does an Endorsement Cross State Lines?

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• READ MORE: Am I Allowed To Review the Aircraft Logbooks Before I Rent?

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Question: I am a U.S.-based pilot, and I recently completed an accelerated program to achieve my private pilot certificate. I was endorsed for the check ride, but unfortunately the morning of the event, there was a mechanical issue with the airplane. The program is out of state for me, and I couldn’t afford to miss any more work, so I left without taking the check ride. The instructor who signed me off told me I would have to return to complete the check ride, because his endorsement is only good in that state because he is a new CFI. Is this accurate?

Answer: No, it isn’t. A flight instructor certificate is a federal certificate—just like a private pilot certificate—therefore, it is good in any state. A search of the FAR/AIM and advisory circulars failed to show a “new CFI” limitation as you describe it. It may be that the CFI was confused or was trying to get more money out of you.

Renting an aircraft for a check ride and a check ride only can be hit or miss. There are some FBOs that won’t allow you to rent their aircraft for a check ride unless you have flown with and been signed off by one of their CFIs, and only if you fly with ‘their’ DPE (designated pilot examiner), citing ‘insurance reasons.’ It doesn’t matter if you already have a private or commercial certificate, have flown with them before, and even trained there. Other FBOs aren’t so restrictive. As long as you possess a valid pilot certificate and medical, you are good to go.

• READ MORE: Am I Allowed To Review the Aircraft Logbooks Before I Rent?

Do you have a question about aviation that’s been bugging you? Ask us anything you’ve ever wanted to know about aviation. Our experts in general aviation, flight training, aircraft, avionics, and more may attempt to answer your question in a future article.

• READ MORE: What Can You Do To Avoid an Incident or Accident?

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Question: I am a fairly new private pilot and I just moved to a new state, which means I need to find a flight school to rent airplanes from. I went to one and when I asked to see the logbooks for the aircraft the person behind the counter refused, saying they weren’t going to do that unless I was from the IRS or the FAA and the owner of the school was there.

I thought it was common practice to review logbooks before you rent an aircraft? Or should I just trust that the school knows what they are doing?

Answer: This sounds like the person behind the counter heard the word “books” and missed the word “log,” so they thought you were asking for the financial records of the school. 

Maintenance logbooks are a completely different entity, and you are correct, reviewing them before you take up an airplane is good practice because it is part of the determination of airworthiness. If an inspection is overdue or an AD not complied with, that makes the aircraft unairworthy and if you are pilot in command, you are responsible for determining airworthiness. Always check the logbooks before you fly something for the first time if you can, and periodically before check rides or after major maintenance.

• READ MORE: What Can You Do To Avoid an Incident or Accident?

I am puzzled by the insistence that the business owner has to be there during the process, unless he or she is the only person who has the keys to the safe or office where the logbooks are kept. It is not uncommon for the flight school to want one of their employees to oversee the process—those logbooks are valuable, but the check shouldn’t take you more than an hour, so it usually isn’t too expensive if you have to pay for the employee’s time.

Do you have a question about aviation that’s been bugging you? Ask us anything you’ve ever wanted to know about aviation. Our experts in general aviation, flight training, aircraft, avionics, and more may attempt to answer your question in a future article.

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Question: What can you do to avoid an incident or accident? 

Answer: The best way to prevent disastrous aviation events is to plan for anticipated threats. 

It all starts with a thorough preflight. Then, before you taxi out to the runway, mentally brief the takeoff and climb. If you’re flying VFR, make sure to stay out of airspace or communicate with ATC. If you’re on an IFR flight plan, verify each fix in the flight management system or GPS. An erroneous route could lead to a violation, which probably won’t kill you, but could jeopardize your certificate. 

• READ MORE: Are There Any Amendment Criteria for a TAF?

Visualize each step of the flight and think through possible threats. What’s your plan for weather events, engine trouble, busy traffic patterns, terrain, etc.? If you only have one engine, where is the best place for an emergency landing? What’s the minimum altitude for returning to the field? What are the odds of a diversion? Do you have enough fuel for a hold or lengthy reroute? Finally, always plan for a go-around or missed approach. 

• READ MORE: How to Fly Into a Big Airshow With Confidence

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Question: Can you tell me if there are any amendment criteria for a TAF (terminal aerodrome forecast)?  If so, what are they and how are they applied?

A. Most of the official aviation weather forecasts you will get on a standard briefing or via your favorite heavyweight aviation app or website are issued by aviation meteorologists located at the Aviation Weather Center (AWC) in Kansas City, Missouri. This includes graphical AIRMETs (G-AIRMETs), SIGMETs (WS) and convective SIGMETs (WST). Terminal aerodrome forecasts or TAFs, however, are not issued by the AWC nor are they issued by Flight Service; they are issued by forecasters physically located at your local NWS Weather Forecast Offices (WFO) throughout the United States and its territories shown below. The meteorologists at the local WFOs are very familiar with any local weather effects and have the best opportunity to produce a quality forecast for aviation. 

Your local WFO typically has the responsibility for issuing the TAFs for six or seven terminal areas on average. At the Greenville-Spartanburg WFO, for example, they issue the terminal forecasts for six airports to include KAND, KGSP, KGMU, KCLT, KHKY, and KAVL.

• READ MORE: Ask FLYING: Why Are Windsocks the Color They Are?

Scheduled TAFs are issued routinely four times a day at 00Z, 06Z, 12Z and 18Z. They are typically transmitted 20 to 40 minutes prior to these times. Once the TAFs hit the wire, the forecaster must continue to compare the forecast to the actual observations for the airport to be sure it accurately depicts the ceiling, visibility, wind, and weather occurring at the airport. When there is a discrepancy or the forecaster feels that the TAF isn’t representative of the weather that may occur in the terminal area within the TAF’s valid period, they will issue what is called an unscheduled TAF, better known as an amendment.   

The forecaster doesn’t literally have to watch the observations minute by minute. In fact, they have a program called Aviation Forecast Prep Software (AvnFPS) that monitors the observations at the respective airports. Based on programmed criteria, the software compares the terminal forecast to the latest observations for each TAF site issued by that forecaster and flags the forecast element as green when they match. When the program highlights a forecast element as yellow or red, this means the difference is near or has exceeded the amendment criteria. As can be seen above, the forecast for the most part matches the current observations for those airports in the Greenville-Spartanburg WFO (most elements are green). However, there are three terminal areas (KAVL, KHKY, and KAND) that show yellow for wind (speed or direction) implying that the forecast is not quite in line with the current observations. This allows the forecaster to quickly scan the display to determine if there is an immediate need for an amendment to one or more of the TAFs they issue. 

Amendments are the absolute best way to provide the highest quality forecast. In general, a forecaster will issue an amendment when it meets specific criteria that are imminent or have occurred and those conditions will, in the forecaster’s estimation, persist for 30 minutes or longer, or new guidance/information indicates future conditions are expected to be in a different flight category than originally forecast, especially in the next one to six hours.

• READ MORE: How to Fly Into a Big Airshow With Confidence

Just like instrument students are taught by their instructors not to “chase the needles,” forecasters are similarly encouraged not to chase the observations. For example, an unexpected, but brief rain shower may quickly develop and pass by the terminal area temporarily lowering visibility below the visibility in the TAF. The forecaster may be tempted to issue a quick amendment, but if the condition is expected to be brief, there’s no value to issuing an amendment—especially if it doesn’t alter the flight category (i.e., VFR, MVFR, IFR, LIFR) for the airport.  

The following categorical amendment criteria table below defines the thresholds of importance. 

In addition to the categorical amendment criteria above, below are other criteria where an amendment may be necessary. 

Weather

The TAF should be amended if thunderstorms, freezing precipitation, or ice pellets occur and are not forecasted, or, if forecasted, do not occur.

Wind Direction, Speed, and Gusts

The forecast mean refers to the mean wind direction or speed expected for the specified forecast group time period.

• The TAF should be amended if the forecast mean wind speed differs by ≥ 10 knots, while original or newly expected mean wind speed is ≥ 12 knots.
• The TAF should be amended if the forecast wind gust (or forecast of no gust) differs from observed wind gust by ≥ 10 knots (or above the observed mean wind speed if no gusts are forecast).

Non-convective Low-level Wind Shear (LLWS)

The TAF should be amended if non-convective LLWS is forecasted and does not occur, or if LLWS occurs and is not forecast.

• READ MORE: How Do I Report Braking Action?

The forecaster that issues the TAFs is assigned to the “short term desk” and has other duties to include the area forecast discussion (AFD) and may also include the issuance of severe thunderstorm or tornado warnings for their county warning area (CWA). The forecaster shown below is located at the Greenville-Spartanburg WFO and has recently transmitted the 1800 UTC scheduled TAFs and is now working on the gridded forecasts for the GSP region. The national gridded forecasts can be found here. The AvnFPS software compares the current observations to the gridded forecasts looking for differences as well.

As mentioned earlier, TAFs are issued at prescribed times every six hours. For the Chicago, Atlanta, and New York City terminal areas, however, TAFs are now issued every two or three hours. The NWS began this about a decade ago as part of an enhanced aviation project for the FAA…and it went over so well that they adopted it permanently. For the Chicago O’Hare airport (KORD), for example, you might even see 2-hourly updates at certain times during the day. The 2-hourly issuance times match the times of the FAA planning conference calls. Unlike other WFOs where forecasters that issue TAFs have multiple duties, these WFOs have a dedicated aviation forecaster. 

Here’s the ugly side of this improvement. The two- or three-hourly forecast is treated as an amended forecast, not a newly constructed TAF. In fact, these non-standard scheduled TAFs will carry the AMD tag when viewed online or via a standard briefing. So, there’s no way to tell if the forecast was changed because the amendment criteria was reached or because it was time for a new forecast. Moreover, you won’t see a new forecast if an amendment has been issued within 90 minutes prior to the next 2- or 3-hour non-standard scheduled forecast. For many pilots, this subtle change won’t cause any significant impact to your current flight planning regiment. If you happen to fly into or out of a busy airspace such as Chicago, Atlanta, or New York, just keep in mind that forecasts will be updated much more frequently even on those not-so-challenging weather days. In the end, if you see a terminal forecast tagged with AMD, it may not be because the previous forecast was misaligned with reality. It simply may be a new and improved forecast for you to ponder.

• READ MORE: How Can I Get a Special VFR?

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The post Are There Any Amendment Criteria for a TAF? appeared first on FLYING Magazine.