All posts tagged 'information'

Refreshing Your Knowledge on RNAV/GPS Approaches

It's beginning to reach that time of year where we transition into Spring, meaning one really important thing:

Low IFR. 

Not that we don't experience low IFR throughout other seasons, but as we transition into warmer temperatures, the temperature/dewpoint spread likes to stay close. This is especially true for nighttime and early mornings until the sun comes out and burns everything off. So now is the perfect time to read up on approaches and make sure you're ready for it!

Specifically, RNAV/GPS approaches. Thanks to the invention of WAAS (wide area augmentation system), these GPS approaches are becoming more common.

GPS approaches are also highly accurate because they require something called RNP-required navigational performance. RNP means that the needle when centered for the course is within .3nm of runway centerline 95% of the time. So next to an ILS approach, GPS approaches can get you some pretty low minimums. 

When it comes to understanding GPS approaches, there are a lot of terms and acronyms to know that can be confusing at first. Understanding them, however, makes for a better IFR pilot! So let's discuss and break these down:

  1. DME: you've probably already heard and remember this term but if not here's a refresher. DME stands for distance measuring equipment. Notice at the bottom of the KHOU chart above categories you see numbers in nautical miles, there's your DME! So you can also identify each fix by their distance.                                                      RNAV GPS Chart
  2. LP: Localizer performance. Remember earlier we talked about WAAS? Well, this requires WAAS and is a mode independent of LNAV AND LPV. The above plate doesn't depict it but it would be the equal counterpart of having localizer only on an ILS approach. Higher minimums but still more sensitivity as you reach closer to the runway area. 
  3. LNAV/VNAV: This is more commonly seen than LP. It has higher minimums than LPV but can still bring you in pretty low on an approach with great accuracy (you won't break out 30 degrees off the centerline). What you should understand about this is it is horizontal and vertical guidance down to minimums. They however are not flown down to an MDA, but a decision altitude. Meaning look outside at this altitude and decide if you're landing or not! The quicker you can reach this (while still being stable), the better. Don't forget to also take a look at baro-VNAV temperature notes. This can raise minimums and get you in a pickle if not adhered to as your airplane has to abide by these corrections (I say get in a pickle...the possibilities of what can happen can truly be unsafe). 
  4. LPV: my favorite type of GPS approach minimums. LPV stands for localizer performance with vertical guidance. In reality how I picture this is it is the next best thing to an ILS approach, but still NONPRECISION. But why is it nonprecision? Well LPV minimums are the lowest of all GPS mins and you must have WAAS onboard. Unlike a localizer, the sensitivity does not increase as you become closer to the threshold. Instead, it caps to linear scaling 700 feet wide AT the threshold but will not become any narrower. They are very operationally similar to an ILS and are flown to a DA just like LNAV/VNAV, but are far more economical because no navigation infrastructure is required at the airport.
  5. Baro-VNAV: and here's one of my least favorite types of GPS approaches. This stands for barometric vertical navigation (that's a mouthful). From what we mentioned earlier, it can constitute for sticky situations if not compensated for. Think of your pitot-static system when you think of baro-VNAV, because that's exactly what it relates to. It uses approach-certified baro-altitude information from the pitot-static system and air data computer to register the vertical guidance.
    RNAV RNP Chart
    - Pictured is a circled noted area on the RNAV 35L Z approach into KOKC. Notice how it gives you temperature restrictions that make the procedure NA? That means don't even try it. 
  6. GBAS: last but not least is ground based augmentation system. GBAS does what is called "augment" the GPS, meaning it provides corrections and improves navigation. This is very much a precision approach. You will also see this termed as GLS, which the FAA uses as GBAS landing system. You likely have never heard of GBAS or shot a GBAS approach, and this is because it is only in use by several airlines around the world. The way it works is by using a 5-digit channel (similar but don't get it confused with WAAS) to tune into the FMS for better accuracy. 

 There are a few other terms this post does not cover, examples including LNAV+V or APV type procedures. There is a lot to know about RNAV/GPS approaches but this covers the most commonly used and also the most commonly covered on instrument check rides. Stick around for a post in the future digging into the rest of this information. The more educated we are, the safer instrument pilots we become.

 

Note: all information here was derived from the AIM and FAA published instrument handbooks. These are subject to change over time so please ensure you keep your materials updated!

Understanding the Fundamentals of Instructing

Picture this: it's your first flight lesson ever. You walk into your brand new flight school, in which you've never flown their planes before, and have yet to meet anyone you know there. This is all fresh to you. Do you think your first flight lesson will be highly productive, or will produce somewhat of a challenge?

The answer is, according to Maslow's hierarchy of needs, that you will not learn as much as if you felt comfortable in your new school. This is the belonging hierarchy. Once you get settled in, learn their fleet, make some friends and are known by the people there then you'll start to unconsciously progress better with each lesson.

Factors such as this are what makes up what is referred to as Fundamentals of Instructing, or FOI's. 

FOI's are important to the instructor in flight training as well as to the student because it defines concepts like human behavior & how we acquire knowledge; why we act the way we do and how we learn. 

Let's discuss some important topics of FOI's that are commonly seen as well as discussed on a flight instructor check ride:

1) Human Needs That Must Be Met to Encourage Learning

Physiological: Biological needs such as water, air, sleep and shelter. It's easier to focus and grasp something when you've eaten and are properly hydrated compared to when you're not.

Security: Feeling safe and secure in the environment around you

Belonging: Just as previously discussed, feeling wanted and including

Esteem: Have you ever heard of a lesson where your instructor refers to it as confidence building? Self confidence is important in flying

Cognitive & Aesthetic: This is connected to when we as humans like or don't like something. We'll learn more from a teacher that we like than one we don't.

Self-Actualization: I like to think of this as knowing where you're at and where you're going. Helping a student achieve their potential is an important job of a flight instructor.

2) Defense Mechanisms

Repression, Denial, Compensation, Projection, Rationalization, Reaction Formation, Fantasy, and Displacement

These are important to recognize because they're excuses (so to speak) that people use when they have a bad experience to protect their ego. One of the most common exhibited by students in flight training is reaction formation; faking a belief opposite to the true belief because it causes anxiety. For example, pretending they don't care how their lesson went after a bad day when in reality it bothers them. These can all be found in more detail in the Aviation Instructor's Handbook chapter 1.

3) Types of Practice

Skipping ahead to chapter 3, there are types of practice instructor's can use to help a student learn a skill. These are:

Deliberate: Aiming a practice at a deliberate goal, such as specifically focusing on slow fight during one lesson. The student and instructor have set a goal to accomplish something before beginning the lesson.

Blocked: This is doing the same drill until the movement becomes automatic, also known as creating a muscle memory. Blocked practice can be seen most often during landings, as the instructor has the student memorize a before landing checklist. The student configures the plane on downwind (mixture full rich, carb heat, gear down etc) then can go to the checklist to ensure they did not forget an item. 

Random: Random practice is mixing up skills, for example going out and giving the student maneuvers to perform randomly so it tests how well they understand and can perform it consistently. 

There are MANY many concepts to learn about when studying FOI's. These are just 3 that will likely be brought up by an examiner, however they will cover much much more. 

The Aviation Instructor's Handbook as well as the Flight Instructor Oral Exam Guide published by ASA are good materials to use when preparing for a CFI check ride. 

After you finish reading about FOI's, go check out some more articles full of aviation information published by Globalair.com as well as reading articles written by our 2019-2020 scholarship recipients! 

Questions are comments about FOI's? Comment below

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