Chuck’s Aircraft 10 Year Anniversary Fly In

Circle to Land Approaches

ByHank Gibson November 20, 2015November 21, 2015

When I was doing my instrument and multi-engine training, we did a lot of circle to land approaches.  As a student, I could never figure out why these types of approaches would ever be practical when you could an approach straight in to another runway.  But, as a good student, I never asked my instructors the purpose of them, I just did them to the best of my ability.

Now, having been flying in the IFR system for almost a decade, I’m finally beginning to fully understand the practical purpose of a circle to land approach.  I have actually elected to do an approach where I had to circle to land on several occasions in actual IMC conditions.

One important note to remember on circle to land approaches is that the minimum descent altitude (MDA) is always higher than on a straight in approach.  The reason for this is that you are basically joining the pattern for a different runway and you have to be able to visually keep yourself clear of towers and other obstacles.  So, you need a higher visibility and a higher ceiling than if you were just lining up to come straight in.

Here are a couple of practical circumstances where it would make sense to do a circle to land approach.

Airports with only 1 straight in approach

This one is easy.  There are a number of airports scattered around the US that have only 1 straight in instrument approach published for it.  Around my part of Texas, the first one that pops into my mind is the RNAV 31 at T85 in Yoakum, TX.  Most of the year, the prevailing wind is out of the south, so 13 is the favored runway at T85.  During the winter is when most of the IMC weather happens in South Texas, so that is why the approach is for 31.

Of course, especially this year during the summer, there are some IMC days where an approach to T85 would be necessary.  When there is a strong wind out of the south, landing on 31 is impractical, so a pilot would fly the approach to 31, then circle to land on 13.

Approaching from the opposite direction

Take a look at the RNAV 19 at KBMQ, Burnet, TX.  The two initial approach fixes (IAF) are IXANY and JIBAJ.  If a flight is approaching BMQ from the west or north, this is an easy approach to join.  If a flight is coming from Austin (directly the the east and a little south) or San Antonio (almost directly south), it would be a bit of extra flying to get configured properly for the approach.  Especially coming from Austin, because the degree of turn to join at JIBAJ wouldn’t make the approach practical.

Well, how about vectors?  Unfortunately, Houston Center doesn’t have this approach depicted so vectors aren’t a possibility.  Center can give you vectors north to make the angle a little easier to join at JIBAJ, but they can’t vector you onto the approach.

Direct DLORA to join is another option, but again, if you are approaching from the southeast, the angle is wrong.

Insert the RNAV 01 approach with a circle to land.  AMUSE is right on V163, so it’s really easy to join the approach there coming from the south.  Coming from Austin, joining the approach at SUBIE works out great. Fly down to the MDA, join the left downwind for 19, and everyone is happy.

VOR Circle to Land Approaches

Every instrument pilot has had an instructor “force” them to do a VOR A or VOR B approach and no one enjoys them.  I personally think they are good practice.  With the number of RNAV systems and RNAV approaches out there, though, VOR approaches are becoming a bit archaic.

They do have a place in this discussion, though.  A VOR approach is given an A or B designation when the angle of the final approach course is greater than 30 degrees to the runway (VOR A KLZZ), or the final approach course is lined up with the runway, but the MDA is too high to practically descend and land (VOR A KGRK or the VOR/DME C KASE).

So, there are practical uses for a Circle to Land approach.  The next time you do some IMC work with an instructor, ask him/her if you can include one.

Synthetic Vision Technology

ByHank Gibson December 5, 2014December 5, 2014

Let’s say you’re flying in the mountains of Colorado on a cloudy day.  There’s a solid layer from the surface all the way up to 14,000 feet.  You’re inbound to Eagle (KEGE) on the RNAV (GPS) D approach.  There are mountains next to you and below you, but you aren’t concerned since you can see them all.  The base of the last reported overcast layer was 3,000 feet, so you know you’ll break out before the MDA and land no problem.

At 11,100 over AWACC, you clearly see the top of the mountain below you.  You are comfortably above it. You already have the runway in sight as well.  You pop out of the clouds on the approach at 9,700 feet, spot the airport and follow the tower’s instructions to circle north of the runway for a left base for runway 7.

How could you see the mountains inside the clouds?  You have Synthetic Vision installed on your glass panel, that’s how.

Synthetic Vision, which has actually been around since the ’70s when NASA and the US Military first developed it, was first FAA certified for the Gulfstream PlaneView flight deck in 2009.  Garmin, Avidyne, and Aspen are the main general aviation manufacturers of synthetic vision these days.  All Garmin PFDs are now equipped with Synthetic Vision while Aspen gives you the option to upgrade to Synthetic Vision when you get one of their PFDs installed.  Avidyne gives you Synthetic Vision in their R9 upgrade for the Cirrus.

What is Synthetic Vision?  Basically, it’s a 3-D picture on the primary flight display showing terrain, obstacles, traffic, and runways.  It greatly enhances situation awareness in areas of terrain or high obstacles during IFR conditions or at night.

The goal behind the development of Synthetic Vision was to decrease the amount of controlled flight into terrain (CFIT) accidents.  A CFIT accident consists of a perfectly airworthy airplane flown by a pilot (or autopilot) unintentionally into terrain. These accidents can happen in low visibility conditions or at night, but the reason is mainly due to the pilot losing track of his position in relation to obstacles or terrain (or water as was the case with JFK Jr.).

With Synthetic Vision, the goal is to enhance pilot knowledge of what is around the airplane at all times. When you’re at altitude, the terrain below you looks flat.  When you start descending down amongst the rocks, the hills or mountains start to rise up on your screen.  For those used to the coloration with the 2-D terrain feature on a GPS unit, it translates very easily to the terrain coloration on a Synthetic Vision equipped PFD. Terrain that is between 100 and 500 feet below the aircraft is shown as yellow, while terrain closer than 100 feet is depicted as red.

One neat feature on Garmin units is the Highway in the Sky.  When a pilot puts a course or a flight plan in the GPS, the PFD displays magenta boxes at the altitude selected displaying the route.  It’s handy when hand flying to just “fly through the boxes.”  They also display descent angles on approaches.

Synthetic Vision is still optional on Garmin and Aspen units, but I highly recommend springing for it.  It will give you a higher level of safety and keep you out of the rocks.

The Aunt Betty Directive: PFD Failures

ByCharles McDougal April 8, 2015April 15, 2015

Glass panel displays, ballistic parachute aircraft recovery systems, portable tablet computers enabling paperless cockpits, and widely available three axis autopilot systems have changed the way we fly, the way we train, and the way we are expected to perform on check rides. Our training and testing paradigms have tried to stay in synch, yet always seem to be catching up to the latest levels of technology.

This is very apparent when we instructors are preparing a student for an FAA practical test. When training aircraft had no autopilots, no GPS, and certainly no parachutes, the general philosophy was that during training, the student should have the lowest level of technology available. This was also the expectation on the check ride. This theory has changed over the years and now the Practical Test Standards require that an applicant integrate all available technology while demonstrating mastery of his or her aircraft. This raises numerous questions from instructors and students about what technology will be available for each task.

One example of this dilemma is found when contemplating an instrument airplane practical test in a Cirrus SR20/SR22. The test requires the task “Instrument Approach without Primary Flight Display”, which has taken the place of what was the partial panel approach, accomplished without use of gyroscopic heading and attitude indicators. In the Cirrus, the standby attitude indicator, standby airspeed, and standby altimeter are available, as is the Multi-Function Display. Guidance from the FAA has us shooting a GPS approach using the moving map display on the MFD after disabling the PFD. Those of us who trained and tested in steam gauge aircraft think that this task should be fairly easy. With a fully functional Attitude Indicator and a nice big moving map display showing our course, a reasonably competent instrument pilot should have little trouble adapting to this setup and flying a good approach.

But, in the Cirrus specifically, and perhaps in other aircraft as well, another question comes up. Can the applicant use the autopilot (which still works just fine after a display failure) during the approach without the PFD? A rather famous DPE who writes for a national magazine says “yes”, opining that not to allow its use would be introducing simultaneous multiple systems failures, which is strictly forbidden in the minds of some. If we follow this logic, we would not test simulated engine failure emergencies in these aircraft either, because to do so would imply failure of not only the engine, but the CAPS parachute system as well. In my former role as a pilot examiner, I always said no, that the approach should be hand flown. Here is my logic.

I was amazed that flight instructors and examiners would accept the substitution of autopilot technology for the skill required to fly an approach without the PFD. I would argue that the intent and the well described emphasis of the PTS is that the applicant must demonstrate the ability to control the airplane after a loss of the primary flight display, not observe and monitor the autopilot controlling the airplane! This argument was generally unpersuasive, so I approached from a different point of view, that of a concerned family member.

“Aunt Betty” represents a future passenger flying with the soon to be rated instrument pilot. Here is the question posed to Aunt Betty: “When we train and test pilots for instrument proficiency, we require them to demonstrate the ability to safely and skillfully fly the airplane without their primary instruments. Now, Betty, in this airplane, we can test this task in one of two ways. We would like your input on which way you would prefer, seeing as you will be a frequent passenger with your nephew. We can either have the pilot (might be your son, brother, husband, or nephew) demonstrate that he can fly the airplane by hand without the PFD, which does require a little more skill and a slightly different technique, or, we can require the pilot to perform this task using the autopilot so that the pilot basically monitors the airplane flying itself on the approach.

“Now, Aunt Betty, a pilot allowed to use the autopilot system on this approach may not have the skill or technique to fly the approach by hand in the clouds should the autopilot shut down due to turbulence or mechanical failure. Should this happen to a pilot without the skill and practice normally required, the odds of a fatal accident occurring would be quite high.

“So what do you think, Aunt Betty? Would you feel more comfortable flying with this fellow if he has demonstrated mastery of the aircraft (sans PFD) without the autopilot or only with its assistance?”

This leads us to a larger discussion about the use of other technology, iPad, GPS moving map, and more. If technology is used as a replacement for pilot proficiency during training and testing, we end up with less skillful, less competent and ultimately less safe pilots. But, if we require that our students demonstrate mastery with the lowest available level of automation and technology (which, by the way, implies excellent fundamental aircraft control skills) then, when technology is added into the equation, we have a safer pilot.

Technology can be a value added safety multiplier, or it can be a crutch needed to make up for lack of fundamental and advanced skills. Crutch or Safety Multiplier, which one will you choose? I know which one Aunt Betty prefers.

Charles McDougal is a flight instructor, corporate pilot, and former DPE ‎who offers basic and advanced flight instruction in the San Antonio area.  To find out more information about Charles or to contact him, visit his website, www.flighttrainingcoalition.com.