Author: Hank Gibson

  • Circle to Land Approaches

    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.

  • PIREP: Austin Bergstrom Recovering After Flood Damage

    The massive storms that rolled through the Austin Bergstrom and San Antonio areas last Friday not only put a dent in the landscape, they put a dent in the skies too.

    The Austin Bergstrom (KAUS) control tower suffered significant flood damage Friday.  6 inches of rainfall in an hour caused water to come pouring into the first floor of the tower, flooding the radar room and knocking out the power.  This led to transmission outages for the tower, ground control, clearance delivery and the ATIS.  Similar to the Chicago Center fire last year (though this was a much smaller section of airspace), the area normally controlled by Austin Approach was replaced by a big, gaping radar hole.

    By 8:45am on Friday morning, the Austin Bergstrom airport actually closed.  One runway eventually opened back up Friday afternoon, but massive delays and cancellations had already taken place.  All the ILS approaches were down and Houston Center had taken over the airspace normally occupied by Austin Approach control.

    Austin Temprorary Tower

    A temporary, emergency tower vehicle was brought in by the FAA (it’s essentially an RV with communications and a giant window) by the end of the weekend.  All arrivals and departures were restricted to 17L and 35R.

    Due to the radar outage, I heard there was as much as a 4 hour delay even for planes coming into Austin Bergstrom from Dallas, and that was in VMC conditions on Sunday and Monday.  Tuesday and Wednesday brought IMC conditions which only enhanced the delays.

    The latest news is that Austin Approach will be opening back up, but in a satellite base in San Antonio.  The Austin controllers will be using the SAT radar room and will be receiving their radar picture via satellite.  The approach frequencies should be up and running today or tomorrow.  The Austin Bergstrom tower is up and running and most of the ILS approaches are operational at this point.

    In the meantime, expect delays going in and out of Austin.  If you don’t have to get to AUS, EDC, or GTU, you’re better off delaying a day or two until Austin Approach is back up and running.

  • Icon A5 Thought to Have Crashed in California

     

    Most pilots have seen the Icon A5 light sport amphibious aircraft.  It’s a neat design that can land on water or on a runway.  The high wing design with a pusher prop has foldable wings that allow it to be put on a trailer and towed behind a vehicle, allowing it to be offloaded at boat ramps (it also begs the question can you wakeboard behind it?).

    Apparently, not all non-pilots know about the Icon A5.  Last week, one landed in the water near a beach in Southern California, but most of the beach goers and local authorities believed it had crash landed in the water.  Emergency crews were dispatched, but everyone was surprised when the two occupants crawled out on the wings, had a cup of coffee, and took back off.

    You can read the full article on the Flying Magazine’s website.

  • Picking Up an IFR Clearance

    Picking up an IFR clearance at first can seem very simple.  But, when taking off from an untowered field, especially if a pilot is based at a towered airport, it can be a little more complex.  Based at an untowered field?  The towered procedures are a little more streamlined, but still different.

    Towered Airports

    Class B or Class C

    At Class B or Class C airports, there is a dedicated frequency to get an IFR clearance and VFR departure instructions called Clearance Delivery.  It is published in the airport facilities directory as well as most approach plates.  Before you call Clearance Delivery, get the ATIS and tell the controller you have it as well as where you are located on the airport.

    CRAFT

    Class D

    Some Class D airports have a Clearance Delivery frequency (see KADS, Addison, TX), but for the most part, you’ll get your IFR clearance on the Ground frequency.  If there is a dedicated Clearance Delivery frequency, the ATIS will specify whether or not to get your clearance on it or on ground control.

    Class D towers are only part time towers, usually closing between 7pm and 10pm local time, depending on how busy the airspace is.  These airports usually have published Clearance Delivery frequencies to contact either the local approach control or center to pick up an IFR clearance on the ground.  They will be published on approach plates and in the A/FD.

    Untowered Airports

    Class E

    There are a number of Class E airports that are Class E all the way down to the surface (see KLFK, Angelina County).  At these airports, there will either be a Clearance Delivery frequency or you call on the Center or Approach frequency to get your clearance (at KLFK, you call Center as there is no Clearance Delivery frequency.  At Temple, KTPL, there is a published Clearance Delivery frequency which you would be talking to Grey Approach).

    Class G

    There are two ways to pick up an IFR clearance at a Class G airport, one typically a little safer than the other.

    The first option is to take off and maintain VFR while calling Center or Approach control.  They will give you your clearance making you IFR and allowing you to enter the clouds.  This option can be unsafe depending on the terrain surrounding the airport and how low the ceiling is.  If the ceiling is overcast at 1,000, you can legally remain VFR in Class G airspace at 500 AGL, but that isn’t the safest option and you might not be able to raise ATC at that altitude.

    The second, and safer option, is to call on the phone.  Flight Service has a nationwide Clearance Delivery phone number that every pilot should have saved in their contacts (888-766-8267).  Typically, you want to wait to call them until after you are done with your runup because they only give you a five or ten minute window to get off the ground.  With bluetooth equipped headsets, this usually isn’t a problem.

    Be prepared when calling Clearance Delivery on the phone to wait a few minutes.  Us pilots aren’t good at being patient sometimes, but the FSS has to call Center on the phone to get your clearance and release and this can take a few minutes.  Be prepared for that going in and just be patient.  Remember, this is the safer option!

    There are a handful of Class G airports around the US that have a GCO, a Ground Communications Outlet. With a GCO, you tune up the frequency, then click the mic 4 times to talk to ATC or 6 times to talk to FSS.  Each mic click must be at least one second, so if you click the mic too quickly, it won’t work.

    At certain airports that are underlying an approach control’s airspace, you can actually call the TRACON directly and get your clearance from them (5C1, the Boerne Stage Airport, for example.  San Antonio approach is the controlling agency and you can call them directly to pick up your clearance).  It’s a good practice to get the TRACON phone number and save that in your contacts as well.

  • Determining Pattern Altitude

    Figuring out the pattern altitude at an airport should be pretty simple, right?  But, in this day of helpful technology, most pilots actually get it wrong.  How can you always get it right?  Well, it just takes about an extra 15 seconds.  Here’s how.

    Traffic Pattern
    John Wayne Airport Traffic Patterns

    As outlined in the Aeronautical Information Manual, section 4-3-3, “traffic pattern altitudes for propeller-driven aircraft generally extend from 600 feet to as high as 1,500 feet above the ground.”  Further, in the Pilot’s Handbook of Aeronautical Knowledge on page 13-10, it states:  “1,000 AGL is recommended pattern altitude unless established otherwise.”

    Okay, so for piston driver’s, we’ve got it narrowed down to 1,000 AGL (Above Ground Level for those who don’t like acronyms).  But wait!  There’s that very important phrase at the end of the last quote:  “unless established otherwise.”  That means not all airports have traffic pattern altitudes of 1,000 AGL, or else they wouldn’t put that line in there!

    How do you find out what the TPA (Traffic Pattern Altitude) is for a certain airport if it’s not 1,000 AGL?  Great question!  Your first guess is probably to look on Foreflight.  Though this is a good start, it is not the full answer.

    Let’s use an example.  Look up KAQO, the Llano Airport on Foreflight.  At the top of the page, the airport elevation is stated as 1,101′ MSL and the pattern altitude is stated as 1,902′ MSL.  From what we just learned, 1,902′ MSL is not 1,000 AGL, so is 1,902′ MSL otherwise established?

    On the Airports page with KAQO pulled up, tap the A/FD tab, second to last on the left.  Scroll down to Llano Muni.  Read the whole entry.  Does it state in the entry that pattern altitude is different than 1,000 AGL?  It sure doesn’t.  So, because it is not otherwise established, pattern altitude at KAQO is 2,102′ MSL not 1,902′ MSL.

    Where did Foreflight get that?  I have no idea.  Too often, though, pilots look at the Foreflight pattern altitude and don’t actually check the Airport Facilities Directory (A/FD).  Then, they get the pattern altitude wrong.

    What does it look like when pattern altitude is otherwise established?  Look up KSGR, Sugar Land Regional, on your Foreflight app.  Foreflight states the elevation as 82′ MSL and the Pattern Altitude as 1,000′ MSL.  Is this correct?  Well, tap that A/FD button again and let’s find out.

    On the second line of the A/FD entry, it says TPA-See Remarks.  Down in the remarks section, we find the following:

    TPA-1000 (918) single engine piston acft, TPA-1500 (1418) for twin and turbojet acft, TPA-500 (418) for helicopters within 2NM.

    Foreflight got it right this time for single engine pistons, but if you are in a twin, the pattern altitude is different.  What’s the lesson here?  Always check the A/FD and don’t always go by what Foreflight says.  The A/FD is always right and usually has a little more detail to help set you straight.

    One last thing.  Both the AIM and the Pilot’s Handbook of Aeronautical Knowledge, when talking about pattern altitude, state, “When operating at an airport, traffic pattern altitudes should be maintained unless otherwise required by the applicable distance from cloud criteria in…section 91.155.”  91.155 defines basic VFR weather minimums.  So, to fully interpret what the AIM is saying, we have to take into account the type of airspace we are in to determine if we can safely and legally operate at pattern altitude at a particular airport.

    For example, let’s say we are at KCVB, the Castroville Airport.  Pattern altitude there is 1,602 feet, which is 829 AGL.  CVB is Class G airspace up to 700 AGL, then Class E above that.  Let’s say there is a 700 AGL broken cloud layer.  Pattern altitude is 829 AGL, so you won’t be able to get up that high with a broken ceiling.  What altitude can you do pattern work at to stay legal?

    Class G VFR weather minimums during the day below 1,200 AGL is 1 SM visibility and clear of clouds.  So, legally, you could fly at 699 AGL (which at CVB would be 1,472 MSL) while in the pattern and be legal.  Safe?  Maybe, but probably not if you are skimming the base of the clouds.  Is 1300 MSL a safer pattern altitude in this example?  Well, that is 527 AGL, so probably not, since towers tend to stick up that high sometimes.

    Let’s go back to KSGR and put a 1,000 AGL overcast ceiling there.  SGR is Class D airspace and we already determined pattern altitude there was 1,000 MSL for piston singles.  VFR visibility and cloud clearance requirements in Class D airspace are 1,000 feet above clouds, 500 feet below clouds, and 2,000 feet horizontally from the clouds with 3 SM visibility.  In order to stay 500 feet below the clouds, you would be flying a 582 MSL pattern.  Safe?  Probably not, though it is legal.

    To summarize, don’t take Foreflight’s word for pattern altitude.  Cross reference the A/FD (it only takes 15 seconds at the most) to verify.  If it’s cloudy, it’s really best to stay on the ground, but if you want to find out your legal pattern altitude with a cloud deck, cross reference 91.155.  I don’t recommend flying below pattern altitude because it is there for a reason.