Home

Aviation News

Flight Training

Aviation History

Theory Of Flight

Airframes

Powerplants

Civilian Aircraft

Military Aircraft

Aviation Wallpapers

Aviation Links

Contact


 

 

 

Contents

Circling to Land
A circle at night is hazardous, combined with low visibility it is suicidal. Low level maneuvering flight with few visual
cues is as dangerous as flying can get. The circle to land is the second option to the straight in and if you have not
briefed the circle you should execute the missed as a safer option. A straight in approach with high minimums or
more than 30 degrees off the center line is going to require a circle because you won't be able to get down to the
runway on the straight in.

Your decision to circle requires that you fly the altitude and distance from the runway according to your airspeed
aircraft category. Fly below 91 knots you are Category A; fly above 91 a bit and you're Category B. The distance difference is 2/10ths of a mile from 1.3 to 1.5. I sense that most pilots would want the extra airspeed but not the distance during the circle until lined up on the runway again. Maintaining the altitude during the circle is critical and the pilot must know the power and trim required to fly the bank angle at one altitude while keeping the runway in sight. Left turns are best if you need to keep the circle tight due to reduced visibility.

Once you lose sight of the runway you are expected to turn toward the airport, intercept the missed approach
and fly the missed as published. If your circle lines you up on the runway get configured and slowed so as to
get down in the runway landing zone.

Avoiding the Circle-to-Land
T
he design of the approach determines the requirements
Straight-in:
Less than 400' per mile from FAF to threshold
Within 30 degrees of centerline
Course must cross extended centerline

Circling:
Descent rate is from FAF to MDA at threshold may exceed 400 fpm.
Exceeds 30 degrees of centerline but not necessarily.
Course must cross extended centerline

You are expected to fly straight in and make descent if able. If unable, you must circle and keep runway in sight during your circle. Do not descend below circling altitude until established on final. Advise ATC of intentions.

On Circling to Land
Circling to land is a relatively dangerous maneuver. It contains the worst elements of IFR flight. There is a minimum obstruction clearance, a limited space in which to maneuver, an absence of visual reference, and trying to keep the runway in sight while preparing to land. At night it is a quite a bit more than dangerous. The required continuous turn in marginal conditions that keeps the airport in sight is hazardous. Many approaches that are aligned with the runway will have only circling minimums. You still may be able to land straight-in. Set up the missed approach procedure before beginning to circle. A circle to land requirement is a contact type of approach or otherwise a visual maneuver done with reference to instruments.

Because of the hazards associated with circling, flying the airplane must not be part of the problem. You must know the power settings and airspeeds that provide some safety margins. Trim the aircraft for the lightest possible touch. Let go when you look for the airport. Practice the flying about an isolated airport in good VFR to hone the MDA skills required in MVFR or LVFR conditions as for actual conditions.

During training you should make every circle to land approach with as close and short approach as you can handle without exceeding a 30-degree bank and your short field approach speed. This will give you a steep approach. If your circle puts you on a right downwind you might opt (tell ATC) to make a left downwind circle for better visual to the runway. Don't hesitate to take advantage of any wind to get down steeper and shorter. You are required to keep an identifiable part of the airport in distinct view except when concealed by a banked wing.

On an ILS approach you must have a localizer approach with a circle to land option. Most other approaches circle to land minimums published as well and straight-in. Circling minimums only are allowed for all approaches with a letter designation such as VOR-A. No straight-in minimums are published if the approach is more than 30 degrees; off the runway or a normal descent cannot made from MDA altitude. However, you are allowed to land straight in with the runway in sight and an ATC clearance. Request a 360 if you need to get down. In any circling approach keep the runway in sight and stay at MDA until clear of obstructions. If the VOR plate has a runway number it means that the approach is within 30-degrees of the runway and straight-in minimums will be published.

If you lose sight of the runway, overfly the airport, turn to your missed approach heading, and climb. The published missed approach is valid only when begun at the missed approach point at the MDA or higher. You are not promised terrain clearance if you do not follow the published procedure. No turns should be made until reaching the published missed approach point. Any other time you are on your own. The circling minimums presume a high degree of pilot proficiency and familiarity with the airport.

You have planned both the circling maneuver toward the airport and the missed procedure. You have pre-decided, because of the ATIS information, the approach angle sets which side to look for the airport. There are no required circling maneuvers. With ATC clearance you are free to maneuver to a landing as long as the runway is in sight. Requirements of distance from airport center (Category A 1.5 nm) and 300' clearance above obstacles are figured into the circling minimums.

Each category has a different minimum circling radii requirement that is stated in nautical miles for the aircraft category. Conversion of this to statute miles equals the visibility in statute miles as stated on the approach plate. The minimum obstacle clearance within each approach category circling maneuvering area is 300 feet. Height Above Airport. (HAA) is 350 feet for Category A planes. VASI and PAPI equipped runways allow descent when within 10 degrees of interception. Publish minimums provide obstacle clearance only within the protected airspace.

ILS descent must not be below circling minimums for circling to be allowed. If there is a circling approach listed for the airport the circling altitude is the MDA. The MAP is based upon the FAF for the procedure as shown on the chart. An ILS approach for runway 27, circle to land runway 9 has its missed approach point at the designated missed approach point based on DME or on time and is a NON-PRECISION approach.

Every circle-to-land approach is a non-precision approach. The MDA of a circling approach gives an obstacle clearance of 300' but this is usually still lower than the normal pattern altitude. Check the charts to see if circling can only be in one direction. Only losing sight of the field due to banking is allowed. Any other failure to see the field requires that you start your climb to the missed-approach altitude, then turn in the direction of the protected obstacle-clearance region and fly the missed-approach heading. If you leave the MDA before intercepting the final approach course the FAA will blame you if you run into anything.

One way to fly circling minimums is to fly the glideslope down to the published circling minimums for the localizer and then proceed at MDA on the localizer by timing or DME if authorized. Another way is to fly the LOC to the straight-in minimums and landing straight in. If the published ILS approach is to be flown as a non-precision it makes sense to use the glide slope down to circling minimums. Basic rule is to fly the shortest path to base of downwind leg even if requiring you to overfly the airport. When appropriate all turns should be to the left.

Since a high descent rate usually has circling minimums only, you must be proficient in getting down quickly and in cleaning up during the missed. If you become visual with the runway by knowing where to look for the runway and are using a created VDP a straight-in is possible. Use no more than 30-degree banks in turns and do not rise above MDA by more than 50 feet. Only normal maneuvers are allowed during descent from MDA. If at any point you lose visual contact with the airport and runway you must execute the missed. Don’t depart from the electronic glide slope until within one mile of the airport.

You could use a 90 left/270 right course reversal in a circle to land situation if conditions require. If possible, the turns should be made in the direction that gives the pilot in command the best view of the runway during the turns. Unless otherwise directed, the AIM procedure, if you lose sight of the runway, requires you to execute a climbing turn back to the landing runway and continue the turn to establish yourself on the published missed approach course. You are required to miss the circling approach when an identifiable part of the airport is not distinctly visible. If ceilings permit fly higher than MDA. A single pilot forced into right turns should not be circling.

The circling approach area is determined by approach category ("A" for C-172). It is a series of arcs 1.3 miles in radius using all the runway ends and sides at the airport. Its size is the largest area possible made from these arcs. Category B is 1.5 miles. Primary obstacle clearance is only 300'. If obstacles are in the way no circling will be allowed. Obstacles of less than 400' may not be charted on the plates!!!! Circling in a specific direction may not be allowed. Study the chart. Occasionally it is necessary to remain at a higher than published altitude when transitioning to the approach. Occasionally, even the minimums vary according to the approach category. If the descent requires you to fly at a higher approach speed you must use the minimums for the higher category. Likewise, you must fly the missed approach published for the higher category. Obstacle clearance is assured only when using higher minimums for the speed flown. Higher minimums apply if an aircraft is flown at a higher category airspeed.

FAA figures a 400-fpm descent rate for the full approach but when circling is required the 400 fpm applies only to the MDA. A higher rate may be required below the MDA for the straight in approach. Don’t force it. Let the tower know if you do not plan to make a straight in. The PTS in Task E of the instrument approach procedures requires that an applicant know all the elements of the circle-to-land procedure. In a 22 word sentence the PTS says that the pilot must check the wind. At an uncontrolled airport this means to overfly the airport and check wind indicators. Basic procedure are to fly to the specified minimum, only if in visual conditions you circle to land on the designated runway into the wind. You are not allowed to descend below minimum altitude, go below visibility criteria or make other than a normal landing.

The circle is after ATC authorization when a straight-in landing is not the preferred option. Even if cleared for a straight-in you can circle only if you have not descended below the circling minimum. You have obstacle clearance if you remain within the radius of your approach category based only on your normal approach speed. The only way the examiner can participate in the flight is by maintaining a traffic watch. The missed approach instructions are based upon a straight in landing.

Since the circling approach will be coming in from nearly the opposite direction the direction of the missed turn will be reversed from the one published. The way you fly the circle is more apt to cause an accident than the weather. Circles are hazardous because you are low, slow, and turning. However, you are more likely to fly into the ground while on the centerline. Don’t circle if there is another option like landing downwind. Don’t circle with ice aboard. Don’t bust MDA. Use shallow banks. Never change from your decision to make the missed. A good missed is preferable to a bad circle. Regardless of the clearance, every missed approach begins with a straight-ahead climb with sufficient time to configure before initiating any turn.
--63% fatal
--51% stalls
--31% icing

Continue To Next Page

 


Copyright 2003-Now www.airman.us All rights reserved. Reproduction in any form is prohibited.