GFC 700 AFCS Supplement 

 

GFC 700 AFCS Supplement Autopilot Basics

Flight Director vs. Autopilot Controls Activating the System Modes Mode Awareness What the GFC 700 Does Not Control Other Training Resources

Automation Philosophy Limitations Modes

Quick Reference Tables Lateral Modes Vertical Modes

Lateral Modes Roll Hold Heading Select (HDG) Navigation (NAV) Approach (APR) Backcourse

Vertical Modes Pitch Hold Altitude Hold (ALT) Glidepath (GP) Glideslope (GS) Go Around (GA) Selected Altitude Capture (ALTS)

Autopilot Procedures Preflight Takeoff / Departure En Route Arrival/Approach

Approaches Without Vertical Guidance Approaches With Vertical Guidance

Revised: 09/24/2019

Missed Approach Autopilot Malfunctions/Emergencies

Annunciations Cautions (Yellow) Warnings (Red)

Emergency Procedures Manual Electric Trim Control Wheel Steering C172 w/ GFC700 Autopilot Checklist C172 Supplement Profile Addendum

Autopilot Basics 

Flight Director vs. Autopilot 

ATP’s newer Cessna 172s come factory-equipped with the GFC 700 Automatic Flight Control System (AFCS). The GFC 700 AFCS, like most autoflight systems, includes both a flight director (FD) and an autopilot (AP). The FD calculates the pitch and bank angles needed to fly the desired course, heading, altitude, speed, etc., that the pilot has programmed. It then displays these angles on the primary flight display (PFD) using magenta command bars. The pilot can follow the desired flight path by manipulating the control wheel to align the yellow aircraft symbol with the command bars. Alternately, the pilot can activate the AP, which uses servos to adjust the elevators, ailerons, and elevator trim as necessary to follow the command bars.

Controls 

The AFCS is activated and programmed using buttons on the left bezel of the PFD and the multifunction display (MFD). The two sets of buttons are identical, but the set on the MFD is easier to reach (and easier for the instructor in the right seat to see, to confirm proper operation). There are 4 buttons on the left side of the pilot’s control wheel that serve to disengage the autopilot and operate the electric trim. These are positioned such that the pilot can press them with their thumb while using the control wheel. One additional button, the Go Around Switch, is located near the throttle so the pilot can advance the throttle and push the button in one motion during a go-around. Operating these controls brings the pilot’s attention inside the aircraft, particularly for pilots who are not yet completely familiar with their operation. This could distract the pilot from their obligation to see and avoid other aircraft. Pilots using autoflight systems must be conscious of how much time they are spending heads-down. Alternate between scanning for traffic and operating the autopilot. If you cannot devote enough heads-up time to collision avoidance while

Revised: 09/24/2019

simultaneously programming the autopilot, stop using the autopilot. Fly by hand, and become more familiar with the GFC 700 before using it on future flights.

Activating the System 

Pressing the FD button will activate the FD but not the AP. Then, to activate the AP, press the AP button. If the FD is not already active, pressing AP will activate both.

Modes 

To use an AFCS, the pilot must select one or more FD modes that tell the system what to track: a heading, a navigational signal, an airspeed, a vertical speed, etc. For the GFC 700, these modes are divided into two groups: vertical modes and lateral modes. The pitch angle shown by the command bars is determined by the vertical mode, and the roll angle is determined by the lateral mode. In some circumstances, the pilot may want the FD to use one mode until some condition is met, then switch to another mode. For example, the pilot might want to fly a particular heading to intercept a VOR radial, or to climb at a particular airspeed before leveling off at a given cruising altitude. In this case, the mode currently being used is called the active mode, and the one to which the AFCS will switch is the armed mode.

Mode Awareness 

One of the most common causes of autoflight errors is a lack of mode awareness. That is, the pilot loses track of which mode the AFCS is in, and therefore fails to anticipate how the AFCS will behave. The key to maintaining mode awareness is to keep the AFCS Status Box in your scan. This box is at the top of the PFD, just below the Navigation Status Box. It is divided into three segments:

● Left: lateral mode annunciations ● Right: vertical mode annunciations ● Center: autopilot status annunciations

Active modes are displayed in green and are towards the center of the PFD. Armed modes are displayed in white and are towards the edges of the PFD. When the AFCS transitions from an armed to an active mode, the white armed annunciation moves to the green active mode field and flashes for ten seconds. If the mode annunciation flashes yellow, the AFCS has lost the sensor or navigation data needed to compute commands in that mode. The aircraft will roll wings level or hold the current pitch angle (depending on the affected axis). The annunciation will flash for 10 seconds, then revert to the Pitch Hold or Roll Hold mode. While the AP is engaged, a green “AP” annunciation appears in the center of the AFCS Status Box. If the AP is manually disengaged, this annunciation will flash yellow for 5 seconds (along

Revised: 09/24/2019

with a two-second disconnect tone) and then disappear. If the AP is automatically disengaged, it will flash red (along with the aural disconnect alert) until the pilot acknowledges the alert. Scanning the AFCS Status Box is critical for mode awareness, but scanning for traffic is critical for collision avoidance. Alternate your scan: traffic, AFCS status, flight instrument readings, back to traffic, etc. If monitoring the automation is requiring so much attention that your traffic scan deteriorates, shut off the automation and fly by hand.

What the GFC 700 Does Not Control 

The GFC 700 AFCS has no control over the throttle setting of the aircraft. The pilot must adjust the power as necessary to maintain the desired flight profile. In descents, failure to sufficiently reduce power could lead to an overspeed condition. In climbs, failure to sufficiently increase power could result in minimal climb rates or dangerously low airspeed. The GFC 700 also has no control over the aircraft’s rudder. It is a two-axis autopilot, meaning that it controls pitch and roll but not yaw. The pilot must keep their feet on the rudder pedals and make appropriate inputs to keep the aircraft in coordinated flight.

Other Training Resources 

The flight environment is a distracting and expensive place to learn how to operate an autoflight system. Fortunately, there are a wealth of resources available to learn about the GFC 700 on the ground:

● “GFC 700 Training” video on the Garmin YouTube channel ● King Schools “Flying the Garmin G1000” course ● Manuals: G1000 Pilot’s Guides, Cockpit Reference Guides, CE-172 POH/AFM ● Garmin G1000 Trainer software

Automation Philosophy 

When using an autoflight system, it is critical to remember that you, the pilot, are still flying the airplane. You are pressing buttons and turning knobs, instead of moving a control wheel, but you must still…

● Evaluate the current flight conditions. ● Choose a course of action that will keep the flight safe and legal. ● Make appropriate control inputs to carry out that course of action. ● Monitor the aircraft’s response to your control inputs. ● Adjust your control inputs if the aircraft is not behaving as desired.

An autopilot is a useful tool for relieving some of the physical workload of flying the airplane, but it cannot take on the mental workload required to exercise good aeronautical decision-making (ADM). Autoflight systems will behave exactly the way they’re programmed by Garmin’s engineers and the pilot, even if that behavior is illogical or unsafe in the current situation. As a result, like any computer, the GFC 700 can only ever be as good as the pilot who is using it.

Revised: 09/24/2019

The autopilot also has no ability to scan for and avoid traffic. Whenever weather conditions allow, all pilots (whether VFR or IFR) are required to maintain vigilance so as to see and avoid other aircraft (14 CFR 91.113). Using an autopilot does not relieve you of this responsibility! The idea of “staying ahead of the airplane” applies very much to the use of autoflight systems as well. When using the autopilot, you should know exactly where you expect the aircraft to be and what you expect it to do well before it actually happens. If you don’t, you won’t be able to catch any errors, malfunctions, or other unexpected behavior. While flying on autopilot, ask yourself occasionally:

● If it disconnected right now, could I immediately jump in and continue with the flight? ● If it started deviating from the flight path I want it to take, would I know immediately?

If you can’t answer “yes” to both questions, you have allowed the autopilot to get ahead of you. It’s taking you places before you have a chance to apply your ADM skills, and it has no ADM skills of its own--this is not a good combination.

Limitations 

The autopilot feature of the GFC 700 AFCS may not be used: ● During takeoffs and landings. ● At airspeeds below 70 KIAS or above 150 KIAS. ● Below 200 feet AGL during approaches, or 800 feet AGL during any other phase of

flight. ● With a fuel imbalance of more than 90 pounds (15 gallons). ● When the audio panel is inoperative. ● On a missed approach, until a positive rate of climb that will meet the procedure’s

altitude requirements is established. ● Without a pilot in the left pilot’s seat. ● For Category II or III ILS approaches.

Additionally, no feature of the GFC 700 AFCS (autopilot, flight director, or manual electric trim) may be used unless the preflight test has been successfully completed.

Modes 

Quick Reference Tables 

Lateral Modes 

Mode Name Button Annunciation Description

Roll Hold (none) ROL Rolls wings level (<6°) or holds current bank angle.

Heading Select HDG HDG Acquires/maintains heading bugged on HSI.

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Navigation NAV GPS VOR LOC

Acquires/tracks selected navigation source displayed on HSI.

Approach APR GPS VAPP LOC

Acquires/tracks selected navigation source displayed on HSI, based on loaded approach. (More sensitive than Navigation mode.)

Backcourse BC BC Tracks a localizer backcourse (accounting for reverse sensing).

Go Around GA GA Wings level, autopilot disengages (for a go-around / missed approach).

Vertical Modes 

Mode Name Button Annunciation Description

Pitch Hold (none) PIT Holds current pitch angle.

Altitude Hold ALT ALT ____ FT Maintains current altitude.

Vertical Speed VS VS ____ FPM Maintains a set vertical speed.

Flight Level Change

FLC FLC ____ KT Climbs or descends at a particular airspeed to a selected altitude.

Vertical Path Tracking

VNV VPTH Descends according to a VNAV profile.

Glidepath / Glideslope

APR GP GS

Descends using SBAS vertical guidance on a GPS approach, or a glideslope on an ILS approach.

Go Around GA GA Pitches 7° nose up, autopilot disengages (for a go-around / missed approach).

Lateral Modes 

Roll Hold 

This is the default mode for roll. This mode is selected automatically when the FD is first activated. The FD will also revert to this mode in certain situations where it is unable to continue in other modes. In roll hold mode, the flight director will command wings level if the aircraft’s bank angle is less than 6°, or if a mode reversion has occurred. At larger bank angles (up to the maximum of 22°), it will maintain the current bank angle.

Revised: 09/24/2019

Heading Select (HDG) 

The FD will turn to and then maintain the heading that has been bugged on the HSI. This heading is also shown in light blue in a small box to the upper left of the HSI. To adjust the heading, use the HDG knob to move the bug. The AFCS will command a turn in the same direction as the bug is moved, which can be used to command turns of more than 180°. To select your current heading (either to maintain that heading, or to avoid a sudden turn to an unexpected heading when HDG mode is activated), press the HDG knob.

Navigation (NAV) 

The flight director will acquire and track the navigation source currently shown on the HSI. This can be a VOR radial, a localizer, or a GPS course from the active flight plan. The annunciation in the AFCS Status Bar will indicate which source is being tracked. If the CDI shows greater than one dot deflection when the NAV Key is pressed, NAV mode will arm but not activate. The pilot must fly the aircraft within one dot for the AFCS to automatically intercept the selected course. This can be done using HDG mode. If NAV mode is active and the pilot manually changes the HSI navigation source (either by switching between VOR1 / VOR2 / GPS or by tuning a different VOR frequency), the FD will revert to Roll Hold mode. This prevents the FD from commanding a sudden turn to follow new course guidance, but it is a prime opportunity for losing mode awareness. Consider switching to HDG mode before changing navigation sources, then resuming NAV mode. (If certain conditions are met while executing an ILS or LOC approach, the G1000 will automatically switch the navigation source from GPS to LOC. Automatic switches like these will not cause mode reversion.)

Approach (APR) 

Approach mode is similar to NAV mode, in that the FD will track the navigation source shown on the HSI that corresponds to the approach loaded into the flight plan. If the APR key is pressed while the CDI is deflected more than one dot, the APR mode will arm rather than activate, pending course intercept. As in NAV mode, manually switching the navigation source after APR mode is activated will cause the flight director to revert to Roll Hold mode. To avoid this, use HDG mode to hold present heading while switching navigation sources, then reactivate APR mode. The FD will also revert from APR mode to Roll Hold if Vectors-to-Final is activated. Follow vectors using HDG mode, and arm APR mode in anticipation of intercepting the final approach course. Two ways in which APR mode differs from NAV mode:

● The flight director will track the signal with greater sensitivity in APR mode. ● Pressing the APR Key arms both roll (Approach) and pitch (Glidepath/Glideslope)

modes, to follow both the lateral and vertical guidance provided by the approach.

Revised: 09/24/2019

The FD can follow DME arcs that are part of published VOR or ILS approaches. However, because it does so based on GPS guidance, it must be in GPS NAV mode while on the arc, with GPS as the active navigation source on the CDI. The AFCS will wait to activate APR mode until after the arc is complete.

Backcourse 

For localizer backcourse approaches, after activating APR mode, press the BC key to activate Backcourse mode. This tells the flight director to account for reverse sensing while flying the “wrong way” on the localizer. On the HSI, use the CRS Knob to set the Selected Course to the front course of the localizer (i.e. with the arrow pointing down) so that the CDI deflects in the correct direction.

Vertical Modes 

ATP’s standard operating procedures do not include the use of all vertical modes available on the GFC 700. In particular, ATP does not use: Vertical Speed (VS), Flight Level Change (FLC), or Vertical Path Tracking (VPTH) modes. More detail on these modes can be found in the G1000 Pilot’s Guide.

Pitch Hold 

This is the default mode for pitch. This mode is selected automatically when the FD is first activated. The FD will also revert to this mode in certain situations where it is unable to continue in other modes. In Pitch Hold mode, the FD maintains whatever pitch attitude the aircraft was at when the mode was selected. The pilot can adjust this reference attitude by using the NOSE UP or NOSE DN keys. When Pitch Hold mode is activated, the FD will also arm Selected Altitude Capture mode (see below). This will cause the aircraft to level off when it reaches the Selected Altitude (the one marked with the blue bug on the altimeter).

Altitude Hold (ALT) 

The FD will maintain the aircraft’s current altitude (to the nearest ten feet) at the moment the ALT Key is pressed. This altitude is displayed in green in the AFCS Status Box, just to the right of the green ALT annunciation. Note that the altitude reference is not the same as the Selected Altitude, the altitude bugged on the altimeter using the ALT Knob. Changing the Selected Altitude while the FD is in ALT mode will not affect the FD.

Glidepath (GP) 

The flight director will track an SBAS-based glidepath (for example, WAAS-based vertical guidance on an RNAV approach flown to LPV minimums). This mode is armed simultaneously with the GPS APR mode by pressing the APR Key. It will arm only if a WAAS-enabled RNAV approach is loaded into the flight plan, and GPS signal integrity is sufficient to provide vertical

Revised: 09/24/2019

guidance. When the aircraft reaches glidepath intercept, GP mode will activate and track the path down to the ground.

Glideslope (GS) 

The flight director will track a glideslope. This mode is armed together with the LOC APR mode by pressing the APR key. When the aircraft captures the glideslope, GS mode activates and tracks the glideslope down to the ground. NOTE: Although the FD will track vertical guidance down to ground level, the pilot must be sure not to:

● Descend below minimums without meeting the requirements of 14 CFR 91.175(c). ● Use the AP below 200 feet AGL, in violation of published limitations. ● Land with the AP engaged.

Go Around (GA) 

The flight director will command a wings-level, 7° pitch up attitude for a missed approach or go-around. (This mode includes both pitch and roll.) It also arms ALT mode, expecting that the pilot has bugged the missed approach altitude as the Selected Altitude. Activating GA mode will disconnect the AP, but the pilot can then reengage it. (Per ATP standard operating procedure, hand-fly the aircraft to at least 1,000’ AGL before reengaging the autopilot.)

Selected Altitude Capture (ALTS) 

The GFC 700 has a vertical mode specifically for capturing altitudes, called Selected Altitude Capture (indicated by an ALTS annunciation). (There is also a VNAV Target Altitude Capture mode indicated by ALTV, but this mode is related to Vertical Path Tracking mode and does not appear during ATP standard operations.) During level-off, the active vertical mode will transition from the climb/descent mode, to the altitude capture mode, and then to ALT mode. The pilot cannot activate ALTS mode directly. Instead, it is automatically armed when the pilot selects other vertical modes. Nevertheless, pilots should still be aware of ALTS mode, due to a potential trap. While Selected Altitude Capture mode is active (indicated by a green ALTS and a white ALT annunciation), if the pilot changes the Selected Altitude, the flight director will revert to Pitch Hold mode and hold its current pitch angle. This angle may or may not “intersect” with the new selected altitude, which could lead to an uncapped climb or descent. To avoid this, wait for the flight director to enter ALT mode (indicated by a green ALT annunciation), then program a second climb/descent as necessary.

Autopilot Procedures 

Preflight 

Aircraft with the GFC 700 AFCS have a few additional steps during the Runup checklist. The pilot must perform an Autopilot Functional preflight check is as follows:

Revised: 09/24/2019

● Engage the autopilot by pressing the AP button. It will activate in Pitch Hold and Roll Hold modes, holding elevator and ailerons neutral.

● Grasp the control wheel and move it through an inch of motion forward and aft, then left and right. The servos will resist this movement, but they are equipped with slip clutches that should allow the pilot to overcome them. If you cannot, terminate the flight and contact ATP Maintenance. (This is not a flight control check - check that you can overcome resistance only to avoid excessive wear on the servos. Do not move the yoke through the full range of motion.)

● Engage heading mode by pressing the HDG button on the PFD ● Click the HDG knob to center the heading bug on the aircraft’s current heading ● Rotate the HDG knob to the left and right verifying the yoke follows the command ● Disconnect the autopilot by moving the left (outboard) side of the manual electric trim

switch on the pilot’s control stick ● Engage autopilot by pressing the AP button on the PFD ● Engage vertical speed mode by pressing the VS button on the PFD ● Press the NOSE UP button on the PFD several times to increase vertical speed as

shown by the bug on the far right vertical speed tape on the PFD. Verify the yoke moves aft.

● Press the NOSE DOWN button on the PFD repeatedly to drive the vertical speed bug to a negative value. Verify the yoke moves forward.

● Press the red A/P TRIM DISC button on the left side of the pilot’s control wheel. The autopilot should disengage, and the pilot should note: a flashing yellow “AP” annunciation in the AFCS Status Box, an audible AP disconnect alert, and no further resistance on the flight controls from the servos. If this does not occur, terminate the flight and contact ATP Maintenance. (The FD will remain active and the control bars will remain visible.)

Takeoff / Departure 

For takeoff, the FD and AP should be turned off. Set the altitude bug to the initial altitude in your clearance, and the heading bug to your initial assigned heading. After rotation, establish the appropriate climb attitude, airspeed, and power setting manually. Upon reaching an appropriate altitude (but no lower than 800 feet AGL, to comply with autopilot limitations), press the AP button to turn the autopilot on. It will initially activate in ROL and PIT modes, so the aircraft will maintain its present attitude. If you are flying an ATC-assigned heading, check that the heading bug is set correctly and then activate HDG mode. If you are navigating to a waypoint or intercepting a leg of your flight plan, arm and/or activate NAV mode. As you climb, use the Nose UP and Nose DN buttons to adjust the pitch attitude to maintain the correct climb airspeed. When you activated PIT mode by turning the AP on, this also armed ALTS mode, so the aircraft is ready to level off at the bugged altitude and then maintain that altitude in ALT mode.

Revised: 09/24/2019

If ATC clears you to a higher altitude while you are still climbing, adjust the bug, but be careful not to move the bug once ALTS mode activates and the aircraft starts to level off. If you have already leveled off when ATC issues a higher altitude, bug the new altitude, then press the ALT button to deactivate ALT mode and return to PIT mode. Set an appropriate climb attitude with the Nose UP button and confirm that this yields the desired airspeed at your chosen power setting.

En Route 

Use ALT mode to maintain your cruising altitude, and NAV mode (with GPS selected as the navigation source) to follow the flight plan you have programmed in the G1000.

Arrival/Approach 

Before beginning your descent, use the 3:1 Rule to determine an appropriate descent rate and the Top of Descent point. Bug the altitude to which you will be descending (as assigned by ATC under IFR, or pattern altitude for a VFR flight). When you reach the TOD point (or when cleared to descend by ATC), press the ALT button to deactivate ALT mode and return to PIT mode. Use the Nose DN button to set an appropriate pitch attitude and reduce power to an appropriate descent setting. Monitor and adjust throughout the descent to maintain the desired descent rate. Load the expected approach, based on current weather and ATC instructions. Use NAV mode to follow the active flight plan; if ATC begins issuing vectors, switch to HDG mode. When ATC clears you for the approach and you are navigating to an IAF or on vectors to final, activate the approach, and set the DA or MDA in the Timer/References window (TMR/REF Softkey).

Approaches Without Vertical Guidance 

Approaches without vertical guidance should be flown with the autopilot in NAV mode. The autopilot will track lateral guidance based on the navigation source selected on the HSI, but the pilot must control the vertical path. For GPS approaches flown from an IAF, the approach works much like the continuation of a GPS flight plan. The autopilot will stay in NAV mode with GPS / “pink needles” on the CDI throughout the entire approach. For VOR or localizer approaches flown from an IAF, the autopilot again remains in NAV mode throughout the approach. However, the navigation source needs to be switched from GPS to VOR/LOC (“green needles”) prior to the final approach segment. If the active approach is a LOC approach, the G1000 will switch navigation sources automatically. However, for VOR approaches, the G1000 will not automatically switch from GPS to VOR; the pilot must do so manually using the CDI Softkey. If the AFCS is in NAV mode when this occurs, it will revert to

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Roll Hold mode. Be sure to reactivate NAV mode, or switch to HDG mode before adjusting the CDI. For approaches flown from radar vectors, use HDG mode to follow the vectors. When cleared for the approach, activate the approach from vectors-to-final. Select the appropriate navigation source for the CDI, set the inbound course, then arm NAV mode. The autopilot will intercept the final approach course and follow it to the runway. (If ATC needs to vector you across final, press the NAV button again to disarm NAV mode before reaching the final approach course.) To manage the descent during the approach, use the same technique as for the arrival:

● Begin with the autopilot in ALT mode holding the correct altitude for the current approach leg.

● Bug the next altitude to which you will descend. ● Once you pass the fix, press the ALT button to revert to PIT mode. ● Use the Nose DN button and reduce power to set pitch/power for an appropriate rate of

descent. ● Monitor and confirm that the autopilot levels off at the bugged altitude. Add power back

in, so that the aircraft does not slow down excessively to maintain altitude. ● Repeat as necessary at each step-down.

Note that the altitude bug can be adjusted in 100-foot increments, but some stepdown fixes or MDAs may not be multiples of 100. In that case, you must round up to the nearest 100. For example, if the MDA is 420 feet, select 500 feet; even though 400 would be closer, that would be an altitude violation. If it is necessary to descend closer to the exact altitude, disconnect the autopilot and hand-fly. Once you level off at the MDA, monitor the aircraft closely to ensure you do not descend below minimums. At the VDP (or on a circling approach, once within the circling radius for your aircraft category), if the requirements of 14 CFR 91.175(c) are met, press the A/P TRIM DISC button and land the aircraft manually. Do not use the autopilot below the MDA, or while circling to land. Call out “Stabilized, Autopilot off” as a reminder not to land with the autopilot engaged. If the requirements of 14 CFR 91.175(c) are not met, upon reaching the missed approach point, proceed with a missed approach.

Approaches With Vertical Guidance 

Approaches with vertical guidance should be flown in APR mode. In this mode, the autopilot will track both lateral and vertical guidance. As with non-precision approaches, use HDG (if radar-vectored) or NAV (if cleared to IAF) modes to guide the aircraft towards the approach course. Press the APR button to arm APR mode as soon as ATC clears you for the approach. Once the course is close enough to

Revised: 09/24/2019

intercept, APR mode will activate (with an annunciation of GPS or LOC, depending on the approach type). For GPS approaches with WAAS-based vertical guidance, this transition is essentially seamless; you remain on pink needles with a mode annunciation of GPS throughout the approach. ILS approaches will require a navigation source switch from GPS to LOC (which will be indicated on both the CDI and the mode annunciation). Conveniently, the G1000 performs this switch automatically as you approach the localizer, assuming you have the approach loaded and the frequency tuned. (Additionally, the FAF must be the next fix, and the aircraft must be within 15 NM of the FAF and getting closer to it.) This automatic switch does not cause mode reversion. Once the aircraft is inbound on the localizer or final approach course, set the heading bug for the missed approach, and watch for the glidepath / glideslope indicator to come in. When the indicator centers, GP or GS mode will activate and the aircraft will descend. Adjust power as necessary to maintain the correct approach airspeed. Once the aircraft begins its descent, set the Selected Altitude bug for the missed approach altitude. (The decision altitude is marked with the Barometric Minimums bug in the References window.) Be aware that GP or GS mode will not activate if the aircraft’s path does not intersect the glidepath/glideslope. For example, if ATC inadvertently issues a vector that joins the localizer after the final approach fix, the glideslope will be below you when you turn onto the localizer. With ALT mode keeping the aircraft in level flight, the aircraft will never reach the glideslope, and so GS mode will never activate. (This could also occur on an RNAV approach if ATC clears you direct to the FAF, and you are above the glidepath intercept altitude upon reaching the FAF.) If GP or GS mode does not activate when expected, disconnect the autopilot by pressing the red A/P TRIM DISC button and fly the approach by hand. At the “Stabilized” callout at 400 feet AGL, add “Autopilot off at minimums” to remind yourself of the minimum altitude limitation. At minimums, if the requirements of 14 CFR 91.175(c) are met, press the A/P TRIM DISC button and land the aircraft manually. Otherwise, proceed with a missed approach. (If you do not disconnect the autopilot, it will track the glideslope all the way to the ground. Note that use of the autopilot below 200 feet AGL is a violation of aircraft limitations.)

Missed Approach 

Once you have added power and initiated a climb, press the GA button (near the throttle for easy reach while adding power). The AP will disconnect; follow the FD’s guidance by hand. Pressing the GA button automatically resumes waypoint sequencing through the flight plan, so when safe to do so, activate NAV mode to follow the missed approach procedure.

Revised: 09/24/2019

Once you have established a rate of climb that ensures all altitude requirements of the procedure will be met (per POH limitations) and are above 1,000’ AGL (per ATP policy), you can activate the AP. Use the Nose UP / Nose DN key to set an appropriate pitch angle and obtain the desired climb airspeed. Bug the missed approach altitude, so that the AP will level off from the climb at the appropriate altitude. Upon reaching the holding fix, the AFCS will enter the hold and continue holding until the FD mode is changed or a new flight plan is programmed.

Autopilot Malfunctions/Emergencies 

Annunciations 

The G1000 can display several annunciations indicating problems with the GFC 700.

Cautions (Yellow) 

● AIL→ / ←AIL: Aileron mistrim. The roll servo is applying a sustained force in the indicated direction. Ensure the slip/skid indicator is centered and that the fuel imbalance limitation is observed.

● ↑ELE / ↓ELE: Elevator mistrim. The pitch servo is applying a sustained force in the indicated direction. Be prepared to apply that force manually when the AP is disconnected.

Warnings (Red) 

● PTCH: Pitch axis control failure. AP is inoperative. ● ROLL: Roll axis control failure. AP is inoperative. ● PTRM: Pitch trim axis control failure, or stuck MET switch. If AP is engaged, take

manual control and disengage the AP. If AP is not engaged, move each half of the MET switch to see if it is stuck.

● AFCS: System failure. AP and MET are unavailable. FD may be available. ● PFT: Preflight system test has failed.

Emergency Procedures 

Regardless of the exact circumstances, the response to any AP failure is essentially the same: disable the AP and revert to manually flying the aircraft. The Autopilot or Electric Trim Failure checklist should be committed to memory:

● CONTROL WHEEL… GRASP FIRMLY, regain control of airplane ● A/P TRIM DISC BUTTON… PRESS AND HOLD ● ELEVATOR TRIM… ADJUST MANUALLY ● AUTOPILOT CIRCUIT BREAKER… OPEN ● A/P TRIM DISC BUTTON… RELEASE, do not re-engage autopilot

When the pilot overpowers the AP in pitch, the automatic trim will run in an attempt to compensate. This may leave the airplane considerably out of trim once the AP is disengaged, so be prepared for larger than normal control forces and retrim as appropriate.

Revised: 09/24/2019

Note that the additional steps on the Before Takeoff Checklist are essentially to confirm that this emergency checklist will work properly. The Autopilot circuit breaker has a plastic collar on it for easy identification in flight. It is the rightmost breaker on the bottom row of the breaker panel.

Manual Electric Trim 

When the AP is not engaged, the pilot can use the pitch trim servo to electrically trim the aircraft, rather than using the trim wheel. The Manual Electric Trim (MET) Switch is located on the left grip of the pilot’s control wheel. It is split into two sides; the left switch arms the MET function, while the right selects nose down (push forward) or nose up (pull backward) trim. Both sides of the switch must be operated together to activate the trim servo. If the left (arm) MET Switch is pressed while the autopilot is active, the autopilot will disengage. This switch can also be used to acknowledge/mute the aural autopilot disconnect alert tone.

Control Wheel Steering 

Control wheel steering (CWS) is a feature where the pilot can hold a button to temporarily disengage the pitch and roll servos and fly the aircraft manually, without fully disengaging the AP. Use of CWS is not included in ATP’s standard operating procedures. Instead, disengage the autopilot with the A/P TRIM DISC button, and re-engage it once you are finished flying manually. (More information on CWS can be found in the G1000 Pilot’s Guide.)

C172 w/ GFC700 Autopilot Checklist 

Download and use the Cessna 172SP (G1000 w/ GFC 700) Checklist for TAA training flights.

C172 Supplement Profile Addendum 

The following pages provide an addendum to the C172 Approach and Missed Approach procedure highlighting additional steps required when the autopilot is in use.

Revised: 09/24/2019

Arrival Procedures

When Established on Downwind• Crab as necessary to maintain

consistent ground track• Complete the Before Landing Checklist

Decision to Go Around• Increase throttle to full power.• Retract flaps to 20˚ (if > 20˚) while

simultaneously; Increase pitch to establish climb.

When airspeed > 55 KIAS. • Retract flaps to 10˚

Establish VX or VYWhen clear obstacles or accelerating through VX (if no obstacles) • Retract flaps to 0˚

1,000' AGL "After Takeoff Checklist" if departing traffic pattern

Missed ApproachA missed approach is a maneuver conducted by a pilot when an instrument approach cannot be completed to a landing. The pilot’s initial actions when initiating a missed approach are the same as a go-around procedure.

Go-Around / Missed Approach Procedure1. Increase throttle to full power

3. Retract flaps to 20° (if > 20°) while simultaneously;4. Increase pitch to establish climb5. Retract flaps to 10° when airspeed is greater than 55 KIAS6. Establish VX or VY as appropriate7. Retract flaps to 0˚ at 65 KIAS and clear of obstacles

(if no obstacles)

11. “After Takeoff Checklist” out of 1,000’ AGL if departing the traffic pattern

If the go-around or missed approach is due to conflicting traffic, maneuver as necessary during the climb to clear and avoid conflicting traffic (usually to the side, flying parallel to the runway).

2. Press Go Around

8. Set CDI to GPS9. Press NAV Key

10. Flight Level Change: 90 KIAS

Arrival Procedures

"After Takeoff Checklist" if departing traffic pattern

Precision Approach (ILS Approach)1. Complete the “Approach Checklist” and identify the localizer as early as

possible2. Slow to 90 KIAS on vectors or when final approach course inbound3. Announce “Localizer Alive” when localizer begins moving toward center4. Announce “Glideslope Alive” when glideslope begins moving toward

center5. Verify no flags at glideslope intercept altitude and marker6. 1⁄2 dot below glideslope intercept: “Before Landing Checklist”7. Reduce power to approx. 1500 RPM, and select flaps 10°.8. Descend on glideslope at 80 KIAS.

10. Announce at 1,000' above DA: “1,000 to go”11. Announce at 100' above DA: “100 to go”12. “Minimums”

14. Runway in sight: descend and slow to 70 KIAS15. On short final, slow to 65 KIAS until 10’ to 20’ above the runway

No Later than 15 Mi. from Airport• Approach Check• Identify the localizer as early as possible

On Vectors or Published Segment• Slow to 90 KIAS

Localizer Movement Toward Center• “Localizer Alive”

Glideslope Movement Toward Center• “Glideslope Alive”• Verify no flags

½ Dot Below Glideslope• “Before Landing Checklist”• Reduce power to

approx. 1500 RPM• Select flaps 10˚

Glideslope Intercept• Descend on glideslope at

80 KIAS

1,000' Above DA• “1,000 to go”

100' Above DA• “100 to go”

DA• “Minimums”

Touchdown • Touchdown on first 1,000’ feet of

the runway at minimum controllable airspeed

• Maintain Centerline Until Taxi Speed• Increase Crosswind Control Inputs as

Airplane Slows

TIP: The airplane is considered established inbound when the localizer is alive.

Runway in Sight• Descend and slow to 70 KIAS• Short final – slow to 65 KIAS until 10' to 20'

above runway

9. Set Missed Approach Altitude

13. Disconnect Autopilot

Arrival Procedures

Non-Precision Approach (GPS, VOR, LOC Approach)1. Load the approach into the GPS, and select appropriate nav source,

and frequency if required.

Within 30 NM of the airport, if flying a GPS approach, the GPS will display "Apch Arm" or “TERM.”

2. Set the desired course on the Nav 1 OBS.3. Complete the "Approach Checklist."4. Slow to 90 KIAS when on a published segment of the approach or if on

vectors.

At 2 NM prior to the FAF on a GPS approach, verify green APCH ACTV or APCH flag on GPS. If no flag appears, DO NOT DESCEND at the FAF.

5. At FAF, complete "Before Landing Checklist" - Flaps 10° - Slow to 80 KIAS.Start time if required.

6. Descend at 400-500 FPM (unless steeper descent required) at 80 KIAS.7. Announce at 100' above minimums: "100 to go."8. Increase power 50’ prior to reaching MDA to maintain 80 KIAS at level

off.9. "Minimums."

11. Maintain MDA (plus 50', minus 0').12. Runway in sight: descend at predetermined VDP or maintain MDA to

MAP.13. Do not leave MDA until landing is assured.

15. When descending from MDA: Flaps 20° - 70 KIAS.16. On short final, slow to 65 KIAS until 10’ to 20’ above the runway.

80 KIAS

70 KIAS

“100 to go”

“Minimums”Increase Power, Maintain 80 KIAS

50’ Above MDALanding Assured: Flaps 20°

Short Final – 65kts

Flaps 10°, Slow to 80 KIASStart Time If Required

10. Set Missed Approach Altitude

14. Disconnect Autopilot