auto pilot

[chaser]

Does it work? or are we waiting the only reason I ask is that this is my first clickable cockpit and im all fingers and thumbs trying to work out the MFD's ect

[Mumby]

Works for me, have fun!

 

 

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[baltic_dragon]

It works, although it is very simple. Attitude hold and altitude hold, that's it. Light years behind M-2000C one.

[Harlikwin]

Works for me.

[seagull1606688860]

It works, although it is very simple. Attitude hold and altitude hold, that's it. Light years behind M-2000C one.

 

 

Is it supposed to be this way or it is actually more complex?

[Shadow_1stVFW]

Is it supposed to be this way or it is actually more complex?

 

A1-AV8BB--NFM--000 starting on page 2-53

2.16.2 Automatic Flight Control

The two AFC mode selection controls are the AFC and ALT HOLD solenoid held switches. All three SAS switches

must be engaged in order to engage the AFC mode selection switches. Also, an interlock with the weight--on--wheels

switch on the main gear inhibits engagement of the AFC mode switches on the ground and disengages the switches

upon main gear touchdown on landings.

The AFC switch has three positions which provide the following functions:

AFC – Solenoid held position. Engages the AFC mode.

OFF – AFC mode is off.

RESET – Momentary position. SAAHS reset.

The ALT HOLD switch has two positions which provide the following functions:

ALT HOLD – Solenoid held position. Engages altitude hold option of AFC mode.

OFF – Altitude hold is off.

The AFC switch must be engaged with the INS switch in NAV or IFA in order to engage the ALT HOLD switch.

The AFC mode may be disengaged by turning the AFC switch off. Disengaging the AFC switch also causes the ALT

HOLD switch to return to the OFF position if it is engaged. Disengaging any of the three SAS switches will disengage

the AFC mode. The AFC and ALT HOLD switches will return to the off position if they are engaged. Pressing the

paddle switch also disengages the AFC and ALT HOLD switches if they are engaged. Both switches will remain in

the off position when the paddle switch is released. The technique of “clicking” the paddle switch may be used to

revert from the AFC mode to the SAS mode. Attitude references are to the aircraft waterline.

2.16.2.1 AFC Mode -- AFC Switch Only Engaged

When the AFC switch is engaged and the ALT HOLD switch is in the off position, the AFC mode provides pitch

attitude hold, roll attitude hold and heading hold. At airspeeds above 50 knots, the AFC will capture and hold pitch

attitudes in the ±30° range and roll attitudes within ±60° which are outside of the ±5° range about wings level.

Heading hold is provided inside the ±5° roll attitude range for airspeeds above 140 knots if gear and flaps are up or

above 0.3 Mach if the gear is down or if STOL flaps are selected (but not both). Heading hold is inhibited at all

airspeeds if both the gear is down and STOL flaps are selected. With heading hold inhibited, roll attitudes within ±5°

are rolled to wings level. Neither pitch nor roll attitude capture will occur for attitudes which exceed one or both of

the ±30° pitch attitude or the ±60° roll attitude ranges. The AFC switch will remain engaged, however, the pilot must

control the aircraft in both pitch and roll as in the SAS mode until the attitudes are within both limits. No cockpit

indication is given to the pilot when he has maneuvered the aircraft outside the attitude capture limits. With the AFC

engaged, mild stick vibration or chatter in pitch may occur during landing approach due to abrupt movement of the

forward reaction control valve caused by flight control computer noise. This is normal and should be disregarded.

At airspeeds below 50 knots, the roll attitude range is restricted to ±20° and the roll to wings level action extends

to the full ±20° range. The pitch attitude capture and hold action is restricted to the +3° to +12° range. Pitch attitudes

outside this range but within --15° to +20° will be driven to the nearest of the +3° to +12° range boundaries. The AFC

switch will disengage and reversion to the SAS mode will occur if either the ±20° roll attitude range or the --15° to

+20° pitch attitude range is exceeded. If the true angle of attack exceeds +15° with the airspeed greater than 60 knots,

the AFC mode will be disengaged and reversion to the SAS mode will occur.

Automatic pitch and roll trim are provided the AFC mode. The automatic trimtracks the aircraft pitch and roll changes

to keep the series servo actuators close to their neutral positions an effort to minimize disengage transients. On aircraft

with departure resistance, the lateral stick to aileron interconnect may prevent the roll auto trim from keeping the

aileron series servos near the center of the ±6° range. The automatic trim rates correspond to approximately 0.25°

per second stabilator and aileron surface rates and cause the control stick to move in the direction the trim change.

2.16.2.2 AFC Mode -- AFC and ALT HOLD Switches Engaged

The ALT HOLD switch permits selection of altitude hold in place pitch attitude hold in the AFC mode. The AFC

switch must be engaged in order for the ALT HOLD switch to be engaged. In addition, the airspeed must be greater

than 160 knots and the climb or descent rate must be less than 2,000 feet per minute for the ALT HOLD switch to

be engaged. Altitude hold may be manually disengaged by “clicking” the pitch manual trim button as well as by

turning the panel switch off. The operation of the roll attitude hold, heading hold and automatic pitch and roll trim

is identical that with the AFC switch only engaged. If either the pitch attitude limits of ±30° or the roll attitude limits

of ±60° are exceeded, the ALT HOLD switch will be disengaged and reversion to the AFC mode without altitude

hold will occur. The ALT HOLD and AFC switches will also disengage if the displayed AOA exceeds +16° ±1°.

Altitude hold is also monitored by logic which will disengage the ALT HOLD switch and revert to AFC without

altitude hold if any of the following events occur:

1. The altitude hold does not lock on to an altitude reference within ±250 feet following manual engagement of

the trim switch or following interruption of altitude hold by longitudinal stick forces exceeding 1 pound. An

altitude reference is established when the altitude rate is driven below 500 feet per minute by the altitude hold

synchronization.

2. An excursion in altitude which differs by more than ±250 feet from the altitude reference.

3. The altitude changes due to stick or trim inputs by a cumulative total of more than ±250 feet following

establishment of an altitude reference.

4. The altitude rate exceeds 2,000 feet per minute or the airspeed falls below 160 knots.

2.16.2.3 Maneuvering Flight In AFC Mode

The AFC mode includes a pitch and roll control stick steering (maneuvering) capability with the AFC switch

engaged. The pilot can use the control stick and the manual trim switch to maneuver the aircraft and lock the AFC

onto new pitch attitude, roll attitude and heading references without disengaging the AFC switch during the

maneuvers. Pilot applied longitudinal and lateral stick forces in excess of approximately 1 pound interrupt the attitude

and heading hold functions and inhibit the pitch and roll automatic trim allowing the aircraft to be maneuvered as

in the SAS mode. Just as in SAS mode maneuvering, the pilot must trim out any stick forces prior to releasing the

stick. This is important because the auto trim capability may have been exceeded when significant trim changes were

made as a result of maneuvering.

Small attitude changes can be made with stick forces below the 1 pound level by inducing aircraft motion with small

stick inputs and “clicking” the manual trim switch. Activating the pitch and roll manual trim switch interrupts the

attitude and heading hold functions and automatic trim so that “clicking” the trim switch has the effect of updating

the attitude hold references to the current aircraft attitudes. If altitude hold is engaged, changes in the roll attitude

can be made in the same manner. “Clicking” the pitch manual trim switch disengages the ALT HOLD switch which

provides a convenient method for reverting to pitch attitude hold for making altitude changes. ALT HOLD shall be

disengaged whenever any pitch maneuvering is done. The ALT HOLD switch must be turned back on to re--engage

altitude hold at the new altitude.

Heading changes can be made by banking outside the ±5° roll attitude range to interrupt the heading hold and rolling

to wings level on the new heading. Small heading changes of a few degrees can be made without banking by

sideslipping the aircraft to the new heading with the rudder pedals, “clicking” the roll manual trim switch to capture

the new heading reference, and slowly releasing the rudder pedal input to minimize the heading transient. A tendency

to hold a heading in a slight bank is indicative of a steady heading sideslip due to rudder mis--trim. This can be

corrected by trimming the rudder.

AFC mode interrupts by stick force and manual trim switch inputs operate independently in pitch and roll within the

AFC mode attitude limits of ±30° in pitch and ±60° in roll above 50 knots and --15° to +20° in pitch and ±20° in roll

below 50 knots. The pilot can maneuver the aircraft in pitch without affecting the roll attitude hold and heading hold

functions or maneuver in roll without affecting pitch attitude or altitude hold.

During significant aircraft trim changes, such as those produced by engine nozzle rotation and aileron droop, the

action of the AFC mode is to hold the aircraft pitch and roll attitudes. The automatic pitch trim adjusts for the

longitudinal trim change and the automatic roll trim adjusts for any roll trim changes due to asymmetric effects. If

the pilot opts to control the aircraft manually during such trim changes, the attitude hold and automatic trim functions

will be inhibited and it will be necessary to retrim the aircraft manually in pitch and roll to smoothly restore the

attitude hold functions. Rapid acceleration or deceleration with asymmetric loaded stores may cause aircraft roll rates

that exceed the response capability of AFC roll trim. If this happens the pilot should take control of the aircraft until

the acceleration or deceleration is over, manually trim the aircraft and then reengage AFC. On aircraft with departure

resistance, at the AOA where departure resistance becomes effective, a slow transition between AFC and departure

resistance occurs.

[baltic_dragon]

Is it supposed to be this way or it is actually more complex?

 

If you read the post above (thanks for that!) you can see that it is intended to work like that.

[Baz000]

In one of Lex's videos where he has his friend come over who was a Harrier pilot in the USMC, he mentions the autopilot in the module is not behaving as it should have in the real jet. They named this system "George"

[bolek]

In one of Lex's videos where he has his friend come over who was a Harrier pilot in the USMC, he mentions the autopilot in the module is not behaving as it should have in the real jet. They named this system "George"

 

I think "George" has been used since the first analog autopilots (named after the inventor). The ubiquitous Bendix/King KAP-140 was also called "George" :).

[Eagle7907]

Excluding anything French.... they refer to the Autopilot as Fefe.

 

 

Sent from my iPad using Tapatalk Pro

[sirrah]

Does it work? or are we waiting the only reason I ask is that this is my first clickable cockpit and im all fingers and thumbs trying to work out the MFD's ect

 

It works, but make sure not to give any stick input, as the smallest input will immediately disengage autopilot

[kengou]

Based on the NATOPS and the previously mentioned video featuring a real Harrier driver, I think the AFC mode is not working as it should right now. He described it as akin to the Hornet's fly-by-wire feel, where it will hold whatever attitude or bank you put in until you change it. As written in NATOPS it sounds like the switch should stay engaged while maneuvering as long as maneuvers are within pitch and roll limits. Right now, it disengages during any maneuvers.

[chaser]

trim adjustments don't turn the auto pilot off btw

[Captain Orso]

Didn't the AV-8B pilots say that with AFC active you CAN change your attitude and AFC would hold it?

 

 

However, from what I've seen, an stick input turns AFC off.

[Badger1409]

In my experience you can change the attitude of the aircraft using the trim switch this does not disable the AFC, although it does disable altitude hold if you change the nose angle

 

edit:oops missed the post by Chaser lol

Edited December 29, 2018 by Badger1409