Attitute hold

[Clyber]

In the Hold Modes section of the manual page 208 

If Attitude Hold (any sub-mode) is off, Heading Hold is engaged when all of the following conditions are true:
• One second has elapsed since Heading Hold was disengaged 

I dont get it .... First how or when do we enter the Submodes like Heading hold or Turn coordination sub mode and how can we take notice of this ?  There is no way to figure out in what submode the aircraft is in.  All these automatic submodes, Turn coordination, Heading Hold, could be engaged without the pilots knowledge ?  So first you switch off Attitude hold mode, trying to meet those 6 conditions and hope that you have entered Heading Hold mode ? Or you could have messed with the buttons, entered a submode but is almost impossible to figure out in what Submode the aircraft is in.  

 

 

 

 

 

 

 

Edited February 8, 2023 by Clyber

[VKing]

What the preconditions mean is that as long as you're flying at less than 40 knots without holding the force trim or moving the pedals from the trimmed position, not yawing, and attitude hold mode isn't enabled, your aircraft will be in heading hold mode.

It wouldn't be correct to say the modes change without the pilot's knowledge, since the pilot puts the helicopter into the different modes by what state he puts the helicopter into. E.g. if you accelerate to more than 40 knots, you know you aren't in Heading Hold any more but in Turn Coordination.

It might be easier to think of it not as a mode you enter, but the default state your helicopter is in for a given set of conditions.

E: Regarding the condition of time elapsed since heading hold was disengaged, I believe this means that if any of the other conditions are broken and then returned to, there will be a grace period before the system engages again, possibly to prevent oscillations or that kind of thing.

Edited February 8, 2023 by VKing

[Clyber]

55 minutes ago, VKing said:

What the preconditions mean is that as long as you're flying at less than 40 knots without holding the force trim or moving the pedals from the trimmed position, not yawing, and attitude hold mode isn't enabled, your aircraft will be in heading hold mode.

It wouldn't be correct to say the modes change without the pilot's knowledge, since the pilot puts the helicopter into the different modes by what state he puts the helicopter into. E.g. if you accelerate to more than 40 knots, you know you aren't in Heading Hold any more but in Turn Coordination.

It might be easier to think of it not as a mode you enter, but the default state your helicopter is in for a given set of conditions.

E: Regarding the condition of time elapsed since heading hold was disengaged, I believe this means that if any of the other conditions are broken and then returned to, there will be a grace period before the system engages again, possibly to prevent oscillations or that kind of thing.

 

Thx for your explaination. 

Ok ok... I was approaching this totally diffrent. I saw the Two Hold modes, Attitude and Bar Alt modes as primary modes to enter and only  after entering those you could enter the other secundary Submodes Turn Coordinated and Heading hold mode.  The way you have explained it is easier to understand.  Instead of submode, default state would be a better term. 

E: Also makes sense. 

thx 

 

Edited February 8, 2023 by Clyber

[Clyber]

Can anyone explain to me what the difference is between Holdmodes and Autopilot as the Apache hold modes may not be considered an autopilot function ? 

Edited March 27, 2023 by Clyber

[admiki]

Hold modes in Apache are an autopilot in technical sense of the word. System moves controls on its own to maintain set parameters. That can be considered lower autopilot modes.

Higher autopilot modes are aircraft capturing set parameter/s by itself, not just maintaining it (eg. following flight plan). Apache doesn't have this.

Might be easier to understand if you compare it to  car cruise control. Apache has cruise control and lane keeping. You need to keep an eye on it and change as needed.

Higher modes would be if you entered destination and your car would get you there all by itself (Tesla cars for example). In theory, you don't even have to be in the car for all it cares.

Edited March 27, 2023 by admiki