Autopilot no heading hold?

[VC]

From the UFC control I can only get to attitude hold and altitude hold. Is heading hold missing, I'm being dumb and can't find it, or the real plane doesn't have it?

[DeathAngel1]

I was wondering the same, I cant find it too...

[Tippis]

From what I can tell, it's pretty much just heading hold with a low enough roll angle — I don't know if that's the intent and what the limit is, but it always seemed like if you are reasonably wing level, the “attitude hold” straightens you out and becomes heading hold.

 

 

It's still not a course hold, though, where you can adjust the AP by turning a course knob somewhere, or (again from what I can tell) where you can momentarily disable the AP to set up a new heading like you can in, say, the Mirage.

[LJQCN101]

AP within 7 deg bank angle should bring you heading hold.

[Jirahfighter]

Such a modern aircraft and no way of turning onto a selected heading?

[VC]

AP within 7 deg bank angle should bring you heading hold.

 

Good to know, thanks. Nice and simple and no need for an additional mode... once you know.

[Matchstick]

Such a modern aircraft and no way of turning onto a selected heading?

 

Modern, but intended to be cheap.

 

Leads to corners getting cut like this, not having a dedicated DL radio and only having FWB on the pitch channel.

 

(The limitations are part of what makes this plane interesting to me)

[VDV]

AP within 7 deg bank angle should bring you heading hold.

 

What means that? Could you explain, pls. Thanks.

[Tippis]

What means that? Could you explain, pls. Thanks.

As long as you haven't rolled too much — as long as your bank angle is <7° — engaging attitude hold makes the AP roll out straight and level, at which point it works as heading hold.

[VC]

Does ALT hold do the same, hold heading if you engage it with minimal roll? Or basically ATT works as an "all in one" ALT/HDG hold if you engage it with small enough deflections?

[Tippis]

I haven't found a way to engage alt hold without engaging attitude hold first, so it sort of becomes implicit: if you engage alt hold with enough bank, it will keep that bank while maintaining altitude; if you engage alt hold with little to no bank, you get alt+heading hold.

[Fri13]

Modern, but intended to be cheap.

 

Leads to corners getting cut like this, not having a dedicated DL radio and only having FWB on the pitch channel.

 

(The limitations are part of what makes this plane interesting to me)

 

It is modern, and why it has very open and easy to program software system in it. It allows almost anyone even in the basic university programming skills to write a code for the whole system and get it operational.

 

It is nothing like the F/A-18C etc where you need to use very special programming codes and very demanding process to get the code working etc.

 

It is literally like comparing a writing code in binary (there are still some of those who do!) and writing code in Python.

 

So in JF-17 kind fighter, you really would just tap in the sensors like compass, GPS and INS and you would make you code and command the autopilot system to keep specific heading.

 

It wouldn't be at all difficult for those engineers who are working with JF-17 fighter.

 

But when it comes to usability for pilot, you don't need a own dedicated button for "Heading AP" or where to enter it etc. As it is far more easier to turn the aircraft yourself to the heading you want and then activate the AP, and as said, if it in +/- 7 degree roll angle will roll to level, it will then automatically keep that heading you have at that moment, as it rolls you to level flight. No need to extra modes, no need for extra buttons or other things to make things more difficult for the pilot.

 

AFAIK, this is the difference between the West and the East ways of thinking. Where west wants a own dedicated widget and mode for everything, east simplifies all by making it more logical and natural, by using the pilot flying maneuvers and other knowledge like looking out of the cockpit to see what you are carrying or use the kneeboard etc. It really goes for the joke (invalidated) about special pen for NASA vs the pencil (yeah, the led in the space that might get in computers or someones eye etc).

[VC]

To be honest, to me it sounds like a case of "less is more". I like it. :)

[Pooter03]

Modern, but intended to be cheap.

 

Leads to corners getting cut like this, not having a dedicated DL radio and only having FWB on the pitch channel.

 

(The limitations are part of what makes this plane interesting to me)

 

The no dedicated DL radio definitely makes for some interesting decisions while flying. I'm never quite sure what combo of datalink, AWACs, and channel to other players I should have open. :)

[toilet2000]

It is modern, and why it has very open and easy to program software system in it. It allows almost anyone even in the basic university programming skills to write a code for the whole system and get it operational.

 

It is nothing like the F/A-18C etc where you need to use very special programming codes and very demanding process to get the code working etc.

 

It is literally like comparing a writing code in binary (there are still some of those who do!) and writing code in Python.

 

So in JF-17 kind fighter, you really would just tap in the sensors like compass, GPS and INS and you would make you code and command the autopilot system to keep specific heading.

 

It wouldn't be at all difficult for those engineers who are working with JF-17 fighter.

 

But when it comes to usability for pilot, you don't need a own dedicated button for "Heading AP" or where to enter it etc. As it is far more easier to turn the aircraft yourself to the heading you want and then activate the AP, and as said, if it in +/- 7 degree roll angle will roll to level, it will then automatically keep that heading you have at that moment, as it rolls you to level flight. No need to extra modes, no need for extra buttons or other things to make things more difficult for the pilot.

 

AFAIK, this is the difference between the West and the East ways of thinking. Where west wants a own dedicated widget and mode for everything, east simplifies all by making it more logical and natural, by using the pilot flying maneuvers and other knowledge like looking out of the cockpit to see what you are carrying or use the kneeboard etc. It really goes for the joke (invalidated) about special pen for NASA vs the pencil (yeah, the led in the space that might get in computers or someones eye etc).

 

 

There are several misleading things in your statement. To the contrary, the "East" way is to autopilot absolutely everything. The Soviets were extremely good at designing autopilot and control systems, with most of their aircraft having some sort of autopilot (including approach autopilot as in the MiG-21 and its SAU). The Buran space shuttle basically needed no pilot.

 

Moreover, nobody codes in "binary". Programming in pure "binary" with opcodes would be an exercise in masochism and you can stay on the same abstraction level by working with human readable assembly.

 

The JF-17 was developped in C++ because it is recent. C++ hasn't been around for very long (especially in the aeronautics world) and that's the reason why most military aircraft are programmed in some older less popular programming language. The F-35 was programmed in C++, as it is much newer.

 

Adding an autopilot is no trivial task and, since as you pointed out, a turn autopilot isn't extremely useful in a military jet, was most probably left out due to cost constraints.

 

Moreover, this is the kind of feature that gets added during the lifetime of the aircraft, so I wouldn't be suprised a "fully equipped block 3 or 4" could get advanced autopilot functions, especially if a customer requests it.

[Teschmacher]

is there a Lnav mode ?

[LastRifleRound]

Altitude hold "adds" a pitch hold to a heading or attitude hold.

 

Let's say you are at 5deg bank and 10 deg nose up.

 

You engage ATT autopilot. The aircraft will roll to 0deg bank an maintain 10 deg nose up with 0 deg roll. If you then engage ALT, the aircraft will maintain the 0 deg roll and level pitch out to 0 deg.