Research on NPP & KPP Indications

[Frederf]

This is the best information about how the NPP and KPP indicators, flags, and pointers are supposed to work in the various radio navigation modes that I have come up with. Differences between this description and the current simulation is largely that items should be inactive while they are currently animating to reflect navigation information.

 

First a quick reminder of indicator names, at least how I'm going to refer to them. Second is a color-coded map of which elements are active under various conditions.

 

[TABLE]|[/TABLE]First notable change is the pitch-bank pointers (and their flags) (blue in picture) which are completely inactive until: when the LANDING switch position is select, PRMG localizer is received, and the landing autopilot (command or automatic) is engaged. At all other times they are neutral in the center of the display in the same manner as when the power supply is disconnected.

 

Similarly the KPP K and G position bars and flags (white) are completely inactive until supplied with PRMG signals which requires the LANDING switch position selected.

 

The NPP position bars lateral and vertical provide horizontal (as well as vertical in the case of LETDOWN) guidance for all three positions of the LETDOWN-NAVIG.-LANDING switch. The lateral guidance is based on the relative position of the bearing pointer and the assigned course needle.

 

The bearing pointer points to the appropriate station in RSBN or ARC navigation.

 

Stuff I know I don't know

• If and when the NPP position bars are inactive are they driven to a hidden position or are they centered similar to when the power supply is disconnected.
  
• What does the bearing pointer point to in the LANDING switch setting if RSBN/ARC is in RSBN?
  
• Does the NPP lateral position bar function during ARC navigation?
  

Edited July 8, 2016 by Frederf

[Beta Sokol]

Hi, Frederf

 

As my knowing about RSBN/PRMG nav, here are some points,

 

questione one, the bars are normally centered and not working,

question two, the pointer shows the RSBN station, bot not sure, might be the PRMG,

question three, the bars are not working, because ARK (ARC) has no radials,

anyone else with other ideas, please reply...

[Art-J]

Wait, what is this thread about actually? Is it the about how KPP and NPP works in current game version, or how they work in real plane (and thus should work in the game as well)?

[Frederf]

If I've done my homework right, the real airplane.

 

First thing I can tell you is that I mixed up the the NPP and KPP labels (fixed with current edit). I keep thinking that K is "курс" so of course that's the course-related compass type instrument. Nope.

 

Навигационный плановый прибор (НПП - NPP) Navigation planning instrument

Командно пилотажный прибор (КПП - KPP) Command flight director instrument

 

Now there's a temptation to believe that the NPP's localizer/glideslope bars are active in the navig. or letdown switch positions but documentation is quite convincing otherwise. The KPP specifically mentions "assigned track position" by "the vertically-disposed, localizer course/assigned track position pointer (bar)" while the NPP does not use these key phrases "track" and "assigned track" when describing the similar bars on the NPP ("position of the localizer course and glide path beams with respect to the aircraft").

 

The reasoning behind this is understandable, providing any signal to these NPP bars runs the risk of the pilot misinterpreting them for landing guidance.

 

I am most confident that the pitch/bank pointers (and their associated warning flags) are inactive except when the landing command-or-auto program is running. Being that they are lower order input indicators (pitch being less abstracted from stick input than altitude) they would have certainly been mentioned.

 

Ultimately this should make the developers' lives easier as generally less indicators are active in many configurations. Instead of worrying how to tune the bank pointer for different modes of flight, you just leave it dead except in the landing autopilot case. You don't have to worry about what navigation scale to use on the NPP for area RSBN navigation because it's dead in the center. You only have to worry about the PRMG scale.

 

I've also been comparing the MiG-21 to the L-39 as they use almost the same equipment but in different ways. Confusingly the L-39 does use the NPP and KPP glide path bars for the cloud penetration mode exactly as during the landing mode (but perhaps without the flags being closed in glide path/letdown mode). Regular RSBN navigation in the L-39 doesn't seem to have an indicator bar for assigned track at all! It must be done strictly by noting the alignment of the bearing and course needs.

Edited July 8, 2016 by Frederf