I am well aware that this topic is not directly related to the upcoming sim itself, however, this is the only topic I know of with a load of fanatics and pros... Concerning the avionics, a lot of secondary sources are very contradictory, probably because of lack of proper reference material.

As far as I am aware, the situation is as follows:

Both crewmembers have the option of placing the monocle in front of their right eye. On this monocle, flight information is displayed in the same way as it is on a regular HUD. So it's basically a very small HUD placed only an inch or so from the eye, right?

How can a crewmember focus on looking through the monocle to see the world around him and at the same time focus on the flight information presented on it? Isn't that like looking through a rifle's ironsight, only ten times worse? Also, how can somebody focus his eyes on text and other shapes displayed on the monocle when it's so closely positioned to the eye? I once tried drawing a very fine line on a an old pair of +/- 0 glasses and it didn't matter how hard I tried, I couldn't focus on the line because it was simply too close to my eye. Oh and I've got a perfect pair of eyes according to the ophthalmologist so that was not the issue.

The symbology on the HUD (regular HUDs too, not just helmet mounted ones) are focused on infinity. So you only need to focus your eyes on something far away to see the HUD symbology clearly. Read about collimation: http://en.wikipedia.org/wiki/Collimation

What arneh said. Also, the monocle is actually what we would call a Helmet Mounted Display - HMD, rather than HUD. Of course, it's also a cueing sight, so it does more than just show information.

Bear in mind that this is state-of-the-art electro-optics with digital symbology in use here, not some old NHS glasses that pervs wear with a scratch on!

Collimation.. I've never heard of that before, but the Wiki is quite explanatory! Thanks so far.

Now for the NVS. In a situation where no NVS is used, the monocle is translucent so that crewmembers can look through it and still see the flight information and symbology. What happens when an NVS is used, does the monocle lens turn from translucent to opaque in order to show both the flight information and symbology as well as the imagery provided by either the PNVS or FLIR sensor?

Also, according to the reference material I have, unless the setting is changed, the default NVS for the pilot is the upper turret's PNVS sensor, while the default NVS for the CP/G is the lower turret's FLIR sensor. Should the CP/G use his NVS with the FLIR sensor, I take it the sensors from the lower turret cannot simultaneously be used as a TADS because the turret is slaved to the CP/G's head?

Also can either of the crewmembers use the DTV signal as an underlay on their monocle, or are the PNVS and FLIR signals the only one able to be viewed on the monocle?

Yeah I was aware of that, thank you. It's just that without the knowledge of the collimation principle, it's hard to imagine how you can focus on something that is like an inch away from your eye.

Woah, so many questions. OK, here we go:

A key difference here is understanding the difference between a sensor and a sight. A sensor is used to aid in pilot situational awareness and is used as a flying aid, similar to NVGs. A sight is used in conjunction with the weapons system for targeting purposes. The PNVS is a sensor only. As a result the turret has a faster slew rate, yet smaller field of regard. The TADS is a sensor and a sight. When used as a part of the NVS, it displays a FLIR image onto the monocle to with similar flight info presented on the FLT page. When the CPG actions the sight select switch from HMD to TADS, it becomes a sight. The TADS bucket can now be zoomed and used to track targets in FLIR and DTV on the TEDAC.



The monocle remains translucent, however the NVS is now projected in addition to the flight symbology. The pilot can adjust the brightness and contrast to his liking, but should be set up to still allow sight through the lens.




Correct, what's your source? As explained above, the PNVS is a superior sensor. The TADS was not originally designed to act as a sensor, but, yes, it can be slaved to the helmet and used as such.



No, DTV is part of the sighting system.

Great explanation Spike!

Furthermore I take it DVO has become obsolete with the introduction of the TEDAC? If not, I wouldn't know what the difference is between the DVO's feed and the DTV's feed, as both sights are displayed on a screen instead of directly...

DVO provided a color image, and is deactivated. DTV is B/W.

But you can also view the TADS imagery on a regular MPD, right?

Sorry for all the questions, I should probably pay more attention to my homework. However, asking those already familiar with it, is much more convenient.

In addition to what Spike said; from what I understand the common thing to do at night nowadays is for the pilot to use the PNVS and the CPG to use external night vision goggles (the light amplifing type, rather than IR-sight like the PNVS is). Light amplification and IR have different strenghts and weaknesses, so having one pilot on each can be an advantage.





The DVO has been removed with TEDAC, yes. While DTV is a tv camera which sends a tv signal which is processed and shown on a monitor, the DVO was a pure optical sight, like a sort of telescope. It used just mirrors and lenses. The only way to view its image was to look through the sight which used to be in the center of the CPG's cockpit. The pilot had no ability to view the DVO image. I hope this helps explain the difference between DTV and DVO.
As a curiousity, the DVO, and similar optical sights is the reason why the gunner sits in the front seat in most helicopters. It would be too cumbersome to make the lenses&mirrors sight in the nose go to the rear co-cockpit. However, some newer helicopters, like the Tiger, and cancelled Comanche have the pilot in the front seat as they have discarded the optical sights, and have just cameras.

Hmm funny, one of the key features that made -and still does- the Apache so prominent, is the relatively advanced sighting system, and now crewmembers are using the older night vision goggles again. By the way, I didn't know the helmet has a rail or clip to mount them on.

I wonder what the advantages and disadvantages are between light amplification goggles and the PNVS.

What makes you think Night Vision Goggles are older? It's not like the PNVS, dating from the late 70s (though it has been updated since) is new technology...




I seem to remember one of the advantages of goggles is that they see tracer rounds, while PNVS doesn't. Also light amplification will look more like regular vision, than IR which "looks in temperature", so things may look less weird and unusual with light amplification.
On the other hand, light amplification requires there to be some light sources, while IR works without any light, and works better with fog, smoke etc. Also the hot items that stand out more with IR may be exactly the sort of things you're looking for, making it easier to see humans or vehicles.

I'm sure there are other advantages/disadvantages of each too.

Perhaps I should've used the word sophisticated.

Interesting points regarding PNVS/goggles. Tho I'm wondering now what the difference in the resulting on-screen image is between FLIR and PNVS. They're both based on thermal imaging if I'm right, tho PNVS keeps being referred to as "night vision" system whereas FLIR is described as an IR-camera.

The PNVS is a FLIR sensor and only a FLIR sensor. The TADS contains a FLIR sensor, a DTV camera, and a laser. The PNVS also has a higher slew rate than the TADS, so it's better at keeping up with head movement.

I was not comparing TADS with PNVS and I know that the FLIR sensor and the PNVS sensor are not the same. I was asking what the exact difference is between the PNVS and the FLIR sensor. And by that I mean the technical difference and the difference between the views displayed on the monocle.

If I'm not mistaken the PNVS have better image quality (Afterall PNVS is oriented for pilot navigation in adverse weather/light contitions) and the TADS FLIR despite having lower image quality (compared to the PNVS) it does have "zoom" capability, a capability that the PNVS doesn't have (Afterall the TADS FLIR is oriented for targetting purposes).

Makes sense yes!

I know that the TADS FLIR image is B/W with the option of WHOT or BHOT. However, when the TADS FLIR or PNVS sensor are displayed on the monocle as NVS, do they show up as green?

No, no. The TADS FLIR is also green as the PNVS is (and not Black and White). What happens is that the Apache TADS recording system records the TADS imaging in Black and White (That's why we see the TADS FLIR imaging in black and white in several videos like we see in Youtube, etc...).

Besides a green FLIR image can also have WHOT or BHOT modes. For example in WHOT, the green is heat and black is no heat while in BHOT the black is heat and green is no heat. Also the reason why most of western/NATO FLIR imaging trends to use the green imaging is that there are studies that claim that the human eye distinguish more shades of green than other color shades.

Heh, finally! I was always wondering why do Youtube clips show B/W if documentation says green. Never thought of the recording system changing it to B/W.

And about the green study thing, the same is said about blue. Hence coaches have these gloomy blue lights over your head. If you don't want to sleep at night, you can still see everything without annoying those who do want to sleep with bright white-ish light.