WT Forums

Wow, thanks a lot. And also for the other info.

Ok, so I finally made it to \"avionics\" chapter. Loosing one job and getting another, I have plenty of time for writing... And being an IT guy and having electrotechnical high school, I was looking forward to this part. Until I found out that as usual, no one seems to know the designations of the systems I was looking for.

For example, the HUD. I intended to dig up something about it's construction, but all I could get is that it was manufactured by Kaiser, has (or had?) 10milliradian symbols, uses P-37 green phosphorus as luminofor - and that's about it.
But - what is it's designation? One site claims it is AN/AVQ-19, but that designation is occupied by \"Pave Spectre\", rendering this one as a fake lead. Would someone know the proper designation? Military or commercial? Or some parameters?
Also, could someone confirm or deny 6inch exit aperture and 20° total FOV?
Plus, there is a study by Armstrong Aerospace Medical Lab, concerning possibility of changing the HUD symbology size from 10 to 7 mrad. Did that ever occur, or was it just a study?




Apart from that, few more questions occured:
A) Is \"CPU-12\" the navigation microcomputer?
B) Does the A-10A (I'm writing a bout the \"A\" variant, \"C\" or \"NAW\" would be too much work) posses with a AN/ARN-118 improved-TACAN?
C) Is Wilcox 807A still installed, or was it superseded with ARC-186? I recall some of you guys claiming Wilcox wasn't too good
D) Is the \"CDU/Cockpit Display Unit\" name for the CRT TV screen, or is it something else?
E) I have red that pilots used the AGM-65D's IR seeker as an infravision during night flights - projecting image from the missile's seeker to the CRT screen. Is that possible and did that ever happen? If yes, I guess there is no way to find out on what wavelenght is the AGM-65D seeker working, is it?
F) Since when did A-10 crews possess with some fort of night-vision? What type it was would be also nice to know.

Thanks for any answers.

All the other question, I have NO idea.

Some of this is going to get confusing since there was actually a variant among the \"A\" models that was flown by the Guard and Reserve but I'll try to keep it simple.



Not certain what you mean since the A-10 uses several types of navigation but the short answer is No.



Yes



The Wilcox 807 was no longer installed after 1978. As a matter of fact, it's no longer legal due to frequency tolerance issues with the world wide standard of 25khz spacing for both military and civilian. It was provisioned with the wiring and the rack but the LRU's (Line Replaceable Units) were not installed. There was an FM unit (called the FM-622) but nothing for VHF AM.



You won't find that information here.


I'm not certain exactly what you're trying to do. If you're trying to be accurate you'll have to pick a particular time frame and even a particular command since the upgrades were not all done at once. Keep in mind that the A-10 was initially concieved as a low cost and very basic ground support platform. The initial deliveries of the aircraft had very little in the way of Avionics. There was no INS/GPS, no chaff/flare, no ILS, no LASTE, no NVS, an antique Radar Warning System and a basic HUD. Since that time the aircraft has constantly undergone upgrades to evolve into what it is today.

OC

Thanks, both of you.

Old Chief: I found out that in 1978, Hog got the \"Pave Penny\"; in 1980 it got AN/ASN-141 TACAN and improved HUD symbology; and in 1989/90's, it finally got radar altimeter alongside with \"bitching betty\" as a part of the LASTE program (which also added primitive autopilot and NVG-compatibile cockpit lightning) - ain't that correct?

From the TO 1A-10A-1 flight manual, I am aware that there were several configurations of cockpit panels, but I thought that aside from changes mentioned above, there were no \"major\" mods maybe except radios - so you are suggesting there were more important changes aside from those mentioned above?
By the way, the AN/ARN-118 was original equipment, or also an add-on?


As for what I'm trying to do - I'm writing a description of the A-10A from the \"System\" viewpoint - by describing major subsystems/devices and putting them into context: what were they for and how they worked (in general); when they were installed if it was an \"add on\" to the original plane; what was the additional functionality over it's predecessor if it was a replacement of older device/unit; and all those irrelevant, but interesting numbers like APU temperature and RPM or number of tire grooves.
So I'm not describing a single aircraft as much as saying something like \"some Hogs had this device: <description>; it was installed from 1980 because <reasoning>\".
Purpose of my work would be to increase knowledge of the plane's construction and original capabilities, eliminate common mis-conceptions, provide as many \"curiosities\"/interesting notes about development and systems as I could find (for example, the \"TACAN killer antenna\" should get it's own note in sub-chapter about TACAN; \"shell\" above the APU output is also such a \"curiosity\") and help plane modelers with some details, like systems placement and operational characteristics (eg. that ground clearance for loaded aircraft, or various moving surfaces positions).
Being only a long-term aviation enthusiast, I don't aspire for perfection; however, I'm trying to be as throughout and precise as my materials allow me to.

That's not a TACAN, that's the LN-93 INS system. To this day, the aircraft still has the ARN-118 TACAN system and it was original equipment. The giveaway that an ASN-141 is not a TACAN is the designation. ASN stands for Airborne Special/Combination Navigation. Any replacement would have the ARN (Airborne Radio Navigation) designation. All systems in the U.S. military are identified by a designator and you can find a list of all the designations by doing a Google search.

1978 was a big year for the A-10. Starting with aircraft 78-0582 it came from the factory with many new avionics systems. An updated radar warning system, ARN-108 ILS, Pave Penny and ALE-40 Chaff/Flare were the major ones and in the early 1980's it lost the forward and rear \"chin\" antennae.

OC

Yes, sorry - I did know that AN/ASN-141 was the INS, but I got it mixed up in my brain and have mistaken it for TACAN somehow while writing here. But I have it correctly in my work.

Thanks for the \"1978\" stuff. That interests me quite a lot. As far as I know, A-10 had three RWRs: AN/ALR-46, -49 and -69 (although -69 should be merely a upgrade of -49). Transition from which to which was the 1978 change?
Apart from that, does that mean that until 1978, A-10 was flying without ILS and without any form of countermeasures? I red that before, but didn't believe that - strike aircraft without any protection, while IR guided MANPAD SAMs were of a concern even within the requirements/concept study?
Or were those rocket-pod-launched flares used instead of regular flare dispensers?
As for the \"chin\" antenaes - these were for what system?

Thanks for your patience.

The A-10 never had the ALR-49. It originally carried the ALR-46, then the upgraded version which was the 46A. The last iteration was the ALR-69 which was installed from the factory in the 78 series aircraft and a totally different system from the 46A. Shoulder launched IR guided weapons were not in widespread use in the 70's or early 80's so it wasn't a serious concern.

Yes, prior to the avionics upgrade, it did not have ILS nor did it have any type of active countermeasures other than the pod. The chin antennae were used with the Radar Warning system.

The rocket pod was/is never/not intended for use as a countermeasure.

OC

That's weird, because AN/ALR-49 is listed here:
http://www.designation-systems.net/usmi ... q2aly.html
But since you saw it on your own eyes, I take what you say.

As for the ALR-46 versus ALR-69, here:
http://wiki.scramble.nl/index.php?title ... on_(Litton)_AN/ALR-69
They say ALR-69 originated as an addon to the original ALR-46... But again, you're the expert with field practice.

As for the rocket pods - I am almoust certain there were rocket pods with flares, as well as rocket pods with chaff - but maybe I mostook that with LAU-62/A pod. Did A-10 fly with LAU-62, or was it lacking any flare/chaff protection at all?

As for the concern about MANPAD SAMs - A-X \"Concept Formulation Package\" explicitly mentioned protection from Redeye missiles. But that one might have been only suggested, not implemented...

For MANPADs in those days, sufficient protection was provided by the shielding of the engines by the wings and tail surfaces.

I don't recall ever seeing an ALR-49 on an A-10. ALR-46 and -69s are very similar externally, but totally different internally.

Rocket launched chaff was usually employed to deny early warning radars (similar to \"window\" used in WWII) on a large scale, not as countermeasures for individual aircraft responding to individual engagements. Rocket launched flares were used for illumination, not as countermeasures.

I never flew an A-10 with an ILS, INS or VTR until I got to RAF Bentwaters in 1984. TACAN was all we had back then.

Coach

I'm done with the avionics - almost. So, more questions to come:
1) as a part of LASTE, the INS was upgraded with GPS. Would that be the LN-93G or some other upgrade?
2) how exactly works the LASTE low-altitude autopilot? Given the controll rods, I assume it would either emulate \"mechanical hand\" or use trims, wouldn't it? What modes does it have or where could i find more info?
3) did A-10As use any kind of LANTIRN-like pods, or was this limited to the NAW-10 prototype and A-10C?
4) consequently - what NVGs did pilots use for night flights? AN/PVS-7? AN/PVS-14? something entirely else?

Again, thank for any answers. I'm especially interested in finding out what NVGs did the aircrews use in the advent of LASTE...

The A-model used the Lightning pod. IDK if it had Sniper pod capability, but IDR seeing the Sniper pod on the A-10 until I got to a C-model unit.

1. Not sure of the designation, but we got a ring-laser gyro when we got EGI.

2. Only pitch and yaw are controlled by the autopilot. I think it uses the trim motors to do it. ALT Hold, ALT/HDG Hold and Path Hold were the three modes when I flew.

3. A-10As used the Litening pod beginning in 2002. It required a box called an AIM to allow the pilot to control the pod using the Maverick controls. I am not aware of A-10s ever using LANTIRN pods, but the 422 did test several different types of pods in the mid-90s as well as a larger HUD to project the FLIR picture for navigation. All A-10Cs are SNIPER-capable now.

4. ITT F4949 was what I flew with, but I believe they are now using panoramic NVGs with four intensifier tubes instead of only two. Not sure of the manufacturer.

Coach

WOW cover72 your last post/questions have so many misconceptions and mistakes I don't even know where to start in answering them?? All I can say is your book should be an interesting read...to say the least.

can anyone say jettison an engine??

Coach: thanks for all that, especially for that NVGs - I was getting desperate searching for that.
As for the EGI - from what i read, A-10 had the LN-93 (SNU-84-1 standard) INS with laser-ring gyros all the time since the installment of the original ASN-141; the \"A-10 systems engineering case study\" claims that EGI == merely an addition of GPS module into the INS unit. I was just wandering whether that ment the LN-93G, which is a variant of the ASN-141 with Collins GPS reciever, or something else.
But now, were you suggesting that ALR-141 didn't have laser ring gyros? Jane's claims it had, but they have been wrong earlier...


Dice-man: well, it's hard do get accurate info when you have conflicting resources. For example, claim of the ALR-69 being an upgrade of the ALR-46 - which has been proved wrong by Coach here - is from Jane's.
It's a sad world when you couldn't trust even Jane's, innit?
As for the engine pylons burning off the plane - that claim comes from this guy, whose work on the A-10 is somewhat famous. Exactly because I wasn't sure whether it's true or not, I came here find out, I got that clear and removed that claim from my book.

If you know any other approach better than getting as much info as you can and talking about not quite clear parts of it with people who know the best, let me know.
The same goes for resources. As for the reliable ones, all I have is the 1A-10A-1 flight manual, \"A-10 FAQ rev1.2\", avionics catalogs, Jane's excerpts and dissertation by Dr. Campbell plus \"A-10 systems engineering case study\". If you could save me from my tardiness and recommend other truly insightful system-level stuff, rest assured I won't object against it. But you see, since I'm trying to go \"deeper\" than most of the official/paper A-10 books, it's kinda hard. I'm just doing everything I can.

Now, are there so many unresolved misconceptions apart from those I got straight/corrected, or are you talking history?

When we went from the Litton INS to EGI, our alignment time went from a minimum of 8 minutes to 90 seconds. We also were able to do mid-air alignments...something a spinning mass gyro can't do. I think that is when we got the RLG.

Coach

I'm little lost with the Litening versions.
From what i read, A-10 got Litening ER in 2002 and upgraded to Litening AT - am I right? But then, is \"Litening AT\" the same as \"Litening III\"? Or what the heck is \"Litening III\" - same as \"Litening G4\"?
If the Litening AT aperture was identical to the Litening III one, it would be great, because in the Zeiss stuff, there is just enough info.

And anyway, I'm geting FLIR FOV inconsistency - which would be correct:

Ahhhh...the evil "explosive bolts".

_________________
\"Those who hammer their guns into plows
will plow for those who do not.\"
- Thomas Jefferson

...egressing like Depth Charges!


Just read through this thread and must admit...really wondering if anyone short of a Flight Test Engineer is the target audience?

I don't believe their is any commercially available book to this detail available of military aircraft in the marketplace.

kudos to actually getting all of that published! will be a hell of a book for armchair enthusiasts to argue over at the BBQ!!

I cringe at the sight of Mil Pubs! But I have to admit any Mil aviation book ive seen in the marketplace has been pure TP surplus!

_________________
\"A good plan violently executed now is better than a perfect plan executed next week. \"

George S. Patton

TheBigThug: thanks. So far, my book has just 29 letter-sized pages of plain text - so it's not such a major work. But still, I'm trying to keep up with expectations that arise from my previous work.

I've recently changed company I work for (now, I'm in american corporation which even does some security for the USN, lol - but not my team, off course), so there wasn't much progress. But I have some time now, so - could someone please help me with that Litening stuff I posted about earlier?

http://en.wikipedia.org/wiki/LITENING_targeting_pod

Coach

Coach, I have, off course, read the wikipedia. Let me requote myself:

I'm little lost with the Litening versions. <see, various soruces - wiki, af.mil, etc. - don't give consistent view/data>
From what i read, the A-10 got Litening ER in 2002 and upgraded to Litening AT - am I right? But then, is \"Litening AT\" the same as \"Litening III\"? Or what the heck is \"Litening III\" - same as \"Litening G4\"? If the Litening AT aperture was identical to the Litening III one, it would be great, because in the Zeiss stuff, there is just enough info.
<You see, Wiki page doesn't really help here, as it doesn't even list the \"Litening III\".>
And anyway, I'm geting FLIR FOV inconsistency <by that, I mean different sources claim different figures for the same device - and only one of those could be correct, right> - which figures would be correct?:

Code:

Wide FOV:  24.1° x 18.4°  xor  24° x 18° ?
Medium FOV:  3.5° x 3.5°  xor  2.8° x 2,8° ?
Narrow field of view:  1° x 1°  xor  0.77° x 0.77° ?

Sorry, just trying to help. I'll quit wasting your time.

Why are you so interested in Litening specs? It's not part of the A-10. Just an accessory.

We had L-II, L-ER and then L-AT, by the way. Now they use Sniper, too.

Coach

Coach: sorry, I didn't mean to be arrogant or anything. I'm just little frustrated from the inconsistency. What is the \"Litening III\"? Is it the same as AT or ER? Nobody seems to know. But yet, all the \"hard\" data seems to be linked to the L-III.

In my work, I have chapter 5 - sensors. A-10 has very few sensors, so I did the NVG system, Maverick IR seeker stuff and have Litening and Pave Penny to go. As TheBigThug suggested, the book is for aviation enthusiasts, so it's trying to present a comprehensive view on A-10 capabilities and equipment, even though it's \"only\" an accessory - you see, given the impact on the machine's capabilities, I do consider it a part of the A-10.