Rob Lyman Posted August 22, 2013 Report Share Posted August 22, 2013 (edited) The first flight with the system (involving EMC checks) was conducted on Dec 14, 2012. It is not part of Build 3.0, which is SPINS/ACO overlay changes to look more like AMPS. Edited August 22, 2013 by Rob Lyman Quote Link to comment Share on other sites More sharing options...
Velocity173 Posted August 22, 2013 Report Share Posted August 22, 2013 Where does it say that?5-1 (4) During IFR flight with equipment that permits the use of Precise Positioning Service (PPS), the GPS will be operated in the PPS mode. Now, to get the definition of PPS you have to do some searching. gps.army.mil is a good one. Also you'll find online a separate DOD document that defines PPS and specifies it has to be properly keyed IOT be PPS. Then you have the 128D users manual as well. Although that allows for a waiver, it still wouldn't override the AR 95-1 requirement. Like I said, I went through one of the initial classes on the 128D in 2006-2007. I asked two questions at the end. 1. Why isn't this thing precision (glidpath) capable? 2. Why do I need to load a fill and operate in Y mode? First, the Army (right now) doesn't want it capable for precision approaches and second, because Y code completes the DOD PPS requirement for anti jamming anti spoofing regardless of in combat or not. He also said the EPE in Y code is less although ive yet to find proof of that. Quote Link to comment Share on other sites More sharing options...
Joe_P148 Posted August 22, 2013 Report Share Posted August 22, 2013 The reason I asked the question above is because I feel that people have a misconception about the 128D and it's IFR configuration. What about SPS mode or standard positioning service or S mode. I specifically remember the -10 in 2009-2010 specifying that the GPS will be in S mode for IFR operations. S mode as opposed to M and Y isolates the GPS to satellite only as opposed to the C mode which stands for combined. So can I have the GPS in S mode but not have a Y key? I dont know. Also, you can load the GPS Y key with a kyk13 through the panel, granted the god damned think is hooked up right, unlikely at Rucker. Quote Link to comment Share on other sites More sharing options...
Velocity173 Posted August 22, 2013 Report Share Posted August 22, 2013 Slightly off topic but aren't you guys getting a new 95-1 soon? Quote Link to comment Share on other sites More sharing options...
Joe_P148 Posted August 22, 2013 Report Share Posted August 22, 2013 lol, when are we not? Quote Link to comment Share on other sites More sharing options...
d10 Posted August 22, 2013 Report Share Posted August 22, 2013 5-1 (4) During IFR flight with equipment that permits the use of Precise Positioning Service (PPS), the GPS will be operated in the PPS mode. Thanks, I remember reading it there before but I couldn't find it when skimming through earlier. I was hoping that was because they removed it, because it's a ridiculous requirement. Thousands of civil aircraft fly IFR GPS every day without the Y code and I have yet to read an NTSB report citing that as a factor in an accident. Quote Link to comment Share on other sites More sharing options...
Velocity173 Posted August 23, 2013 Report Share Posted August 23, 2013 Thanks, I remember reading it there before but I couldn't find it when skimming through earlier. I was hoping that was because they removed it, because it's a ridiculous requirement. Thousands of civil aircraft fly IFR GPS every day without the Y code and I have yet to read an NTSB report citing that as a factor in an accident.Believe me I'm in total agreement with ya. It's a stupid rule and there were those of us wanting to get it removed. No point in have Y code for IFR ops. That's why I was hoping with the new 95-1 they'd take that out of there. Quote Link to comment Share on other sites More sharing options...
Joe_P148 Posted August 23, 2013 Report Share Posted August 23, 2013 It's a hardware issue not a Y code issue. The 128D could be updated to not require it for SPS mode. Or as 95-1 calls it FPS. Quote Link to comment Share on other sites More sharing options...
Rob Lyman Posted August 23, 2013 Report Share Posted August 23, 2013 (edited) Prior to Selective Availability being turned off, the only way to get the precision out of a GPS that is required for operation in the NAS was to have Y codes. Even though selective availability was turned off in 2000, the capability to turn it back on is still there. Turning it back on (which can be done regionally) would deny precision service to everyone without Y codes. I believe that the military wants its aircraft to be prepared to operate immediately (in flight) should such an event occur, whether it is in a combat theater or our NAS. If you are operating a 128D in IMC you should be familiar with AWR 1753, Appendix A 4.b(2). This is where the requirement (referenced in AR 95-1 for applicable AWRs) to operate in "combined, mixed and keyed mode" is stated. Edited August 23, 2013 by Rob Lyman 1 Quote Link to comment Share on other sites More sharing options...
Joe_P148 Posted August 23, 2013 Report Share Posted August 23, 2013 Prior to Selective Availability being turned off, the only way to get the precision out of a GPS that is required for operation in the NAS was to have Y codes. Even though selective availability was turned off in 2000, the capability to turn it back on is still there. Turning it back on (which can be done regionally) would deny precision service to everyone without Y codes. I believe that the military wants its aircraft to be prepared to operate immediately (in flight) should such an event occur, whether it is in a combat theater or our NAS. If you are operating a 128D in IMC you should be familiar with AWR 1753, Appendix A 4.b(2). This is where the requirement (referenced in AR 95-1 for applicable AWRs) to operate in "combined, mixed and keyed mode" is stated. Thank you for clarifying... Quote Link to comment Share on other sites More sharing options...
lawilm Posted September 4, 2013 Report Share Posted September 4, 2013 I know I have zero to contribute here at all on this topic but.... I must say I have been mind blown by the acronyms and such used here to a degree my head is literally hurting. i even read every single post to see how much of it I actually understood! Quote Link to comment Share on other sites More sharing options...
henni8a5 Posted November 3, 2013 Report Share Posted November 3, 2013 Although I am getting in a little late on the discussion it is very informative and answers a lot of questions. Although the 128D does meet the requirements of TSO-C129a as a Class A1 device, 95-1 could/does inhibit mission execution for IFR operations. Its extremely frustrating coming from an environment flying Hawks that were outfitted with COTS equipment (UNS-1D) that were extremely effective for RNAV operations. User friendly, easy to update, and durable. Moving on to the 128D in my last assignment (2-2 AVN, Korea) was like going back 30 years in technology. Although I made every pilot know the device like the back of their hand, it still has limitations both hardware, software, and DAFIF. However, our TACOPS officer was excellent at ensuring we had the most current DAFIF. Each month he would update the AMPS, then create a few DAFIF PCMCIA cards, then have the pilots sign them out with the usual gear to update the aircraft. It was extremely efficient requiring minimal time resulting in current databases in every aircraft every month. However, it took some time to refine the process due to hardware limitations as indicated below. The PCMCIA cards have to be the 128mb type single drive format which can be ordered though the supply system (we ordered several and they came in very quick). I tried purchasing a COTS card but they do not work as they have multiple drives contained within the card. The 8Gb card (I ordered) was useful at transferring data between AMPS but would not work in the aircraft. The only way we figured this out was from one of our genius pilots that used to work at Geek Squad at Best Buy and was brilliant on computer technology. If he didn't know it, it didn't exist. On the 95-1 rewrite, is the PPS reference going to be excluded to give Army Aviation more flexibility? Is there any updates to the 128D on the horizon or are we stuck with what we have? Being able to pull SID's/STAR's from the database meeting the requirement as outlined in the AIM 5-5-16(a)(2) would also be great along with a "gap" function. Anyway, I could talk about this for days but better end it here. Attached is the DOD PPS Procedures Specification for your reading pleasure. Rob DOD PPS Performance Standard.pdf Quote Link to comment Share on other sites More sharing options...
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