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GPS INTERFERENCE MILITARY EXERCISE...


Dreamlifter

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Just a heads up! My company sent out this bulletin which you will receive through FAA advisories that may affect all of us in the area of concern.

 

Background
Starting February 6th thru February 10th the DOD will be conducting exercises off the South Carolina coast.  Crews can expect a level of intermittent GPS interference during this exercise.  GPS interference will vary depending on altitude and distance from the jamming source, crews can reference the FMS ANP and compare it to the RNP to determine RNAV compliance.

As a reminder our mainline aircraft (except for the last GFMS MD-80) are capable of navigating in the enroute environment without a GPS signal.  All RNAV approaches require GPS. Most arrivals and departures do not require GPS.  But because some do, reference the notes section of all SIDs and STARs within the affected area to determine if GPS is required.  If GPS is required for a SID or STAR, advise ATC only if you experience a loss of GPS.  Otherwise it is not a requirement to notify ATC if a loss of GPS is experienced. 
  
CONUS enroute navigation requirements are RNP 4.0 while RNAV SIDs and STARs will typically require a 1.0 RNP.  WATRS area navigation performance requirements are RNP 10.  It is required to notify ATC if the ANP value is greater than the RNP for that segment.  An UNABLE REQD NAV PERF –RNP message will notify crews of RNP exceedances.

If the on board navigation experiences a downgrade or loss of GPS signal please fill out a CERS report for our records.  We use these reports to notify the FAA of the impacts to the airspace due to the GPS interference experienced from this and other DOD exercises.

mail?url=https%3A%2F%2Fcci.aa.com%2FCrewCheckin%2FuploadedFiles%2FAAPI%2FBoeing_GPS_Interference_46930.jpg&t=1549563967&ymreqid=fba27931-d1ae-eb95-1c05-20000101f800&sig=pVE3w5SY7Y8Ru2JJxwG5rQ--~C

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I love the map @Dreamlifter.  <whinge>  When I read the NOTAMS and am confronted with a GPS outage notice I try to estimate where in the world they are talking about, my eyelids get droopy,  and I start to imagine that it doesn't matter to my lil' ol' Mooney, then I give up.   Why can't they produce a map?   Maybe when they produce an announcement that they are going to disturb GPS reception- the FAA could _require_ them to produce a map?   Maybe that map could then be put in the NOTAMS in the enroute navigation section of the briefing? </whinge>  Compare your map against this gem:

GPS 02/025 (KZDC A0032/19) ZDC NAV GPS (CSG4 GPS 19-01) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A 555NM RADIUS CENTERED AT 313339N0793740W (CHS173083) FL400-UNL, 509NM RADIUS AT FL250, 436NM RADIUS AT 10000FT, 388NM RADIUS AT 4000FT AGL, 338NM RADIUS AT 50FT AGL 1902101500-1902101900

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13 minutes ago, Fred₂O said:

I love the map @Dreamlifter.  <whinge>  When I read the NOTAMS and am confronted with a GPS outage notice I try to estimate where in the world they are talking about, my eyelids get droopy,  and I start to imagine that it doesn't matter to my lil' ol' Mooney, then I give up.   Why can't they produce a map?   Maybe when they produce an announcement that they are going to disturb GPS reception- the FAA could _require_ them to produce a map?   Maybe that map could then be put in the NOTAMS in the enroute navigation section of the briefing? </whinge>  Compare your map against this gem:

GPS 02/025 (KZDC A0032/19) ZDC NAV GPS (CSG4 GPS 19-01) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A 555NM RADIUS CENTERED AT 313339N0793740W (CHS173083) FL400-UNL, 509NM RADIUS AT FL250, 436NM RADIUS AT 10000FT, 388NM RADIUS AT 4000FT AGL, 338NM RADIUS AT 50FT AGL 1902101500-1902101900

You know, back in the good old days of teletype machines or dial-up modems to deliver information, I could understand the need to abbreviate everything. Now days,  however, it makes no sense! Why aren’t notams (or for that matter METARs, TAF’s, etc.) written out in complete sentences?

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Isn't the new ADSB mandate that 's being force implemented going to suffer from these kinds of "tests"?

It sounds funny when I say it aloud: You must have a GPS source to be ADSB compliant... but the government reserves the right to completely disable it.:wacko:

Edited by David_H
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I'm a Dreamliner Captain but my Mooney lifts my dreams!!
Gotcha! If you were flying the Dreamlifter (full of Dreamliner parts) then you'd likely come to Wichita and we could rendezvous for a Mooney session. One of those erroneously landed at my base several years ago...that was exciting.

Sent from my LG-US996 using Tapatalk

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On 2/7/2019 at 5:15 PM, Fred₂O said:

I love the map @Dreamlifter.  <whinge>  When I read the NOTAMS and am confronted with a GPS outage notice I try to estimate where in the world they are talking about, my eyelids get droopy,  and I start to imagine that it doesn't matter to my lil' ol' Mooney, then I give up.   Why can't they produce a map?   Maybe when they produce an announcement that they are going to disturb GPS reception- the FAA could _require_ them to produce a map?   Maybe that map could then be put in the NOTAMS in the enroute navigation section of the briefing? </whinge>  Compare your map against this gem:

GPS 02/025 (KZDC A0032/19) ZDC NAV GPS (CSG4 GPS 19-01) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A 555NM RADIUS CENTERED AT 313339N0793740W (CHS173083) FL400-UNL, 509NM RADIUS AT FL250, 436NM RADIUS AT 10000FT, 388NM RADIUS AT 4000FT AGL, 338NM RADIUS AT 50FT AGL 1902101500-1902101900

That's actually the same map I got from the FAA in the email notice I received a couple days ago (see link below).  Dreamlifter just attached a screenshot of it....

Advisory: https://www.faasafety.gov/files/notices/2019/Feb/CSG4_19-01_(Revision_1)_GPS_Flight_Advisory.pdf

Here's the link to reporting any GPS anomalies/outages: https://www.faa.gov/air_traffic/nas/gps_reports/

Cheers,

Brian

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1 hour ago, Fred₂O said:

I'll bet a lot of us have the KX155 NAV/COM + GNS430W in VOR/OBS mode!  B)

 

Yeah and it brings up a question in my mind.  Does the 430 in VLoc mode determine distance to station using DME from the VOR, or is that value not available if GPS signals are inop?  I had old tech DME in my C, but only have the 430 to rely on for this information in my F.

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1 hour ago, MBDiagMan said:

 

Yeah and it brings up a question in my mind.  Does the 430 in VLoc mode determine distance to station using DME from the VOR, or is that value not available if GPS signals are inop?  I had old tech DME in my C, but only have the 430 to rely on for this information in my F.

The DME part of the 430 is definitely GPS based, not actual time-of-flight DME.  So, you lose that.   But, you do have marker beacons!  Stopwatch too!

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3 hours ago, MBDiagMan said:

 

Yeah and it brings up a question in my mind.  Does the 430 in VLoc mode determine distance to station using DME from the VOR, or is that value not available if GPS signals are inop?  I had old tech DME in my C, but only have the 430 to rely on for this information in my F.

DME is not received through a VOR receiver.  My understanding is that it is a UHF signal, so it's completely separate.  The 430 and 530 solely base distances on GPS (and AFAIK cannot receive any signal from a DME receiver).

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DME is a separate system from VOR.   DME operates in the 960 to 1215 MHz band in paired frequency channels.  

Each VOR frequency is associated with a DME channel.  When you tune your VOR receiver it sends that VOR frequency information to your DME box.  The DME then tunes to the associated channel. 

In ancient aircraft radios the DME channel had to be separately selected.  To this day charts still provide the DME channel just in case a vintage DC-4 rumbles along:

C9DFD02E-AA51-432B-9114-604DAB435371.jpeg.6216e6acd26c344919871eb5e300f543.jpeg

The radio operator would crank in 111.4 on the VOR receiver.  Then he would select Channel 51 on the DME control head.  Finally he would listen to the DME audio and copy the Morse ID (sent every 30 seconds) to verify it was using the proper ground station.  

You do listen to the DME audio whenever you switch to a new VOR/DME, yes?  Me neither.  

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3 hours ago, Jerry 5TJ said:

You do listen to the DME audio whenever you switch to a new VOR/DME, yes?  Me neither.  

You mean Tune-Identify-Monitor (TIM).  Yep, I make my students do that for every and all NAVAIDS used to include VOR, LOC, TAC, NDB & OMs.  We can't separate the VOR ident from the DME, but since the radios auto tune the paired DME we rely on the VOR ident.   They do get a break from listening to Morris Code on RNAVs, but only after they check RAIM and verify the courses, distances, altitudes, names and sequence of the loaded approach matches the plate.

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32 minutes ago, kpaul said:

...... We can't separate the VOR ident from the DME, but since the radios auto tune the paired DME we rely on the VOR ident.....

There is an audio output from the DME and if it is routed to the audio panel you can monitor it.  

Glad to hear you teach the use of the Morse ID.  The presence of the Morse verifies the ground Navaid’s self-test is passing.  

Edited by Jerry 5TJ
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1 minute ago, Jerry 5TJ said:

Glad to hear you teach the use of the Morse ID.  The presence of the Morse verifies the ground Navaid’s self-test is passing.  

That and it is a great way to make sure you dialed/typed in the correct frequency.  I have witnessed folks putting in the wrong LOC freq either by "memory" or being off by one approach plate initially.  My favorite question to ask while flying down a LOC final is "are how confident are you that you have the correct frequency dialed in?'  That is usually closely followed by "so how's your timing working out?"  Yep, I make them time on every approach.  It only takes once or twice before they realize that I usually won't ask them questions inside the FAF so long as they TIM and complete the 6Ts.  

My student yesterday flew 8 approaches, 3 were full procedure, 3 were circling, 2 were single engine, one was flown to a published missed and hold.  It was a combination of VORs, LOCs, ILS and RNAVs.  Not bad for a 150hr pilot trying to think at 200kts.  W logged 4.5 hours on two flights that included 2 drop-in locations and 2 full stop locations. He learned a valuable lesson on the final RNAV approach to a full stop.  Unlike the previous RNAVs of the day, he elected to skip the confirmation steps after loading the approach.  Who knew that it is difficult to fly a RNAV when the ILS is loaded into the GPS?  The clue light finally came on as were approaching the FAF and the name was wrong and the coupled AP did not descend on the VNAV profile.  I finally had to step in and reload the correct approach.  It was nice that we were in VMC conditions and the RNAV and ILS are near identical ground tracks, it kept me from being violated while still allowing him to learn the lesson.

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6 hours ago, Jerry 5TJ said:

DME is a separate system from VOR.   DME operates in the 960 to 1215 MHz band in paired frequency channels.  

 

Great point and explanation from @Jerry 5TJ!

With ground based nav-aids being decommissioned we will be relying on space based navigation. ADS-B / ADS-C will be used for ATC and position reporting.

Maybe satellite comm will be affordable someday.....^_^

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