[SystemSafety] GPS jamming
Peter Bishop
pgb at adelard.com
Sat Jul 13 12:18:19 CEST 2019
I am not an expert, but I understand EGNOS works out corrections to
standard GPS signals
based on a limited number of ground stations (who obviously know where
they are).
If spoofing is in a localised area, the ground stations (located
elsewhere) would not see the spoof (just the regular satellite signals),
so the resultant broadcast Egnos correction data would just make a small
correction to the spoofed GPS signal.
Or have I got this completely wrong?
Peter Bishop
On 12/07/2019 13:16, Dewi Daniels wrote:
> Peter,
>
> That is indeed very chilling. It seems that we have an aircraft
> operating with certified kit that ended up 12nm off course in
> mountainous terrain. Either the certified equipment on board the
> aircraft did not work as intended, or even more chilling, there is a
> fundamental problem with WAAS. I hope it's not the latter. The WAAS
> technical specification promises that "WAAS provides the additional
> accuracy, availability, continuity and integrity necessary to enable
> users to rely on GPS for all phases of flight, from en route through
> approaches with vertical guidance, at all qualified airports within
> the WAAS LPV coverage area". This does not appear to have been the
> case in this instance.
>
> Yours,
>
> Dewi Daniels | Director | Software Safety Limited
>
> Telephone +44 7968 837742 | Email d
> <mailto:ddaniels at verocel.com>ewi.daniels at software-safety.com
> <mailto:ewi.daniels at software-safety.com>
>
> Software Safety Limited is a company registered in England and Wales.
> Company number: 9390590. Registered office: Fairfield, 30F Bratton
> Road, West Ashton, Trowbridge, United Kingdom BA14 6AZ
>
>
>
> On Fri, 12 Jul 2019 at 12:32, Peter Bernard Ladkin
> <ladkin at causalis.com <mailto:ladkin at causalis.com>> wrote:
>
>
>
> On 2019-07-12 12:21 , Mike Rothon wrote:
> > The incident report is available on the NASA ASRS database at
> > https://asrs.arc.nasa.gov/search/database.html. Search by Report
> Number (ACN) for 1565516.
> >
> > It was a Cessna Citation 560XL, a mid-size business jet. These
> are reasonably well equipped, usually
> > a single or dual Honeywell Primus 1000 package (when built).
> >
> > I thought this system was capable of DME/DME as well, but I have
> no idea how the solution would be
> > compared or prioritised against a solid WAAS signal.
>
> There is a presentation about the airport (KSUN, Hailey-Friedman
> Memorial Airport at Sun Valley,
> Idaho, from 2012 at
> http://iflysun.com/wp-content/uploads/2016/12/FMAA-Power-Point-Presentation-010312.pdf
> Horizon Air
> seems to fly in there, with Q400 aircraft and a custom RNP (one
> slide says they don't use the "Y"
> procedure). There are two poor-resolution approach plates, RNP-W
> and RNP-Y, both for RWY 31.
>
> There are better-resolution plates available on the WWW, for example:
> RNAV Y RWY 31
> https://resources.globalair.com/dtpp/globalair_06239RY31.PDF
> RNAV X RWY 31
> https://resources.globalair.com/dtpp/globalair_06239rx31.pdf
> RNAV W RWY 31
> https://www.platinumairways.org/files/DOTW_Charts/KSUNcharts.pdf
>
> There is part of the sectional at
> https://skyvector.com/?ll=43.503780556,-114.295558333&chart=301&zoom=1
> There is a fairly wide E-W
> plain south of the airport, at elevations 4800'-6000' it seems,
> and the mountains start about where
> the airport is, with peaks at over 10,000' N, E and W.
>
> Besides the RNAV, there is an NDB/DME approach also, coming off an
> NDB and DME which is about 10nm
> away from the airport. Decision point (visual contact) is about
> 5nm away from the runway, and 5nm
> beyond the NDB/DME installation. There is no kit at the airport
> itself.
>
> Fix PRESN is named in the report. PRESN is an IAF for all these
> approaches. Note the controller says
> tower says AC just reported PRESN, and ARTCC radar was showing him
> 12nm NW of that.
>
> The plates give the WAAS data, so KSUN is served by WAAS. Hard to
> say how well, though.
>
> The MSA is 13,000, and they were performing an approach to an
> airport at 5320' (note two of the
> above plates have this, and one has 5318'), so they will be
> spending a lot of time on that approach
> below the tops of the terrain, which in the vicinity of the
> airport go up to almost 9000'. To be
> 12nm off track in that situation is exceptionally dangerous. To
> see on the plate where the AC was
> when he thought he had just passed PRESN, note that JUNOL to CAKIR
> (the go-around point on the RNAV
> approach) is about 10nm.
>
> I agree with Mike's assessment that the incident is "chilling".
>
> In comment on Dewi's and John's speculation that he might have
> been operating with non-certified
> kit, given it was a Citation I doubt it. In response to Dewi's
> query if it is legal to fly IFR with
> non-installed kit, the answer is no. The aircraft can only use
> installed and regularly calibrated
> kit and it is in the maintenance logbook what that is (with the
> certificates if it is installed
> post-delivery).
>
> That doesn't stop the cowboys, though. But they tend to stop
> themselves, in Darwinian fashion -
> every US flight school has its story about the pilot who used to
> go file IFR here and there without
> an IFR rating - and how long he lasted (it is invariably a male,
> and invariably a couple of years at
> most).
>
> PBL
>
> Prof. Peter Bernard Ladkin, Bielefeld, Germany
> MoreInCommon
> Je suis Charlie
> Tel+msg +49 (0)521 880 7319 www.rvs-bi.de <http://www.rvs-bi.de>
>
>
>
>
>
> _______________________________________________
> The System Safety Mailing List
> systemsafety at TechFak.Uni-Bielefeld.DE
> <mailto:systemsafety at TechFak.Uni-Bielefeld.DE>
> Manage your subscription:
> https://lists.techfak.uni-bielefeld.de/mailman/listinfo/systemsafety
>
>
> _______________________________________________
> The System Safety Mailing List
> systemsafety at TechFak.Uni-Bielefeld.DE
> Manage your subscription: https://lists.techfak.uni-bielefeld.de/mailman/listinfo/systemsafety
--
Peter Bishop
Chief Scientist
Adelard LLP
24 Waterside, 44-48 Wharf Rd, London N1 7UX
http://www.adelard.com
Recep: +44-(0)20-7832 5850
Direct: +44-(0)20-7832 5855
Registered office: 5th Floor, Ashford Commercial Quarter, 1 Dover Place,
Ashford, Kent TN23 1FB
Registered in England & Wales no. OC 304551. VAT no. 454 489808
This e-mail, and any attachments, is confidential and for the use of
the addressee only. If you are not the intended recipient, please
telephone 020 7832 5850. We do not accept legal responsibility for
this e-mail or any viruses.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.techfak.uni-bielefeld.de/mailman/private/systemsafety/attachments/20190713/d1110226/attachment.html>
More information about the systemsafety
mailing list