Words of Advice:

"If Something Seems To Be Too Good To Be True, It's Best To Shoot It, Just In Case." -- Fiona Glenanne

Flying the Airplane is More Important than Radioing Your Plight to a Person on the Ground Who is Incapable of Understanding or Doing Anything About It." -- Unknown

"There seems to be almost no problem that Congress cannot, by diligent efforts and careful legislative drafting, make ten times worse." -- Me

"What the hell is an `Aluminum Falcon'?" -- Emperor Palpatine

"Eck!" -- George the Cat

Sunday, June 9, 2019

Dear FAA, I Toljaso, You Meatheads

Something strange has been going on in the friendly skies over the last day or so. Flights are being canceled. Aircraft are grounded. Passengers are understandably upset. The core of the issue is GPS and ADS-B systems.
I have said, over and over again, that cutting back the VOR network was a stupid move.

And so it has come to pass.


CenterPuke88 said...

So overjoyed that my last clearance was likely last Thursday, I’m missing all the fun! A number of older controllers have been saying this too, but the younger ones don’t believe there is an issue...let’s see if that changes.

B said...

What is causing the issues? I flew yesterday in Indiana and had RAIM on my 430 and my Ipad worked with ForeFlight. WX brief didn't say anything when I called either.

CenterPuke88 said...

No official word on the problem, but the GPS position degradation is causing ADS-B issues. When the GPS signal accuracy drops below a certain threshold, the ADS-B ground stations can’t use the data from the aircraft properly and effectively drop offline.

As you know, the RAIM issue is a problem for GPS approach’s across about 50% of the US, based upon the map provided.

The fact it seems to be Rockwell-Collins units, and that the FAA offered a waiver for operations below RVSM airspace for CRJ-700 and 900 aircraft, suggests it’s not a simple fix. If we start see business aircraft having issues, with their ProLine 21 hardware, that’ll confirm that it’s more of a specific issue...but I wonder how issues seem compare to 5G testing locations or similar events.

Eck! said...

And they had to turn off the rather cheap to run LORAN C.

When you have multiple systems that are string dependent it
only takes one to fail.

Only one word for the mess, dumbass.


CenterPuke88 said...

Collins now says the issue is with their GPS-4000S sensor and it’s communications internal to its equipment. They have identified the issue and a solution. Planes with varying impacts are the CRJ-700 and 900, the Challenger 300/350, B-737-900, Hawker 750 and 850XP, Citation CJ3, Gulfstream 200 and 280, A-320 and MD-11.

In related news, Hawaiian grounded their B-717 fleet due to a failure in the new Multi-Mode unit installed to comply with ADS-B requirements.

Iron City said...

I understand the problem is to do with how some Collins boxes handle a week rollover in the GPS. Not exactly earth shattering but enough. And don't drink the LORAN C koolaide. Low cost my eye. There was a sole source manufacturer of the transmitter ( Racal Megapulse) , the antennas and infrastructure was corroding away as you looked at it costing a kings ransom to replace all for the people that didn't mid the diurnal variations and using wormed over fishing boat gear to get the navigation information. And CONUS has about twice the number of VORs necessary for enroute navigation.

CenterPuke88 said...

Iron City...since a VOR-L has a usable transmission range of 40 NM, and even a VOR-H is limited to 40 NM usable range below FL180, in order to have a usable enroute navigation system you will need a mesh of VOR’s across the country. Incidentally, this is exactly what the VOR system was built to do, so removing half the VOR’s will simply turn a navigational fabric across the US into lace...pretty, but ultimately useless. The current rush to decommission non-GPS/RNAV approaches to locations, including those that have and will keep nearby VOR’s, makes it clear this is simply a headlong rush to cut the costs involved in maintaining VOR’s and keeping approaches certified.

VOR’s are old, proven technology whose overall cost is greatly overstated, and whose usability is constantly denigrated by those who deride a belt and suspenders approach with the GPS systems of today. The question you must ask is, a what cost savings? We have a very safe and flexible airspace system that has had the margins ruthlessly chopped away for years, how certain are you that this surgery won’t cut flesh and bone instead of fat? Those who work within the system see the impending changes and challenges, it’s not how it’s portrayed before the purse holders by the bean counters...remember the FAA places a dollar value per life.

Pete said...

This reminds me of a sadly funny story from my days as an air traffic controller with the FAA. I was working at Memphis Tower and Tracon (MEM) back around 2006-7, and we were receiving a radar feed from Memphis Center (ZME) because our primary radar was out of service and the secondary was out for routine maintenance, or vice versa. Suddenly, we lose the ZME feed, so we try to go to back-up. Nothing. We declare ATC-Zero and scramble. The techs stop the routine maintenance and get that radar feed back up and working. Took about 45 mintues to an hour, but felt like a whole lot more. We come to find out that the ZME feeds--both primary AND secondary--came to MEM in the SAME cable. The cable was severed when a car hit a cable box near the ZME building. The FAA called it SINGLE REDUNDANCY!


PS Long time listener, first time caller. I came for the aviation and stayed for Caturdays.

CenterPuke88 said...

Yep, the killing of FTI, which mandated dual, redundant paths, occurred in the early 2000’s. Since then, one line cut can disable all three transmitter/receivers at a single or multiple sites.

Comrade Misfit said...

Scrapping the ADF approaches was a similarly chuckleheaded move. Simple transmitters and they couldn't keep it going.

The FAA has put all of its eggs into one basket. This one is just a foreshadowing of the future.