Lost a GPS today

MAKG1

MAKG1

Touchdown! Greaser!
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Jun 19, 2012
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California central coast
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MAKG
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KPAO and KRHV
Going missed, 800 AGL, just entering the clouds.

The 430W gave me an abrupt INTEG alarm on an LPV missed approach.

Worse, there is no reliable contact with Approach below 2000 at that airport. So, no vectors.

Fortunately, I had entered clouds from above on final, so I knew the tops were below 2000. And the missed approach procedure called for runway course to 6000, and went over the ocean. So I held runway heading until on top. Then the GPS came back.

The RAIM prediction had been clean
 
Well another lesson learned,glad everything worked out for you. I like to use foreflight on the IPad as my backup.
 
I wasnt on approach, but last week I got a GPS fail msg on the gns. Came back after a couple min. Stratus was fine. Happened again a bit later, this time both the 430 and the stratus failed. I think I flew through the twilight zone.

Pretty sure ."they" were jamming. I didn't see a notam on it though.
 
Been happening to me fairly often here on the east coast too. Raim alert, big red x, goes away after about 2 mins. Shop checked all the antenna connections and came up empty. No notam posted.

Don't know what's going on, but hasn't occurred in IMC.
 
keep in mind ....a bad antenna from another GPS can cause this.

Another method to diagnose this is to begin turning "other" GPS boxes off one at a time....till the problem goes away. Newer GPS boxes use a powered "active" antenna that requires a good reference ground. Some antennas have a known failure mode that causes those antennas to transmit junk to other GPS when that ground is compromised.

If you only have one GPS source....there could be another box emitting junk RF causing interference also.....

or....the Gummint black Ops folks are just jamming the area with no NOTAMS. :D
 
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Checkout_my_Six said:
keep in mind ....a bad antenna from another GPS can cause this.

Another method to diagnose this is to begin turning "other" GPS boxes off one at a time....till the problem goes away. Newer GPS boxes use a powered "active" antenna that requires a good reference ground. Some antennas have a known failure mode that causes those antennas to transmit junk to other GPS when that ground is compromised.

If you only have one GPS source....there could be another box emitting junk RF causing interference also.....

or....the Gummint black Ops folks are just jamming the area with no NOTAMS. :D
Click to expand...
I've heard truckers have GPS jammers they turn on when they don't want the company tracking their whereabouts.
 
There was a big surfing event going on at the time, and a fair amount of VFR traffic despite the undercast. Couldn't see a damn thing on the ground, so I don't know what the hell they were doing.

Government interference is unlikely at that locale. It has intervening terrain blocking the entire US, hence poor contact with Approach.
 
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The entire GPS cluster was off by 13 ms two weeks ago. USAF published an apology/press release. The system is not infallible.
 
Happened to me again today around little rock. Got the Dead Reconing message. Lost the Stratus right after the 430W. Tuned off the 430 and stratus came back within about 30 seconds.
 
About the time you were in the air several of us were using gps equipment. Worked fine.
 
Sh*t happens.
Got RAIM message on my GPS during a practice RNAV approach in training.
Told the CFII "cannot continue approach, we have to go missed ... unless you agree to ignore the RAIM msg and continue since we are VMC". He agreed. At the debrief, he commended me on recognizing the problem and following the correct procedure. Life is good when things click. :)
 
BigBadLou said:
Sh*t happens.
Got RAIM message on my GPS during a practice RNAV approach in training.
Told the CFII "cannot continue approach, we have to go missed ... unless you agree to ignore the RAIM msg and continue since we are VMC". He agreed. At the debrief, he commended me on recognizing the problem and following the correct procedure. Life is good when things click. :)
Click to expand...

So you continued?

If that's the case sounds like a crap CFII.

You train how you want to preform and you'll preform like how you train, a GPS message like that isn't popping up to spark a conversation, it means GO AROUND....NOW!

In the real world that crap will straight get you killed.
 
James331 said:
So you continued?

If that's the case sounds like a crap CFII.

You train how you want to preform and you'll preform like how you train, a GPS message like that isn't popping up to spark a conversation, it means GO AROUND....NOW!

In the real world that crap will straight get you killed.
Click to expand...

Re-read my post. We were in VMC (all day), it was a training flight, last approach of the day into a crowded towered airport. A missed would have been a good exercise but harder on everybody. We never created any danger. *shrug*
 
I've had that. Seems like a ground issue in the plane. So what did you do? Come back and shoot it again and it all worked?
 
BigBadLou said:
Re-read my post. We were in VMC (all day), it was a training flight, last approach of the day into a crowded towered airport. A missed would have been a good exercise but harder on everybody. We never created any danger. *shrug*
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In that case re read what I said, I would have fired that CFI on the spot.

He had you preform a approach which would have gotten you killed in many instances.

Going missed is always harder then taking a crap approach even further, hey just a couple hundred feet, or, hey that GPS acts funny sometimes, going missed is always a pain in the arse, but it's a black and white situation and requires Z E R O hesitation, he not only demonstrated hesitation, but had you continue a approach, even with flashing lights and messages from your GPS, that's a fail as a CFII all day long and twice on Sundays.


Basic CFI stuff

Law of primacy – shows that instructors must teach all facts correctly the first time.

Law of recency – states things most recently learned will be best remembered. Post flight critiques and lesson summaries reinforce this law.
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If this was a instrument lesson you should have gone missed, period.
 
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James331 said:
In that case re read what I said, I would have fired that CFI on the spot.

He had you preform a approach which would have gotten you killed in many instances.

Going missed is always harder then taking a crap approach even further, hey just a couple hundred feet, or, hey that GPS acts funny sometimes, going missed is always a pain in the arse, but it's a black and white situation and requires Z E R O hesitation, he not only demonstrated hesitation, but had you continue a approach, even with flashing lights and messages from your GPS, that's a fail as a CFII all day long and twice on Sundays.


Basic CFI stuff



If this was a instrument lesson you should have gone missed, period.
Click to expand...


Wow...


The student ended the lesson understanding what RAIM means and what to do if he received a RAIM alert on an approach. Mission accomplished :confused:
 
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dell30rb said:
Wow...
Click to expand...

Indeed.

The wx outside is irrelevant, you're teaching.

As I said, common knowledge is you train like how you want to preform and you'll preform like how you trained.


Same logic as your "CFII",

Let's say I'm teaching stalls in a 7ECA, new 0 time student never really done stalls before, safe altitude, plane is safe for spins, and I'm proficient, should I teach him to use the ailerons to pick up the dropping wing in a stall? No danger, plane is good for stalls, as am I, or maybe I should just teach him the right way to do it from the start :lol:


Believe it or not there is a reason the FAA requires CFIs understand the FOIs.

There are some things where a little slop is bad form and should be fixed, there are other areas where it will end very poorly, not exciting a misused immediately when needed is one of those areas.


dell30rb said:
Wow...


The student ended the lesson understanding what RAIM means and what to do if he received a RAIM alert on an approach. Mission accomplished :confused:
Click to expand...

...so after a RAIM alert you continue the approach land and talk to your CFII?
Man, I've been doing it all wrong :rofl:
 
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James331 said:
Indeed.

The wx outside is irrelevant, you're teaching.

As I said, common knowledge is you train like how you want to preform and you'll preform like how you trained.


Same logic as your "CFII",

Let's say I'm teaching stalls in a 7ECA, new 0 time student never really done stalls before, safe altitude, plane is safe for spins, and I'm proficient, should I teach him to use the ailerons to pick up the dropping wing in a stall? No danger, plane is good for stalls, as am I, or maybe I should just teach him the right way to do it from the start :lol:


Believe it or not there is a reason the FAA requires CFIs understand the FOIs.

There are some things where a little slop is bad form and should be fixed, there are other areas where it will end very poorly, not exciting a misused immediately when needed is one of those areas.




...so after a RAIM alert you continue the approach land and talk to your CFII?
Man, I've been doing it all wrong :rofl:
Click to expand...

This is sort of like saying you shouldn't use a view limiting device because you won't be using one in actual IMC.
 
"Hey, the GPS is giving us a RAIM message but we just broke out 1200AGL, let's go back into the clouds with a bad GPS signal instead of landing safely in VMC".

Staying visual usually beats venturing into IMC.
Contrary to others' beliefs, I personally think we made a perfectly safe decision on a CAVU day. *shrug*
 
I should've started off earlier with this, I'm totally not knocking you Lou, you were the student and didn't know what you didn't know.

That said my understanding of the situation was you were basically CAVU on a IFR training flight, shooting that last approach of the day when during the approach phase of the flight your GPS threw the message.

Normally all the IFR training I've done you're simulating with a view limited, or just in how you fly, shooting a approach to mins. If that box tossed that warning he should have had to execute as you would have if you were in IMC that went to, or near mins ---> missed for a new approach or a retry of the existing approach if the earlier option wasn't a option.

Second bet, if you really had to, he could say, well Lou you broke out 100' ago and it's straight VFR to the runway, disregard your NAV and just do it COMPLETELY visual with no reference to that GPS what so ever.

But I'm 100% sticking with what I said about continuing the approach and following a GPS with it tossing messages at you as being completely inappropriate for a IFR student on a VFR instrument training flight.
 
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