iPad primary navigation :)

midlifeflyer

midlifeflyer

Touchdown! Greaser!
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No, not trying to start a fight (well, maybe....).

There's a discussion on another board about the use of an expired GPS database for IFR. That's not a big deal; according to the AIM, you may fly just about anything IFR without a current database so long as you verify the currency and accuracy of the information (and there isn't a more restictive limitation in the GPS POH supplement). We've seen that discussion before.

What struck me as a bit ironic, though, is that, while I've never seen any guidance beyond that, I suppose the way you verify accuracy is by comparing the procedure in the database with the procedure on a current chart (a good idea anyway when using GPS). My current charts are in Foreflight on my iPad.

So... I get to use my non-certified, not usable for primary navigation iPad in order to verify the currency of the information in my certified, usable for primary navigation on-board GPS.

Yeah, I know - the difference between certified and non-certified equipment is more of a hardware than a database issue, but it still struck me as a bit ironic.
 
midlifeflyer said:
[snip]
So... I get to use my non-certified, not usable for primary navigation iPad in order to verify the currency of the information in my certified, usable for primary navigation on-board GPS.
Click to expand...

Careful. That question may cause people to "clarify" the rule in such a manner that would make the uncertified iPad data unusable for verifying the GPS database.
 
midlifeflyer said:
So... I get to use my non-certified, not usable for primary navigation iPad in order to verify the currency of the information in my certified, usable for primary navigation on-board GPS.
Click to expand...

You're using a current chart to verify the accuracy of GPS waypoints used in a certified GPS. Whether that chart is printed on paper or displayed by electronic means is irrelevant. You're still verifying the data with a chart. This has been done for many years using earlier (bulkier) EFBs.

You're not using navigation data from your iPad to steer the plane. Ie. Your iPad isn't driving the CDI. Well, maybe one day...
 
You're right, Jason. As I said, the issues are different. But it is a kinda interesting juxtaposition.
 
So, how does one use a current chart (paper or electronic) to verify an approach in the GPS DB?

How would you be able to tell if a waypoint moved?

How would you be able to tell if a holding entry is there or not in the GPS?

I'm gonna go see if the 430 manual describes the process.
 
OK, I checked the 430 manual. You can file and fly /G for enroute nav if you have verified the enroute waypoints. No, description of how to verify waypoints though.

You cannot fly approaches with an expired DB (for the 430). See page 198 in the manual. I would assume that the manual for the device overrules the AIM in this case.

Edit: Here's a quote straight from the 430 pilots guide.

Can I file slant Golf (“/G”) using my GPS?
Yes, you may file your flight plan as /G if your 400Wseries
unit is an authorized IFR installation. The 400W
series is a TSO C146a Gamma-3 (Class 3) authorized
GPS navigator. If you are flying en route, you may file
/G with an expired database only after you have verified
all route waypoints. Approaches may not be flown with
an expired database. See your approved Airplane Flight
Manual Supplement for more information.
Click to expand...
 
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COFlyBoy said:
OK, I checked the 430 manual. You can file and fly /G for enroute nav if you have verified the enroute waypoints. No, description of how to verify waypoints though.

You cannot fly approaches with an expired DB (for the 430). See page 198 in the manual. I would assume that the manual for the device overrules the AIM in this case.
Click to expand...

Whether or not you can fly an approach with an expired database is dependent on the wording in the Limitations section of the AFMS for the GNS430. There is a sample AFMS provided by Garmin for the GNS430, but it is not FAA approved. It is left to the installer to modify the AFMS and obtain FAA approval thru the 337 process. The sample wording is: "The GPS equipment database must incorporate the current update cycle". Some AFMS had the wording modified to match the GNS430W wording and FAA approval was obtained.

The GNS430W wording is different and its AFMS is already FAA approved, so it only needs to be printed out. It reads "GPS instrument approaches using the 400W Series units are prohibited, unless the 400W Series unit's approach data is verified by the pilot or crew to be current."

So it depends on the AFMS wording, not the Pilot Guide wording.
 
COFlyBoy said:
So, how does one use a current chart (paper or electronic) to verify an approach in the GPS DB?

How would you be able to tell if a waypoint moved?

How would you be able to tell if a holding entry is there or not in the GPS?

I'm gonna go see if the 430 manual describes the process.
Click to expand...

Assuming you had a current paper or electronic chart for the approach in question, you would compare the effective date of the database with the effective date of the approach chart. If the effective date of the approach chart is before the effective date of the database, you can use the approach in the expired database.

On the newer approach charts, there is a procedure amendment date that gets updated anytime there is a change in the procedure that would affect the database. If the procedure amendment date is prior to the effective date of the database, the approach in the expired database may be used, even if the effective date of the chart is after the effective date of the database. An example of a change to an approach chart that would not affect the procedure in the GPS database would be if the approach control frequency was changed. There are many other changes that would fall into this category.
 
John Collins said:
Assuming you had a current paper or electronic chart for the approach in question, you would compare the effective date of the database with the effective date of the approach chart. If the effective date of the approach chart is before the effective date of the database, you can use the approach in the expired database.
.
Click to expand...

The IAPs I looked at have a date range of 28 days, which happens to exactly match the DB update cycle for the GPS.
There appears to be no way to tell if the IAP in your hand does not match the IAP in the GPS. The GPS tells you at startup if the DB has expired based on the same 28 days listed on the plate.
 
COFlyBoy said:
The IAPs I looked at have a date range of 28 days, which happens to exactly match the DB update cycle for the GPS.
There appears to be no way to tell if the IAP in your hand does not match the IAP in the GPS. The GPS tells you at startup if the DB has expired based on the same 28 days listed on the plate.
Click to expand...

Look for the date at the bottom left of NACO IAPs or the top center on Jepps. See below

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COFlyBoy said:
I have not seen lat/lon listed on either enroute or IAP charts for waypoints.
Click to expand...

Enroute low charts have Latitude/Longitude for navigation facilities and waypoints with depicted holds. Other waypoints on airways can be determined by distance from a VOR. Approach charts can be verified by the effective date or the procedure amendment date.
 
Jaybird180 said:
Do you just count 28 days from that point to determine legality?
Click to expand...

No. If the GPS database effective date is on/after the last chart amendment date published on the chart, then you are legal. The logic is that the fixes on the IAP haven't changed if the approach chart hasn't changed.
 
Jaybird180 said:
Do you just count 28 days from that point to determine legality?
Click to expand...

No.

The database is updated every 28 days and has an effective date. The effective date is displayed on the GNS430 every time it is turned on and the pilot must press the enter key to clear the screen. This date may also be checked anytime in flight by using the AUX Utility function, Database Versions.

Each approach chart has an effective date. Approaches are updated on a 28 day cycle, with most being updated on a 56 day cycle. AeroNav publishes their approach charts every 56 days in hard copy and every 28 days in the electronic format. The effective date of each AeroNav chart is a Julian date, yyddd (07298 for Oct 24 2007). In the old format, the Julian date is in the lower left hand corner of the chart. In the new format, it is relocated to the upper right hand corner of the chart. The new format also includes a procedure amendment date in month, day, year format (Jan 15, 2011) and it is located in the lower left hand portion of the chart where the Julian date used to be located. The database effective date needs to be compared with the Julian date or the procedure amendment date, whichever is older, to compare with the database effective date. If the database effective date is the same as or after the chart date, then the expired database may be used for the approach.
 
AeroNav fairly recently (in the last year or 2) began changing the Julian dates to more easily understandable dates for the last time a procedure was amended. If your chart is current and (a) the GPS database is later than the procedure last-amended date or (b) the fixes, courses and distances on the approach in the database are identical to the current chart, then the GPS is usable.

What I'm finding a bit surprising (considering I had the bad taste to start this thread with a bad joke) is that we now seem to be moving into a discussion of Chart Reading 101. Since there seems to be some confusion on that score, I'm glad I started it.
 
If a chart is lying around the FBO without an owner claiming it, how do I know if that chart is still good (legally valid - not expired) or not?
 
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Jaybird180 said:
If a chart is lying around the FBO without an owner claiming it, how do I know if that chart is still good or not?
Click to expand...

A low altitude enroute chart or a sectional has an effective date range on the cover. An AeroNav US Terminal Procedures Publication (TPP) approach chart booklet also has an effective date range on its cover and on each page inside, both front and back, on both side margins. If the chart is within its effective date range, then it is the current chart. If it is an approach chart and is outside of its effective date range, you must compare it to a known current approach chart, for example using AeroNav.com, AOPA.org, or other website that provides current data, a current booklet, or a software application that provides current data and verify that the effective date is the same as the known current chart.
 
Jaybird180 said:
If a chart is lying around the FBO without an owner claiming it, how do I know if that chart is still good (legally valid - not expired) or not?
Click to expand...
AFAIK, the FAA has not yet installed a system to imprint biometric ID data on each paper chart sold so that if someone other than the buyer picks it up, it self-destructs in 10 seconds.

Good luck, Jim.
 
A chart has an effective date, but no expiration date?
The charts on my iPad (using FF) have both dates (don't know the source).
 
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Jaybird180 said:
A chart has an effective date, but no expiration date?
Click to expand...
Yes, they have both, but the fact that the expiration date has passed doesn't mean the data on the chart have necessarily changed. That's why they put that date in the lower corner -- so you know when the data last changed. However, once you're past the chart expiration date, you don't know if the new chart has a new amendment date, and thus, you cannot confirm that the data for that procedure in your database are still valid.
 
Jaybird180 said:
A chart has an effective date, but no expiration date?
The charts on my iPad (using FF) have both dates (don't know the source).
Click to expand...

The enroute charts and sectionals have an expiration date. An approach chart does not have a expiration date for the data on the chart as it remains effective until it is updated or cancelled. There is a date range printed on the chart that describes the effective date of the publication, but there isn't an expiration date for the approach itself.
 
Ron Levy said:
Yes, they have both, but the fact that the expiration date has passed doesn't mean the data on the chart have necessarily changed. That's why they put that date in the lower corner -- so you know when the data last changed. However, once you're past the chart expiration date, you don't know if the new chart has a new amendment date, and thus, you cannot confirm that the data for that procedure in your database are still valid.
Click to expand...

What Ron said, plus, even if the date is within the effective date range, there can always be a NOTAM that changes the chart or makes the approach NA. These NOTAMS can occur at any time.
 
midlifeflyer said:
AeroNav fairly recently (in the last year or 2) began changing the Julian dates to more easily understandable dates for the last time a procedure was amended. If your chart is current and (a) the GPS database is later than the procedure last-amended date or (b) the fixes, courses and distances on the approach in the database are identical to the current chart, then the GPS is usable.

What I'm finding a bit surprising (considering I had the bad taste to start this thread with a bad joke) is that we now seem to be moving into a discussion of Chart Reading 101. Since there seems to be some confusion on that score, I'm glad I started it.
Click to expand...

I never bothered to look at the date at the bottom, mostly because a julian date is not really reconizable as a date. And the dates along the sides seemed sufficient for my needs. It looks like a lot more work to verify that an exipred DB can be used than it is to just update the stupid DB. It took me 10 minutes today.
So, I spent that time carefully reading the FM supplement for my 420. I can use an expired DB for both enroute and approach if I verify waypoints and approaches before use, which is counter to the pilot guide.
Also, I learned that my GNC-420W is not approved as a sole means of navigation even though it is a WAAS GPS. The supplement said that the installation did not comply with the TSO to allow sole means nav, so I still have to file alternates that have VOR or ILS approaches. I'm guessing the issue is not having a backup GPS.
 
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COFlyBoy said:
I never bothered to look at the date at the bottom, mostly because a julian date is not really reconizable as a date. And the dates along the sides seemed sufficient for my needs. It looks like a lot more work to verify that an exipred DB can be used than it is to just update the stupid DB. It took me 10 minutes today.
So, I spent that time carefully reading the FM supplement for my 420. I can use an expired DB for both enroute and approach if I verify waypoints and approaches before use, which is counter to the pilot guide.
Also, I learned that my GNC-420W is not approved as a sole means of navigation even though it is a WAAS GPS. The supplement said that the installation did not comply with the TSO to allow sole means nav, so I still have to file alternates that have VOR or ILS approaches. I'm guessing the issue is not having a backup GPS.
Click to expand...

The Julian date is easy to decode. Rarely do you have to get the month right any closer than +/- 1 month for comparison purposes, much less the specific day of the month. The first two digits are the year and the next three digits are the day of the year. If you divide day of the year by thirty, the result will be close to the month-1. The remainder is the approximate day of the month. If dividing by thirty is tough for you, count by 30 starting at 0. 0, 30,60,90,120, ... are Jan, Feb, Mar, Apr, May, ... . Using your fingers to keep count will give you the number of the month. You should be able to convert the Julian date to a month within less than 20 seconds. Usually that is all that is needed for comparison purposes.

You have the old AFMS for your 420W, this means you are likely to have down level software or an outdated AFMS. Software version 2.X is way out of date. You should update to at least version 3.3 (4.0 is the latest) and get your AFMS updated to reflect the current version. This will allow you to use the GPS as the sole source for IFR flight, use RNAV (GPS) approaches as alternates, and fly the LP approach type.
 
John Collins said:
You have the old AFMS for your 420W, this means you are likely to have down level software or an outdated AFMS. Software version 2.X is way out of date. You should update to at least version 3.3 (4.0 is the latest) and get your AFMS updated to reflect the current version. This will allow you to use the GPS as the sole source for IFR flight, use RNAV (GPS) approaches as alternates, and fly the LP approach type.
Click to expand...

Thanks for the info. I think the AFMS said I had version 3.0. It seems hard to believe I'd be that out of date since it was installed last January.
 
COFlyBoy said:
Thanks for the info. I think the AFMS said I had version 3.0. It seems hard to believe I'd be that out of date since it was installed last January.
Click to expand...

The original AFMS dated Nov 6, 2006 had the IFR limitation. The AFMS that goes with Version 3.0 software or later does not have the limitation. The AFMS used with Version 3.0 is dated Nov 20, 2007. The AFMS that is used with Version 3.3 is dated July 31, 2009. Find out what version of software you have installed for the Main SW and the GPS SW by displaying the AUX function "Software Versions". They should be at least Main SW = 3.3 and GPS SW = 3.2.
 
HPNPilot1200 said:
You're using a current chart to verify the accuracy of GPS waypoints used in a certified GPS. Whether that chart is printed on paper or displayed by electronic means is irrelevant. You're still verifying the data with a chart. This has been done for many years using earlier (bulkier) EFBs.

You're not using navigation data from your iPad to steer the plane. Ie. Your iPad isn't driving the CDI. Well, maybe one day...
Click to expand...

I have just now begun my IR reading, starting in the FAR/AIM. I just read the part about expired databases and it does seem that charts can be used to verify obstructions and such.

Since the FAA is now wanting to charge the people who distribute charts in electronic format (expect higher subscription prices for Foreflight and the like) then it sounds like they are admitting that the electronic version equals the paper version.
 
Do named waypoints/intersections ever change position? It would make safety sense for them not to, and instead to make up a new 5-letter name if a move was necessary. I haven't seen a reference for this one way or another.
 
pericynthion said:
Do named waypoints/intersections ever change position? It would make safety sense for them not to, and instead to make up a new 5-letter name if a move was necessary. I haven't seen a reference for this one way or another.
Click to expand...

Yes, they can change position and frequently when GPS approaches are upgraded to the new RNAV criteria, they get moved. There are limits on how far they can be moved without requiring a name change, I think it used to be 5 NM and now is 1 NM, but I could be wrong on the distance.

For approaches, the best way to check is to verify the date of the database against the effective date of the current chart. For enroute stuff, you would have to verify the Latitude - Longitude.
 
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