DME Substitution With an Out of Date Database

[Palmpilot]

A Cessna 182 that I rent has a KLN94 IFR GPS, but the database is not kept up to date. According to the flight manual supplement, you can use it for enroute IFR if you verify the waypoints, but to fly approaches, it says you must have a current database. (I don't remember what it says about terminal use.)

The plane has no DME. Based on the above, it appears that you can use the GPS to substitute for DME in the enroute phase of flight (and possibly the terminal phase) by verifying the waypoints, but what about identifying DME-based stepdown fixes on a VOR-DME approach, such as the one at my home airport (PAO)?

http://download.aopa.org/ustprocs/current/SW-2/pao_vor_dme_rwy_31.pdf

What about the ILS at Santa Rosa (STS), which requires DME for the missed approach?

http://download.aopa.org/ustprocs/current/SW-2/sts_ils_or_loc_rwy_32.pdf

What about substituting for the ADF when the missed approach is at an NDB, like at Livermore (LVK)?

http://download.aopa.org/ustprocs/current/SW-2/lvk_ils_rwy_25r.pdf

If the database were up to date, then clearly all those would be allowed, since none of them involves substituting for the lateral guidance on final approach, but when the database is not up to date, that complicates things.

 

[poadeleted20]

If the AFMS prohibits approach use without a current database, that supersedes the guidance in the AIM Table 1-1-6 Note 3. Thus, you cannot use it for substitution during approach procedures unless they update the database. Further, I know that by FAA definition, the Terminal phase ends at the IAF, so you cannot substitute for the stepdowns between the IAF and MAP. OTOH, I can't find the definition about where the approach phase ends and the terminal phase begins on the missed, so I can't answer your question about the missed approach questions. However, John Collins probably knows this off the top of his head, and I hope he'll show up to answer.

 

[gismo]

I thought most GPS navigators allowed the pilot to use any DB function including a full approach and certainly a "DME" fix as long as the DB components to be used are verified to be current. For an approach it can be as simple as checking the procedure revision date against the DB's expiration date. If the most recent procedure revision precedes the DB expiration you should be good to go. Ron is correct in that the AFMS must not preclude this though, but you also need to make sure the AFMS is current as many were changed WRT this specific point when the FAA decreed that current data in expired DBs is legal to use.

 

[poadeleted20]

I thought most GPS navigators allowed the pilot to use any DB function including a full approach and certainly a "DME" fix as long as the DB components to be used are verified to be current.

True.

For an approach it can be as simple as checking the procedure revision date against the DB's expiration date. If the most recent procedure revision precedes the DB expiration you should be good to go.

Generally true, per the AIM.

Ron is correct in that the AFMS must not preclude this though, but you also need to make sure the AFMS is current as many were changed WRT this specific point when the FAA decreed that current data in expired DBs is legal to use.

The problem is that the fact that Garmin or King changed the baseline AFMS doesn't automatically change the one for your specific installation. You'd have to consult your avionics shop to see about obtaining a new/revised AFMS for your specific installation. In the interim, if your AFMS is more restrictive than the AIM, you are stuck with what it says in your AFMS.