Simtech Aviation

How do I determine which GPS procedures my G-1000 Cessna is legal to fly?

Here is part 1 "How do I determine which GPS procedures my airplane is legal to fly?"

Cessna does things slightly differently.

If you look in Section 2: Limitations of the AFM of a G-1000 equipped Cessna for what procedures are approved, it will direct you to look at the Garmin “Cockpit Reference Guide,” for more information.  Software is a huge component in the capability of modern avionics and is updated fairly regularly, which may add capabilities to the avionics, so Cessna defers to a supplemental avionics manual for the final answer. 

For all the Cessna models you can find certification and approach information in the cockpit reference guide.  You’ll also see the Garmin Cockpit Reference Guide as a required item on the Kinds of Operations Equipment List in all G-1000 Cessna models.  See the attached excerpts of a Cessna AFM and the Cockpit reference guide.

C172S-G1000-FMSupplement pg Cessna g1000 LPV Cessna g1000 TSO

Can my 1968 airplane fly to LPV minimums on a GPS approach?

If you got this far you might be saying, “That’s great, but I fly a 1968 Bonanza with a brand new WAAS GPS, my AFM was written before GPS was invented, how do I find what procedures can I can fly?”  In this scenario we’ll say that a G530W or a GTN750 was installed in the vintage airframe - this is not Bonanza specific information. 

The flight manual supplement will hold your answer in this case.  The supplement is formatted in the exact same order as a standard contemporary AFM.  That means you’ll look in section 2: Limitations for the approved procedures.  Find AFM supplement excerpts below for the 530W and GTN750.  

The AFM supplement MUST be onboard the aircraft, it is part of the airworthiness documentation for the aircraft - even if your aircraft is not required to have a POH or AFM onboard.  

One other document with mentioning here is form 337, “Major repair and alteration.”  This is a maintenance document that you can find with the aircraft maintenance logs and AD compliance sheets.  You’ll want to take a look at the associated 337 to prove that the unit was properly installed. More importantly, the reverse side of the 337 has “instructions for continued airworthiness.” The requirements for continued airworthiness are required to be completed and logged as specified (usually at annual).  If you’re buying a used airplane, then there should be a collection of form 337’s, assuming some updates to the avionics or other systems have been made since the plane rolled off the factory floor, otherwise the installation is not airworthy.

GTN750 AFM Supplement excerpt:


GNS530W AFM Supplement excerpt:


Form 337 for a GNS530W installation, front:530-337-1

Form 337 for a GNS530W installation, back:Form 337 for a GNS530W installation, back: