FAA Updates Advisory Circular for the use of Electronic Flight Bags

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AC 91-78A offers guidance to Part 91 operators for EFBs

iPad in Aztec

AC 91-78A describes the use of EFBs in Part 91 operations.

The FAA recently published Advisory Circular (AC) 91-78A, Use of Electronic Flight Bags (EFB), which replaces the original AC on the topic that was published in 2007. The AC provides operational guidance to aircraft owners, operators, and pilots operating aircraft under Part 91 who want to replace required paper information. By definition, the information contained in an AC is not mandatory, but does describe an acceptable means of regulatory compliance.

The updated AC recognizes the advancement and reliability of EFBs on the flight deck and affirms that EFBs may be used in conjunction with, or to replace, the paper reference material that pilots historically carried such as manuals, minimum equipment lists, weight and balance information, aeronautical charts, and terminal procedures.

ac 91-78

AC 91-78A can be found at FAA.gov.

Like the previous version, the AC states that EFBs can be used during all phases of flight operations in lieu of paper reference material when the information displayed meets the following criteria:

  1. The EFB system does not replace any system or equipment (e.g., navigation, communication, or surveillance system) that is required by Part 91.
  2. The EFB system on board the aircraft displays only information which is functionally equivalent to the paper reference material which the information is replacing or is substituted for.
  3. The interactive or precomposed information being used for navigation or performance planning is current, up to date, and valid, as verified by the pilot.
  4. The operator complies with requirements of § 91.21 to ensure that the use of the EFB does not interfere with equipment or systems required for flight.

What was previously referred to as Class 1 and 2 EFBs, are now referred to as portable and installed EFBs. The updated AC continues to encourage operators to consider the human interface component of EFB use and suggests operators parrticipcate in training for each operational function of the EFB.

The updated Advisory Circular, AC 91-78A, Use of Electronic Flight Bags, can be accessed at FAA.gov.

16 replies
  1. Doug H
    Doug H says:

    Well what do you know. The federal government making a decently smart decision. They’ve entered the 20th century finally.

    Reply
  2. Art Bridge
    Art Bridge says:

    I still care paper VFR and IFR maps and approach plates within easy reach. It is disconcerting for an iPad to “go dark” from loss of battery or over-heating en route, on approach, or notably on a procedure in the weather. Very good for distraction training, however.

    Reply
    • Jeff
      Jeff says:

      I’m with you! Redundant systems on the plane are a big part of flight safety.
      The devices battery, overheating, or even a software update can render the EFB InOp.

      Reply
    • Jeff
      Jeff says:

      Progress is good. But I’m with you! Redundant systems on the plane are a big part of flight safety.
      The devices battery, overheating, or even a software update can render the EFB InOp.

      Reply
    • Chris M
      Chris M says:

      I carry a spare iPad. I have never needed it. To keep my primary iPad cool in summer, I have a fan cooling unit that I mount the primary iPad to.

      Reply
  3. Richard G
    Richard G says:

    Am I reading 10.2.3 correctly?
    The iPad mount must be FAA approved if used in aircraft. An SAtC is the only way I know how to do that and I don’t know of a single STC out for a mount inside a GA aircraft.
    I guess only knee board type are legal for now. Every picture in this article is violating this advisory circular…
    YIKES!

    Reply
    • Richard G
      Richard G says:

      An STC is the only way I know to get a mount approved. Imagine how many different mounts there are times aircraft and how many STCs that would require.

      Reply
    • Ben Heaston
      Ben Heaston says:

      No, what it is telling you in sec. 91.21 is to go test out in VFR weather, and test where you put/ or mount your iPad, and make sure it doesn’t interfere with your compass or other nav or comm equipment.
      Also: make tests to see that it receives information FROM your installed nav / gps correctly. These tests ARE crucial.

      Reply
  4. Ron
    Ron says:

    A portable EFB may not receive “data from any aircraft system.” (See AC 10.1(3))
    I guess that means my iPad may NOT receive a flight plan for display in ForeFlight (or Garmin Pilot) via wifi from the Garmin 175 GPS in my panel. I am pretty sure the Garmin mounted in the panel of my 210 is an aircraft system. So I will have to disable that feature, which enhances situational awareness, in future flights. Perhaps turning off wifi on the iPad will put me in compliance with this AC. Once again, the FAA is going out of its way to degrade safety.

    Reply
    • J
      J says:

      I thing that means that for an efb to comply, the information it is replacing must be resident on the device and not have to retrieve it from the panel.

      Reply
  5. T Boyle
    T Boyle says:

    “ The EFB system on board the aircraft displays only information which is functionally equivalent to the paper reference material which the information is replacing or is substituted for”

    That “only” is a huge problem. It literally means that the EFB may not display any information unless the pilot can produce a paper-based “functional equivalent.” I would struggle to come up with paper-based products “functionally equivalent” to every single page of the weather briefing and imagery (including the NOAA imagery) or the terrain elevation profile or the suggested routes. Unless, of course, I were to print screenshots of those items, turning the restriction into a silly circular definition.

    Reply
  6. Ted
    Ted says:

    I called the local FSDO about the two changes regarding mounting and the transfer of data between the aircraft and my portable EFB. The first comment is it is an advisory circular not regulatory. Regarding the mounting of the portable device, the pilot can determine if the removable mount is safe for flight. He had no response for sharing information between aircraft systems and the portable device other than to suggest emailing the link at the end of the AC. I have not yet accomplished that step. The display on my portable EFB using data from the aircraft systems is far better and more easily used than native aircraft displays. Why would Garmin and other avionics companies provide links to portable EFBs if it were not to enhance safety?

    Reply

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