Tuesday, October 01, 2013

IFR Cert and WAAS Upgrade.

08Romeo is back at Wilmington's Red Eagle for her 24 month IFR Certification. Of course my landing was so smooth I not only didn't feel it, but I didn't even hear a chirp. I do miss that smooooth long runway. Here is what's on tap for 08Romeo's upgrade.


Annual – Every aircraft operated under part 91 regulations is required to undergo an “annual” inspection in accordance with FAR part 43 every 12 calendar months.  This regulation applies to VFR and IFR flying and is not dependent on how the aircraft is used (i.e. for hire).   The applicable regulation is actually FAR 91.409(a).

VOR – In order to use VOR navigation in IFR flying, the accuracy of the device must be checked every 30 days.  There is a list of the types of inspections that can be performed to check its accuracy (all covered in the regulation below), but the key element of this accuracy check is that it only applies to IFR flying.  The complete regulation and required inspection types can be found in FAR 91.171.

100 Hour – In certain operations when an aircraft is being used “for hire” and specifically, for an aircraft used in flight instruction for hire, the aircraft is required to undergo a “100 hour” inspection every 100 hrs of engine operation (normally a tachometer time reading).  This would apply to either a VFR or IFR flight, but is specific for flights being operated for hire.  FAR 91.409(b).

Altimeter/Pitot-Static System Check – Each altimeter and static pressure system must undergo an inspection to ensure accuracy and compliance with standards every 24 calendar months if the aircraft is to be used for IFR flight.  There are no circumstances where this inspection is required for a VFR flight.  Additional information can be found in FAR 91.411.

Transponder – Transponders are required to be inspected for accuracy and standards every 24 calendar months, if required.   FAR 91.413 specifies the inspection interval of 24 calendar months.

ELT– Every aircraft (with some limited exceptions) is required to have an  Emergency Locator Transmitter (ELT), and that unit must be inspected every 12 calendar months as found in FAR 91.207(d).  This regulation applies to both VFR and IFR flying.  In addition to the required 12 calendar month inspection, you should also be familiar with FAR 91.207(c) which states requirements for battery replacement and recharging under specific conditions (1 hour of cumulative use or half of the battery useful life) and is just as important as the 12 calendar month inspection.

WAAS Upgrade

From the Garmin home page - Garmin WAAS Upgrades

By adding WAAS capability to your Garmin GNS 400/500 series unit, your world becomes a much easier place to navigate. The FAA’s WAAS is designed to provide the additional accuracy, availability and integrity to enable users to rely on GPS for virtually all phases of flight anywhere within the WAAS coverage area.

Now, with WAAS, thousands of previously access-limited general aviation airports can offer full LPV “glidepath” vertical approaches similar to a Category 1 ILS (where suitable airport conditions exist) without adding the costly on-site infrastructure required to install a ground-based precision approach system.

Already outnumbering ILS approaches in the U.S. — with more than 1,500 published LPVs now in service — these affordable WAAS approaches are rapidly changing the landscape of IFR navigation.

WAAS Benefits:
  • improved overall efficiency of aviation operations
  • increased runway capability
  • increased position accuracy
  • new precision approach services
  • reduced and simplified equipment requirements for aircraft
  • significant government cost savings due to the reduction of maintenance-intensive, ground-based infrastructure

From IFR Refresher magazine:

If an approach is a standard GPS approach with no vertical guidance then "LNAV" will be displayed. If a GPS approach with LNAV-only minimums has a vertical profile coded into the database - referred to as advisory vertical guidance (Jeppesen chart users will see this as a dashed line on the vertical profile) - then "LNAV+V" will be annunciated, meaning that an electronic glidepath is provided via the glidescope pointer, allowing for a stabilized descent to the LNAV MDA.

This vertical guidance is advisory and therefore may be ignored, which is good news for pilots who prefer the "chop and drop" method of flying a non-precision approach. If the GPS approach has LNAV/VNAV minima, "L/VNAV" will be annunciated and the approach is flown just like an ILS, using the vertical deviation information displayed via the glideslope pointer.

If the GPS approach has LPV minima, then the unit has a bit more work to do. About one minute prior to reaching the FAF, the unit will check the required Horizontal Alarm Limit (HAL) and Vertical Alarm Limit (VAL) to ensure the GPS position integrity is within the limits to complete the LPV approach. If the HAL or VAL limits are exceeded, the approach will be downgraded to a non-precision approach indicated by "LNAV" on the moving map, a message will display indicating that the approach is downgraded ("Approach downgraded - Use LNAV minima"), and the glideslope pointer will be flagged. In this case, you may continue the approach using the published LNAV non-precision minimums.

When flying the vertically guided approaches (LPV, LNAV/VNAV, and LNAV with advisory vertical guidance), the glideslope pointer will come into view prior to the final approach fix and you intercept it and fly it down to the DA or MDA, just as you would an ILS.

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