New Edition of AC 00-6 Aviation Weather

FAA has published a new edition of AC 00-6B – Aviation Weather (PDF), the 1975 handbook that explains weather theory for pilots.

New scientific capabilities now necessitate an update to this AC. In 1975, aviation users were not directly touched by radar and satellite weather. In 2016, much of what airmen understand about the current atmosphere comes from these important data sources. This AC is intended to provide basic weather information that all airmen must know. This document is intended to be used as a resource for pilot and dispatcher training programs.

The new edition of the companion handbook, AC 00-45 Aviation Weather Services, which explains aviation weather reports and forecasts and the briefings available to pilots, should be available soon from the FAA website.

Simulated Wake-Turbulence Encounter

I do the exercise below with my stall/spin/upset students to simulate the disorienting effect of a wake-turbulence encounter. We perform 1-1/2 aileron rolls to inverted and then push and roll to recover to normal upright flight. The exercise is confusing at first, and the nose always drops well below the horizon during the “upset.” It’s a great way to help pilots understand what could happen if they were caught in a wintip vortex.

Wake turbulence caused by wingtip vortices is major hazard to small aircraft.


The wingtip vortices are a by-product of lift. You can find detailed information about wake turbulence in FAA Advisory Circular AC 90-23 and in the Aeronautical Information Manual (Chapter 7, Safety of Flight; Section 3, Wake Turbulence).




FAA Releases List of VORs to be Shut Down

FAA has published a list of 308 VORs that it plans to shut down in phases by 2025. The notice in the Federal Register appeared on July 26, 2016. The notice includes a list of VORs that the FAA wants to decommission.

This document provides the discontinuance selection criteria and candidate list of VOR Navigational Aids (NAVAIDs) targeted for discontinuance as part of the VOR MON Implementation Program and United States (U.S.) National Airspace System (NAS) Efficient Streamline Services Initiative. Additionally, this policy addresses the regulatory processes the FAA plans to follow to discontinue VORs.

For background on the FAA’s plans, see Latest Info on VOR Shutdowns here at BruceAir. Note that under this plan, only about one-third of the existing network of VORs will be decommissioned.

According to the FAA notice:

The following criteria were used by the FAA to determine which VORs would be retained as a part of the MON:

— Retain VORs to perform Instrument Landing System (ILS), Localizer (LOC), or VOR approaches supporting MON airports at suitable destinations within 100 NM of any location within the CONUS. Selected approaches would not require Automatic Direction Finder (ADF), Distance Measuring Equipment (DME), Radar, or GPS.Show citation box

— Retain VORs to support international oceanic arrival routes.

— Retain VORs to provide coverage at and above 5,000 ft AGL.

— Retain most VORs in the Western U.S. Mountainous Area (WUSMA), specifically those anchoring Victor airways through high elevation terrain.

— Retain VORs required for military use.

— VORs outside of the CONUS were not considered for discontinuance under the VOR MON Implementation Program.

The following considerations were used to supplement the VOR MON criteria above:

— Only FAA owned/operated VORs were considered for discontinuance.

— Co-located DME and Tactical Air Navigation (TACAN) systems will generally be retained when the VOR service is terminated.

— Co-located communication services relocated or reconfigured to continue transmitting their services.

According to the FAA notice:

The FAA remains committed to the plan to retain an optimized network of VOR NAVAIDs. The MON will enable pilots to revert from Performance Based Navigation (PBN) to conventional navigation for approach, terminal and en route operations in the event of a GPS outage…

The VOR MON is designed to enable aircraft, having lost Global Navigation Satellite System (GNSS) service, to revert to conventional navigation procedures. The VOR MON is further designed to allow aircraft to proceed to a MON airport where an ILS or VOR approach procedure can be flown without the necessity of GPS, DME, ADF, or Surveillance. Of course, any airport with a suitable instrument approach may be used for landing, but the VOR MON assures that at least one airport will be within 100 NM.

FAA Updates Two Handbooks

FAA has released updated editions of two key handbooks for pilots and flight instructors.
The new version of Pilot’s Handbook of Aeronautical Knowledge (FAA-H-8083-25B) is a key reference for pilots training for the private pilot, commercial pilot, and flight instructor certificates.

You can find free PDFs of these handbooks and other FAA training manuals on the FAA website here and here.


The Pilot’s Handbook of Aeronautical Knowledge provides basic knowledge that is essential for pilots. This handbook introduces pilots to the broad spectrum of knowledge that will be needed as they progress in their pilot training. Except for the Code of Federal Regulations pertinent to civil aviation, most of the knowledge areas applicable to pilot certification are presented. This handbook is useful to beginning pilots, as well as those pursuing more advanced pilot certificates.

The Weight & Balance Handbook (FAA-H-8083-1B) is aimed at pilots and maintenance technicians.


The Aircraft Weight and Balance Handbook has been prepared in recognition of the importance of weight and balance technology in conducting safe and efficient flight. The objective of this handbook is twofold: to provide the airframe and powerplant mechanic (A&P) with the method of determining the empty weight and empty weight center of gravity (EWCG) of an aircraft and to furnish the flight crew with information on loading and operating the aircraft to ensure its weight is within the allowable limit and the center of gravity (CG) is within the allowable range.

You can find free PDFs of these handbooks and other FAA training manuals on the FAA website here and here.

Short Aerobatic Videos

I have collected short excerpts from a recent aerobatic flight near Seattle, WA to demonstrate a few basic aerobatic maneuvers. Each video shows the maneuver first from the left wingtip and then from my perspective in the rear cockpit of the Extra 300L.

You can find many more videos at my YouTube channel, BruceAirFlying.

Latest Info on VOR Shutdowns

The FAA recently provided an update on its plans to decommission about 30 percent (308) of the existing network of 957 VORs by 2025. The presentation, made at the April 2016 meeting of the Aeronautical Charting Forum, is available here (PDF).

Some highlights:

As I’ve noted in previous posts on this topic (e.g., here), the basic plan remains as follows:

  • Decommission about 308 VORs in two phases. Phase 1 runs from FY2016-FY2020. Phase 2 runs from FY2021-FY2025.
  • About 649 VORs will remain in service. In fact, many of those VORs will be upgraded to expand their service volumes.
  • Most of the VORs to be shut down will be in the Central (162) and Eastern (131) U.S. Only about 15 VORs will be decommissioned in the West.

The list of the first VORs to be shut down is available from AOPA here (PDF). AOPA also has good background about the program to decommission VORs on its website.

To provide backups should GPS signals fail or be disrupted, the FAA will retain a minimum operational network (MON) of VORs and MON airports that have ILS and/or VOR approaches.

Those MON airports and VORs are designed to enable pilots to:

  • Revert from PBN [i.e., GPS-based] to conventional navigation in the event of a Global Positioning System (GPS) outage;
  • Tune and identify a VOR at a minimum altitude of 5,000 feet above ground level or higher;
  • Navigate to a MON airport within 100 nautical miles to fly an Instrument Landing System (ILS) or VOR instrument approach without Distance Measuring Equipment (DME), Automatic Direction Finder (ADF), surveillance, or GPS where the capability currently exists; and
  • Navigate along VOR Airways especially in mountainous terrain where surveillance services are not available and Minimum En Route Altitudes (MEAs) offer lower altitude selection for options in icing conditions.

You can learn more about MON airports in this presentation (PDF) from the ACF meeting.

Early Summer Aerobatic Ride

Here are highlights from an early summer aerobatic ride in the Extra 300L east of Seattle.

The passenger from Switzerland enjoyed the view of the “Cascade Alps” east of Seattle as we flew through a series of aileron rolls; loops, half-Cuban 8s; big, lazy barrel rolls; slow rolls; hammerheads, and a little inverted flight.