Taking the Extra 300L for a Spin

Here’s a basic intentional spin in the Extra 300L. The camera shows the instruments in the front cockpit. Note the airspeed during the spin.

Landing at Yerrington, NV (O43)

I landed the A36 at Yerrington, NV (O43) for fuel on the way home from Las Vegas. Yerrington is a good fuel stop in the Reno area. Relatively inexpensive self-serve avgas and a pilot’s lounge. A strip mall is a short walk away if you need food or other supplies.

A Dose of Vitamin G

I practiced a series of basic aerobatic maneuvers on this flight out of Boulder City, NV (KBVU). I’d been busy working with instrument students in Seattle, so I needed to refresh my G tolerance and get ready for summer aerobatic flights. Keen observers will note lots of bobbles and other flaws. But it was fun to be back in the Extra 300L, which is a thoroughbred.

I mounted one camera so that you can see the control stick in the front cockpit. Note how little the stick has to move during basic maneuvers–only a slight deflection of the ailerons and elevator is required to achieve large effects.


NWS to drop ALL CAPS, but not for aviation

The National Weather Service plans to drop ALL CAPS from some of its public forecast products. Alas, aviation reports and forecasts will continue to use the teletype-era format.

The NWS announcement is here. Excerpts:


Better late than never, but the slow change was not for lack of trying. The National Weather Service has proposed to use mixed-case letters several times since the 1990s, when widespread use of the Internet and email made teletype obsolete. In fact, in web speak, use of capital letters became synonymous with angry shouting. However, it took the next 20 years or so for users of Weather Service products to phase out the last of the old equipment that would only recognize teletype…

Certain forecast products with international implications, such as aviation and shipping, will continue to use upper case letters, per international agreements that standardize weather product formats across national borders. [Emphasis added]


Paperless in the Cockpit

Most pilots who regularly fly IFR or travel beyond the local area are now using electronic charts and apps like ForeFlight, WingX, Garmin Pilot, or FltPlan to plan trips and navigate while in the air. In addition to charts, these apps include information about airports (from the Chart Supplement, formerly the A/FD), weather, fuel prices, and other details.

iPad Pilot News at Sporty’s is a good source of information about the latest hardware and software for use in the cockpit.

As I noted in Downloading Avionics Manuals, you can also copy handbooks for avionics and other key aircraft references to tablets and phones. But many pilots aren’t sure if those electronic references are legal substitutes for paper copies of required documents.

FAA offers guidance for Part 91 operators in AC 91-78 Use of Class 1 or Class 2 Electronic Flight Bag (EFB):

1. PURPOSE. This advisory circular (AC) provides aircraft owners, operators, and pilots operating aircraft under Title 14 of the Code of Federal Regulations (14 CFR) part 91, with information for removal of paper aeronautical charts and other documentation from the cockpit through the use of either portable or installed cockpit displays (electronic flight bags (EFB)).

2. APPLICABILITY. This AC is applicable to instrument flight rules (IFR) or visual flight rules (VFR), preflight, flight, and post flight operations conducted under part 91, unless prohibited by a specific section of 14 CFR chapter I.

The advisory circular notes that use of electronic documents can extend beyond charts:

Electronic Flight Bag (EFB). An electronic display system intended primarily for cockpit or cabin use. EFB devices can display a variety of aviation data (e.g., checklists, navigation charts, pilot’s operating handbook (POH)) or perform basic calculations (e.g., performance data, fuel calculations)….Operators have long recognized the benefits of using portable electronic devices (PED), such as commercially available portable computers, to perform a variety of functions traditionally accomplished using paper references. EFB systems may be used in conjunction with, or to replace, some of the paper reference material that pilots typically carry in the cockpit. EFBs can electronically store and retrieve information required for flight operations, such as the POH and supplements, minimum equipment lists, weight and balance calculations, aeronautical charts and terminal procedures. EFB systems are being developed to support functions during all phases of flight operations.

And the AC specifically notes that:


a. EFBs/ECDs 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 components or systems onboard the aircraft which display precomposed or interactive information are the functional equivalent of the paper reference material.

(2) The interactive or precomposed information being used for navigation or performance planning is current, up-to-date, and valid…

b. The in-flight use of an EFB/ECD in lieu of paper reference material is the decision of the aircraft operator and the pilot in command. Any Type A or Type B EFB application, as defined in AC 120-76 may be substituted for the paper equivalent. It requires no formal operational approval as long as the guidelines of this AC are followed.

c. It is suggested that a secondary or back up source of aeronautical information necessary for the flight be available to the pilot in the aircraft. The secondary or backup information may be either traditional paper-based material or displayed electronically.

The FAA also points out several common-sense considerations to keep in mind when going paperless, and it outlines a process for testing and training to ensure that the use of electronic handbooks won’t interfere with the safe, efficient operation of the aircraft:

a. The operator should carry out an assessment of the human-machine interface and aspects governing Crew Resource Management when using the EFB. General considerations for the assessment includes workload, integration of the EFB into the cockpit, display and lighting issues, system shutdown, and system failures…Attention must be given to the physical EFB. Some items to consider are placement issues such as stowage during takeoff or landing, and the operation of an unsecured EFB. Use of the controls and input devices may be easy on the ground, but demanding in flight.

(1) Training should include preflight checks of the system, the use of each operational function on the EFB, the conditions (including phases of flight) under which the EFB should not be used, and procedures for cross-checking data entry and computed information.

b. Operators transitioning to a paperless cockpit should undergo an evaluation period during which the operator should carry paper backups of the material on the EFB. The backup should be readily available to the crew. During this period the operator should validate that the EFB is as available and reliable as the paper-based system being replaced.

It’s not explicitly clear from this advisory circular if an electronic copy of the aircraft flight manual (AFM), keyed to a specific aircraft serial number/registration number, is acceptable. But the AC does seem to allow use of PDF copies of avionics handbooks, weight-and-balance data, and STC supplements. For an example of an FAA legal interpretation that addresses some of these issues, see the Sweet letter (2011).

Downloading Avionics Manuals

Many pilots like to have PDF copies of the handbooks for the avionics installed in their aircraft or for reference when considering upgrades. As a flight instructor, I fly a variety of aircraft, so I keep PDFs of the pilot’s guides and cockpit references for many GPS navigators, autopilots, and other avionics on my iPad for quick reference when working with customers—and in the cockpit, as noted in AC 91-78. (The Documents feature in ForeFlight is handy way to keep these items organized and available.)

To save you the trouble of tracking down references, I keep PDF versions of the handbooks for many popular avionics in my Aviation Documents folder at OneDrive, ready for you to download. But to ensure that you always get the latest (or, if necessary, earlier versions of the manuals), visit the manufacturers’ websites.

Most avionics manufactures provide free PDF versions of their handbooks on their websites. But sometimes navigating those websites to find the references can be daunting. Here’s a quick guide to finding the handbooks for the popular Garmin GTN 750 Touchscreen GPS/Nav/Comm/MFD. You can follow a similar process to locate the handbooks for other Garmin products or the references for products sold by other avionics manufacturers.

You can find handbooks for other popular avionics at the following manufacturers’ websites. If the name of the manufacturer you’re interested in doesn’t appear in the following list, Google is your friend:


Garmin GTN 750 Handbooks

Start at the main Garmin website, www.garmin.com. In the search box in the upper-right corner, type gtn 750 (or the name of any other Garmin product).


In the list of the search results, click the name of the product you’re interested in.


On the product page, click Manuals.


When the Manuals page appears, click Appliance Data in the Choose product version drop-down box. (Why Garmin chose Appliance Data as the name for this option is any engineer’s guess.)


A list of all of the handbooks and references for the GTN 750 appears. Choose the document you want to download, and copy the PDF to your device. Repeat the download step as often as necessary to collect all the documents you want. Note the revision dates and revision letters to ensure that you copy the documents that correspond to the system software installed in the units installed in your airplane.


Garmin GTN Avionics and RF Legs

The release of updated operating software for Garmin GTN-series avionics brings new capabilities to many typical general aviation pilots who fly under IFR. One of the new features is the ability to fly curved radius-to-fix (RF) legs on some instrument approaches.


Until recently, RF legs were published only on so-called RNP procedures with authorization required (AR) restrictions (for more information, see AIM 5−4−18: RNP AR Instrument Approach Procedures). But FAA has started publishing some approaches with RF legs (like the example above) that are not designated as RNP AR procedures. And, with some limitations, pilots who fly aircraft equipped with GTN-series avionics should be able to fly the RF legs used as transitions/feeder routes on those approaches. (Note that so far, these approaches don’t require RF capability–conventional transitions/feeder routes and/or radar vectors are also available.)

For more information about RF legs, see RNP Procedures and Typical Part 91 Pilots and Garmin Radius to Fix Leg Project Report here at BruceAir. For additional background on GPS navigation and RNP procedures, see also Updated AC 90-105A.

The revised STC for the GTN series (document 190-01007-A5) notes that:

GPS/SBAS TSO-C146c Class 3 Operation
…The Garmin GNSS navigation system complies with the equipment requirements of AC 90-105 and meets the equipment performance and functional requirements to conduct RNP terminal departure and arrival procedures and RNP approach procedures including procedures with RF legs subject to the limitations herein [emphasis added].

Sections 2.12 RF Legs and 2.13.1 RNP 1.0 RF Leg Types of the STC add the following information:

2.12 RF Legs
This STC does not grant operational approval for RF leg navigation for those operators requiring operational approval. Additional FAA approval may be required for those aircraft intending to use the GTN as a means to provide RNP 1 navigation in accordance with FAA Advisory Circular AC 90-105. [Note that per AC 90-105A, domestic Part 91 operations do not require additional approval–only Part 91 subpart K operations and commercial operations need LOAs or the equivalent FAA approval.]

The following limitations apply to procedures with RF legs:

  • Aircraft is limited to 180 KIAS while on the RF leg
  • RF legs are limited to RNP 1 procedures. RNP AR and RNP <1 are not approved
  • Primary navigation guidance on RF legs must be shown on an EHSI indicator with auto-slew capability turned ON
  • GTN Moving Map, EHSI Map, or Distance to Next Waypoint information must be displayed to the pilot during the RF leg when flying without the aid of the autopilot or flight director.
  • The active waypoint must be displayed in the pilot’s primary field of view…

2.13.1 RNP 1.0 RF Leg Types
AC 90-105 states that procedures with RF legs must be flown using either a flight director or coupled to the autopilot.

This STC has demonstrated acceptable crew workload and Flight Technical Error for hand flown procedures with RF legs when the GTN installation complies with limitation set forth in Section 2.12 of this document. It is recommended to couple the autopilot for RF procedures, if available, but it is not required to do so. See section 4.5 of this manual to determine if this capability is supported in this installation.

At present, only a few non-AR approaches with RF legs meet the criteria in the STC and AC 90-105A. But RF legs could become more common on “standard” procedures to provide paths that offer better noise abatement, reduce airspace conflicts, and improve ATC efficiency, and pilots flying with GTN avionics (or similar navigators offered by other manufacturers) will be able to fly those procedures.


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