Points for Pilots

Our original installation of the Rotax 912/914 r egulator/ r ectifier. 24 years later, the two brown wires on the left were replaced by yellow wires of a new stator, see photo below. The Rotax 912/914 electrical system may fail unexpectedly. I t happened to us once at a really inconvenient time : S ee Rotax Goes South As We Go West . Most likely the electrical failure is caused by the voltage regulator/rectifier.  To ver ify this , we now carry in the plane a small multimeter that measures AC/DC voltage and resistance and use the checklist below. The checklist assumes a standard installation as described in the Rotax installation manual Section 24-00-00, without additional external generator, and that the voltage is not in the normal range. Testing Electrical System Beyond Regulator/Rectifier It is possible, though quite unlikely, that the electrical failure is caused by something other than the generator and regulator/rectifier. There is an almost infinite variety of poss

Garmin GDL 39 receiver Completed in 1995, our Zenith 601HDS plane, N314LB, has steam gauges plus an outdated GPS unit. The latter equipment drives the 2010 installed Digitrak autopilot. Recently we added to the cockpit a Garmin GDL 39, which is an ADS-B "In" receiver, and an iPad2, thus getting the capabilities of a glass cockpit. Cost of the addition was under $1,300 and thus a fraction of the expense associated with standard glass cockpit conversions. The cost figure covers everything: GDL 39; iPad2 with 16GB storage; 12V charger, 3M screen protector, and protective cover for the iPad2; and sales tax. A bargain, really. Subscription cost for the Garmin Pilot Data, which are required for the operation, is a reasonable $49.99/year. There is no additional charge for weather data. We do not use optional subscriptions for the Garmin Geo-Ref FliteCharts, cost $49.99/year, or SafeTaxi, cost $29.99/year. Installation and use of the new equipment forced us onto a steep learn

We have installed the 3M Natural View Screen Protector for iPad2 on the iPad2 used with a Garmin GDL 39 receiver, as described in the blog Garmin GDL 39 + iPad2 = Economy Glass Cockpit .   The screen pro tector suppresses glare quite well with no noticeable effect on brightness. It also is very tough. A perfect installation, without any air or dust bubbles between protector and screen, can be achieved as follows. First, watch the 3M installation video . A key consideration is the avoidance of dust particles. For this, we try to create a sort of clean-room environment. Wear upper-body clothing that likely will not shed fiber particles. For example, a long-sleeve cotton/polyester shirt is a good choice. Carefully wash hands. We turn a bathroom into a clean-room. Run the hot shower for a few minutes, until the air has something like 70-80% humidity. This eliminates the problem of static electricity attracting airborne dust particles when you work with plastic bags and parts. Prepar

The Rotax 912 engine and the related 912S and 914 engines have many parts made of rubber or closely related material. To guard against failure of these parts, Rotax recommends replacement based on hours in service and elapsed calendar time. If that replacement policy is to work for all possible installations, in particular in very hot Africa and very cold Alaska, then the replacement intervals must be quite small. As the US Air Force discovered many decades ago, such frequent replacement triggers so many new problems that the cure becomes worse than the effects of the aging process. Since that discovery, the Air Force has used on-condition replacement, where parts are replaced as needed and not due to some time-in-service or calendar-time rule. The conclusions drawn by the Air Force apply to the Rotax engines as well. My friend Philip tells horror stories about the difficulties created when wholesale replacement of all rubber parts is done every few years on his Rotax 912S, as ma

In the AOPA Pilot article “Maintain Thy Groundspeed,” Barry Schiff analyzes in detail what can go wrong when wind shear is encountered on short final approach. Of course, there is the traditional formula to prevent mishaps: Airspeed is increased by half of the gust factor. But how large is the gust factor? If an ASOS station is based at the airport, it provides that information about gusts. But even that supposedly timely information can prove to be quite wrong when a huge gust randomly occurs. Instead, Barry Schiff recommends that the pilot maintain groundspeed equal to normal approach speed, and argues that this suffices regardless of the speed of the gusts. Recently, we had several opportunities to try out the rule. A particularly nasty case of gusts occurred at Aero Country Airport, the final destination after a trip to New Mexico and back. Winds were given as 20 kts gusting to 29 by a message broadcast from the nearby McKinney Airport. The information is updated e