Points for Pilots

With ADS-B In, we have lots of information on board: weather, airport information, TFRs, AIRMETs, SIGMETs, and more, all integrated into the map display of the iPad. Recently we added Terrain. On a flight from Dallas to Deming, NM, we intended to try out the Terrain feature. The trip produced a scary learning experience. For the flight we got current sectionals and updated the aviation data base in the iPad. We marked the route on the paper sectional with a red pen and circled potentially troublesome towers. Departing from Aero Country Airport, we had marginal VFR due to 1,500 ft ceilings in the Dallas area. The weather was to become VFR according to the airport data once we were 50 nm beyond the outer ring of the DFW class B space. So this was a simple trip, right? Just fly 1,000 ft AGL until VFR is reached, then climb to cruise altitude. Since the Terrain feature was new, we paid more attention to the iPad displaying the map with route and airplane icon. About 5 nm southwest ...

Route Kansas City to Dallas with Winds Aloft at 12,000 ft There are several definitions of efficient flight. For example, a flight could be considered most efficient if (1) the least amount of fuel is used to cover a given distance; or if (2) the least amount of time is spent in the air for the given distance; or if (3) the least amount of fuel per knot of speed is used. In the landmark technical paper Fuel Efficiency of Small Aircraft (AIAA-80-1847, 1980), B. H. Carson argues that the third criterion, which minimizes expenditure per knot of airspeed, is a good compromise between the first two criteria, which minimize fuel used or time in the air. The airspeed producing the least expenditure per knot is now known as the Carson speed . The optimal speed for the first criterion is the best-glide speed . Carson's paper establishes a neat formula that links Carson speed and best-glide speed. It says that the Carson speed is the best-glide speed times sqrt ( sqrt (3)) = 1.31607...

Diagram taken from Apple iPad2 User Manual When the iPad is used in the cockpit as part of the navigational information system, such as in the iPad + Garmin GDL 39 configuration, the pilot must make sure that the iPad does not get too hot, since it then turns itself off and does not start up again until 15-20 minutes later. According to Murphy's Law, if this event happens, it will likely occur in a critical phase of flight where a waiting time of 15-20 minutes will seem like eternity. How can we avoid that troubling scenario? Here are obvious remedial steps. 1. If the iPad is enclosed in a case, remove it from the case. If you still want to protect the screen, use a light-colored cover such as Apple's iPad Smart Cover with light-gray color option. 2. Turn off the iPad temporarily and have an air vent blow cold air on the aluminum backside. 3. Turn down brightness and delete all processes that are not needed but are running in the background. 4. Shield the scre...

USB plug of connecting cable with ferrite core On long flights where the iPad runs for extended periods in our Garmin GDL 39 + iPad  setup, we must recharge the iPad in flight.  That operation may  cause radio interference. In this post, we analyze that problem and describe a remedy that has worked for us. Initially, we bought a charger with the appropriate connecting cable to be kept permanently in the plane. In the cockpit, the 10W charger was plugged into the 12V receptacle . During the first test flight, we hooked up the iPad to the charger and saw that the iPad was properly charged. We concluded that all was well.  As it turned out, we were quite wrong. Interference Problem The evaluation changed on our first long trip with the Gd L 39 + iPad, where on the first day, coping with significant weather, we were more than 7hr in the air and used the iPad extensively. When the iPad charge became less than 80 %, we decided to hook up the charg...

Dallas - Plainview - Albuquerque - Deming - Andrews - Dallas:  Start at rightmost node and proceed counter clockwise We have tested the iPad + GDL39 equipment installed in our Zenith 601 HDS, N314LB, during three days of cross-country VFR flights along the following route: Dallas, TX - Plainview, TX - Albuquerque, NM - Deming, NM - Andrews, TX - Dallas. The route is displayed in the above screenshot of  the iPad.   Weather on days 1 and 3 was difficult, thus forcing full use of the system. The performance evaluation below consists of four parts: The Good, the Not-so-good, the Unexpected, and Further Thoughts and Recommendations. The Good The Garmin Pilot supplies many useful pieces of data, carries out tasks that previously were difficult or impossible to do, and generally helps to make flight safer. Four aspects stand out for pilots restricted to VFR flight. 1. The Weather option of the map overlays delivers the VRF/MVFR/IFR/LIFR classification for ea...

Sensenich two-blade ground-adjustable propeller The Sensenich  t wo- b lade  c omposite  p ropeller for  Rotax and  Jabiru en g ines is  light-weight, strong, and  very efficient.   For  our Zenith 601HDS plan e with a Rotax 912 engine, the ground-adjustable propeller  de livers  strong take-of f performance as well as good cruise speed . S moothness through out the entire rpm range rivals that of more complicated and less efficient three-blade pro pellers.  The secret to outstanding pe rformance is a very pr ecise setting of the propeller pitch so that the angles of attack of the two blades differ by less than 0.1 degrees.   Such precision can be achieved with a high-quality propeller protractor where accuracy is guaranteed to be +/-0. 05 degrees for each blade, since then total error between blades is +/-0. 1 d egrees.   The same accuracy can be ach ieved with basic workshop tools and parts....