Points for Pilots

O n low-level VFR flights, we typically enter the next destination airport into the GPS unit and deal with deviations forced by high towers, controlled airports, TFRs, restricted areas, and so on, with temporary deviations from the direct course.   This approach forces us to track the course on the sectional chart — a good thing. If the navigation equipment ever fails, we will be well prepared for appropriate action.  For the same reasons, we never let the autopilot execute the flight plan in the GPS unit. Instead, we input the GPS bearing to the destination into the autopilot, and adjust that setting manually as needed. Suppose we are approaching an obstacle forcing a course change. If we detour close to the obstacle, we add some distance — a bad thing. We avoid that through a course correction for the autopilot while we are relatively far from the obstacle. In the past, we carried out estimation of the course correction 30-60miles out as follows.  We w...

Oil temperature of the plane's engine plays a much more important role than often assumed. The manufacturer typically gives a range of acceptable values. As long as oil temperature is within that range, the pilot assumes that all is well. So did we, until recently. The Rotax manual specifies a normal oil temperature range of 190-230 deg F. For short periods, the temperature may go as high as 285 deg F with synthetic oil. Let's evaluate these numbers. Oil oxidation doubles for every 18 deg F temperature increase, and oil life decreases by 50% for every 15 deg F above 140 deg F. So the rate of oxidation approximately increases by a factor of 4 over the range 190-230 deg F. At the same time, oil life is reduced to less than 20%. Over the range 190-285 deg F, the oxidation rate increases approximately by a factor of 32, and oil life is reduced to less than 2%. These are substantial factors and reductions.  In the past we wondered why the oil drained during an oil change...

The Digitrak autopilot by TruTrak keeps the plane level and on the selected true course. We have used that autopilot for several months and are impressed by its performance. Two situations have come up where the autopilot took a strange action. In both cases, we had caused the problem. Below, we describe the two problems and appropriate remedial action. Case 1 The autopilot is engaged in flight, holding a specified true course. My passenger asks for something in the baggage compartment. Turning around, I grab the item and give it to the passenger. He suddenly says, “Look, we are turning.” Indeed, we are in a gentle left turn. I disengage the autopilot and go back to the original course. Engaging the autopilot again, it immediately begins a left turn again. Once more, I disengage the autopilot. Something must be wrong with the autopilot, right? Just then I look down and see that the ball is out of center. Apparently, when I turned around to grab the item in ...

Passengers in my plane almost always aren’t rated pilots, but typically have some piloting experience and in principle are able to take over in case of pilot incapacitation – a very unlikely, but nevertheless possible event.  It is a useful idea to discuss that scenario with the passenger. Here is a summary of the main points for that discussion. I keep a copy in the plane to be used as checklist by the passenger if the real thing happens.  It is assumed that this is a VFR flight outside class B, C, and D space in a plane with fixed tricycle gear. Checklist for Pilot Incapacitation 1. Stabilize the airplane to straight and level before undertaking anything else.  Get the pilot away from the control stick, but otherwise do not try to help the pilot.  Just focus on action to get the plane safely on the ground.   2. Check fuel gauge(s) and estimate endurance. If the plane has a complicated fuel management system, do no try to master it, but es...

Rocky Mountains west of Denver, Colorado Each time I plan a flight to the Rocky Mountains and beyond, I think ,"Now, what are the important things to consider when flying into mountainous areas?" and then, "Wouldn’t it be nice if I had a summary of those things for review!" So, here is an attempt at such a summary. It is based on many sources: flight instructors, fellow pilots, various publications such as Sport Aviation and AOPA Pilot, and, last but not least, Nature, which has had an impressive way of teaching lessons. The discussion below introduces some formulas that I have found useful. If you hate mathematics and formulas, just ignore that st uff . For me, doing these computations while flying is a way to stay alert and to have something to talk about with my copilot. 1. Takeo ff 1.1 Density Altitude We must know the density altitude to estimate the minimum runway length required for takeo ff . An approximate formula for density altitude is D = A ...

At 14,000 ft MSL over Rollins Pass east of Denver For most of us, the highest altitude of flight is 12,500 ft MSL, with an increase to 14,000 ft MSL allowed for up to 30 minutes. Due to these restrictions, crossing the Rockies requires careful planning. Easiest Crossing The easiest crossing is at El Paso, TX. The highest point there is at 7,200 ft MSL.  A More Challenging Crossing A bit more altitude is required at Albuquerque, NM, where the highest point is at 7,800 ft MSL due to the Sandia Mountains. If you choose an altitude above 9,400 ft MSL, then you can overfly the Albuquerque class C space and get a nice view of the international airport, sometimes with a jet taking off or landing below. If you cross the Sandia Mountains from east to west and have westerly winds, as is typically the case, be prepared for light to moderate turbulence below 12,000 ft MSL.  To avoid this, you should start climbing toward 12,500 ft ahead of time. We typically start th...