Top Letters And Comments, January 4, 2019

I learned to fly in the 70s and have been flying my own airplane since then. At that time, I didn't think the private pilot flight training was overly difficult. Over the past 40 years since getting my license I have been upgrading the equipment in my plane primarily to make flight planning and execution simpler and more efficient. As part of the upgrades, I installed a Loran in the 80s and after that transitioned to a variety of more capable GPSs. Now I find that much of the equipment and training that I received in the 70s isn't valuable and often more complicated than it needs to be.

My primary area of concern deals with Magnetic Heading/Compass equipment and Altimeter/pressure sensing equipment. Equipment for both of these would no longer be needed if we transitioned to True North Headings and GPS derived altitudes. While there may be some value in knowing how to use the associated equipment, flying would be much easier to learn and accomplish if we transitioned to the use of even simple GPS equipment.

This would accomplish several improvements. We no longer would have to make the many corrections in determining headings using the relatively inaccurate compass, corrections for flight track when experiencing cross winds, calculating corrections in headings on long flights due to magnetic variation, and periodic remarking of runway numbers and VOR adjustments as magnetic poles change and adjustments when local magnetic variation is inaccurate in some areas. I can see no reason, from a pilot's perspective, for continuing to use compass and magnetic headings in my flying. In addition, I would be happy to dispose of my Compass, Directional Gyro, and unreliable vacuum pump. This would reduce cost, improve equipment reliability and safety of flight.

The other major irritant is our continuing to rely on pressure instruments to determine altitude. The fact that I have to rely on an external source for the barometric pressure and often find that this info is not correct for the area where I am flying makes any altitude reading incorrect. I have often found that the altimeter reading is as much as 500 ft off from my GPS altitude even after getting a current baro. pressure reading from ATC. This fact is not only dangerous when flying in mountainous areas but also when flying in the pattern or flying when air temps vary widely.

I recently added ADS-B out and in equipment and find that the unit puts out a signal which includes the inaccurate pressure derived altitudes but also the GPS altitude. This to me makes absolutely no sense. The aviation world would be much better served if we only used one altitude which can be derived more simply and more accurately using a WAAS enabled GPS. Personally, I would be happy to ditch both my Altimeter and Vertical Speed Indicator. For new airplanes, this would save more money than the cost of one or two simple GPS's.

Now I know this would require several changes in International rules and equipment and there would be some upfront cost in making these changes, but I don't think anyone could make the argument these changes would not only increase safety, decrease equipment costs, and simplify training.

Vern Schulze

Cut the poetic reporting! We want aviation reporting not some "flower child" approach to AvWeb.

Bill

Interesting. I vaguely remember that crash. That was in my freshman high school days. In those days, NYC was so far away from our little city north of Boston. The local Boston TV news covered the incident as did the newspapers. How times have changed. Prior to that incident, Northeast Airlines ran DC3s into our city airport (Lawrence, KLWM). I remember them flying over our house heading to the airport. In summer, dad would take me and my sister to the airport for ice cream and to watch the airplanes land. That is where I caught the aviation disease. Your article brought those memories from the dark depths of my pea sized brain. How aviation has changed. Yet, as you mention, the human element, whether in ATC, the cockpit, maintenance shop, design offices or manufacturing floor, are the key ingredient of a very bad situation.

Leo LeBoeuf

Didn't appreciate the snarky tone of Paul Berge's article about the TWA/United crash over Staten Island.

John Cowan

I read the article on your daily AVweb newsletter this morning and was underwhelmed by the problem you reported: "Airline Cancels All Flights, Blames Pilot Shortage." There's no "Pilot Shortage," there's just a shortage of pilots who will work for peanuts. This California "fledgling airline" needs to add money to their wage scale if it wants to attract qualified, competent, and willing pilots to join its unproven, zero track record venture. Meanwhile, the headline is just another great lie in the "fake news" cycle.

John

I wonder what they are paying their pilots. With fares at $100 how can an airline flying jets afford to pay flight crews and ground crews and still make a profit to stay in business? Cheap fares for a startup airline just don't work, especially now that pilot salaries are rising to the level they should have been all along. My guess along with low salaries the other issue is that their training dept is not up to training enough pilots to keep up with the airline's schedules. That is a management problem, not a pilot shortage!

Matthew Wagner

How airplanes fly seem to this student pilot of small airplanes and sailor of boats to be a collection of "force differentials" converted, directed and channeled into forward and upward motion. I think about the basic properties of Physics working in concert giving the airplane the ability to overcome gravity:

Thinking about the "wing" shape in a slightly different way we can see the cross section of the wing is a highly specialized "wedge" shape. Push this wedge shape thru air and "force" is generated in an exponential way. The wedge at high speed can generate a tremendous force!

Because air has mass and weight, the hollow spaces of the airplane while standing on the ramp, has the same weight inside as outside. As soon as the airplane gains velocity the weight of the outside air is greater than inside and this differential increases (possibly exponentially) as feet per second increases. This then makes the aircraft (wings AND fuselage) "lighter-than-air" relative to the compressed air outside the surface of the aircraft. A portion of the force for flying is very much like that fishing bobber floating in the pond. This is also the idea of "displacement hulls" for ships and boats; the hull displaces more "weight of water" then the vessel actually weighs.

The outside air rushing past the wings and fuselage is also compressed to a liquid state and with careful control the airplane can "ride" up this nearly hard surface. Think about "surface tension" of water; insects can walk across water; a speed boat lifts out of the water to ride up out of the water on a very small section of its planning hull. (Note too that speedboat hulls are wedge-shaped)

So now we have all this "force." Now what? Because velocity is the critical part of force and we want to move downrange somewhere, velocity and going places fast go hand-and-hand. We only need to direct, control and channel some of the force into the "vertical component" which can be called "lift!" The Bernoulli Effect is convenient because the lower pressure on top of the wing plays into the direction we want to go: up! The airplane "falls up" into the lower pressure zone relative to the higher pressure under the wings. Ailerons, elevator and rudder direct forces for attitude control.

I don't have time to do the math as my CFI wants his car washed and then I have to pick up his lunch. But I can prove my theory; fly your airplane to at least 5,000 AGL; then bring forward velocity to a stop. Yep. Speed is everything.

Frank Kalinski