Articles | Index

The Compass 2010-03-18
The ancients recognized the pole star as being a constant reference for determining direction. The Norsemen in the 11th century used a needle of magnetic iron inserted in a straw and floated on water to point to the pole star. Petrus Peregrinus de Maricourt invented the pivoted floating compass with lubberline and sight for bearing. The modern compass is little more than one hundred years old.The compass card, due to wind rose origins is older than the magnetic needle. Names of the cardinal compass points are from the ancient terms for wind direction. Variation was understood by 1800 as a problem. Edmond Halley at end of 17th century mapped lines of variation and drew isogonic lines (lines of variation) on his maps. George Graham showed that variation was subject to diurnal (seasonal) changes with variation being less in winter. John Smith wrote about deviation in 1627 by John Smith. He saw it as a problem encountered through use of metal nails in his compass box. Captain. Mathew Flinders in 1801-2 found way to correct by use of "Flinder's Bars as did Lord Kelvin through use of Kelvin spheres. Placement of soft iron spheres at sides of compass could be used to correct deviation. The magnetic compass depends on the horizontal component of the earths' magnetic field. The directional properties of the lodestone were known to early man. The term magnet comes from the name of a region in southern Europe which was a major source for lodestone. The development of the magnet grew form a floating needle in a straw, to the needle in a cork, a pivoted needle, the pivoted card, the pivoted card in a bowl, to the use of gimbals, and finally the liquid chamber with a pivoted card. Compasses were in use as early as the 12th century but their operation was imperfect and not fully understood. About 18090 Mathew Flinders discovered a solution to the problem of local attraction. Deviation as used in aviation. Flinder's Bars, large masses of unmagnetized iron, are universally used on ships. In 1838 Sir G. B. Airy used magnets and iron to neutralize effects of iron ships. The initial dry card compass was developed by Lord Kelvin who determined that a cards steadiness depended on the natural period of vibration of card and needle. A light card with a heavy rim was suspended by a pyramid of threads to a central pivot point. This produced a steady card. The use of a liquid float chamber with the buoyancy of the magnet and card only slightly less than weight to reduce fraction. The liquid has a dampening effect as well. The development of the gyro compass began in 1851 when Leon Foucault used suspended cannon shot on a long wire pendulum to show the rotation of the earth as well as the inertia of the free swinging ball. By 1852 he had created the gyroscope but had trouble applying continuous power. By 1900 the electric gyroscope was invented by both Elmer A. Sperry and Anschutz-Kampfe of Germany. By 1911 gyro compasses were in use soon to be followed by gyro repeaters (selysn(sp) units) flux-gate compasses and gyro pilots.. Comment		External Links  Recent articles Pilotage and Dead Reckoning Course within 3 nautical miles BR Altitude U U 200í BR Arrival within 5 minutes BR Heading within 15 degrees... Calming Flying Anxiety P Anxiety is generalized fear Your body prepares you to run fight or act to protect yourself Your heart and blood pressure rise blood... Associated Airport (Two Mile final into CCR 19R) Clyde as it exists now is two small rows of homes along one side of a railroad spur track and Port Chicago Highway I was once... About Questions P A friend was hauling a body from a remote location in Canada Only a caretaker was around the strip After considering the trees that lined... Taildraggers 19 of fleet are taildraggers BR 6 to 29 of landing accidents P P ... Ground Radio to Taxi P Never transmit on the radio without practicing what to say while holding the microphone to your lips It does no good to practice without the microphone... Ground Reference Turns around a point BR B 600 to 1000 feet 45 degree bank U U 100 feet U... Cross-Country Planning I REFERENCES: AC 61 21 AC 61 23 AC 61 84 Charts A FD AIM I BR ... On Flight Instructors Almost anyone can learn to fly an airplane if exposed to the environment long enough and teaching someone properly is extremely hard work ... Operating Without a MEL (Minimum Equipment List) P B Minimum Equipment List B P P Most older aircraft have been certified without a MEL but everything operational... The Plotter The first aircraft plotter was invented by a Naval officer named Weems He adapted the much larger shipboard plotter into a plastic model which... Wearing Thin Pants In many respects flying an airplane is much like riding a horse A horse goes where its head points so does an airplane ... On Checklists ol li Flying an airplane requires that a series of relatively complex procedures A checklist is most viable if a long series ... Runup P Use a run up checklist Always face the wind Engine cooling is the reason We are not teaching a flying career made only... Special Use Airspace (SUA) P Not on charts but often mentioned by VOR Tower broadcasts Locally by Livermore ATIS to warn of National Guard firing range near Danville San Ramon border... Factors in Successful Learning P B 1 Time of year B BR Summer flying gives longer days but does not provide the most desirable range of experience... One CFI + One CFI = Problems One several occasions I have flown with both experienced and inexperienced CFI for a number of reasons In practically every instance peculiar things have... Spins Were A One Time Thing In 1914 An unheralded aviation pioneer is British scientist F A Lindemann quot;The Prof quot; as he was known led a very ... Take Practical Test FAR 61 105 and 61 125 BR Private or commercial pilot must receive and have logged ground as well as flight training from authorized instructor or a home study... The Nature of Certainty In my careers as a school teacher and flight instructor I have developed student classifications that appear universal There are students who make things... Pilot Error 50 Years Ago P In December of 1947 an Air Force study released the following analysis of pilot errors that precipitate accidents There is no reason to think things have... Courtesy P Airport courtesy extends beyond the rules of right of way Don #39;t use strobe lights on the ground Give preference to aircraft which operate on... Knowing Know He who knows not and knows not that he knows not is a fool shun him BR He who... Run-up Control check BR Engine check BR Instrument settings BR Uses checklist BR Airspeed distances review BR Emergency and departure review... Good Judgement font size 1 color 339966 b Good Judgement b font br P Even the best instruction will not suffice if the... Unusual Attitudes P During the proficiency phase of hood work #39;unusual attitudes #39; should be practiced This means that you will put on the hood close his... Course Reversal P The course reversal is a new addition to the Private Pilot Practical Test standards After the completion of a ground reference pattern in one direction it... Thoughts on Thoughts ul li Flying is not dangerous; crashing is dangerous BR li Flying is the perfect vocation for a man who wants to... Sequence of Decision for Airworthiness Is it required by FAR 91 2095 or 91 213 d 2 ii BR I If not I Is it required... CFI Hours I took my intro flight a few days ago and when I asked my prospective CFI how many hours he had he said over 600 hrs... Night Flight (Discussion) Use of checklist BR Preflight BR Chart reading BR Hazards and precautions BR Lighting systems of plane and airport BR... FAR 61.39(a)(5) Completion of Prerequisites for PT I have given name flight instruction in preparation for a type test within the preceding 60 days and find him competent to pass the test and... Sleep P The most common cause of diminished alertness and proficiency is lack of sleep This condition is said to affect 30 of the U S ... Warning Areas P Same as Restricted area but over international waters beyond 3 mile P P limit of our borders Contains hazards related... Maintenance Records P The owner operator is responsible for all required maintenance inspections and logbook entries on an aircraft FAR 43 gives entry examples of #145;appropriate quot;... Ground Procedures - Taxiing Renewal P By the time we solo we should be using power and brakes with great restraint Minimum power required to move at a good pace and smooth... Shirt Tails There has been a long tradition in aviation related to cutting off the shirt tails of newly soloed student pilots One story has it that the practice ... Accidents By Experience Level Less experienced pilots are more susceptible to accidents BR li Flying less than 10 hours in 30 days or less than 25 hours... The Aircraft Make model serial number and quot;N quot; number can identify an aircraft You should know the year the aircraft was built ... Soft-field Takeoff P Introduction BR The situation is a takeoff area of unlimited length but having a soft surface the nature of which would prevent acceleration ... Engine Failure Accidents ul li 22 of all accidents BR li 4 only partial failure BR li... Preliminaries to Flight P 1 Medical student license br 2 Flight Training Handbook BR 3 Student Pilot Guide 4 San Francisco Sectional BR ... Utilizing Hood Training P The FAA integrated mix of VFR and IFR instruction is a violation of the very instructional precepts considered basic to flight instruction The purpose of the... Opinion On Trim Trimming the airplane is something that comes with practice Like many others have said here the best way to learn is to ... Power-off Stalls No lower that 1500 #39; BR Stabilized approach landing configuration full flaps BR Stall induced in back side of the power curve and heading ... Determining Performance and Limitations P I REFERENCES: AC 61 21 AC 61 23 AC 61 84 Airplane Handbook and Flight Manual I P ... Taxiing Brake check speed control BR Knows and obeys signs lines and lights BR Speed and yoke positions for wind BR ... Thinking Through Patterns P Depending on the student or airport weather conditions I will use paper diagrams and walk through the patterns on the ramp I will illustrate turns about... The Unteachable Student I have found that my methods and I am incompatible with about 5 of my students This was true when I was teaching... Self-Doubt is Normal P Every so often the instructor finds a student who is going through a phase of flying that is very disturbing to the student A student may...  Related Links
©2010 4VFR.COM, All Rights Reserved	Powered by 4vfr.com