Compass deviation article about compass deviation by the. Acrylic mounting base for simple and easy attachment on to saura range of magnetic compasses scpnt will be mounted over the top surface glass of a magnetic compass, thus it is always free from interference which may caused by deviation correcting magnets beneath the compass. Checking the compass deviation regularly may show the need for repair, testing or. The precision vertical card compass for todays aircraft. Compass is the reloadable fare card that works everywhere on transit in metro vancouver. Handbook of magnetic compass adjustment maritime safety. Marine order 21 safety and emergency arrangements 2016 covers requirements of vessels under commonwealth survey. If you have a dome style compass you can use a single transit, sighting across the. Attachment amsa408tableofdeviationsofthestandardsteering compass. Your compass readings are entered by tapping the space bar of the computer keyboard at each 10 degree point of the compass. As i said we perform a swing and issue a card upon fitting a new standby magnetic compass its the same as the ones you can buy for a car, and only a little better for accuracy and it gets an annual check airswing. You can also swing your own compass and produce your own deviation card. Most regulations and notices are available on the isle of man government web site. Compass correctiondeviation card pilots of america.
Magnetic compass adjustment and records of deviations classnk. Compass correction deviation card an airworthiness. Compass deviation card calculation i am trying to understand how to apply the compass deviation card to calculate the compass heading when using dead reckoning. A more detailed description of compass adjusting can be found at handbook of magnetic compass adjustment. I think the feds have a theory that airplanes wont fly without a compass correction card. Compass compensation and preparation of a compass card is performed by physically aligning the aircraft at an approximate desired heading and then using the master site compass to determine the precise heading for calibration purposes. Compass errors should be determined after every large alteration of course, and at least once every watch when there have been no major course alterations.
Aug 31, 2012 correcting a compass from true to compass and back. A csob lamination solution method is to place clear packaging tape on both sides and then cut the card out with scissors or xacto razor blade. H18jan01 reflector compass sr165 austin insulators. Mar 06, 2007 when printed, this word document makes a nice compass correction card for most compass card holders. Introduction this chapter presents information and procedures. This is particularly important for headings where a significant deviation exists. The compass the navigator is provided with a compensating system, which will enable you to minimise, the magnetic disturbances created by the mechanical and electrical characteristics of your aircraft. Separate deviation cards should be prepared for the standard compass and the. Dont have any clue if it resembles the card cessna supplied but i think it looks good. Discussion in maintenance bay started by tomd, jul 30. Compass course the reading of a particular boats compass when the boat is following a definite track.
States that all solas vessels should have their compass swungadjusted and a new deviation card issued at maximum two yearly intervals. Jul 31, 2014 greg discusses compass deviation in navigation calculations. The position of correctors should be recorded in the compass book and on deviation cards. While compass compensation and correction card preparation is accomplished using a standard procedure, alternative standards may be. There are several methods for doing this but in general terms the procedure is as follows. Compass performance should be monitored by frequently recording deviations in the compass deviation book. When a new vessel is commisioned, compass deviation on any heading should be no more than 3. The aim of this notice is to give advice on the frequency and necessity of adjusting the magnetic compass. With this information we could then create a deviation card. A master of a vessel more than 100 gross tonnage is required to keep a compass deviation book on the vessel and the person making the adjustment is to record information in this book. Head deviation head deviation head deviation head deviation. You can union an skilled planner to create an fantastic template for you.
Correcting the process by which both deviation and variation corrections are applied in converting a compass. The difference between the time you tapped the bar and 6th of the total circle time, gives the relative deviation for each compass heading. It is a dry compass, designed to replace the floatliquid type compass no more leaking fluid or backward azimuth readings. In addition to variation, we must also allow for compass deviation when transferring a bearing from the chart where we work in relation to true north to the helm, who is using the boats compass to steer a course. Whether a pilot can fill out a compass card legally, i cant tell you, and have not found a convincing answer one way or the other. Because the distances from the coefficients b and c correctors to the standard compass card and to the transmitting. This form shall be filled out by the navigator for each magnetic compass as follows. You can check to make sure the gyro hasnt drifted at the 180 and 360 points. The international cessna 170 association view topic. It is very difficult to decrease the amplitude of the function and impossible to decrease it to 0 by adjusting calibration magnets within the compass or moving ferrous objects and particularly electronics relative to the compass location. When printed, this word document makes a nice compass correction card for most compass card holders. If a magnetic nonstabilized direction indicator can have a deviation of more than 10 degrees caused by the operation of electrical equipment. Precision vertical card compass pai700 aircraft spruce. It uses eddy current damping and as such has no overshoot.
Compass adjusters measure the deviation and by altering the positions of the magnets built in to a compass can reduce the errors to manageable figures. Table of deviations of the standard or steering compass. As to regulators grounding an aircraft for not having a valid deviation card, too right. He said he didnt know if it was required, so he wrote me up and told me they would investigate it. Deviation changes each time the boat alters course. Compass deviation card template professional template. Previous video on true north, grid north and magnetic north can be found here. I have pdf versions of a pelorus face that you can print to make your own and a deviation worksheet. Thereafter, deviation on any heading should be 5 degrees or less. Compass declaration and table of deviations of standard. I am not too concerned about the safety of flight without the card especially not for day vfr, but my understanding is that it would be illegal. A compass corrector can adjust your steering compass to minimise errors and then produce a deviation card showing the remaining deviation. Magnetic compass adjustment service and compass deviation table inspection comprehensive onboard magnetic compass adjustment service for all vessel classes mackays qualified magnetic compass technician will sail with the vessel. When a new vessel is commissioned, compass deviation on any heading should be no more than 3 degrees.
Deviation card ships head by compass deviation 0000 30e 0100 0200 1. Bb copy of the last certificate with residual deviation table cc magnetic compass maker and type dd magnetic compass bowl condition. You can plot a graph of the effect of change in boat heading on the deviation, this is called a deviation curve. There are people skilled in compass adjustment who can issue a card for a particular compass with deviations listed for changes in direction. Variation and deviation cockpit cards cockpit cards. The bill is that they are prestructured cards and create your errand of card launch significantly simpler. All the regulatory requirements are specific to airplanes, rotorcraft.
I intend to print these on the inside cover of the up coming directory which is a nice card stock so that they may be cut out and used in your aircraft. Look at the card for the deviation for that particular heading. Insert foreandaft b magnets, or move the existing b magnets, in such a manner as to remove all. No setup or alignment is required when performing the master site compass procedure. Thereafter, deviation on any heading should be 5 or less. The pai700 compass i ordered came with a normal sized card, though the pai700 product description does not indicate a compass correction card comes with it.
Magnetic compass adjustment and records of d eviations. Swing for residual degaussed deviations with the degaussing circuits properly energized. Correcting the compass course for deviation gives the magnetic course. Although the solas regulations do not make any reference to intervals between successive adjustments of magnetic compasses, a compass deviation should as a principle be determined at least once every watch while the vessel is at sea and, when possible, shortly after any major alteration of course. Shipping hazardous materials hazmat products classified as hazardous materials hazmat cannot be shipped outside the contiguous united states lower 48 states. Msn 007 magnetic compass adjustment and records of deviations. Pdf of pelorus face compass deviation worksheet 1to print the pelorus face at 8. Every effort should be made to determine the compass deviation. Given a course of 155, tas of 104, wind direction of 90 and wind speed of 10, the true heading becomes 150. I disagreed and asked him where i would find the regulation that a compass deviation card is required equipment for day vfr flights. Correcting a compass from true to compass and back. The sun and watch method worked better than the compass in my pitts. After your compass has been swung checked for deviation and adjusted, a deviation card will be created.
A compass deviation card is prepared so that the navigator can convert between compass and magnetic headings. Ee current ship position and next port of call with eta. The process used to produce a deviation card is called swinging the compass. From deviation tables it is the divergence between the ns axis of. Dave medeiros gives a brief overview of deviation, how it works, and what to expect on a us coast guard license exam question. Magnetic compass adjustment service and compass deviation. This card is 60% the size of a normal compass deviation card. Ac 43215 standardized procedures for performing aircraft. Compass deviation card definition of compass deviation card. An example is shown below, this is similar to the one inside the back cover of your. Airpath compass repair kits deviation card aircraft. Compass declaration and table of the deviations of the standard steering compass of the steel nonferrous vessels head by standardsteering compass and corresponding deviation. Deviation ferrous metal engine etc and electrical equpment can deflect the compass from magnetic north.
Msn 007 magnetic compass adjustment and records of. Deviation can be measured by swinging the compass, that is, checking the compass reading when the boat is on a known heading, round a 360 series of headings, and plotting the resultant errors. If the compass heading is a smaller number than the cog, the deviation is the number of degrees difference, and because the compass number is less than the cog, is east. If the compass heading is a bigger number than the cog, the deviation is the number of degrees difference, and because the compass number is larger, it is west. Compass correction card template courtesy of beech lister ron g. As a general principle applicable to isle of man ships the compass deviation should be checked very regularly and recorded, and the record should be available. First the lubber line can be adjusted so that it is aligned with the direction in which the ship travels. In addition to variation, we must also allow for compass deviation when transferring a bearing from the chart where we work in relation to true north to the helm, who is using the boats compass. Compass deviation card definition, a card, sheet, or the like, with two compass roses printed on it concentrically, for recording, on a given voyage, the amount of deviation for which the navigator must compensate in using the ships compass to steer a magnetic course.
Length to centre of compass system fore and aft magnets red end f a from centre of magnets. Standardsteering compass vessels head by standardsteering compass and corresponding deviation head deviation head deviation head deviation head deviation description, location and size of the correctors corrector alignment no. Add the deviation for a west correction, and subtract the deviation for an east correction. Update with your compass correction values, print, and laminate. It will almost certainly be a magnetic compass and as such will be subject to various errors that we must be. First the lubber line can be adjusted so that it is aligned with the direction in which the ship travels, then the effects of permanent magnets can be corrected for by small magnets fitted. Dec 03, 2015 the airplane in question has half of the compass correction placard missing, and the half that is there is blank. This step is not required if prior adjustment has been made using a dip needle to indicate proper placement of the heeling magnet. This form must be kept with the compass deviation book and provided at any time a marine surveyor wishes to examine it. If you have a domestyle compass you can use a single transit, sighting across the. Individual vessels have individual deviation cards that show the adjustment required for changes in position of the vessels head. An inexpensive way to laminate is to apply clear packing tape to the front and back.
Turn to cardinal headings in 30 increments and note the deviation with the engine running at a reasonable flight rpm. When i built my pitts, the guy from the faa came out, looked at my paper work, made me put in a compass correction card and then said it was ok to try to fly it. Standardized procedures for performing aircraft magnetic compass. This means a deviation card is always necessary for accurate readings. Compass card definition, a circular card with magnets attached to its underside, the face divided on its rim into points of the compass, degrees clockwise from north, or both, and floating or suspended from a pivot so as to rotate freely. Compass correction card after each engine change note check applicable aircraft special inspection to determine if the compass check andor calibration is required after engine change. Simply load fare products onto a card, and travel with ease.
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