Vertical card compass questions

MartyB

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MartyB
I installed the tso unit last night.... Way easy to adjust and might have taken longer to get the old one out! Solder and heat shrink on the lighting wires and away I went to the compass rose. Had a helper to get me lined up on the 4 cardinal headings with all avionics on and enging running.

Question is: Do I need a a/p signoff? (my a/p is out of town a few days)

Or just a log entry from me....
 
From the FARs:

43.3(d) A person working under the supervision of a holder of a mechanic or repairman certificate may perform the maintenance, preventive maintenance, and alterations that his supervisor is authorized to perform, if the supervisor personally observes the work being done to the extent necessary to ensure that it is being done properly and if the supervisor is readily available, in person, for consultation. However, this paragraph does not authorize the performance of any inspection required by Part 91 or Part 125 of this chapter or any inspection performed after a major repair or alteration.

I did not see replacement of the compass specifically as a preventative maintenance item under Part 43 Appendix A.

Len
 
Agreed. Until you get an A&P to sign off on it, you just made your airplane unairworthy. Legally, anyway.
 
you will need to do more than just the cardinal headings! Seriously it takes an hour.
Good luck, find a recent compass rose!
 
We just had our compass replaced this year and I asked the A&P if I could do it he said yes but you need me to check it out/set it up and sign the log.

Bob
 
rmciottijr said:
We just had our compass replaced this year and I asked the A&P if I could do it he said yes but you need me to check it out/set it up and sign the log.

Bob
Bob, for IFR I believe you have to swing the compass and create a new compass deviation card.
 
RotaryWingBob said:
Bob, for IFR I believe you have to swing the compass and create a new compass deviation card.

IIRC you would need the deviation card to be airworthy period.
 
The legal answer is yes you need an A&P sign off the install and new compass card (required placard) in accordance with part 91. This means you should take your aircraft to a compass rose that has been surveyed within the last year. The local airport should be able to tell you if the compass rose is surveyed. If it is not, take your aircraft to your local avionic shop and have they swing the compass and provide you with a new deviation card.

Stache
 
Make your own rose, 4 garden stakes, 2 pieces of chalk line 20' long and a pocket compass, park the aircraft 1/4 mile away, and set up the rose, and taxi into it with chalks at te lines you set up.

copied from "the Compass Company" web page

The compass rose has appeared on charts and maps since the 1300's when the portolan charts first made their appearance. The term "rose" comes from the figure's compass points resembling the petals of the well-known flower.

Originally, this device was used to indicate the directions of the winds (and it was then known as a wind rose), but the 32 points of the compass rose come from the directions of the eight major winds, the eight half-winds and the sixteen quarter-winds.

In the Middle Ages, the names of the winds were commonly known throughout the Mediterranean countries as tramontana (N), greco (NE), levante (E), siroco (SE), ostro (S), libeccio (SW), ponente (W) and maestro (NW). On portolan charts you can see the initials of these winds labeled around the edge as T, G, L, S, O, L, P, and M.

The 32 points are therefore simple bisections of the directions of the four winds (but the Chinese divided the compass into 12 major directions based on the signs of the Zodiac). For western apprentice seamen, one of the first things they had to know were the names of the points. Naming them all off perfectly was known as "boxing the compass".

There is no absolute standard for drafting a compass rose, and each school of cartographers seems to have developed their own. In the earliest charts, north is indicated by a spearhead above the letter T (for tramontana). This symbol evolved into a fleur-de-lys around the time of Columbus, and was first seen on Portuguese maps. Also in the 14th century, the L (for levante) on the east side of the rose was replaced with a cross, indicating the direction to Paradise (long thought to be in the east), or at least to where Christ was born (in the Levant).

The colors on the figure are supposedly the result of the need for graphic clarity rather than a mere cartographical whim. On a rolling ship at night by the light of a flickering lamp, these figures had to be clearly visible. Therefore the eight principle points of the compass are usually shown on the compass rose in black which stands out easily. Against this background, the points representing the half-winds are typically colored in blue or green and since the quarter-wind points are the smallest, they are usually colored red.

References:

Cartographical Innovations: an International Handbook of Mapping Terms to 1900 ed. by Helen M. Wallis and Arthur H. Robinson. - Tring, Herts: Map Collector Publications in association with International Cartographic Association, 1987. - ISBN 0-906430-04-6. (This was really quite good, and full of interesting history and details about maps - Bill

Mapping by David Greenhood. - The University of Chicago Press, 1964. ISBN 0-226-30696-8

More on Compass Roses: Chart Compasses http://www.ruf.rice.edu/~feegi/compass.html

More Compass Roses from Portuguese Nautical Charts (images) vhttp://www.ruf.rice.edu/~feegi/rose.html

A Modern Version from a Nautical Chart http://www.chartinteractive.com/chart_no1/12.html

URL: http://www.ctmap.com/gisnet/notebook/comprose.html -- Last updated: Sept 1999 © 1999 by Bill Thoen
 
cherokeeflyboy said:
IIRC you would need the deviation card to be airworthy period.

Had the club swing the compass and post a new card (half of the old one was missing) before my checkride 5 years ago. Not airworthy without it.
 
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