Primarily for general aviation discussion, but other aviation topics are also welcome.
By patowalker
FLYER Club Member  FLYER Club Member
#1520720
nkt2000 wrote: I also think that the angles for ships navigation lights may pre-date the IMO by several decades, if not centuries.


Invented by famous Welsh chess player, Captain William Davies Evans, and adopted by the Admiralty in the 1840s.

http://www.walesonline.co.uk/lifestyle/nostalgia/welsh-history-month-william-davies-10338210

The arcs of red and green were 10 points of the compass and the arc of the white stern light was the remaing 12 points. Now expressed in degrees as 112.5 x 2 + 135.

I can't find why it was decided aircraft navigation lights should be 110 x 2 + 70 x 2.
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By foxmoth
FLYER Club Member  FLYER Club Member
#1520746
I can't find why it was decided aircraft navigation lights should be 110 x 2 + 70 x 2.


Well presumably it is because 110 is exactly 1/3 of a compass though you would have thought they would keep them the same as maritime!
#1520753
Just be glad that you don't require a rotating amber beacon light as for surfaced submarines - like they have on a bliddy gritting lorry . Goodness knows how the two men on the fin can keep lookout night vision with that contraption above them.
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By Grumpy One
FLYER Club Member  FLYER Club Member
#1520776
aerofurb wrote:So do seaplanes have two sets of nav lights...? :?

Errrr? ..... Nope :D
When a seaplane is bobbling about on the water, it is obliged to comply with the International Regulations for the Preventing Collisions at Sea, in regards to the lights and signals our intrepid hero in charge of it, is duty bound to exhibit. (And indeed the steering and sailing aspects too - but that's another diatribe)

However, and this is where you can probably relax...

The Rules do consider that a Seaplane may have a practical problem when it comes to lights and signals... You see they don't actually, or even usually, conform to the general shape of a boat. Not many people know that :) .
Small differences in outline and construction could, potentially, get in the way of things .
Ships have wings - Bridge wings.
They have rudders - But one doesn't generally see much of them.
They have propellers - they tend to rotate far slower and, much like their rudders, spend most of their life underwater.
Despite these similarities, somehow or other, the two entities are somewhat different in scale and outline.

There's a problem with Seaplanes. It ain't so easy to find a decent place to slap on navigation lights that will fully satisfy the Regulations.
There isn't usually a handy bulwark, stanchion mast or Samson post available just when & where you need one.
It's a bit of a bu33er really.
All is not lost.
Nosirree - The Rules emphatically give the Seaplane designers, builders & pilots a let out clause.
Part E - Rule 31 - Simply gives some leeway (an apt phrase for a sea-going aeroplane methinks). If it's impractical to exhibit the lights & shape required, then they shall be exhibited as closely as possible as to the characteristics and positions that are required by the Rules...... Phew!!

Bottom line - You don't need two sets of navigation lights. :thumleft:
Do I hear a collect sigh?