Landing light aiming

[jmaynard]

I had to replace the landing light on my Zodiac today. (I have this thing about being seen, so I turn it on whenever I'm in the pattern.) The mounting screws are also the aiming screws, so I wound up having to guess at the aiming. I'd like to do a bit better than that. Where should I aim the light? It's out near the left wingtip.

 

[KennyFlys]

Are there no specifics in the aircraft maintenance manual?

If not, I'd suggest toward the center line or as close as practical with the design while still giving you sufficient lighting of the center line ahead at least 50-75 feet.

 

[Skip Miller]

Where should I aim the light? It's out near the left wingtip.

The manual should say where the aiming point is. It should be aimed low, to illuminate the runway below when you are at short-final-approach attitude. Horizontally, a wing-mounted light should be aimed inward, to cross the centerline at a distance near the effective range of the light.

-Skip

 

[jmaynard]

The manual should say where the aiming point is.

Unfortunately, the maintenance manual is completely silent on the subject. When I spoke to the manufacturer, they told me that I should aim the light inward the same amount as the taxi light, and down a bit from it. That's what I did, for now, but I suspect I'll have to play with it a bit.

 

[weirdjim]

And remembering that the taxi light illuminates important stuff while in a 3-point level stance, while the most critical time for a runway light is while pitched up x degrees in the landing configuration...unless you like to "drive" it onto the runway.

Jim

 

[Greg Bockelman]

And remembering that the taxi light illuminates important stuff while in a 3-point level stance, while the most critical time for a runway light is while pitched up x degrees in the landing configuration...unless you like to "drive" it onto the runway.

Jim

Which is exactly why

they told me that I should aim the light inward the same amount as the taxi light, and down a bit from it.

 

[Stache]

I have performed several field approvals on landing lights and from my experience I would recommend you go out at night start the engine and taxi around the ramp with the light on. This will tell you if it is aimed to high and will reflect off the propeller blinding the pilot.

It should be aimed slightly down as not to reflect off the propeller to much. Each aircraft I have work on has had a slightly different angle from 5 to 9 degrees depending on the installation.

Once you have it set on the ground a flight test is required to see if you can see the runway at the critial time on landing. It also important to have an spotter assist you.

Part 23.1383
(a) States no dangerous glare is visable to the pilots.
(b) The pilot is not seriously affected by halation.
(c) It provides enough light for night operations.

The rest is up to the maintenance manual or if not guidance is availble then follow part 23.1383. This will be a trail and error process to get it right.

 

[KennyFlys]

Stache, thanks for posting that. I looked but it wasn't sticking out on word searches.

But, I see it has brackets around the title as well as the entire subsection. Why is that? I would have guessed it's a recent change but it shows last amendment effective 3/11/1996.

Part 23.1383
(a) States no dangerous glare is visable to the pilots.
(b) The pilot is not seriously affected by halation.
(c) It provides enough light for night operations.

The rest is up to the maintenance manual or if not guidance is availble then follow part 23.1383. This will be a trail and error process to get it right.

 

[Stache]

The brackets don't mean anything. The way the rules are written is odd numbers rules are original rules and even numbers are new rules. If it is ammended the number system does not change only the ammendment number such as 3/11/1996.

 

[ScottM]

The brackets don't mean anything.

Don't put money on that bet. They are there for a purpose but for most outside of those that draft these things it means nothing once the text is approved and published.

Each drafting group has different marks to indicate new text, proposed text, or text to be deleted.

For the FARs and this section the entire section was rewritten and inserted with revision. Hence the square brackets showing that it is all new text. If there was stuff outside of the square brackets that would show what was there prior to the revision.

Section 23.1383 Taxi and Landing Lights
The landing light requirements of Sec. 23.1383 would be revised by adding taxi lights to this section. When the landing light requirements were included in the normal, utility, acrobatic, and commuter category requirements, the same lights were used for both night landing and taxiing of the airplane. Due to availability of different types of lights, separate lights are now frequently installed for landing and for taxiing. Including the word "taxi" in the heading would clarify that the requirements cover both kinds of lights.

Current Sec. 23.1383(a), which requires the lights to be acceptable, would be deleted because it is unnecessary to state this. All lights that are found to meet the requirements of this section and other directly related airworthiness requirements are acceptable. The paragraphs would be redesignated accordingly.
Current Sec. 23.1383(b)(3) requires that a landing light must be installed to provide enough light for a night landing. Proposed Sec. 23.1383(c) would revise "night landing" to "night operation" since the requirements would also cover taxiing and parking. Proposed new paragraph (d) would require the lights to be installed so that they do not cause a fire hazard. This clarifies the need for such an evaluation.

 

[Stache]

Don't put money on that bet. They are there for a purpose but for most outside of those that draft these things it means nothing once the text is approved and published.

Each drafting group has different marks to indicate new text, proposed text, or text to be deleted.

For the FARs and this section the entire section was rewritten and inserted with revision. Hence the square brackets showing that it is all new text. If there was stuff outside of the square brackets that would show what was there prior to the revision.

Scott I am aware of that, however when the final is released and published the brackets are removed in most cases. I just don't want someone to get hung up on it. Thanks for explaining it better them I did.

 

[ScottM]

Scott I am aware of that, however when the final is released and published the brackets are removed in most cases. I just don't want someone to get hung up on it. Thanks for explaining it better them I did.

No problem. I live my life in the world of regulation and standards development. Square brackets is where most of my work is at these days.

 

[weirdjim]

Which is exactly why

And the devil is in the "a bit" detail. The "bit" is also variable as a function of pilot training. I spent my first two thousand hours in taildraggers and any landing that wasn't full stall was a lot of "kitten on the keys" rudder machinations. I still have the horn go off in the 182 on almost all landings, so my "bit" is going to be a little more pitch down than most.

Contrast that with somebody that spent their formative years in a low wing Piper where more than three or four degrees pitch up seems like you are begging to fall out of the sky and there is no such thing as full stall landings (or so it seems). They would transition to your airplane and ask that the landing light pitch down be nearly level.

Mostly we split the difference and pitch the landing light down somewhere between 5 and 8 degrees to take care of a majority of the pilots in the one sigma part of the bell curve. But, since it is YOUR airplane and YOU are going to be the one to fly it, pitch it down some. If you don't like the way it works, pitch it up or down some more. And, in an emergency landing at night, if you don't like what you see on short final, just turn the damned thing off

.