An intriguing discussion started early this week in SL Aviation about aircraft lighting rules (yes an actual aviation topic!). The basis of the conversation was about proper use of lighting, such as when to use certain lights, and more importantly, when NOT to use certain lights. The overarching theme of this discussion demonstrated some disagreement even among many in the group with live aviation experience.
Now, I am not an aviation expert, nor do I play one on TV. But I do play one in SL and am much interested in getting it right. So thanks to the powers of Google, some pointing in the right direction by a couple of the members of the SL aviation community, and a desire to publish a new article this week while the topic was still fresh, I set out to find the answers as they are written. The sources of the information I am presenting is based primarily on FAA documentation and information about the runway collision of US Airways flight 1493 with Skywest flight 5569 at Los Angeles International Airport (LAX) in February 1991 (NTSB communications and National Geographic special).
There were really two key points of confusion during the discussion:
- Beacon Light
- Strobe Lights
The key to the confusion likely resulted from a change of rules concerning aircraft lighting that was recommended (and in the case of strobe lights apparently implemented) as a result of the 1991 accident. The NTSB issued Air Safety Recommendation A-21-112 which reads as follows (emphasis added, typos not corrected):
“THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: EVALUATE AND IMPLEMENT, AS APPROPRIATE, SUITABLE MEANS FOR ENCHANCING THE CONSPICUITY OF AIRCRAFT ON AIRPORT SURFACES DURING NIGHT OR PERIODS OF REDUCED VISIBILITY. INCLUDE IN THIS EFFORT MEASURES, SUCH AS THE DISPLACEMENT OF AN AIRCRAFT AWAY FROM THE RUNWAY CENTERLINE, WHERE APPLICABLE, AND THE USE OF CONSPICUITY ENHANCEMENTS, SUCH AS HIGH-INTENSITY STROBE LIGHTING AND LOGO LIGHTING BY AIRCRAFT ON ACTIVE RUNWAYS, AND ENCOURAGE OPERATORS OF AIRPLANES CERTIFICATED PRIOR TO SEPTEMBER 1, 1977, TO UPGRADE THEIR AIRPLANES TO THE PRESENT HIGHER INTENSITY STANDARDS FOR ANTICOLLISION LIGHT INSTALLATIONS.”
The only guidance from CFR I was able to locate was 14 CFR Section 91.209 which reads:
No person may: (b) Operate an aircraft that is equipped with an anticollision light system, unless it has lighted anticollision lights. However, the anticollision lights need not be lighted when the pilot-in-command determines that, because of operating conditions, it would be in the interest of safety to turn the lights off.
This seems to leave a lot of discretion to the pilot in command in most cases. The Pilots Handbook of Aeronautical Knowledge, Appendix 1 -Runway Incursion Avoidance, along with the NTSB finding above, would seem to remove that discretion when it comes to the runway:
- Crossing a runway—illuminate all external lights when crossing a runway. You should consider any possible adverse affects that illuminating the forward facing lights may have on the vision of other pilots or ground personnel during runway crossings.
- “Line up and wait”—when entering the departure runway without takeoff clearance, turn on all exterior lights (except landing lights) to make your aircraft more conspicuous.
Below is a table from Appendix 1 which shows the recommended lighting usage. My take-away from the pilot discretion vs the NTSB finding is that in the table below, pilot discretion really only applies to taxiing. On the runway, turn on every external light you have except for the landing light. When cleared for takeoff, turn it on too.
The handbook contains bullet points following this table with more specifics. Will leave that to your perusal.
In summary, it appears much of the aircraft light usage rules are more guidance than codified law except for 14 CFR Section 91.209 which is quite brief. Guidance and common sense from the above information therefore seems to line up like this:
- Turn on the beacon before starting the engine.
- Turn on navigation lights, logo lights and taxi light if equipped before taxiing.
- Turn on everything but the landing light before entering the runway (including crossing runway).
- Turn on the landing light when cleared for departure.
- Keep all lights on below 10,000 feet unless poor weather conditions cause light issues.
- Strobes optional above 10,000 unless poor weather conditions make them a hazard.
- Turn strobes and landing light off as soon as you clear runway after landing.
- Keep beacon and navigation lights on until engine is shut down.
The final caveat to this is, that all of this is based on the standards set in the US, by the FAA and the NTSB. Some of these “rules” differ under different jurisdictions. And “handbooks” don’t qualify as legal references.
What does this mean for SL Aviation? Simple. Remember, in the end we are here to have fun. Don’t make it too complex. If you want to understand the guidelines and implement them for your flying in SL, check out the full Pilot Handbook of Aeronautical Knowledge. Until digging into this issue I was not aware of this. But it is a wealth of information.
For SL, of course you would need to translate things into SL equivalents. 10,000 feet for example might turn into “three or four sims out”, or 175 meters above the runway.
Above all…enjoy the experience. Whether you just want to fly around, or you want to use realism to add to your experience, do what works for you. That’s what we’re here for.
Natl Geo Video: Air Crash Investigations – US Airways 1493 (Lights reference begins at 37:15)