Lights, Camera, Action!  We’ve all done it, we’ve mostly all been taught it.  But how many actually understand not just the safety factors associated with aircraft lighting, but also the legal requirements. Quiz question:  You are flying a 1979 Cessna 172N model.  The aircraft is equipped with navigation lights, a red rotating beacon, strobe lights, and a landing and taxi light.  Are you required to have the strobes on during daytime operations in VFR conditions?

If you answered no, keep reading.  If you answered yes, go get some leftover turkey and come back in a few.  To ensure we are speaking from the same playbook, I’m specifically referring to Day VFR. You are, in fact, required to have your strobe lights on for movement on the ground and certainly when taking off.

Lights are a constant topic around the virtual, Zoom-controlled, water cooler for instructors and there are as many opinions about light usage as their are instructors (320 at this writing).  Some turn on navigation lights prior to takeoff, some don’t. Some use strobes, landing and taxi lights for takeoff, some don’t.  Many have no idea why they have their own light habits.  I would prefer some kind of logic to engage in a conversation about lighting aside from “my instructor told me to do it.”  

Let’s start with the landing light, it is much easier to review those details:

Operation Lights On (AIM 4-3-23) is a safety program from the FAA that appears in the Airplane Flying Handbook as well as the AIM.  Paraphrasing the program, it says you should turn your landing light on after receiving takeoff clearance, keep them on below 10,000′, within 10 miles of an airport, or when there may be flocks of birds present (lakes, coastlines, rivers, etc..).  Translated, turn your landing light on and leave it.  How many of you frequently fly above 10k’ anyway?  I know that anyone I’ve flown with have heard “lights are cheap” preached anytime I discuss lights.  Besides, with the alleged jet-man making an appearance near LAX at 6,000′, you might as well leave them on so he can see what hits him.

At the airline I worked for, the procedure was to turn the landing light on when receiving takeoff clearance, turn it off above 10,000′, and turn it back on descending through 18,000′.  There was an unwritten rule to flip on the taxi light switch on when receiving a landing clearance as a reminder that we did, in fact, receive the clearance.  I’ve adopted that procedure since.

On to the beacon and strobes, aka anticollision system.

Let’s start with ground operation.  91.209(b) states that “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.”

In a letter to Mr. Murphy (Legal Interpretation – Murphy/2011) in 2011, the FAA further went on to define “operate” to effectively mean (paraphrasing) anytime you getting ready to go fly.  That seems pretty straightforward.  Turn on your anticollision lights prior to starting up the engine.  Well duh, we already do that.  Rotating Beacon ON, Start.  That isn’t enough.  Get those strobes on.  But wait Captain Shane (self-imposed nickname), why would I use my strobe lights for daytime when the conditions are clear and the only cloud in the sky is the chem-trail from the airliner above you polluting the atmosphere with mind-altering chemicals.

Actually, the reason for the strobes on during the day is, well, because the feds say so.  Most arguments around this topic bring up March 1996 as the certification date when those lights are required.  That is partially true.  The actual regulation says that aircraft certificated after March 11, 1996 must be equipped with an approved aviation red or white anticollision system.  This doesn’t deal with operation, only equipment requirements (91.205(b)(11)).  What about operation you ask?

Let’s continue our example above with the 1979 C172N.  In this scenario, it has both a red rotating beacon and a white strobe light system (albeit on different switches).  Let’s go back to 91.209(b), which states once again that “No person may:… (b) Operate an aircraft that is equipped with an anticollision light system, unless it has lighted anticollision lights.”   We can see from this regulation that all lights in your anticollision system must be operating.  Are you with me so far?  

Next, we just need to determine whether both the rotating beacon and strobe lights are part of said system.  Referencing the above letter to Mr. Murphy, “Because the strobe light and the rotating beacon are both approved anti collision lights under § 23.1401 ( a)(l ), they are both part of the same anti collision system. Accordingly, the FAA considers the aircraft’s rotating beacon and strobe lights to be part of the same anticollision system.” (Legal Interpretation – Letts/2017)

Still not convinced?  The final paragraph in the Letts legal interpretation (above) sums up the FAA’s position.  “Accordingly, operation of an aircraft using only the aircraft’s strobe lights after placarding its red rotating beacon as inoperative and making an entry in the aircraft logbook would not be permitted unless such action is authorized by a waiver.”

While the scenario contained in the letter references the red rotating beacon being inoperative, it could be concluded that the reverse is also true if the strobes were inoperative and the rotating beacon worked.  

One final word.  During the comment period for the revision of this regulation in 1996, a commenter asked why the FAA would consider a perfectly good airplane to be grounded if a silly little light didn’t work.  Here’s there answer: “The FAA agrees that there will be incidents where an airplane will be temporarily grounded from daylight operations until a failure in the light system can be repaired. However, the additional safety cue provided to pilots by operating anticollision light systems will outweigh the cost of maintaining the light system.” (61FR5158; February 9, 1996). 

I turn my strobes on before takeoff.  I have determined that strobe lights in/around people and planes in a parking area should not be used in interest of safety.  I turn them off once I land.