FAR 107.31 Visual line of sight aircraft operation. Conflicting language?

Davidblezard · Mar 9, 2019

If I may ask a related question? Flying during normal daylight and have a strobe on the UAS. This allows for a longer VLOS. Is this legal ?

BigAl07 · Mar 9, 2019

Davidblezard said:
If I may ask a related question? Flying during normal daylight and have a strobe on the UAS. This allows for a longer VLOS. Is this legal ?

That's a tough question. Keep in mind that the requirement isn't just to see a small speck on the horizon but to be able to see and determine the orientation of the aircraft. IMHO you'd have to add lights that not only beacon but also allow for orientation determination at greater distances.

The strobes are more for See & Avoid than for extending VLOS... again this is my own opinnion and you'd need to contact your FSDO to get the official word that you can take to the bank.

Earnest Ward · Mar 9, 2019

BigAl07 said:
That's a tough question. Keep in mind that the requirement isn't just to see a small speck on the horizon but to be able to see and determine the orientation of the aircraft. IMHO you'd have to add lights that not only beacon but also allow for orientation determination at greater distances.

The strobes are more for See & Avoid than for extending VLOS... again this is my own opinnion and you'd need to contact your FSDO to get the official word that you can take to the bank.

Big Al is once again spot on. When you need the definitive answer with regards to regs ALWAYS contact your FISDO.

Here's a little food for thought tho'. Even if an omnidirectional strobe legally extends your VLOS range, if you're sUAS is, say, 1/2 a mile out will you have adequate visual acuity/depth perception to maintain clearance from small obstacles? Or, if your drone unexpectedly announces a switch to Atti mode, can you reasonably expect to RTB safely?

Roadking · Mar 9, 2019

Scenario: you’re shooting four sides of a three story building. The PIC has VLOS along side one. There is a VO at each corner of the building and all are in constant commmnication. VO1 has VLOS along side 2, VO2 has VLOS along side 3 and VO3 has VLOS along side 4. I believe that is perfectly legal. Visual observers can transfer LOS responsibility to other VOs or to RPIC.

BigAl07 · Mar 9, 2019

Roadking said:
Scenario: you’re shooting four sides of a three story building. The PIC has VLOS along side one. There is a VO at each corner of the building and all are in constant commmnication. VO1 has VLOS along side 2, VO2 has VLOS along side 3 and VO3 has VLOS along side 4. I believe that is perfectly legal. Visual observers can transfer LOS responsibility to other VOs or to RPIC.

You'll want to run that scenario by the FSDO because at one point they specifically said "Daisy Chain VO was not allowed under current regulations".