I personally think it would be great if the FAA (for the USA UAS operators) would create some guidelines about what to do in cases like this. Undoubtedly as this hobby becomes more popular and the skies begin to be a bit more congested, there should be some set recommendations between UAS and manned operators to ensure safe flying.
There are already guidelines. The FAA recognizes the
Academy of Model Aeronautics as the community based standard bearer and defer to their guidelines. Unfortunately the AMA is somewhat hostile to drones and if you follow their guidelines, this is where you can fly:
Yes, I am a member of the AMA. I recommend that you join the AMA even if you find their drone guidelines to be unworkable, their insurance umbrella is worth the cost of membership.
The FAA has already said what you should do in this situation in the discussion of the Part 107 NPRM:
iii. Yielding right of way
Now that we have discussed how a small UAS operator sees other users of the NAS, we turn to how that operator avoids those users. In aviation, this is accomplished through right-of-way rules, which pilots are required to follow when encountering other aircraft. These rules specify how pilots should respond to other NAS users based on the types of aircraft or the operational scenario.
The operation of small UAS presents challenges to the application of the traditional right-of-way rules. The smaller visual profile of the small unmanned aircraft makes it difficult for manned pilots to see and, therefore, avoid the unmanned aircraft. This risk is further compounded by the difference in speed between manned aircraft and the often slower small unmanned aircraft. Because of these challenges, the FAA proposes to require, in § 107.37(a)(2), that the small UAS operator must always be the one to initiate an avoidance maneuver to avoid collision with any other user of the NAS. Optimally, the small UAS operator should give right-of-way to all manned aircraft in such a manner that the manned aircraft is never presented with a see-and-avoid decision or the impression that it must maneuver to avoid the small UAS.
When a small UAS operator encounters another unmanned aircraft, each operator must exercise his or her discretion to avoid a collision between the aircraft. In extreme situations where collision is imminent, the small UAS operator must always consider the safety of people, first and foremost, over the value of any equipment, even if it means the loss of the unmanned aircraft. To further mitigate the risk of a mid-air collision, the FAA also proposes to codify, in § 107.37(b), the existing requirement in 14 CFR 91.111(a), which prohibits a person from operating an aircraft so close to another aircraft as to create a collision hazard.
In other words, the FAA would prefer that you crash your drone to the ground.
