UAS is not a time critical item. Pilots need to assess what the aircraft is doing. A modern cockpit gives so many ways to do that. You have VSI’s, GPS speed, aircraft attitude, thrust, back up pitot static indications and even ground speed from controllers. Every professional pilot should know the basic attitude/power for the normal flight regimes. You can’t go very far wrong if power and attitude are correct for a given phase of flight. My experience losing airspeed on both sides on a 767 during approach was simple. Maintain 2 degrees nose up and adjust power to maintain the proper VSI and glide slope indications while cross checking GS. It was I admit easier than some situations because we were fully configures and stable at the time. Had we gone around it would have become a much more complicated problem. I recently lost airspeed in a high performance light aircraft without a lot of fancy backups. Managed to center punch what must have been a very large bug and block the pitot completely. Attitude plus power equals performance! Held my normal climb attitude/power until 3000’. Leveled off and drug out my IPad to get a GPS backup for speed and returned to land.