Small Aircraft
Flight Crew Glider; Flight Crew Private
Flight Crew Last 90 Days 32; Flight Crew Total 450; Flight Crew Type 66
Communication Breakdown
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors
The S-10 VT that I was flying is a German high performance motor glider with a L/D with engine off of over 50/1. I regularly switch from power to glide mode; after all; that is what the aircraft is made for. In this particular instance; I was flying to [ZZZ]. At approximately 15NM from [ZZZ] I called the tower at [ZZZ] to request landing. Tower informed me that communication was unreadable. I tried three additional times with the same result. Since the aircraft only has one radio; I tried different techniques to make the radio work. Finally; I tried shutting the engine off to see if that was better. It worked; so I let the controller know that I had turned the engine off. After some silence; he cleared me to land. On final approach; I heard another aircraft calling to land behind me when the controller announce there was an emergency in progress. After landing I realize the emergency was called because I shut the engine off.I believe the cause of the event is the result of miscommunication and radio equipment malfunction. There could also be a possibility that the controller was not familiar with the Stemme S-10 capabilities. At 4;000 feet of altitude and 5NM from the airport; there was no risk whatsoever as the aircraft could have glided for about 30NM and stay in the air for about 30 minutes. To avoid having a similar problem in the future; the aircraft is schedule to have a new radio installed.
Stemme S-10 VT motor glider pilot reported the Tower controller at his destination was apparently not aware of his glide capabilities and overreacted when he shut the engine down on approach.