Stemme S-10 vt motor glider pilot reported the tower controller at his destination was apparently no...

Narrative:

The S-10 vt that I was flying is a german high performance motor glider with a left/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.

Original NASA ASRS Text

Title: 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.

Narrative: 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.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1282402
Time
Date	201507
Local Time Of Day	1201-1800
Place
Locale Reference	CRQ.Tower
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft
Flight Phase	Landing
Route In Use	Visual Approach Direct
Flight Plan	None
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Glider Flight Crew Private
Experience	Flight Crew Last 90 Days 32 Flight Crew Total 450 Flight Crew Type 66
Events
Anomaly	ATC Issue All Types Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy

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.