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Registered aircraft · FAA record as of October 23, 2026Stemme Gmbh & Co S10-VT
N5121 is a Stemme Gmbh & Co S10-VT, a glider with a four-stroke engine. It has 2 seats. It is registered to Mountain Stemme LLC, an LLC in Boulder, Colorado. The registration is valid: it was issued on August 26, 2025 and expires on August 31, 2032. No airworthiness certificate is on file, which is normal for drones and for aircraft still being built or tested.
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Flight history: where it flew in the last seven days · follow it on the live map
Aircraft
- Maker
- Stemme Gmbh & Co
- Model
- S10-VT · all S10-VTs and related versions
- Built of
- compositeThe airframe is composite: carbon fibre or glass fibre set in resin, moulded in large pieces with few joints, which gives smooth shapes but needs different inspection and repair methods from metal. A carbon-fibre motor glider. This is how the Stemme Gmbh & Co S-10 family is built; the FAA does not record construction for each aircraft, and the type certificate data sheet is the authority for this one.
- Serial number
- 11-023
- Type
- GliderFAA type of aircraft code 1 (the FAA's broad category for the airframe). Every aircraft with this code · All codes
- Power
- Four-cycle pistonFAA type of engine code 8 (what powers it, as the FAA classes engines). Every aircraft with this code · All codes, 1 motor
- Seats
- 2
- Year built
- Not given
- Transponder code
- A66B58 (octal 51465530)
Registration
- Status
- Valid registrationFAA registration status code V (whether the registration certificate is in force). Every aircraft with this code · All codes
- Certificate issued
- August 26, 2025
- Expires
- August 31, 2032
- Last FAA action
- August 26, 2025
- Airworthiness
- None on file
- FAA region
- Northwest MountainFAA region code S (the FAA regional office that handles the record). All codes
- FAA record id
- 00085752
Owner as the FAA publishes it
- Name
- Mountain Stemme LLC
- Type
- LLCFAA type of owner code 7 (who holds the registration: a person, a company, a trust or a government body). Every aircraft with this code · All codes
- Address
- PO Box 17088
Boulder, CO 80308-0088
Owners can ask the FAA to withhold their name and address from public files. When they do, those fields are blank here as well. How that works.
Documents on file 0
No bills of sale, loans or other documents are indexed against this tail number.
Connections how N5121 links to the rest of the register
- Stemme Gmbh & Co S-10 37 registered
- Stemme Gmbh & Co 42 aircraft on the register
- Built of composite · as the model family is built; the register does not record it per aircraft
- Mountain Stemme LLC 1 aircraft registered to this organisation
- Boulder, CO 221 aircraft registered in this town
- Boulder Municipal · BDU
- Colorado 7,454 aircraft registered
- Failure reports filed on the Stemme Gmbh & Co S-10 2 reports since 1995
The whole map of how records connect · these connections as data: /graph/aircraft/N5121.json.
Records check free · 1 to understand · 4 clear
The public federal record on N5121, read the way a buyer, lender or insurer reads it: FAA registration, prior tail numbers keyed on the serial number, reuse of the tail number, recent registry filings, and the NTSB accident record under this and every earlier registration.
Valid registration to Mountain Stemme LLC, an LLC, certificate issued August 26, 2025, expires August 31, 2032. No fractional interest recorded. [1]
No airworthiness certificate is on file. Usual for a newly registered aircraft, a project, or an aircraft that has not flown since a change of registration; ask for the certificate. [1]
No earlier tail number is recorded against serial 11-023 for this model in the deregistered file. [2]
No other airframe has carried N5121 according to the deregistered file. [2]
No bills of sale, loans or releases have reached the registry in recent weeks. The index covers only recent filings; older liens are in the records file. [3]
No NTSB investigation records located under N5121. CLEAR means the query ran and returned nothing, not that nothing ever happened. [4]
These live in the FAA aircraft records file (every document ever filed against the aircraft) and, for larger aircraft, the International Registry. Part of the full report.
AD compliance against the logbooks and flight-activity reconciliation are researched layers of the full report.
- FAA Releasable Aircraft Database, master file, file of October 23, 2026. registry.faa.gov/
- FAA deregistered aircraft file (part of the same download), file of October 23, 2026. registry.faa.gov/
- FAA document index: registry documents received in recent weeks, file of October 23, 2026. registry.faa.gov/
- NTSB aviation accident database (CAROL), records through September 30, 2026. data.ntsb.gov/carol-main-public/basic-search
This automated check reads the public federal record. Nothing here is a legal opinion, an appraisal or a statement about the aircraft's condition; a CLEAR line is a statement about the searched record, not the aircraft.
Source: FAA Civil Aviation Registry, Releasable Aircraft Database, October 23, 2026. See this record on the FAA site · This record as data