# N421MT: 1979 Thunder Balloons AX7-77

- Status: Valid registration
- Airframe: [Thunder Balloons AX7-77](https://openairdocs.org/model/thunder-balloons-ax7-77) (registry code 8970107, 4 seats)
- Engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000)
- Serial number: 180
- Year built: 1979
- Type: Balloon
- Engine type: None
- Airworthiness: Standard, balloon
- Airworthiness date: April 18, 1979
- Certificate issued: March 24, 2020
- Expires: March 31, 2030
- Mode S code: A5007B
- Registered owner: [Wind Surfer Ballooning LLC](https://openairdocs.org/faa-owner/WIND%20SURFER%20BALLOONING%20LLC)
- Location: [Carlisle, IA](https://openairdocs.org/faa-place/IA/Carlisle)
- Owner type: LLC
- Owner's area on the map: 41.4751° N, 93.4673° W: Placed by OpenAirDocs at the center of ZIP code 50047, within about 5 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based
- FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=421MT
- Page: https://openairdocs.org/aircraft/N421MT

From the FAA registry file of October 24, 2026. ADs below are matched by the registry's airframe and engine model codes. They may apply; each AD's applicability can narrow it by serial number, part number or installed equipment. This is not a compliance determination.

## ADs that may apply (OpenAirDocs): 2 in force

### Matched by airframe (Thunder Balloons AX7-77)

- [AD 2013-03-10](https://openairdocs.org/ad/2013-03-10): Hardware · Aeronaut Instruction Research Skysailor 105, Skysailor 90, 110C and 439 more. Effective Mar 19, 2013
- [AD 2008-04-15](https://openairdocs.org/ad/2008-04-15): Self seal valves · Cameron Balloons AX10-160 (S.1), AX10-160(S.2), AX10-180 (S.1) and 24 more. Effective Mar 25, 2008

### Matched by engine (NONE)

None in force.

## Information bulletins (advisory) (1 in force)

- [SAIB CE-11-44](https://openairdocs.org/saib/CE-11-44): Fuel: Cylinder Strap Installation. Issued Jul 13, 2011

## NTSB investigations

None matched to N421MT.

## FAA accident and incident reports

None matched to N421MT.

## Service difficulty reports

None filed for this aircraft. Matched to this aircraft by N-number and event date, checked against the reported serial number, make and model.

## STCs that may be installed (OpenAirDocs)

None matched to this aircraft's models.

## Related

- Other Thunder Balloons AX7-77 aircraft: https://openairdocs.org/model/thunder-balloons-ax7-77/aircraft.md
- The NONE engine: https://openairdocs.org/engine/none.md

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