Aircraft model · Fixed wing single engine · Airplane · registry code 7101821

Manufacturer (registry)
PIPER
Model
PA-18-135 (L-21B)
Registry code
7101821
Registered
1 aircraft
Type
Fixed wing single engine
Engines
1 · Reciprocating
Seats
2
Weight class
Up to 12,499 lb
Certification
Type certificated
Data sheet
TCDS1A2
Holder
Piper Aircraft Inc.

Model codes come from the FAA registry’s reference file. ADs are matched to them by model name and maker.

On this page

Aircraft by year built · 2

1955Registered nowDeregistered2026
Aircraft by the year they were built: 2 aircraft
19551
19561

Airworthiness directives that may apply · 14

ADs whose products match this airframe model. Each AD’s applicability may narrow it by serial number, part number or configuration.

1956In forceSuperseded2026
ADs by the year they took effect: 16 ADs
19561
19601
19621
19681
19721
19781
19851
19961
19991
20011
20051
20061
20141
20151
20221
20251
See all 16 ADs
Query with SQL
duckdb -csv -c "SELECT d.ad_number, d.status, d.subject, d.effective_date
  FROM 'https://openairdocs.org/data/latest/faa_directive.parquet' d
  WHERE d.ad_id IN (SELECT ad_id FROM 'https://openairdocs.org/data/latest/faa_aircraft_model_directive.parquet' WHERE aircraft_model_code IN ('7101821'))
  ORDER BY coalesce(d.effective_date, d.publication_date, d.issue_date) DESC, d.ad_number DESC"

Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.

Information bulletins that may apply · 1

Query with SQL
duckdb -csv -c "SELECT s.saib_number, any_value(s.title) AS title, max(s.issue_date) AS issue_date, any_value(s.status) AS status
  FROM 'https://openairdocs.org/data/latest/faa_saib.parquet' s
  WHERE s.saib_id IN (SELECT saib_id FROM 'https://openairdocs.org/data/latest/faa_aircraft_model_saib.parquet' WHERE aircraft_model_code IN ('7101821'))
  GROUP BY s.saib_number ORDER BY issue_date DESC"

Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.

Registered aircraft · 1

Query with SQL
duckdb -csv -c "SELECT n_number, serial_number, year_manufactured, status, registrant_name, registrant_city, registrant_state
  FROM 'https://openairdocs.org/data/latest/faa_aircraft_registration.parquet'
  WHERE aircraft_model_code IN ('7101821')
  ORDER BY n_number"

Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.

NTSB investigations

No NTSB investigations matched to aircraft with this modelMatched through the registry by N-number, so foreign aircraft and some older cases aren’t counted.

FAA incident reports

No reports matched to aircraft of this modelMatched through the registry by N-number, so foreign aircraft and some older reports aren’t counted.

Service difficulty reports · 9

SDR 2026FA0000405Mount · brokenENGINE MOUNT COMPLETE BROKEN IN TWO PARTS.May 19, 2026 · N9974Q · Piper PA18135 · Engine Mount SectionSDR 2010FA0000503Carburetor · malfunctionedTHE CARBURETOR WAS REBUILT AND YELLOW TAGGED. FLOAT LEVEL WAS SET AT 9/32 INSTEAD OF THE REQUIRED 7/32 CAUSING A LEAN CONDITION THAT BURNED THE TOP END OFF THE MOTOR.May 21, 2010 · N9966Q · Piper PA18135 · Fuel Control/Reciprocating EnginesSDR LA02003F00000Spinner · crackedSPINNER CONTACTS PROPELLER BLADES AT LEADING EDGE AND TRAILING EDGE OF BLADE CUTOUTS IN THE SPINNER. A GROOVE HAS BEEN WORN INTO THE PROPELLER BLADES, WITH THE WORST BEING .080 INCH DEEP AND .9 INCH LONG ON THE LEADING EDGE OF ONE BLADE. SPINNER AND BOTH SPISep 23, 2003 · N1590P · Piper PA18135 · Propeller Spinner SectionSDR 2001FA0000665Rudder Pedal · wornDURING DISASSEMBLY FOR REBUILD ALL 4 RUDDER PEDALS WERE FOUND TO BE DAMAGED DUE TO THE RETURN SPRING (40941-00) CUTTING THROUGH LOWER HINGE SHAFT WALL. ALL 4 HAD BEEN WELD REPAIRED BUT WERE AGAIN WORN THROUGH. ALL REPLACED NEW AND APPEAR TO HAVE SAME WALL THNov 18, 2001 · N9952Q · Piper PA18135 · Rudder Control SystemSDR 2001FA0000664Rudder Pedal · wornDURING DISASSEMBLY FOR REBUILD ALL AND RUDDER PEDALS WERE FOUND TO BE DAMAGED DUE TO THE RETURN SPRING(40494100) CUTTING THROUGH LOWER HINGE SHAFT, WALL. ALL HAD BEEN WELD REPAIRED BUT WERE AGAIN WORN THROUGH, ALL REPLACED NEW AND APPEAR TO HAVE SAME WALL THINov 18, 2001 · N9952Q · Piper PA18135 · Rudder Control SystemSDR 98ZZZX2559Crankshaft · failedAIRCRAFT SUFFERED CATASTROPHIC ENGINE SEIZURE. MADE SUCCESSFUL GOLF COURSE LANDING. ENGINE DISASSEMBLY RECEIVED BROKEN CRANKSHAFT AT THE FORWARD SIDE OF NR 4 ROD JOURNAL.Jun 30, 1998 · N3257B · Piper PA18135 · Reciprocating Engine Power SectionSDR 97ZZZX4958Hose · failedLINING OF INDUCTION HOSES SWELLED INWARD THEN CRACKED AROUND THE INSIDE DIAMETER CIRCUMFERENCE. SOME LINING BROKE OFF AND PASSED THROUGH COMBUSTION CHAMBERS. THE SWELLED LINING THAT REMAINED SWELLED OUT ENOUGH TO OBSTRUCT FLOW CAUSING THE ENGINE TO RUN ROUGHNov 1, 1997 · N1458C · Piper PA18135 · Engine Air Intake SystemSDR 96ZZZX5126Float · failedAN AIRCRAFT EXPERIENCED TOTAL POWER LOSS DURING A PERSONAL FLIGHT. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT LANDED WITHOUT INCIDENT. INVESTIGATION OF THE ENGINE INCIDENT REVEALED THE FAILURE WAS CAUSED BY A FAULTY METAL FLOAT ON CARBURETOR. THE METAL FLOAOct 2, 1996 · Piper PA18135 · Fuel Control/Reciprocating EnginesSDR CA960524026Mount · broken tubing(CAN) CUSTOMER REPORTED THAT COWLING WAS RUBBING ON THE OIL COOLER. INSPECTION REVEALED THAT ENGINE WAS SAGGING TO THE RIGHT DUE TO A BROKEN ENGINE MOUNT.May 1, 1996 · Piper PA18135 · Engine Mount Section
Query with SQL
duckdb -csv -c "SELECT sdr_id, difficulty_date, n_number, aircraft_make, aircraft_model, part_name, part_condition, jasc_code, discrepancy
  FROM 'https://openairdocs.org/data/latest/faa_service_difficulty_report.parquet'
  WHERE aircraft_model_key = 'PA18135'
  ORDER BY difficulty_date DESC"

Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.

STCs that may be installed · 366

Approved for this model: the STC’s model list names it on its data sheet, or a series that includes it. The registry doesn’t record which STCs an aircraft has.

See all 366 STCs
Query with SQL
duckdb -csv -c "SELECT s.stc_number, s.description, s.holder, s.status, s.status_date, m.matched_model
  FROM (
    SELECT stc_number, min(matched_model) AS matched_model
    FROM 'https://openairdocs.org/data/latest/faa_aircraft_model_stc.parquet'
    WHERE aircraft_model_code IN ('7101821')
    GROUP BY stc_number
  ) m JOIN 'https://openairdocs.org/data/latest/faa_stc.parquet' s USING (stc_number)
  ORDER BY s.status = 'Current' DESC, s.status_date DESC, s.stc_number"

Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.

PMA parts · 487

Current parts manufacturer approvals (PMA): parts the FAA has approved companies to make as replacements or modifications. Each record lists its models as free text; OpenAirDocs matched them to this model on its data sheet, so check the FAA record before relying on it. Newest first.

See all 487 PMA parts
Query with SQL
duckdb -csv -c "SELECT drs_guid, part_number, part_name, holder, pma_number, replaces_part, supplement_date, tcds_models
  FROM 'https://openairdocs.org/data/latest/faa_type_certificate_pma.parquet'
  WHERE tcds_number IN ('1A2')
    AND len(list_intersect(tcds_models, ['PA-18-135 (Army L-21B)'])) > 0
  ORDER BY supplement_date DESC, drs_guid DESC"

Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.

The same model under other registry codes

Amateur-built copies and renamed makers get their own codes.

Query with SQL
duckdb -csv -c "SELECT m.code, m.manufacturer, m.model, count(g.n_number) AS aircraft
  FROM 'https://openairdocs.org/data/latest/faa_aircraft_model.parquet' m LEFT JOIN 'https://openairdocs.org/data/latest/faa_aircraft_registration.parquet' g ON g.aircraft_model_code = m.code
  WHERE m.match_key = 'PA18135' AND m.code NOT IN ('7101821')
  GROUP BY ALL
  ORDER BY aircraft DESC
  LIMIT 12"

Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.