diff --git a/src/derive_from_faa_master_txt.py b/src/derive_from_faa_master_txt.py
index e8dcadc..259532c 100644
--- a/src/derive_from_faa_master_txt.py
+++ b/src/derive_from_faa_master_txt.py
@@ -3,14 +3,13 @@ import zipfile
 import pandas as pd
 from faa_aircraft_registry import read
 
-def convert_faa_master_txt_to_csv(zip_path: Path, csv_path: Path, date: str = None):
+def convert_faa_master_txt_to_df(zip_path: Path, date: str):
     with zipfile.ZipFile(zip_path) as z:
         registrations = read(z)
 
     df = pd.DataFrame(registrations['master'].values())
     
-    if date is not None:
-        df.insert(0, "download_date", date)
+    df.insert(0, "download_date", date)
     
     registrant = pd.json_normalize(df["registrant"]).add_prefix("registrant_")
     df = df.drop(columns="registrant").join(registrant)
@@ -45,8 +44,6 @@ def convert_faa_master_txt_to_csv(zip_path: Path, csv_path: Path, date: str = No
     reg_idx = cols.index("registration_number")
     cols.insert(reg_idx + 1, "planequery_airframe_id")
     df = df[cols]
-    
-    df.to_csv(csv_path, index=False)
     return df
 
 
diff --git a/src/get_historical_faa.py b/src/get_historical_faa.py
index 4683ad8..573942c 100644
--- a/src/get_historical_faa.py
+++ b/src/get_historical_faa.py
@@ -11,7 +11,7 @@ import subprocess, re
 from pathlib import Path
 import shutil
 from collections import OrderedDict
-from derive_from_faa_master_txt import convert_faa_master_txt_to_csv, concat_faa_historical_df
+from derive_from_faa_master_txt import convert_faa_master_txt_to_df, concat_faa_historical_df
 import zipfile
 import pandas as pd
 import argparse
@@ -106,7 +106,7 @@ for date, sha in date_to_sha.items():
     print(f"{date} {sha[:7]} -> {day_dir} (master parts: {len(parts)})")
     # 4) Convert ZIP -> CSV
     out_csv = day_dir / f"ReleasableAircraft_{date}.csv"
-    df_new = convert_faa_master_txt_to_csv(zip_path, out_csv, date)
+    df_new = convert_faa_master_txt_to_df(zip_path, out_csv, date)
     if df_base.empty:
         df_base = df_new
         print(len(df_base), "total entries so far")
@@ -119,5 +119,5 @@ for date, sha in date_to_sha.items():
     print(len(df_base), "total entries so far")
 
 assert df_base['download_date'].is_monotonic_increasing, "download_date is not monotonic increasing"
-df_base.to_csv(OUT_ROOT / f"MASTER_{start_date}_{end_date}.csv", index=False)
+df_base.to_csv(OUT_ROOT / f"planequery_aircraft_{start_date}_{end_date}.csv", index=False)
 # TODO: get average number of new rows per day.
diff --git a/src/snapshot_faa.py b/src/snapshot_faa.py
index 0d7712f..e86528f 100644
--- a/src/snapshot_faa.py
+++ b/src/snapshot_faa.py
@@ -1,4 +1,3 @@
-import zipfile
 from pathlib import Path
 from datetime import datetime, timezone
 date_str = datetime.now(timezone.utc).strftime("%Y-%m-%d")
@@ -6,10 +5,8 @@ date_str = datetime.now(timezone.utc).strftime("%Y-%m-%d")
 out_dir = Path("data/faa_releasable")
 out_dir.mkdir(parents=True, exist_ok=True)
 zip_name = f"ReleasableAircraft_{date_str}.zip"
-csv_name = f"Master_{date_str}.csv"
 
 zip_path = out_dir / zip_name
-csv_path = out_dir / csv_name
 
 # URL and paths
 url = "https://registry.faa.gov/database/ReleasableAircraft.zip"
@@ -25,5 +22,12 @@ with urlopen(req, timeout=120) as r:
     body = r.read()
     zip_path.write_bytes(body)
 
-from derive_from_faa_master_txt import convert_faa_master_txt_to_csv
-convert_faa_master_txt_to_csv(zip_path, csv_path)
+OUT_ROOT = Path("data/planequery_aircraft")
+OUT_ROOT.mkdir(parents=True, exist_ok=True)
+from derive_from_faa_master_txt import convert_faa_master_txt_to_df, concat_faa_historical_df
+from get_latest_planequery_aircraft_release import get_latest_aircraft_csv_df
+df_new = convert_faa_master_txt_to_df(zip_path, date_str)
+df_base, start_date_str = get_latest_aircraft_csv_df()
+df_base = concat_faa_historical_df(df_base, df_new)
+assert df_base['download_date'].is_monotonic_increasing, "download_date is not monotonic increasing"
+df_base.to_csv(OUT_ROOT / f"planequery_aircraft_{start_date_str}_{date_str}.csv", index=False)
\ No newline at end of file