NTSB investigations, 1990
334 cases where the phase of flight was Approach.
Cases per year
| 1962 | 14 |
|---|---|
| 1963 | 10 |
| 1964 | 530 |
| 1965 | 502 |
| 1966 | 600 |
| 1967 | 640 |
| 1968 | 597 |
| 1969 | 572 |
| 1970 | 583 |
| 1971 | 550 |
| 1972 | 522 |
| 1973 | 543 |
| 1974 | 541 |
| 1975 | 530 |
| 1976 | 504 |
| 1977 | 586 |
| 1978 | 567 |
| 1979 | 541 |
| 1980 | 508 |
| 1981 | 473 |
| 1982 | 433 |
| 1983 | 445 |
| 1984 | 433 |
| 1985 | 408 |
| 1986 | 382 |
| 1987 | 327 |
| 1988 | 342 |
| 1989 | 324 |
| 1990 | 334 |
| 1991 | 308 |
| 1992 | 291 |
| 1993 | 276 |
| 1994 | 251 |
| 1995 | 301 |
| 1996 | 272 |
| 1997 | 261 |
| 1998 | 238 |
| 1999 | 244 |
| 2000 | 256 |
| 2001 | 230 |
| 2002 | 232 |
| 2003 | 236 |
| 2004 | 216 |
| 2005 | 229 |
| 2006 | 225 |
| 2007 | 258 |
| 2008 | 211 |
| 2009 | 190 |
| 2010 | 176 |
| 2011 | 194 |
| 2012 | 181 |
| 2013 | 189 |
| 2014 | 178 |
| 2015 | 158 |
| 2016 | 160 |
| 2017 | 191 |
| 2018 | 172 |
| 2019 | 163 |
| 2020 | 156 |
| 2021 | 178 |
| 2022 | 204 |
| 2023 | 186 |
| 2024 | 163 |
| 2025 | 186 |
| 2026 | 88 |
Where
Latest cases
Query with SQL
duckdb -csv -c "WITH phase_names(main, name) AS (VALUES (100, 'Prior to flight'), (150, 'Standing'), (200, 'Pushback/towing'), (250, 'Taxi'), (300, 'Takeoff'), (350, 'Initial climb'), (400, 'Enroute'), (450, 'Maneuvering'), (500, 'Approach'), (550, 'Landing'), (600, 'Emergency descent'), (650, 'Uncontrolled descent'), (700, 'Post-impact'), (750, 'After landing'), (800, 'Other'), (990, 'Unknown')),
crosswalk(code, main, name) AS (VALUES (500, 150, 'Standing'), (501, 150, 'Standing - pre-flight'), (502, 150, 'Standing - starting engine(s)'), (503, 150, 'Standing - engine(s) operating'), (504, 150, 'Standing - engine(s) not operating'), (505, 150, 'Standing - idling rotors'), (510, 250, 'Taxi'), (511, 200, 'Taxi - pushback/tow'), (512, 250, 'Taxi - to takeoff'), (513, 250, 'Taxi - from landing'), (514, 250, 'Taxi - aerial'), (520, 300, 'Takeoff'), (521, 300, 'Takeoff - roll/run'), (522, 350, 'Takeoff - initial climb'), (523, 300, 'Takeoff - aborted'), (530, 400, 'Climb'), (531, 400, 'Climb - to cruise'), (540, 400, 'Cruise'), (541, 400, 'Cruise - normal'), (542, 400, 'Maneuvering - holding (IFR)'), (550, 400, 'Descent'), (551, 400, 'Descent - normal'), (552, 600, 'Descent - emergency'), (553, 650, 'Descent - uncontrolled'), (560, 500, 'Approach'), (561, 500, 'Approach - VFR pattern - downwind'), (562, 500, 'Approach - VFR pattern - base turn'), (563, 500, 'Approach - VFR pattern - base leg/base to final'), (564, 500, 'Approach - VFR pattern - final approach'), (565, 500, 'Go-around (VFR)'), (566, 500, 'Approach - IAF to FAF/outer marker (IFR)'), (567, 500, 'Approach - FAF/outer marker to threshold (IFR)'), (568, 500, 'Circling (IFR)'), (569, 500, 'Missed approach (IFR)'), (570, 550, 'Landing'), (571, 550, 'Landing - flare/touchdown'), (572, 550, 'Landing - roll'), (573, 550, 'Landing - aborted'), (574, 550, 'Emergency landing'), (575, 550, 'Emergency landing after takeoff'), (576, 600, 'Emergency descent/landing'), (580, 450, 'Maneuvering'), (581, 450, 'Maneuvering - aerial application'), (582, 450, 'Maneuvering - turn to reverse direction'), (583, 450, 'Maneuvering - turn to landing area (emergency)'), (590, 450, 'Hover'), (591, 450, 'Hover - in ground effect'), (592, 450, 'Hover - out of ground effect'), (600, 800, 'Other'), (610, 990, 'Unknown')),
current_codes AS (
SELECT e.case_mkey, TRY_CAST(e.\"tier1Number\" AS INTEGER) AS code,
row_number() OVER (PARTITION BY e.case_mkey ORDER BY coalesce(e.\"isDefiningEvent\", false) DESC, e.position) AS n
FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' e
WHERE e.aircrafts_position = 1 AND e.\"tier1Number\" GLOB '[1-9][0-9]*'
AND (e.\"isDefiningEvent\" OR e.case_mkey IN (SELECT \"mKey\" FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' WHERE \"isPre1982\"))
),
phases AS (
SELECT case_mkey, 'current' AS scheme, code, CASE WHEN code >= 990 THEN 990 ELSE code // 50 * 50 END AS main
FROM current_codes WHERE n = 1
UNION ALL
SELECT o.case_mkey, 'older', o.\"phaseOfFlightCode\", w.main
FROM 'https://openairdocs.org/data/latest/ntsb_occurrences.parquet' o JOIN crosswalk w ON w.code = o.\"phaseOfFlightCode\"
WHERE o.aircrafts_position = 1 AND o.\"occurrenceNumber\" = 1 AND o.case_mkey NOT IN (SELECT case_mkey FROM current_codes)
),
case_phases AS (
SELECT p.*, c.\"eventDate\", c.\"highestInjuryLevel\" = 'Fatal' AS fatal, a.aircraft_model_code
FROM phases p JOIN 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c ON c.\"mKey\" = p.case_mkey
LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = p.case_mkey AND a.position = 1
WHERE c.\"eventDate\" >= DATE '1962-01-01' AND p.main IN (SELECT main FROM phase_names)
)
SELECT c.\"ntsbNumber\", c.\"eventDate\", c.\"eventType\", c.\"eventCity\", c.\"eventStateOrRegion\", a.n_number, a.\"aircraftMake\", a.\"aircraftModel\", c.\"highestInjuryLevel\", c.\"totalFatal\", c.\"completionStatus\", c.report_url
FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = c.\"mKey\" AND a.position = 1
WHERE year(c.\"eventDate\") = 1990
AND c.\"mKey\" IN (SELECT case_mkey FROM case_phases WHERE main = 500)
ORDER BY c.\"eventDate\" DESC, c.\"ntsbNumber\" 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.
WITH phase_names(main, name) AS (VALUES (100, 'Prior to flight'), (150, 'Standing'), (200, 'Pushback/towing'), (250, 'Taxi'), (300, 'Takeoff'), (350, 'Initial climb'), (400, 'Enroute'), (450, 'Maneuvering'), (500, 'Approach'), (550, 'Landing'), (600, 'Emergency descent'), (650, 'Uncontrolled descent'), (700, 'Post-impact'), (750, 'After landing'), (800, 'Other'), (990, 'Unknown')),
crosswalk(code, main, name) AS (VALUES (500, 150, 'Standing'), (501, 150, 'Standing - pre-flight'), (502, 150, 'Standing - starting engine(s)'), (503, 150, 'Standing - engine(s) operating'), (504, 150, 'Standing - engine(s) not operating'), (505, 150, 'Standing - idling rotors'), (510, 250, 'Taxi'), (511, 200, 'Taxi - pushback/tow'), (512, 250, 'Taxi - to takeoff'), (513, 250, 'Taxi - from landing'), (514, 250, 'Taxi - aerial'), (520, 300, 'Takeoff'), (521, 300, 'Takeoff - roll/run'), (522, 350, 'Takeoff - initial climb'), (523, 300, 'Takeoff - aborted'), (530, 400, 'Climb'), (531, 400, 'Climb - to cruise'), (540, 400, 'Cruise'), (541, 400, 'Cruise - normal'), (542, 400, 'Maneuvering - holding (IFR)'), (550, 400, 'Descent'), (551, 400, 'Descent - normal'), (552, 600, 'Descent - emergency'), (553, 650, 'Descent - uncontrolled'), (560, 500, 'Approach'), (561, 500, 'Approach - VFR pattern - downwind'), (562, 500, 'Approach - VFR pattern - base turn'), (563, 500, 'Approach - VFR pattern - base leg/base to final'), (564, 500, 'Approach - VFR pattern - final approach'), (565, 500, 'Go-around (VFR)'), (566, 500, 'Approach - IAF to FAF/outer marker (IFR)'), (567, 500, 'Approach - FAF/outer marker to threshold (IFR)'), (568, 500, 'Circling (IFR)'), (569, 500, 'Missed approach (IFR)'), (570, 550, 'Landing'), (571, 550, 'Landing - flare/touchdown'), (572, 550, 'Landing - roll'), (573, 550, 'Landing - aborted'), (574, 550, 'Emergency landing'), (575, 550, 'Emergency landing after takeoff'), (576, 600, 'Emergency descent/landing'), (580, 450, 'Maneuvering'), (581, 450, 'Maneuvering - aerial application'), (582, 450, 'Maneuvering - turn to reverse direction'), (583, 450, 'Maneuvering - turn to landing area (emergency)'), (590, 450, 'Hover'), (591, 450, 'Hover - in ground effect'), (592, 450, 'Hover - out of ground effect'), (600, 800, 'Other'), (610, 990, 'Unknown')),
current_codes AS (
SELECT e.case_mkey, TRY_CAST(e."tier1Number" AS INTEGER) AS code,
row_number() OVER (PARTITION BY e.case_mkey ORDER BY coalesce(e."isDefiningEvent", false) DESC, e.position) AS n
FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' e
WHERE e.aircrafts_position = 1 AND e."tier1Number" GLOB '[1-9][0-9]*'
AND (e."isDefiningEvent" OR e.case_mkey IN (SELECT "mKey" FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' WHERE "isPre1982"))
),
phases AS (
SELECT case_mkey, 'current' AS scheme, code, CASE WHEN code >= 990 THEN 990 ELSE code // 50 * 50 END AS main
FROM current_codes WHERE n = 1
UNION ALL
SELECT o.case_mkey, 'older', o."phaseOfFlightCode", w.main
FROM 'https://openairdocs.org/data/latest/ntsb_occurrences.parquet' o JOIN crosswalk w ON w.code = o."phaseOfFlightCode"
WHERE o.aircrafts_position = 1 AND o."occurrenceNumber" = 1 AND o.case_mkey NOT IN (SELECT case_mkey FROM current_codes)
),
case_phases AS (
SELECT p.*, c."eventDate", c."highestInjuryLevel" = 'Fatal' AS fatal, a.aircraft_model_code
FROM phases p JOIN 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c ON c."mKey" = p.case_mkey
LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = p.case_mkey AND a.position = 1
WHERE c."eventDate" >= DATE '1962-01-01' AND p.main IN (SELECT main FROM phase_names)
)
SELECT c."ntsbNumber", c."eventDate", c."eventType", c."eventCity", c."eventStateOrRegion", a.n_number, a."aircraftMake", a."aircraftModel", c."highestInjuryLevel", c."totalFatal", c."completionStatus", c.report_url
FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = c."mKey" AND a.position = 1
WHERE year(c."eventDate") = 1990
AND c."mKey" IN (SELECT case_mkey FROM case_phases WHERE main = 500)
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESCRun it at the DuckDB prompt, or in any tool that reads Parquet over HTTPS. More ways to query the release are on Use the data.
NTSB BFO91LA022Accident · No injuriesLimited investigationFinal reportPiper PA-32R · Mitchellville, MDPilot failure to maintain altitude clearance above an obstacle after the aircraft encountered a downdraft.NTSB ATL91FA035Accident · 1 fatalField investigationFinal reportBeech B95 · Austell, GAThe loss of engine power which resulted from the pilot's failure to properly use the carburetor heat. The pilot failed to maintain flying speed during the emergency descent which resulted in a stall on final approach. A factor in the accident was weather…NTSB MIA91FA057Accident · 1 fatalField investigationFinal reportMooney M20C · Pensacola, FLThe pilot's failure to use carburetor heat resulting in loss of engine power due to carburetor ice. A factor in the accident was the pilot's medical condition.NTSB LAX91LA060Accident · Minor injuriesLimited investigationFinal reportCessna 172N · Yucca Valley, CAThe pilot's improper use of the flaps. Contributing to this accident was the loss of control during tailwind landing, and his tailwind and the pilot's inadequate inflight planning.NTSB CHI91LA051Accident · No injuriesLimited investigationFinal reportCessna 152 · Plymouth, MIThe pilot-in-command (CFI)'s inadequate supervision of the dual student.NTSB ANC91FA017Accident · 1 fatalField investigationFinal reportPiper PA-31-350 · Evanston, WYThe pilot's premature descent. Contributing to the accident was the pilot's fatigue and poor weather.NTSB NYC91LA050Accident · No injuriesLimited investigationFinal reportCessna 210 · Warwick, NYA power failure for undetermined reasons, resulting in a forced landing in unsuitable terrain.NTSB NYC91LA048Accident · Minor injuriesLimited investigationFinal reportCessna 150L · Nw Philadelphia, OHThe failure of the pilot to maintain airspeed during an attempted go-around which resulted in an inadvertent stall. Factors related to the accident were: improper use of the mixture control and carburetor heat.NTSB NYC91LA047Accident · No injuriesLimited investigationFinal reportPiper PA-28-161 · Easton, PAThe flight instructor allowed the airplane to get too low on final approach during the demonstration of a power off landing.NTSB CHI91DEM02Accident · 1 fatalFinal reportTaylorcraft BC12-D1 · North Muskegon, MIThe pilot-in-command's not maintaining sufficient airspeed and entering into an inadvertent stall. Factors related to this accident were fuel starvation and the pilot-in-command's not selecting a proper fuel tank selector position.NTSB ANC91LA015Accident · No injuriesLimited investigationFinal reportPiper PA-32 · Kongikank, AKThe pilot in command's failure to maintain airspeed during approach resulting in an inadverrtent stall annd uncontrolled descent into the ground.NTSB CHI91LA042Accident · No injuriesLimited investigationFinal reportCessna 150 · Portage, WIDelayed go-around and stall encountered. Contributing factors were a snow bank, proper alignment not attained, and raising the flaps not performed by the PIC.NTSB ATL91FA026Accident · Serious injuriesField investigationFinal reportBeech D-55 · Greer, SCFuel starvation. A contributing factor was the pilot's failure to follow normal fuel system operational procedures which resulted in the total loss of engine power.NTSB BFO91LA016Accident · 1 fatalLimited investigationFinal reportCessna 172P · Axton, VAThe pilot's failure to maintain adequate clearance with an obstacle. Contributing was an unmarked powerline and the pilot's lack of familiarity with the geographical area.NTSB SEA91LA032Accident · No injuriesLimited investigationFinal reportPiper PA-46-310P · Seattle, WAThe pilot's failure to maintain airspeed while on an instrument approach under instrument meteorlogical conditions, resulting in the aircraft stalling and enter a spin.NTSB MIA91LA036Accident · No injuriesLimited investigationFinal reportCessna 550 · Sebring, FLThe pilot's delayed go-around after encountering a fog bank on short final. The fog and the dark night were factors.NTSB CHI91FA035Accident · 1 fatalField investigationFinal reportPiper PA-31T2 · Des Moines, IAThe pilot's improper emergency procedures by not feathering the left engine after it lost power and/or was shut down, and his failure to keep the aircraft at or above the minimum control airspeed (VMC), which resulted in a loss of aircraft control. A factor…NTSB FTW91LA019Accident · Minor injuriesLimited investigationFinal reportCessna 172 · Granbury, TXTotal loss of engine power due to fuel exhaustion. Factors were the pilot's improper fuel consumption calculations, and the darkness of the night.NTSB CHI91FA033Accident · 2 fatalField investigationFinal reportCessna 150K · Valley Center, KSContinued VFR flight by the pilot into instrument meteorological conditions (IMC), and his failure to maintain control of the aircraft after becoming spatially disoriented. Factors related to the accident were: darkness, adverse weather conditions, and the…NTSB CHI91LA030Accident · No injuriesLimited investigationFinal reportCessna 177 · Mount Ayr, IAProper touch-down point not attained and go-around delayed by the PIC. Contributing factors were a downwind, crosswind, weather evaluation misjudged, wrong runway selected and lack of total experience by the PIC.NTSB NYC91FA035Accident · 1 fatalField investigationFinal reportCessna 414A · Atlantic City, NJFailure of the pilot to follow the published ILS procedure and his continued descent below the decision height. Darkness and the adverse weather conditions were related factors.NTSB NYC91FA034Accident · 2 fatalField investigationFinal reportCessna 172M · Perham, METhe pilot initiating flight into known icing conditions which resulted in an accumulation of airframe ice and a failure to maintain airspeed. The contributing factor was the existing icing conditions.NTSB SEA91LA024Accident · Minor injuriesLimited investigationFinal reportCessna 182L · Kamiah, IDThe pilot's inadequate compensation for the wind conditions.NTSB SEA91FA021Accident · 3 fatalField investigationFinal reportBeech 95-55 · Hayden Lake, IDThe pilot's improper IFR procedure in failing to intercept the proper glideslope path.NTSB LAX91LA041Accident · Serious injuriesLimited investigationFinal reportCessna 180 · Young, AZThe pilot selected the wrong runway and attempted to land with a tailwind.NTSB LAX91FA036Accident · 2 fatalField investigationFinal reportBeech 95-A55 · Woodland, CAThe pilot's misjudgement of his altitude to assure terrain clearance during a night visual approach. Contributing factors were the dark night, unlit terrain, the pilot's lack of recent night time, the pilot's lack of familiarity with the airport, and an…NTSB CHI91FA031Accident · 4 fatalField investigationFinal reportPiper PA-32-RT300 · Gaylord, MIThe pilot's failure to maintain adequate terrain clearance. Factors which contributed to the accident were: the dark night, adverse weather conditions, and the pilot's overconfidence in continuing VFR flight into these conditions.NTSB DEN91FA020Accident · Serious injuriesField investigationFinal reportCessna T210L · Clovis, NMAn inadvertent descent into the ground while conducting a non-precision instrument approach, as a result of the pilot failing to stop his descent at mda. A factor is low visibility due to fog.NTSB NYC91LA030Accident · No injuriesLimited investigationFinal reportCessna 150H · Freeport, PAThe pilot's miscalculations of the amount of fuel on the airplane required for the flight. A factor was the unsuitable terrain.NTSB SEA91LA015Accident · Minor injuriesLimited investigationFinal reportGrumman American AA-1C · Port Townsend, WAThe pilot's failure to use carburetor heat which resulted in a loss of engine power and a forced landing.NTSB LAX91LA029Accident · No injuriesLimited investigationFinal reportCessna 150F · San Diego, CAThe failure of the student pilot to maintain an adequate airspeed while maneuvering in the traffic pattern; maintain control of the aircraft and the inadvertent stall mush. A factor in the accident was the pilot's limited total expereince.NTSB MIA91GA025Accident · 3 fatalFinal reportBeech A-90 · Crestview, FLThe pilot-in-command/cfi improper supervision of the dual student. This resulted in an in flight loss of control, and collision with terrain for failure to maintain minimum control airspeed (VMC) while conducting a simulated emergency procedure.NTSB CHI91LA028Accident · No injuriesLimited investigationFinal reportPiper PA-24-250 · Oswego, KSFuel starvation due to improper placement of the fuel tank selector by the pilot.NTSB DEN91DQA01Accident · 1 fatalFinal reportYoung 2/3 Scale · Alamogordo, NMPartial loss of engine power for an undetermined reason, improper planning/decision by the pilot, and the pilot's failure to maintain adequate airspeed, which resulted in an inadvertent stall.NTSB FTW91FA012Accident · 5 fatalField investigationFinal reportPiper 601P · Nacogdoches, TXFailure of the pilot to follow IFR procedures and maintain the proper altitude. Factors related to the accident were: the adverse weather conditions, dark night, low fuel state of the aircraft, and trees at the accident site.NTSB CHI91DEP01Accident · No injuriesFinal reportDean Bartel Avid Flyer Stol · New London, WIThe pilot's failure to obtain a proper touchdown point and his delay in initiating a go-around.NTSB CHI91LA023Accident · No injuriesLimited investigationFinal reportCessna 172 · Fort Scott, KSThe mixture control was set incorrectly resulting in fuel starvation, and the check list was not followed by the cfi/pic.NTSB FTW91LA011Accident · Minor injuriesLimited investigationFinal reportCessna 172 · Abilene, TXPilot's failure to compensate for gusty wind condition.NTSB LAX91LA021Accident · No injuriesLimited investigationFinal reportCessna 152 · Maricopa, AZThe failure of the flight instructor to ensure that an adequate airspeed was maintained during the final approach for the existing wind conditions; to adequately supervise the conduct of the flight; and to arrest the rate of descent prior to touch down.NTSB SEA91LA009Accident · No injuriesLimited investigationFinal reportCessna T210N · Laramie, WYThe pilot did not properly set the mixture control.NTSB NYC91LA019Accident · Minor injuriesLimited investigationFinal reportPiper PA-28-180 · Columbia, PAThe failure of the pilot to maintain a proper altitude on final approach and compensate for the headwind. A factor to the accident was the failure of the pilot to recognize his low altitude and execute a go-around.NTSB MIA91LA016Accident · Minor injuriesLimited investigationFinal reportPiper PA-28-181 · Orlando, FLInadequate planning by the pilot.NTSB BFO91LA006Accident · No injuriesLimited investigationFinal reportCessna 150L · Lexington, KYThe pilot's inadequate inflight decision causing fuel exhaustion.NTSB LAX91FA012Accident · 1 fatalField investigationFinal reportCessna 172M · Goleta, CAThe pilot's failure to maintain proper glidepath while on final approach. A contributing factor was sunglare.NTSB ATL91FA006Accident · 1 fatalField investigationFinal reportOlsen-Gordon Veri EZE · Hohenwald, TNThe failure of the left rudder control cable which rendered the airplane uncontrollable.NTSB NYC91LA015Accident · No injuriesLimited investigationFinal reportCessna 152 · Kent, OHFailure of both pilots to maintain visual separation in the landing traffic pattern. Factors to this mid-air collision were the excessive number of airplanes in the airport traffic pattern and radio frequency congestion.NTSB FTW91LA006Accident · No injuriesLimited investigationFinal reportBeech 77 · Arkadelphia, ARFuel starvation to the engine due to a blocked fuel system vent. Factors contributing to the accident were the pilot's inadequate preflight, and contacting high vegetation and low trees during the landing roll.NTSB SEA91LA004Accident · No injuriesLimited investigationFinal reportPiper PA28-140 · Hamilton, MTThe pilot's inadequate compensation for wind conditions.NTSB LAX91FA005Accident · 2 fatalField investigationFinal reportPiper PA-28-235 · Redlands, CAA total loss of engine power due to fuel starvation as a result of a fuel system leak of an undetermined origin.NTSB DEN91LA006Accident · No injuriesLimited investigationFinal reportCessna T210M · Englewood, COEngine failiure resulting from maintenance discrepancies.