NTSB investigations, IA
185 cases where the phase of flight was Takeoff.
Cases per year
| 1964 | 4 |
|---|---|
| 1965 | 8 |
| 1966 | 7 |
| 1967 | 15 |
| 1968 | 4 |
| 1969 | 10 |
| 1970 | 7 |
| 1971 | 4 |
| 1972 | 6 |
| 1974 | 4 |
| 1975 | 3 |
| 1976 | 3 |
| 1977 | 6 |
| 1978 | 4 |
| 1979 | 4 |
| 1980 | 5 |
| 1981 | 5 |
| 1982 | 6 |
| 1983 | 4 |
| 1984 | 3 |
| 1985 | 1 |
| 1986 | 2 |
| 1987 | 3 |
| 1988 | 1 |
| 1990 | 4 |
| 1991 | 4 |
| 1992 | 1 |
| 1993 | 1 |
| 1994 | 4 |
| 1995 | 1 |
| 1997 | 2 |
| 1998 | 2 |
| 1999 | 1 |
| 2000 | 1 |
| 2001 | 1 |
| 2002 | 1 |
| 2003 | 1 |
| 2004 | 2 |
| 2005 | 4 |
| 2007 | 1 |
| 2008 | 3 |
| 2009 | 5 |
| 2010 | 3 |
| 2011 | 2 |
| 2012 | 2 |
| 2013 | 2 |
| 2015 | 2 |
| 2017 | 1 |
| 2018 | 2 |
| 2019 | 1 |
| 2020 | 2 |
| 2021 | 2 |
| 2024 | 2 |
| 2025 | 2 |
| 2026 | 4 |
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 c.\"eventStateOrRegion\" = 'IA' AND c.\"eventCountry\" = 'USA'
AND c.\"mKey\" IN (SELECT case_mkey FROM case_phases WHERE main = 300)
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 c."eventStateOrRegion" = 'IA' AND c."eventCountry" = 'USA'
AND c."mKey" IN (SELECT case_mkey FROM case_phases WHERE main = 300)
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 CEN27LA019Accident · Minor injuriesClass 3 · LimitedInvestigation openPiper PA-28-235 · Cedar Rapids, IANTSB ANC26LA082Accident · Minor injuriesClass 4 · LimitedInvestigation openRobinson Helicopter R44 · Macedonia, IANTSB CEN26LA260Accident · No injuriesClass 4 · LimitedFinal reportRobinson Helicopter R44 · Emerson, IAThe failure of the pilot to verify the loading hose had been disconnected before taking off and the failure of the loader to disconnect the fuel hose from the helicopter.NTSB CEN26LA100Accident · No injuriesClass 3 · LimitedPreliminary reportPiper PA 46-350P · Sioux City, IAOn January 24, 2026, about 0712 central daylight time, a Piper PA-46-350P airplane, N91MK, was substantially damaged when it was involved in an accident near Sioux City, Iowa. The pilot and passenger were uninjured. The airplane was operated as a Title 14…NTSB CEN25LA316Accident · Serious injuriesClass 4 · LimitedFinal reportXag P100 PRO · Depew, IAThe pilot’s failure to maintain clearance from the unmanned aircraft system during takeoff.NTSB CEN25LA303Accident · No injuriesClass 4 · LimitedFinal reportAir Tractor AT-400A · Lamoni, IAThe pilot’s failure to maintain airplane control during an aborted takeoff.NTSB CEN24LA303Accident · No injuriesClass 3 · LimitedFinal reportRobinson Helicopter R44 · Bryant, IAA loss of engine power during takeoff for reasons that could not be determined, resulting in impact with terrain.NTSB CEN24LA154Accident · No injuriesClass 4 · LimitedFinal reportDehavilland Tiger Moth DH 82A · Council Bluffs, IAThe pilot's failure to maintain directional control during the takeoff with a direct gusting crosswind.NTSB CEN21LA257Accident · No injuriesClass 3 · LimitedFinal reportQuad City Challenger · Wallingford, IAImpact with trees and terrain during takeoff for reasons that could not be determined based on the available information.NTSB CEN21LA118Accident · No injuriesClass 4 · LimitedFinal reportBeech 300 · Davenport, IAThe pilot’s failure to maintain directional control of the airplane, and the flight instructor’s inadequate oversight during a simulated engine out takeoff that resulted in a runway excursion and impact with a snowbank.NTSB CEN20CA253Accident · Minor injuriesClass 4 · Data collectionFinal reportBeech 23 · Davenport, IAThe pilot's failure to properly configure the airplane for takeoff, which resulted in the exceedance of the airplane's critical angle of attack, an aerodynamic stall, and subsequent impact with terrain.NTSB CEN20CA155Accident · No injuriesData collectionFinal reportVans RV 3 · Independence, IAThe pilot's failure to maintain directional control during a high-speed taxi with a quartering tailwind, which resulted in a runway excursion and impact with a fence and terrain.NTSB GAA19CA428Accident · Minor injuriesData collectionFinal reportRobinson R44 · Council Bluff, IAThe pilot's improper cyclic input during liftoff from a landing deck, which resulted in the right skid hooking onto an opening on the landing deck and a subsequent dynamic rollover.NTSB CEN18LA288Accident · No injuriesLimited investigationFinal reportAir Tractor AT 301 · Milford, IAThe pilot's loss of airplane control during takeoff for reasons that could not be determined because no anomalies consistent with a flight control system malfunction were observed.NTSB CEN18LA137Accident · Serious injuriesClass 3 · LimitedFinal reportQuicksilver GT 400 · Maxwell, IAThe noncertificated pilot's unfamiliarity with the airplane, which resulted in a loss of airplane control when the pilot encounter a wind gust.NTSB GAA17CA433Accident · No injuriesData collectionFinal reportStinson SR9 · Bode, IAThe pilot’s decision to take off from an unimproved bean field with insufficient length for the airplane to clear adjacent corn stalks.NTSB GAA15CA193Accident · Minor injuriesData collectionFinal reportLuscombe 8A · Oxford, IAThe pilot's selection of unsuitable terrain for takeoff based on the runway and density altitude conditions, which resulted in a runway excursion and impact with terrain.NTSB GAA15CA125Accident · No injuriesData collectionFinal reportCessna 180B · Waterloo, IAThe incorrect installation of the secondary seat stop reel which resulted in the pilot's loss of control when the seat moved full aft during takeoff.NTSB CEN13CA529Accident · No injuriesData collectionFinal reportCessna 172R · Council Bluff, IAThe student pilot's loss of directional control during takeoff.NTSB CEN13LA463Accident · No injuriesLimited investigationFinal reportBell 47G-3B-1 · Vinton, IAThe pilot's operation of the helicopter at high gross weight and high density altitude while still in ground effect, which reduced the efficiency of the rotor system and the amount of lift produced, which resulted in a collision with terrain. Contributing to…NTSB CEN12LA408Accident · Serious injuriesLimited investigationFinal reportCessna 172M · Griswold, IAThe pilot’s failure to maintain adequate airspeed during an attempted go-around, resulting in an aerodynamic stall.NTSB CEN12LA247Accident · No injuriesLimited investigationFinal reportHughes 269A · Grinnell, IAThe pilot's improper liftoff technique, which resulted in ground resonance, and the pilot's delayed recognition of the ground resonance.NTSB CEN11LA366Accident · No injuriesLimited investigationFinal reportCessna 150F · Sully, IAThe pilot's failure to attain an adequate climb rate during the initial takeoff, resulting in the airplane settling back down and departing the runway. Contributing to the accident was the pilot's inadequate preflight planning and preparation.NTSB CEN11CA282Accident · No injuriesData collectionFinal reportDelf Tim Zenith CH-701 · Davenport, IAThe improper installation of the rudder cable to rudder pedal attachment hardware.NTSB CEN11LA048Accident · No injuriesLimited investigationFinal reportPiper PA-32R-301T · Waterloo, IAThe separation of a stabilator control cable turnbuckle due to stress corrosion cracking, which resulted in a loss of airplane control during takeoff.NTSB CEN10CA434Accident · No injuriesData collectionFinal reportAir Tractor 502B · Whittemore, IAThe pilot's failure to abort the takeoff, which resulted in an aerodynamic stall.NTSB CEN10CA323Accident · Serious injuriesData collectionFinal reportMcculley Ronald W-8 · Lamoni, IAThe non-certificated pilot's decision to attempt a takeoff that exceeded the airplane's performance capability, which resulted in an overrun.NTSB CEN10CA077Accident · No injuriesData collectionFinal reportCessna 172P · Ames, IAThe pilot's failure to maintain directional control while attempting a takeoff on an ice-covered runway.NTSB CEN09CA599Accident · Minor injuriesData collectionFinal reportPiper PA-28-180 · Sibley, IAThe pilot's long and fast landing and her delayed decision to execute a go-around.NTSB CEN09LA534Accident · No injuriesLimited investigationFinal reportWSK PZL Mielec M-18A · Audubon, IAA loss of engine power due to failure of the compressor turbine resulting from exposure to elevated operating temperatures for undetermined reasons.NTSB CEN09CA533Accident · No injuriesData collectionFinal reportAir Tractor AT-502B · Whittemore, IAThe pilot's lack of preflight planning and remedial action with resulted in the airplane's inability to climb out of ground effect.NTSB CEN09CA516Accident · No injuriesData collectionFinal reportGrumman Acft ENG Cor-Schweizer G-164A · Harlan, IAThe pilot's failure to perform accurate weight and balance calculations which resulted in exceeding the maximum takeoff weight and the airplane's climb capability.NTSB CHI08CA260Accident · No injuriesData collectionFinal reportCessna A188B · Camanche, IAThe pilot took off on an unsuitable airstrip which resulted in the airplane becoming prematurely airborne with inadequate airspeed after it contacted a rise in the terrain.NTSB CHI08CA204Accident · Serious injuriesData collectionFinal reportIndy T-Bird II · Independence, IAThe takeoff airspeed not attained and the aborted takeoff not performed by the pilot. An additional cause was the lack of familiarity with the airplane by the pilot.NTSB CHI08CA074Accident · No injuriesData collectionFinal reportSwearingen SA-226AT · Ankeny, IAThe pilot's failure to maintain directional control during the takeoff roll. Contributing to the accident was the snow on the runway and the snowbank.NTSB CHI07CA220Accident · Minor injuriesData collectionFinal reportSchweizer G-164B · West Liberty, IAThe pilot's inadvertent encounter with birds immediately after takeoff and the resulting loss of engine power. Contributing factors were the fence and ditch encountered during the overrun.NTSB CHI06CA046Accident · Minor injuriesData collectionFinal reportCessna 150M · Algona, IAThe pilot's inadvertent flight into unexpected instrument conditions and his visual look out not possible during takeoff leading to the nose over during the emergency landing after takeoff. Factors were the unexpected fog and the dark night conditions.NTSB CHI05LA214Accident · Minor injuriesLimited investigationFinal reportGrumman G-164 · Marshalltown, IAThe loss of engine power for an undetermined reason. A factor was the corn crop.NTSB CHI05LA213Accident · Serious injuriesLimited investigationFinal reportWeatherly 620-B · Osage, IAThe partial loss of engine power for an undetermined reason. Contributing factors were the wires and the trees.NTSB CHI05FA080Accident · 3 fatalField investigationFinal reportPiper PA-28-235 · West Union, IAThe pilot's failure to abort the takeoff, his failure to maintain adequate airspeed during the takeoff, and the pull-up to avoid obstacles which resulted in an inadvertent stall. Factors associated with the accident were the pilot's failure to maintain…NTSB CHI05LA047Accident · No injuriesLimited investigationFinal reportLearjet 25B · Cedar Rapids, IAThe pilot was not able to maintain directional control of the airplane due to the failure of the nose gear strut seal which prevented the nose wheel from centering. A factor associated with the accident was the berm that the airplane contacted.NTSB CHI04FA234Accident · 2 fatalField investigationFinal reportCessna 172E · Decorah, IAThe pilot's intentional operation of the airplane with a defective magneto, his failure to abort the takeoff due to degraded aircraft performance, and his failure to obtain or maintain airspeed which resulted in a stall/spin and subsequent impact with the…NTSB CHI03LA203Accident · Serious injuriesLimited investigationFinal reportAerotrike DPS · Brandon, IAThe non-certificated pilot selected unsuitable terrain for takeoff when he departed from a bean field, and the airplane stalled as a result of low airspeed during takeoff climb. Factors to the accident included the pilot's total lack of experience, the…NTSB CHI02LA076Accident · No injuriesLimited investigationFinal reportCessna 172N · Ottumwa, IAthe student pilot failed to maintain directional control during takeoff. A contributing factor was the snowbank.NTSB CHI01LA142Accident · Minor injuriesLimited investigationFinal reportBaldwin RV-6 · Muscatine, IAThe engine failure for undetermined reasons. Factors were the low altitude, the trees, the presence of the irrigation system, the ditch and the soft ground.NTSB CHI00LA122Accident · No injuriesLimited investigationFinal reportCunningham Pietenpol Aircamper · Boone, IAthe pilot not maintaining directional control. Factors were the gusts and the fence.NTSB CHI99LA179Accident · Minor injuriesLimited investigationFinal reportPiper PA-28-140 · Traer, IAThe pilot's not maintaining proper runway alignment during the aborted takeoff, and the airport personnel not maintaining the runway. Factors were rough terrain and a dirt bank.NTSB CHI98LA362Accident · Minor injuriesLimited investigationFinal reportPiper PA-28-140 · Iowa City, IAA loss of engine power for undetermined reasons.NTSB CHI98LA203Accident · No injuriesLimited investigationFinal reportPiper PA28-151 · Jefferson, IAthe pilot's lack of total experience in this type of aircraft and his failure to maintain directional control during an aborted takeoff. A factor was the ditch.NTSB CHI97LA288Accident · No injuriesLimited investigationFinal reportBeech 35-C33A · Amana, IAthe pilot's improper planning/decision. The fence (location) was a related factor.