# JASC 3417: Air Data Computer

- Type: JASC system/component code (FAA)
- ATA chapter: 34 Navigation
- Title in the code table: AIR DATA COMPUTER
- Service difficulty reports: 1,210
- FAA code table: https://www.faa.gov/sites/faa.gov/files/JASC_Code.pdf#page=37
- Page: https://openairdocs.org/jasc/3417

## What it covers

The computer and its integral parts which receives data from various environmental sensing systems, computes this data, and makes it available to the various navigation systems. Does not include external hardware such as cables, mounting racks, remote switches, etc., which are filed in JASC code 3410.

## Service difficulty reports (1,210, newest 50)

- [SDR IPXA2026101554657](https://openairdocs.org/sdr/IPXA2026101554657), Oct 14, 2026: Boeing 75724APF. ADC. MALFUNCTIONED. ATB DUE TO CAPTAINS PFD BEING UNRELIABLE ALSO RECEIVED MACH TRIM AT RUDDER RATIO EICAS MESSAGE. FUEL 36.1 AFTER ATB. PER (N431UP)
- [SDR DXTA2026092209794](https://openairdocs.org/sdr/DXTA2026092209794), Sep 19, 2026: Cndair CL6002B16. ADC. DEFECTIVE. TWICE DURING FLIGHT (ONCE ON CLIMB OUT AND ONCE ON DESCENT), LEFT PILOT LOST ALL AIRSPEED, ALTITUDE AND VERTICAL SPEED I (N268QS)
- [SDR QR9R2026091600002](https://openairdocs.org/sdr/QR9R2026091600002), Sep 16, 2026: Bolkms BK117C2. AIR DATA MODULE. INACCURATE. RIGHT AIRSPEED INDICATOR INDICATED 30+ KNOTS CONSISTENTLY, ALL OTHER AIRSPEED INDICATORS INDICATED 0. MAINTENANCE ATTEMP
- [SDR AALA202609145096](https://openairdocs.org/sdr/AALA202609145096), Sep 10, 2026: Boeing 7378. AIR DATA MODULE. FAULTY. AIRCRAFT WAS GROUNDED: DURING TAKEOFF ROLL AFTER 80 KTS WE HAD AN AIRSPEED UNRELIABLE. CAPTAIN AND STBY ISFD SPEED WERE  (N341SV)
- [SDR AALA202609148861](https://openairdocs.org/sdr/AALA202609148861), Sep 10, 2026: Boeing 7378. AIR DATA MODULE. FAULTED. AIRCRAFT WAS GROUNDED: DURING TAKEOFF ROLL AFTER 80 KTS WE HAD AN AIRSPEED UNRELIABLE. CAPTAIN AND STBY ISFD SPEED WERE  (N341SV)
- [SDR QR9R2026091000002](https://openairdocs.org/sdr/QR9R2026091000002), Sep 10, 2026: Bolkms BK117C2. AIR DATA MODULE. OUT OF TOLERANCE. #2 ADC FAILURE INDICATION DURING TAKEOFF. TROUBLESHOOTING REVEALED #2 ADC TO BE OUT OF TOLERANCE. REMOVED AND REPLACED A
- [SDR I5PA2026083068810](https://openairdocs.org/sdr/I5PA2026083068810), Aug 30, 2026: Boeing 757230. ADC. FAULTED. ETOPS SIGNIFICANT REPORT, CAPT AND FO AIRSPEED INDICATION INOPERATIVE. REPLACED LT AND RT AIR DATA COMPUTERS IAW AMM. (N688SL)
- [SDR A6WA202607208901](https://openairdocs.org/sdr/A6WA202607208901), Jul 20, 2026: Cndair CL6002B19. ADC. MALFUNCTIONED. IN FLT A/P DISENGAGED, YAW 1 INOPERATIVE, ALT , VERT SPEED AND IAS INOP/FLAGGED, C/W QRH FLAGS CLEARED( SWITCHED TO #2 A (N457AW)
- [SDR DXTA2026072108896](https://openairdocs.org/sdr/DXTA2026072108896), Jul 18, 2026: Bombdr BD1001A10. ADC. DEFECTIVE. DURING SHORT FLIGHT, JUST AFTER LEVELING OFF AT 12,000', AMBER EFIS MISCOMPARE AND ALT FLAG (ON PFD2) DISPLAYED. THE RIG (N754QS)
- [SDR AALA202607132429](https://openairdocs.org/sdr/AALA202607132429), Jul 10, 2026: Boeing 737823. MODULE. UNRELIABLE. AIRCRAFT WAS GROUNDED: AIRSPEED UNRELIABLE INDICATIONS ON CAPTAINS SIDE. AIRSPEED INDICATIONS DROPPED TO APPROXIMATELY 1 (N961AN)
- [SDR UIEA2026070200567](https://openairdocs.org/sdr/UIEA2026070200567), Jul 2, 2026: Boeing 74747UF. ADC. FAULTED. LOSS OF RT ADC, AND RT AOA IN FLIGHT WITH C/B TRIPPED. R & R RIGHT ADC IAW AMM 34-12-01-401, REV 116 & IPC 34-12-01-01B, (N476MC)
- [SDR 2026FA0000569](https://openairdocs.org/sdr/2026FA0000569), Jun 23, 2026: Boeing 737436. ADC. NO TEST. RIGHT ADC SELF TEST FAILED AMM 34-12-11 REV 103 - 25-MAR-2026. ADC WAS REPLACED AND OPERATIONAL TEST WAS PERFORMED BY AM (N853AT)
- [SDR FDEA202605280647](https://openairdocs.org/sdr/FDEA202605280647), May 28, 2026: Boeing 75723A. ADC. FAULTED. ALTITUDE DISAGREE TWO TIMES DURING DESCENT. FO ALTIMETER MATCHED THE STANDBY AND WAS 400 FEET DIFFERENT THAN CAPTAINS AM (N920FD)
- [SDR IPXA2026042110711](https://openairdocs.org/sdr/IPXA2026042110711), Apr 21, 2026: Boeing 75724APF. ADC. FAULTY. EMERGENCY DECLARED, AIRSPEED UNRELIABLE INDICATIONS DURING CLIMBOUT. FLT CREW REPORTS AIRSPEED DROPPED OFF DURING CLIMB  (N436UP)
- [SDR UIEA2026042000226](https://openairdocs.org/sdr/UIEA2026042000226), Apr 20, 2026: Boeing 747409. ADC. FAULTED. CAPTAIN AIRSPEED DROPPED FROM 250 KNOTS TO MINIMUM ON CLIMBOUT. PERFORMED LEAK CHK OF CAPT'S AND FO'S PITOT STATIC SYS I (N249BA)
- [SDR UIEA2026041400181](https://openairdocs.org/sdr/UIEA2026041400181), Apr 14, 2026: Boeing 747409. ADC. FAULTED. CAPTAINS AIRSPEED INDICATION UNRELIABLE. FO INDICATION APPEARED TO BE NORMAL(<P>LH AIR DATA COMPT FAILED. REMOVED &AMP;  (N249BA)
- [SDR HNAA2026040800277](https://openairdocs.org/sdr/HNAA2026040800277), Apr 7, 2026: Emb EMB145LR. ADC. ABNORMAL. AMMENDED: ADC 1 FAIL W/SPS ADVANCED IN FLIGHT. FACT 08APR26 07:42 PHL RR ADC 1 COMPUTER IAW AMM 34-15-01. NO FAIL MSG PR (N925AE)
- [SDR N6WA2025032704](https://openairdocs.org/sdr/N6WA2025032704), Mar 26, 2026: Cndair CL6002C11. ADC. FAULTED. AIRSPEED, ALTITUDE, AND VSI FLUCTUATING ON F/O SIDE OF FLIGHT DECK. VSI INTERMITTENT RED V/S DISPLAY DURING STRAIGHT AND (N503GJ)
- [SDR IPXA2026032306832](https://openairdocs.org/sdr/IPXA2026032306832), Mar 21, 2026: Boeing 747428F. ADC. WARNING MESSAGE. AIR TURN BACK, ADC RIGHT STATUS MESSAGE REMOVED AND REPLACED THE RIGHT ADC IAW AMM 34-12-01-401. OPS CHECK GOOD. (N580UP)
- [SDR IPXA2026030541774](https://openairdocs.org/sdr/IPXA2026030541774), Mar 5, 2026: Boeing 75724APF. ADC. INOPERATIVE. AIR TURN BACK - UNRELIABLE AIRSPEED DURING CLIMB OUT. R&R L/H ADC , OPS CHECK GOOD IAW 757 AMM 34-12-01. WORK DONE BY CA (N466UP)
- [SDR UIEA2026022200065](https://openairdocs.org/sdr/UIEA2026022200065), Feb 22, 2026: Boeing 74747UF. ADC. FAULTED. ALT DISAGREE EICAS MSG LEVEL FLIGHT AT FL280 GREATER THAN 200' L 27760 R/R CAPT LH AIR DATA COMPUTER IAW AMM 34-12-01/40 (N493MC)
- [SDR AALA202603064269](https://openairdocs.org/sdr/AALA202603064269), Feb 17, 2026: Boeing 737823. AIR DATA MODULE. FAULTY. AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS NOT DECLARED DUE TO: CAPTAINS PRIMARY FLIGHT DISPLAY (PFD) FLASHED INTERMITTENTL (N335PH)
- [SDR AALA202603061844](https://openairdocs.org/sdr/AALA202603061844), Feb 17, 2026: Boeing 737823. ADC. FAULTED. AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS NOT DECLARED DUE TO: CAPTAINS PRIMARY FLIGHT DISPLAY (PFD) FLASHED INTERMITTENTL (N335PH)
- [SDR HNAA2026020100107](https://openairdocs.org/sdr/HNAA2026020100107), Feb 1, 2026: Emb EMB145LR. ADC. FAILED. ADC 1 FAILED IN FLIGHT FACT 01FEB26 17:47 ALB R&R'D ADC1 AT POS 100 IAW EMB145 AMM 34-15-01. PERFORMED LEAK CHECK IAW AM (N689EC)
- [SDR UIEA2025122001354](https://openairdocs.org/sdr/UIEA2025122001354), Dec 19, 2025: Boeing 7474H6F. ADC. FAULTED. IAS DISAGREE EICAS MSG AFTER T/O & ALT DISAGREE EICAS MSG AT 7000 FT. REMOVED AND REPLACED L/H AIR DATA COMPUTER IAW AMM (N430GT)
- [SDR CALA2025122112274](https://openairdocs.org/sdr/CALA2025122112274), Dec 18, 2025: Boeing 767322. ADC. FAULTED. IAS DISAGREE EICAS MSG. CAPT SIDE SHOWING .785 FO SIDE SHOWING. 815 AT 340 CREW VERBAL. STAND BY IND MATCHED F/O SIDE, C (N657UA)
- [SDR CALA2025112811570](https://openairdocs.org/sdr/CALA2025112811570), Nov 25, 2025: Boeing 737924ER. ADIRU. FAULTY. FO SPEED AND ALTIMETER BLANK FO 10 SEC. CLIMB CRUISE AND DESCEN T RETRIEVED LST FLT LEG FAULT. FOUND MULTIPLE FAULTS REL (N75425)
- [SDR AALA202511265913](https://openairdocs.org/sdr/AALA202511265913), Nov 25, 2025: Airbus A321231. ADIRU. FAULTED. AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO CLT DUE TO AN AIR DATA FAULT MESSAGE. THE  (N165NN)
- [SDR ABXA20251120304](https://openairdocs.org/sdr/ABXA20251120304), Nov 20, 2025: Boeing 767383. ADC. INOPERATIVE. DURING CRUISE, LEFT ADC BECAME INOPERATIVE. FOLLOWED QRH, CA SWITCHED TO ADC ALT REMAINDER OF FLIGHT OK. AIRCRAFT DIVERT (N226CY)
- [SDR HEEA202510240001](https://openairdocs.org/sdr/HEEA202510240001), Oct 24, 2025: Skrsky S92A. ADC. INOPERATIVE. NR 2 ADC FAIL IN CRUISE FLIGHT. PERFORMED APPROPRIATE CHECKLIST AND RETURNED TO HMAN. (N925PH)
- [SDR CALA2025101610187](https://openairdocs.org/sdr/CALA2025101610187), Oct 13, 2025: Airbus A319131. ADR. FAULTED. NAV ADR 1 FAULT LAND VERIFY REQUIRED CYCLED RELATED BREAKERS, RERACKED ADIRU 1 AND PERFORMED BITE TEST OF ADIRU AND IRU  (N844UA)
- [SDR GTIA2025092939103](https://openairdocs.org/sdr/GTIA2025092939103), Sep 26, 2025: Airbus A320232. ADR. MALFUNCTIONED. ADR 1 FAULT INCRUISE, PREFORMED OPS TEST IAW AMM 34-13-00 OPS CHECK GOOD NO FAULT MSGS MOC 69661 (N622NK)
- [SDR IPXA2025092531819](https://openairdocs.org/sdr/IPXA2025092531819), Sep 25, 2025: Boeing 75724APF. ADC. MALFUNCTIONED. ATB, LOSS L AIR DATA DURING CLIMB-OUT AROUND 400FT. REMOVED AND REPLACED LEFT ADC PER AMM 34-12-01. OPS CHECK NORMAL. (N475UP)
- [SDR QR9R2025091500001](https://openairdocs.org/sdr/QR9R2025091500001), Sep 15, 2025: Bolkms BK117C2. AIR DATA MODULE. INACCURATE. COPILOT ALTIMETER HAS 80 FOOT ERROR. 30.15 READ IN KOLSMANN WINDOW WITH FIELD ELEVATION OF 301 SET. CURRENT ALTIMETER AT
- [SDR HEEA202509120001](https://openairdocs.org/sdr/HEEA202509120001), Sep 11, 2025: Airbus H160B. ADC. INOPERATIVE. AIR1 DATA FAIL DISPLAYED ON MASTER LIST DURING CRUISE FLIGHT. RTB HOUMA NORTH RAMP. BRIEFED PASSENGERS AND RELEASED AIRC (N675P)
- [SDR IPXA2025080451310](https://openairdocs.org/sdr/IPXA2025080451310), Aug 1, 2025: Boeing 76734AF. ADC. INOPERATIVE. ***AIR TURN BACK*** AIRCRAFT DISPLAYED FLAP LIM & SPD LIM AT 255 KTS AND 3000 FT ON CLIMBOUT. FLAP LEVER WAS IN UP POSIT (N331UP)
- [SDR DXTA2025072204291](https://openairdocs.org/sdr/DXTA2025072204291), Jul 18, 2025: Bombdr BD1001A10. ADC. DEFECTIVE. IN LEVEL FLIGHT AT 6000 FT GEAR & FLAPS UP SPEED 250 KTS. WE GOT AN AMBER ALT BOX MESSAGE ON BOTH PFD'S AND AN EFIS MISC (N777QS)
- [SDR QR9R2025070300001](https://openairdocs.org/sdr/QR9R2025070300001), Jul 3, 2025: Bolkms BK117C2. AIR DATA MODULE. INOPERATIVE. VAR NR INOPERATIVE DURING START RUN-UP. REMOVED AND REPLACED AIR DATA UNIT IAW AMM 34-11-00, 4-1. TEST FLIGHT COMPLETED 
- [SDR IPXA2025070212307](https://openairdocs.org/sdr/IPXA2025070212307), Jul 1, 2025: Airbus A300F4622R. ADC. FAULTED. ATB, DURING CRUISE @FL300 NAV ADC-PRED W/S DET FAULT. ALSA WEATHER FAIL. TRIED TO RESET IW SYSTEM RESET TABLE\ AOM NO EF (N174UP)
- [SDR YENA2025070200674](https://openairdocs.org/sdr/YENA2025070200674), Jun 29, 2025: Airbus A320232. MODULE. FAILED. FLT#1962, PBI-LGA. (REJECTED TAKE OFF) F/O AIRSPEED INDICATOR STAGNATED INDICATION REJECTED TAKE OFF 60.70 KTS INDICATED (N729JB)
- [SDR CALA2025063006104](https://openairdocs.org/sdr/CALA2025063006104), Jun 26, 2025: Boeing 737724. MODULE. FAULTED. REJECTED T/O AROUND 90 KIAS USING AUTO BRAKES, FOR AIRSPEED DISAGREE F/O IND HAD DISAGR FLAGSVERBAL TURNOVER W/ PILOTS,  (N54711)
- [SDR HEEA202506200001](https://openairdocs.org/sdr/HEEA202506200001), Jun 17, 2025: Skrsky S92A. ADC. INOPERATIVE. #2 ADC FAILED IN FLIGHT. (N937PH)
- [SDR FDEA202506100993](https://openairdocs.org/sdr/FDEA202506100993), Jun 10, 2025: Boeing 757236. ADC. INOPERATIVE. ON DEPARTURE THE LEFT ADC FAILED GIVING ERRONEOUS AIRSPEED AND ALTITUDE INDICATIONS ALONG WITH MULTIPLE FLAGS. WE WERE I (N910FD)
- [SDR DALA2025052704057](https://openairdocs.org/sdr/DALA2025052704057), May 24, 2025: Airbus BD5001A10. PROBE. FOD. SHIP 8109 - ATB - DUE TO "EFIS MISCOMPARE" CAUTION MESSAGE WITH UNRELIABLE AIRSPEED. CORRECTIVE ACTION: FOUND INSECT DEB (N109DU)
- [SDR DXTA2025051903487](https://openairdocs.org/sdr/DXTA2025051903487), May 14, 2025: Emb EMB505. AIR DATA MODULE. DEFECTIVE. CAPTAIN ALTITUDE/AIRSPEED INDICATION: AFTER ROTATION, THE LEFT SIDE INDICATED AIR SPEED BECAME UNRELIABLE. THE SYSTEM AN (N439QS)
- [SDR DXTA2025051603480](https://openairdocs.org/sdr/DXTA2025051603480), May 13, 2025: Emb EMB505. AIR DATA MODULE. FAULTED. CAPTAIN ALTITUDE/AIRSPEED INDICATION: AFTER ROTATION, THE LEFT SIDE INDICATED AIR SPEED BECAME UNRELIABLE. THE SYSTEM AN (N439QS)
- [SDR QR9R2025051200001](https://openairdocs.org/sdr/QR9R2025051200001), May 12, 2025: Bolkms BK117C2. AIR DATA MODULE. FAILED. DURING FLIGHT, LIMIT ILLUMINATED ALONG WITH VNE AMD THE WARNING GONG. ISOLATED THE ADU TO #1 AND THE CAUTION/WARNINGS/AD
- [SDR DALA2025050503403](https://openairdocs.org/sdr/DALA2025050503403), May 4, 2025: Airbus A319114. ADR. INOPERATIVE. ATO - AT 80 KNOTS DUE TO CAPTAIN'S AIRSPEED READING ZERO. SWAPPED ADIRU #1 AND #3. PLACED ADIRU #3 ON MEL. OK FOR SERVIC (N353NB)
- [SDR DXTA2025043003258](https://openairdocs.org/sdr/DXTA2025043003258), Apr 28, 2025: Cessna 680A. ADC. FAULTED. DURING CLIMB BOTH ON ADC 2 MESSAGE DISPLAYED. COMPLIED WITH QRH. ALSO NOTED A SLIGHT RUDDER KICK PASING THROUGH 17,000'. (N645QS)
- [SDR A6WA202504028867](https://openairdocs.org/sdr/A6WA202504028867), Apr 27, 2025: Cndair CL6002B19. ADC. FAULTED. AT 28000 FT DURING DECENT F/O AIRSPEED DECREASING AND EFIS COMP MON IAS CAUTION PRESENT AT 16000 FT F/O AIRSPEED RETURNE (N471ZW)

All 1,210: https://openairdocs.org/jasc/3417/reports.md

## Other codes in chapter 34

- [JASC 3400](https://openairdocs.org/jasc/3400): Navigation System (692 reports)
- [JASC 3410](https://openairdocs.org/jasc/3410): Flight Environment Data (218 reports)
- [JASC 3411](https://openairdocs.org/jasc/3411): Pitot/Static System (1,586 reports)
- [JASC 3412](https://openairdocs.org/jasc/3412): Outside Air Temperature Indicator/Sensor (254 reports)
- [JASC 3413](https://openairdocs.org/jasc/3413): Rate of Climb Indicator (157 reports)
- [JASC 3414](https://openairdocs.org/jasc/3414): Airspeed/Mach Indicator (860 reports)
- [JASC 3415](https://openairdocs.org/jasc/3415): High Speed Warning (39 reports)
- [JASC 3416](https://openairdocs.org/jasc/3416): Altimeter, Barometric/Encoder (1,256 reports)
- [JASC 3418](https://openairdocs.org/jasc/3418): Stall Warning System (1,641 reports)
- [JASC 3420](https://openairdocs.org/jasc/3420): Attitude and Direction Data System (772 reports)
- [JASC 3421](https://openairdocs.org/jasc/3421): Attitude Gyro and Indicating System (1,142 reports)
- [JASC 3422](https://openairdocs.org/jasc/3422): Directional Gyro and Indicating System (649 reports)
- [JASC 3423](https://openairdocs.org/jasc/3423): Magnetic Compass (101 reports)
- [JASC 3424](https://openairdocs.org/jasc/3424): Turn and Bank/Rate of Turn Indicator (153 reports)
- [JASC 3425](https://openairdocs.org/jasc/3425): Integrated Flight System (1,150 reports)
- [JASC 3430](https://openairdocs.org/jasc/3430): Landing and Taxi Aids (56 reports)
- [JASC 3431](https://openairdocs.org/jasc/3431): Localizer/VOR System (129 reports)
- [JASC 3432](https://openairdocs.org/jasc/3432): Glide Slope System (66 reports)
- [JASC 3433](https://openairdocs.org/jasc/3433): Microwave Landing System (26 reports)
- [JASC 3434](https://openairdocs.org/jasc/3434): Marker Beacon System (27 reports)
- [JASC 3435](https://openairdocs.org/jasc/3435): Heads Up Display System (10 reports)
- [JASC 3436](https://openairdocs.org/jasc/3436): Wind Shear Detection System (70 reports)
- [JASC 3440](https://openairdocs.org/jasc/3440): Independent Position Determining System (261 reports)
- [JASC 3441](https://openairdocs.org/jasc/3441): Inertial Guidance System (289 reports)
- [JASC 3442](https://openairdocs.org/jasc/3442): Weather Radar System (3,442 reports)
- [JASC 3443](https://openairdocs.org/jasc/3443): Doppler System (110 reports)
- [JASC 3444](https://openairdocs.org/jasc/3444): Ground Proximity System (552 reports)
- [JASC 3445](https://openairdocs.org/jasc/3445): Air Collision Avoidance System (214 reports)
- [JASC 3446](https://openairdocs.org/jasc/3446): Non Radar Weather System (23 reports)
- [JASC 3450](https://openairdocs.org/jasc/3450): Dependent Position Determining System (106 reports)
- [JASC 3451](https://openairdocs.org/jasc/3451): DME/TACAN System (197 reports)
- [JASC 3452](https://openairdocs.org/jasc/3452): ATC Transponder System (624 reports)
- [JASC 3453](https://openairdocs.org/jasc/3453): Long-Range Navigation (LORAN) System (175 reports)
- [JASC 3454](https://openairdocs.org/jasc/3454): Visual Omnirange (VOR) System (317 reports)
- [JASC 3455](https://openairdocs.org/jasc/3455): Automatic Direction Finder (ADF) System (164 reports)
- [JASC 3456](https://openairdocs.org/jasc/3456): Omega Navigation System (9 reports)
- [JASC 3457](https://openairdocs.org/jasc/3457): Global Positioning System (635 reports)
- [JASC 3460](https://openairdocs.org/jasc/3460): Flight Management Computing Hardware System (4,690 reports)
- [JASC 3461](https://openairdocs.org/jasc/3461): Flight Management Computing Software System (68 reports)
- [JASC 3497](https://openairdocs.org/jasc/3497): Navigation System Wiring (269 reports)

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