Engines · two-cycle piston · data as of October 5, 2026

Rotax 503 series

449 aircraft on the U.S. register carry a Rotax 503 series engine, rated at about 52 horsepower. The Quad City Ultralight Acft Corp CHALLENGER II is the model most often fitted with it (8 aircraft). The aircraft carrying it were built between 1983 and 2025.

The FAA records engines by code, usually at the level of a series ("O-320 series") rather than the exact variant; this page gathers every FAA code that reads as Rotax 503 series. FAA spelling: 503 SERIES.

Fitted to model families

Quad City Ultralight Acft Corp CHALLENGER II8Quicksilver SPORT5Quad City Ultralights CHALLENGER II4Quicksilver GT-4004Quicksilver SPRINT II4Air Creation GTE3Air Creation TWIN3Buckeye DREAM MACHINE3Buckeye Industries DREAM MACHINE3North Wing APACHE3Pipistrel TAURUS3Powrachute Corp SKY RASCAL3

Quad City Ultralight Acft Corp CHALLENGER II · Quicksilver SPORT · Quad City Ultralights CHALLENGER II · Quicksilver GT-400 · Quicksilver SPRINT II · Air Creation GTE · Air Creation TWIN · Buckeye DREAM MACHINE · Buckeye Industries DREAM MACHINE · North Wing APACHE

Where they are owner's state

California29Florida28Texas22Indiana20Illinois20Wisconsin17Oklahoma15North Carolina15Ohio14Arizona14

Kind of aircraft

Piston singles321 (71%)Weight-shift and powered parachutes108 (24%)Gyroplanes9 (2%)Helicopters6 (1%)Gliders5 (1%)

When the aircraft were built by decade

Connections how this engine series links to the rest of the register

Fitted to

Quad City Ultralight Acft Corp CHALLENGER II 8 with this engine series
Quicksilver SPORT 5 with this engine series
Quad City Ultralights CHALLENGER II 4 with this engine series
Quicksilver GT-400 4 with this engine series
Quicksilver SPRINT II 4 with this engine series
Air Creation GTE 3 with this engine series
Air Creation TWIN 3 with this engine series
Buckeye DREAM MACHINE 3 with this engine series

Where they are

California 29 of these aircraft
Florida 28 of these aircraft
Texas 22 of these aircraft
Indiana 20 of these aircraft
Illinois 20 of these aircraft

Biggest operators

Tsi Holdco INC 1 of these aircraft

Analytics

These connections as data: /graph/engine/rotax-503-series.json · about the eFlight graph.

Aircraft newest certificates first · 449

Tail no.	Maker and model	Group	Owner and base	Certificate	Registered	Status
N420DM	Quad City Ultralights CHALLENGER II	Fixed-wing, single engine	Individual owner Missouri	Experimental	2026-07-29	Valid
N4042J	Parsons Jason W CHALLENGER II CWS	Fixed-wing, single engine	Individual owner Ohio	Experimental	2026-07-27	Valid
N524NR	Raymond C Ring KOLB MARK 3 CLASSIC	Fixed-wing, single engine	Individual owner Nevada	Experimental	2026-07-11	Valid
N7500Q	Quicksilver MXIIA	Fixed-wing, single engine	Individual owner Michigan	Experimental	2026-07-04	Valid
N380RW	Hamilton Richard D Jr RANS S9	Fixed-wing, single engine	Individual owner Florida	Experimental	2026-06-23	Valid
N9172F	Kretschman Thomas J QUICKSILVER GT 400	Fixed-wing, single engine	Individual owner Wisconsin	Experimental	2026-06-19	Valid
N6154F	Gledhill Erik SPRINT II	Fixed-wing, single engine	Individual owner California	Experimental	2026-06-02	Valid
N82001	Cgs Aviation HAWK B	Fixed-wing, single engine	Individual owner Oklahoma	Experimental	2026-06-01	Valid
N610RG	Gilson Ronald V CHALLENGER 1	Fixed-wing, single engine	Individual owner New York	Experimental	2026-05-12	Valid
N61439	Quad City Ultralight Acft Corp CHALLENGER II	Fixed-wing, single engine	Individual owner New York	Experimental	2026-04-26	Valid
N66NL	Leech Oliver D AFFORDAPLANE	Fixed-wing, single engine	Individual owner Ohio	Experimental	2026-04-26	Valid
N720SC	Avenger HURRICANE	Fixed-wing, single engine	Individual owner New Mexico	Experimental	2026-04-09	Valid
N392RA	Carpenter Carol C QUICKSILVER GT400	Fixed-wing, single engine	Co-owned owner New Mexico	Experimental	2026-04-04	Valid
N946KG	Gary Burtoft KOLB FIRESTAR	Fixed-wing, single engine	Co-owned owner Kentucky	Experimental	2026-03-03	Valid
N503VG	Perdue Frederick V A-VA-GYRO	Gyroplane	Individual owner Virginia	Experimental	2026-02-27	Valid
N1731C	Jones Brian K CHALLENGER II	Fixed-wing, single engine	Individual owner Ohio	Experimental	2026-02-21	Valid
N103RW	Quad City CHALLENGER	Fixed-wing, single engine	Individual owner Mississippi	Experimental	2026-02-16	Valid
N9954C	Snyder Stanley L SSJ-3 KITTEN	Fixed-wing, single engine	Individual owner North Carolina	Experimental	2026-02-15	Valid
N7077B	Excalibur Aircraft EXCALIBUR	Fixed-wing, single engine	Individual owner Tennessee	Experimental	2026-02-12	Valid
N2396B	Black Christopher RELIANT	Fixed-wing, single engine	Individual owner Tennessee	Experimental	2026-02-10	Valid
N870SD	Quicksilver SPRINT II	Fixed-wing, single engine	Individual owner Arizona	Experimental	2026-01-07	Valid
N981CS	Rans S-14	Fixed-wing, single engine	Individual owner Oklahoma	Experimental	2025-09-15	Valid
N2532T	Harmaning High Flyers Inc HIGH FLYER	Powered parachute	Individual owner Michigan	Experimental	2025-09-04	Valid
N4312Q	Happy Valley Trikes 2P	Weight-shift control	Individual owner Georgia	Experimental	2025-08-26	Valid
N8879D	Lee Does SUPER KOALA	Fixed-wing, single engine	Individual owner New Mexico	Experimental	2025-08-10	Valid
N116MG	Goldner Leslie M CHALLENGER II	Fixed-wing, single engine	Individual owner Washington	Experimental	2025-08-06	Valid
N424GE	Gerald Egan CHALLENGER II	Fixed-wing, single engine	Individual owner Georgia	Experimental	2025-08-02	Valid
N10059	Long Danny P CHALLENGER II LSS	Fixed-wing, single engine	Individual owner Virginia	Experimental	2025-07-28	Valid
N2580K	Smith Joseph C CHALLENGER II	Fixed-wing, single engine	Individual owner Iowa	Experimental	2025-07-28	Valid
N392CP	Quad City Ultralight CHALLENGER II	Fixed-wing, single engine	Individual owner Missouri	Experimental	2025-07-22	Valid
N3599F	Powrachute SKY RASCAL	Powered parachute	Co-owned owner Utah	Experimental	2025-07-10	Valid
N59BR	Arlie L Raber Iii CHALLENGER 1	Fixed-wing, single engine	Individual owner Mississippi	Experimental	2025-05-27	Valid
N432YK	Steven Kim XP DUAL SEAT	Fixed-wing, single engine	Individual owner California	Experimental	2025-05-22	Valid
N722JS	Sharp Jack D CHALLENGER II	Fixed-wing, single engine	Co-owned owner California	Experimental	2025-04-28	Valid
N2558W	Mackey Lanny J ABLE FLYER	Weight-shift control	Individual owner California	Experimental	2025-04-08	Valid
N150ED	Gordon James L CHALLENGER II CLIP W	Fixed-wing, single engine	Can Do Moq LLC Balch Springs, Texas	Experimental	2025-03-25	Valid
N7947X	Samuel W Smith TITAN II	Fixed-wing, single engine	Individual owner North Carolina	Experimental	2025-02-10	Valid
N7030V	Airborne Windsports Pty Ltd REDBACK 503	Weight-shift control	Individual owner Idaho	Experimental	2025-02-05	Valid
N129R	Robert T Belcher CHALLENGER II	Fixed-wing, single engine	Individual owner Georgia	Experimental	2025-01-29	Valid
N26383	Sidney M Wood Jr CHALLENGER II LSS	Fixed-wing, single engine	Individual owner Maryland	Experimental	2025-01-21	Valid
N94155	Quicksilver MXII SPORT	Fixed-wing, single engine	Individual owner Mississippi	Experimental	2025-01-06	Valid
N666KF	Frey Kip R KOLB FIRESTAR II	Fixed-wing, single engine	Individual owner Oregon	Experimental	2024-12-18	Valid
N16SL	Steve Lemke CHALLENGER II	Fixed-wing, single engine	Individual owner Alabama	Experimental	2024-12-16	Valid
N239RJ	Johnson Rickie G CHALLENGER II	Fixed-wing, single engine	Individual owner Florida	Experimental	2024-11-06	Valid
N503EE	Peterson Bill BLUE GOOSE	Fixed-wing, single engine	Jsham LLC Sheridan, Wyoming	Experimental	2024-10-07	Valid
N310SC	Six Chuter Inc SKYE RYDER 2	Powered parachute	Individual owner Arkansas	Experimental	2024-08-24	Valid
N157JD	Quad City Challenger 2 PLACE LW	Fixed-wing, single engine	Individual owner North Dakota	Experimental	2024-08-06	Valid
N8688A	Air Command SINGLE PL GYROPLANE	Gyroplane	Individual owner Texas	Experimental	2024-07-31	Valid
N564PH	Peter Houba PH-4	Gyroplane	Individual owner Nevada	Experimental	2024-07-30	Valid
N9003T	Mitchell Bill CHALLENGER II	Fixed-wing, single engine	Individual owner Iowa	Experimental	2024-07-16	Valid
N94290	Bardin William D SPORT II	Fixed-wing, single engine	Individual owner California	Experimental	2024-06-22	Valid
N916KL	Louis D Sheffler Jr CHALLENGER II	Fixed-wing, single engine	Individual owner Maryland	Experimental	2024-06-18	Valid
N7526Y	Quicksilver SPORT	Fixed-wing, single engine	Individual owner California	Experimental	2024-06-14	Valid
N755AG	Mason Harris Griff CHALLENGER II	Fixed-wing, single engine	Individual owner Illinois	Experimental	2024-06-14	Valid
N93006	Newman John D CHALLENGER II	Fixed-wing, single engine	Individual owner Arkansas	Experimental	2024-05-24	Valid
N422RC	Cochran Craig SPAD 13 BIPLANE	Fixed-wing, single engine	Tsi Holdco INC Virginia Beach, Virginia	Experimental	2024-05-16	Valid
N803SM	Pfeifer Michael A CHALLENGER LSS II	Fixed-wing, single engine	Individual owner Iowa	Experimental	2024-05-15	Valid
N392DM	Rans RANS S-9 CHAOS	Fixed-wing, single engine	Carroll Mark e Murray, Kentucky	Experimental	2024-05-08	Valid
N227EH	Air Creation GTE	Weight-shift control	Individual owner New York	Experimental	2024-05-07	Valid
N926P	Quad City Challenger CHALLENGER II	Fixed-wing, single engine	Individual owner Oregon	Experimental	2024-04-28	Valid
N138NA	Quad City Ultralight Acft Corp CHALLENGER II	Fixed-wing, single engine	Individual owner Florida	Experimental	2024-04-25	Valid
N256DH	Hale David W CHALLENGER II	Fixed-wing, single engine	Individual owner Alabama	Experimental	2024-04-03	Valid
N2587E	North Wing APACHE	Weight-shift control	Individual owner Oregon	Experimental	2024-03-07	Valid
N2490H	Clapp Daniel W GT 400	Fixed-wing, single engine	Individual owner Texas	Experimental	2024-01-23	Valid
N2277X	Quad City Ultralights CHALLENGER II	Fixed-wing, single engine	Individual owner Michigan	Experimental	2024-01-22	Valid
N503MX	Bonzer Mark MXL	Fixed-wing, single engine	Individual owner Kansas	Experimental	2023-12-13	Valid
N4633F	Kolb FIRESTAR KXP	Fixed-wing, single engine	Individual owner Kentucky	Experimental	2023-12-06	Valid
N742HG	Quad City Ultralight Acft Corp CHALLENGER CHII	Fixed-wing, single engine	Individual owner Virginia	Experimental	2023-11-14	Valid
N4451G	Flying K Enterprises SKY RAIDER	Fixed-wing, single engine	Individual owner Texas	Experimental	2023-11-05	Valid
N415HC	Quicksilver GT-400 R503	Fixed-wing, single engine	Individual owner California	Experimental	2023-10-14	Valid
N8050Q	Hall B/Hain G CHALLENGER II	Fixed-wing, single engine	Co-owned owner Kansas	Experimental	2023-09-30	Valid
N239SC	Six Chuter Inc LEGEND P103	Powered parachute	Individual owner Oklahoma	Light sport	2023-09-25	Valid
N26228	Aero Trike SAFARI	Weight-shift control	Individual owner Indiana	Experimental	2023-08-23	Valid
N728NN	Quicksilver SPORT II	Fixed-wing, single engine	Individual owner Louisiana	Experimental	2023-08-05	Valid
N234GK	Steve Busby CHALLENGER II	Fixed-wing, single engine	Individual owner North Carolina	Experimental	2023-07-26	Valid
N4404H	Quad City Ultralight Acft Corp CHALLENGER II	Fixed-wing, single engine	Individual owner Ohio	Experimental	2023-07-22	Valid
N436DZ	Pipistrel TAURUS	Electric airplane	Eagle Aviators INC Eagle, Colorado	Standard	2023-07-10	Valid
N258AB	Challenger CHALLENGER II	Fixed-wing, single engine	Adams Bruce A Greenwood, Florida	Experimental	2023-07-01	Valid
N1287F	Downs Dennis Alexander QUICKSILVER SPORT II	Fixed-wing, single engine	Individual owner Alabama	Experimental	2023-06-28	Valid
N4900E	Vyff Randy RANS S-12XL	Fixed-wing, single engine	Co-owned owner Oregon	Experimental	2023-06-08	Valid
N2680E	Breen Charles GT 400	Fixed-wing, single engine	Individual owner Colorado	Experimental	2023-06-07	Valid
N159ZX	J&J Tukan SPECIAL EDITION	Weight-shift control	Individual owner North Carolina	Experimental	2023-06-06	Valid
N339AF	Ramsey E C FIRESTAR II	Fixed-wing, single engine	Individual owner Alabama	Experimental	2023-06-03	Valid
N191DR	Stoll Darrell R CHALLENGER II	Fixed-wing, single engine	Mcminn Brian R Rushville, Indiana	Experimental	2023-05-28	Valid
N8554Z	Bb TRIKE	Weight-shift control	Individual owner Florida	Experimental	2023-05-15	Valid
N536DF	Finberg Kenneth Dale PRECEPER N3 PUP	Fixed-wing, single engine	Individual owner Oregon	Experimental	2023-05-01	Valid
N6124A	Quad City Ultralight Acft Corp CHALLENGER I	Fixed-wing, single engine	Individual owner Texas	Experimental	2023-05-01	Valid
N567NW	North Wing Uum Inc SPORT X2	Weight-shift control	Individual owner Wisconsin	Light sport	2023-04-26	Valid
N942YM	Gardner R RANS S6 ESD	Fixed-wing, single engine	Individual owner Oklahoma	Experimental	2023-04-07	Valid
N5994A	Rans S-14	Fixed-wing, single engine	Individual owner Texas	Experimental	2023-04-05	Valid
N75508	Powrachute M6352885	Powered parachute	Individual owner Michigan	Experimental	2023-04-05	Valid
N4078S	Travis G D/Fly Lite Avia CHALLENGER II	Fixed-wing, single engine	Individual owner New Jersey	Experimental	2023-03-29	Valid
N9162A	Thibodeaux James QUICKSILVER	Fixed-wing, single engine	Individual owner Louisiana	Experimental	2023-03-24	Valid
N6135K	Golden Circle Aircraft T-BIRD I	Fixed-wing, single engine	Individual owner Georgia	Experimental	2023-03-11	Valid
N65500	Quad City CHALLENGER II	Fixed-wing, single engine	Individual owner Missouri	Experimental	2023-03-03	Valid
N9516Z	Stellar Aircraft ASTRA 220	Weight-shift control	Individual owner Kansas	Experimental	2023-03-01	Valid
N758LK	Knuth Loren TWINSTAR	Fixed-wing, single engine	Co-owned owner Florida	Experimental	2023-02-26	Valid
N87204	Rans S-14 AIRAILE	Fixed-wing, single engine	Individual owner Colorado	Experimental	2023-02-21	Valid
N728H	Middleton Ben H TXP 503	Fixed-wing, single engine	Individual owner Arizona	Experimental	2023-02-17	Valid
N545RR	Runyan Roger L FLIGHTSTAR II	Fixed-wing, single engine	Individual owner Pennsylvania	Experimental	2023-02-15	Valid

Source: FAA Civil Aviation Registry, Releasable Aircraft Database (the engine reference table and each aircraft's engine code), October 5, 2026. Horsepower and thrust are the FAA's figures for the series, not for a particular aircraft.