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
N244DC	Cornelius Dana J CHALLENGER II	Fixed-wing, single engine	Co-owned owner Texas	Experimental	2023-02-14	Valid
N5163B	Wishon George F Jr PHANTOM	Fixed-wing, single engine	Individual owner Alabama	Experimental	2023-01-30	Valid
N4878P	Kolb FIRESTAR II	Fixed-wing, single engine	Individual owner Ohio	Experimental	2023-01-23	Valid
N7110U	Aeroprakt VISTA A-20	Fixed-wing, single engine	Individual owner Pennsylvania	Experimental	2023-01-22	Valid
N2734R	J&J Ultralights TUKAN	Weight-shift control	Co-owned owner Arizona	Experimental	2023-01-18	Valid
N853GM	James Edward Manning Jr FIREFLY	Fixed-wing, single engine	Individual owner Ohio	Experimental	2023-01-18	Valid
N888YQ	Robert Saltz SALTZ CHALLENGER II	Fixed-wing, single engine	Individual owner Mississippi	Experimental	2023-01-05	Valid
N6129U	Airborne Australia REDBACK	Weight-shift control	Individual owner New Hampshire	Experimental	2022-12-31	Valid
N148SE	Powrachute Corp SKY RASCAL	Powered parachute	Individual owner Nevada	Experimental	2022-12-27	Valid
N769W	Flightstar Inc FLIGHTSTAR II	Fixed-wing, single engine	Individual owner Indiana	Experimental	2022-12-27	Valid
N43563	Brannan Richard A RANS S14 AIRAILE	Fixed-wing, single engine	Individual owner Illinois	Experimental	2022-12-13	Valid
N12XA	Highcraft Aero-Marine Inc BUCCANEER XA	Fixed-wing, single engine	Individual owner Florida	Experimental	2022-11-30	Valid
N28RT	Tharp Richard CHALLENGER II	Fixed-wing, single engine	Individual owner Florida	Experimental	2022-11-25	Valid
N237AS	Cgs Hawk ARROW	Fixed-wing, single engine	Pittsburgh Aircraft Sales & Leasing INC Port Saint Lucie, Florida	Experimental	2022-11-09	Valid
N94130	Pegasus QUANTUM	Weight-shift control	Individual owner Indiana	Experimental	2022-11-08	Valid
N702D	Ratliff John B CHALLENGER II	Fixed-wing, single engine	Individual owner Iowa	Experimental	2022-10-18	Valid
N748TP	Keyes Russ SKY RAIDER I	Fixed-wing, single engine	Individual owner Washington	Experimental	2022-10-17	Valid
N265CD	Quicksilver Enterprises Inc MXL II SPORT	Fixed-wing, single engine	Individual owner Mississippi	Experimental	2022-10-12	Valid
N769AB	Alden Buerge QUICKSILVER SPORT	Fixed-wing, single engine	Individual owner Iowa	Experimental	2022-09-28	Valid
N3797A	Yilk Thomas R CHALLENGER II	Fixed-wing, single engine	Individual owner Arizona	Experimental	2022-09-27	Valid
N5610N	Starkey Alan M BEAVER RX 550	Fixed-wing, single engine	Co-owned owner Texas	Experimental	2022-09-26	Valid
N53PP	Pipistrel TAURUS	Electric airplane	Vortex Maritime LLC Chesapeake, Virginia	Light sport	2022-09-01	Valid
N2617A	Quicksilver Enterprises Inc MX SPRINT II	Fixed-wing, single engine	Individual owner Washington	Experimental	2022-08-30	Valid
N3594D	Flightstar FLIGHTSTAR SLII	Fixed-wing, single engine	Individual owner Tennessee	Experimental	2022-08-02	Valid
N369YV	John A Pratt QUADCITY-PRATT CH II	Fixed-wing, single engine	Individual owner New Hampshire	Experimental	2022-06-16	Valid
N7725B	Burns Robert J CHALLENGER II LONG W	Glider	Individual owner Delaware	Experimental	2022-04-26	Valid
N4459A	Smith John N CHALLENGER II	Fixed-wing, single engine	Individual owner Illinois	Experimental	2022-03-07	Valid
N184A	Quad City Ultralight Acft Corp CHALLENGER II	Fixed-wing, single engine	Individual owner Illinois	Experimental	2022-02-25	Valid
N56998	Cgs Aviation HAWK	Fixed-wing, single engine	Individual owner New York	Experimental	2022-02-14	Valid
N56181	Six Chuter Skye Rider Ii SIX CHUTER	Powered parachute	Individual owner North Dakota	Experimental	2022-01-20	Valid
N1754C	Quad City Ul A/C CHALLENGER	Fixed-wing, single engine	Individual owner Tennessee	Experimental	2021-12-20	Valid
N2569T	Quad City Ch CHALLENGER II	Fixed-wing, single engine	Individual owner Missouri	Experimental	2021-11-04	Valid
N543RP	Purvis Ronald E RANS S-6ES COYOTE	Fixed-wing, single engine	Co-owned owner Pennsylvania	Experimental	2021-11-01	Valid
N587F	Phantom Aeronautics Llc PHANTOM X 1	Fixed-wing, single engine	Individual owner Colorado	Experimental	2021-10-26	Valid
N904UA	Benjamin D Eggers CHALLENGER II	Fixed-wing, single engine	Individual owner Tennessee	Experimental	2021-10-25	Valid
N492MA	Angus Catchot CHALLENGER 2	Fixed-wing, single engine	Individual owner Mississippi	Experimental	2021-09-24	Valid
N5607M	Cosmos PHASE II	Weight-shift control	Individual owner Ohio	Experimental	2021-09-20	Valid
N8024M	Knight John AIR COMMAND 503	Gyroplane	Individual owner Ohio	Experimental	2021-09-07	Valid
N55UE	Quick Silver M Ii MII-2 SEAT	Fixed-wing, single engine	Individual owner Arkansas	Experimental	2021-08-30	Valid
N8559J	Bardin William D CHALLENGER II	Fixed-wing, single engine	Individual owner Nevada	Experimental	2021-08-23	Valid
N317PD	Phantom Aeronautics Llc X-1	Fixed-wing, single engine	Individual owner Michigan	Experimental	2021-08-18	Valid
N711PC	Phillip H Cotter CHALLENGER II	Fixed-wing, single engine	Individual owner Missouri	Experimental	2021-08-14	Valid
N526RW	Wright Ron W SKY RAIDER 1	Fixed-wing, single engine	Individual owner Florida	Experimental	2021-08-07	Valid
N187S	Pterodactyl Ltd ASCENDER II	Fixed-wing, single engine	Individual owner Washington	Experimental	2021-07-30	Valid
N520AA	Kildall Gary FALCON-XP	Fixed-wing, single engine	Individual owner Oregon	Experimental	2021-07-28	Valid
N43986	Six Chuter SR2	Powered parachute	Individual owner Montana	Experimental	2021-07-27	Valid
N3534L	Buckeye Industries DREAM MACHINE	Powered parachute	Individual owner Florida	Experimental	2021-07-26	Valid
N140MR	Riley Mike CHALLENGER II LSS	Fixed-wing, single engine	Individual owner Wisconsin	Experimental	2021-07-14	Valid
N716CW	Odonnell Clyde W HAWK-SPORT	Fixed-wing, single engine	Individual owner Texas	Experimental	2021-07-10	Valid
N428ZG	Gray Mark J FIRESTAR	Fixed-wing, single engine	Individual owner Wisconsin	Experimental	2021-07-07	Valid
N6870	Challenger CHALLENGER II	Fixed-wing, single engine	Individual owner Ohio	Experimental	2021-06-29	Valid
N9086M	Ratte Jim SCII	Weight-shift control	Individual owner Georgia	Experimental	2021-06-24	Valid
N7531S	Livesay Charles CHALLENGER II STAND	Fixed-wing, single engine	Individual owner Alabama	Experimental	2021-05-03	Valid
N4358G	Macurdy Harold RANS S-9	Fixed-wing, single engine	Individual owner North Carolina	Experimental	2021-04-20	Valid
N25LA	Auxter Larry A MAVERICK	Weight-shift control	Individual owner Nevada	Experimental	2021-04-16	Valid
N3066	Howard James B CHALLENGER II	Fixed-wing, single engine	Individual owner Alabama	Experimental	2021-04-10	Valid
N115DE	North Wing APACHE	Weight-shift control	Individual owner Texas	Experimental	2021-03-23	Valid
N116DB	Beresford Damien SABRE TRIKE	Weight-shift control	Individual owner Idaho	Light sport	2021-03-20	Valid
N5615U	Quad City Ultralight Acft Corp CHALLENGER	Fixed-wing, single engine	Individual owner Mississippi	Experimental	2021-02-23	Valid
N4848A	Quicksilver SPORT	Fixed-wing, single engine	Individual owner Florida	Experimental	2021-01-06	Valid
N249MP	Pace Monte D RANS S-17 STINGER	Fixed-wing, single engine	Individual owner Florida	Experimental	2020-12-28	Valid
N2484Q	Quicksilver EIPPER GT 400	Fixed-wing, single engine	Individual owner Indiana	Experimental	2020-12-23	Valid
N7071N	Kammerer Allan W QUICKSILVER	Fixed-wing, single engine	Individual owner Illinois	Experimental	2020-12-19	Valid
N5182W	Air Creation BUGGY 503 SL	Weight-shift control	Individual owner Kentucky	Experimental	2020-12-03	Valid
N75556	Beller Richard E QUICKSILVER MXLII	Fixed-wing, single engine	Individual owner Florida	Experimental	2020-11-02	Valid
N464AR	Dale Rose ROSE FLYER	Fixed-wing, single engine	Individual owner Iowa	Experimental	2020-10-17	Valid
N46EJ	Miller R Emmet MX11 SPRINT	Fixed-wing, single engine	Individual owner Wisconsin	Experimental	2020-09-30	Valid
N1283W	Erc Wings Ltd CHALLENGER 2	Fixed-wing, single engine	Paxair LLC Minneapolis, Minnesota	Experimental	2020-09-04	Valid
N7109J	Phantom Aircraft Co X1	Fixed-wing, single engine	Individual owner North Carolina	Experimental	2020-08-26	Valid
N95124	Lobello Vincent HIPERLIGHT SNS-9	Fixed-wing, single engine	Individual owner Massachusetts	Experimental	2020-08-18	Valid
N94453	Becker David C FLIGHTSTAR IISL	Fixed-wing, single engine	Individual owner California	Experimental	2020-07-28	Valid
N65740	Harmening HIGH FLYER	Powered parachute	Individual owner North Carolina	Experimental	2020-07-17	Valid
N9455W	Challenger/Elwood II	Fixed-wing, single engine	Individual owner Wisconsin	Experimental	2020-07-07	Valid
N911BC	Washburn Dewey W WASHBURN	Weight-shift control	Individual owner Alabama	Experimental	2020-07-01	Valid
N388HS	Suissa Benjamin VORTEX	Rotorcraft	Individual owner Guam	Experimental	2020-06-25	Valid
N167PN	Nichol Peter CHALLENGER II	Fixed-wing, single engine	Individual owner Nebraska	Experimental	2020-06-24	Valid
N5685Q	Powrachute Corp SKY RASCAL	Powered parachute	Individual owner New York	Experimental	2020-05-19	Valid
N8743J	Kolb TWINSTAR MARK II	Fixed-wing, single engine	Individual owner Wisconsin	Experimental	2020-05-08	Valid
N628KB	Bloom Kenneth W CHALLENGER II	Fixed-wing, single engine	Individual owner Illinois	Experimental	2020-05-05	Valid
N2612T	Air Creation TWIN	Weight-shift control	Individual owner Massachusetts	Experimental	2020-04-17	Valid
N75787	Quicksilver Mfg Co Inc QUICKSILVER MXIIA	Fixed-wing, single engine	Individual owner Minnesota	Experimental	2020-03-17	Valid
N31729	Lorberter Daryl R LORBERTER/CHALLNGRII	Fixed-wing, single engine	Individual owner Wisconsin	Experimental	2020-02-26	Valid
N387GK	Kurrle James E CHALLENGER II	Fixed-wing, single engine	Individual owner Illinois	Experimental	2020-02-25	Valid
N61199	Quicksilver SPRINT II	Fixed-wing, single engine	Individual owner Maryland	Experimental	2020-02-20	Valid
N95228	Curtiss Mark A CHALLENGER II	Fixed-wing, single engine	Individual owner Montana	Experimental	2020-01-31	Valid
N335SR	Brunet Raymond A CHALLENGER II	Fixed-wing, single engine	Individual owner New York	Experimental	2020-01-07	Valid
N1652L	Bunnis Alan K CHALLENGER II	Fixed-wing, single engine	Individual owner Washington	Experimental	2019-11-05	Valid
N21427	Air Creation Trike TWIN	Weight-shift control	Individual owner California	Experimental	2019-11-05	Valid
N1017K	Koop Richard P CHALLENGER II	Fixed-wing, single engine	Individual owner Minnesota	Experimental	2019-10-28	Valid
N135JG	Quad City Challenger Acft Corp CHALLENGER II	Fixed-wing, single engine	N135Jg LLC Albuquerque, New Mexico	Experimental	2019-09-11	Valid
N3007E	Pegasus QUANTUM	Weight-shift control	Individual owner Tennessee	Experimental	2019-09-11	Valid
N415YT	James E Robinson CHALLENGER II	Fixed-wing, single engine	Individual owner Illinois	Experimental	2019-09-09	Valid
N8852	Johnson Philip B 404	Fixed-wing, single engine	Individual owner Massachusetts	Experimental	2019-08-29	Valid
N114GX	Burnett George CH-II	Fixed-wing, single engine	Individual owner Kentucky	Experimental	2019-07-17	Valid
N726BC	Tim Allen FOKKER DVIII	Fixed-wing, single engine	Individual owner Michigan	Experimental	2019-06-25	Valid
N9514P	Geister Allan A CHALLENGER II	Fixed-wing, single engine	Individual owner Washington	Experimental	2019-05-29	Valid
N2572J	Quad City Ultralights CHALLENGER II	Fixed-wing, single engine	Individual owner Connecticut	Experimental	2019-05-28	Valid
N311TH	Peterson Bruce L CHALLENGER II	Fixed-wing, single engine	Co-owned owner Wisconsin	Experimental	2019-04-23	Valid
N75755	Kolb TWINSTAR	Fixed-wing, single engine	Individual owner South Dakota	Experimental	2019-04-11	Valid
N808TT	Steve Flynn TITAN TORNADO I	Fixed-wing, single engine	Individual owner Illinois	Experimental	2019-03-12	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.