The Pilot Chronograph Ref. 103 is a pilot's chronograph by Sinn.

The Sinn Ref. 103 is the “traditional” pilot's chronograph (“Fliegeruhr”) from Sinn. It has been produced for many years in many different combinations of case, dial, and strap. All Ref. 103 chronographs use the Valjoux 7750 movement, most with the traditional 6-9-12 arrangement of subdials and day and date window at 3 00. A few models use alternate derivative movements with subdials arranged differently, day removed, date moved or removed, and so on. Some use Sinn's DIAPAL escapement or feature an additional UTC hour hand.

The Sinn 103 has a modern 41 mm case with angled lugs 20 mm across. Many models have a solid caseback and are 15.5 mm thick, while some have a sapphire display caseback and are 17 mm thick. Cases are made of stainless steel or titanium.

The 103 Ti Ar won the Goldene Unruh award in 1998.

• 103 A Sa - Steel case, screw-down pushers, sapphire crystal, black dial and bezel, white subdials
• 103 A Sa B - Steel case, screw-down pushers, sapphire crystal, Ar-Dehumidifying Technology, blue dial and bezel, silver subdials
• 103 Classic - 3-6-9 subdial arrangement, date only, steel case, screw-down pushers, sapphire crystal, Ar-Dehumidifying Technology, black dial and bezel, white subdials
• 103 Sa B E - sapphire crystal, Blue dial, bezel, and subdials, ivory hands and markers
• 103 St - Steel case, black dial, bezel, and subdials, white hands and markers
• 103 St C - 3-9 subdial arrangement, no day/date, steel case
• 103 St DIAPAL - UTC hand, date only, steel case, screw-down pushers, anthracite bezel and dial, black subdials, off-white hands and markers, DIAPAL escapement
• 103 St Sa - Steel case, screw-down pushers, sapphire crystal, black dial, bezel, and subdials, white hands and markers
• 103 St Sa Ar UTC - UTC hand, date only, steel case, screw-down pushers, sapphire crystal, Ar-Dehumidifying Technology, black dial, bezel, and subdials
• 103 St Sa E - Steel case, screw-down pushers, sapphire crystal, black dial, bezel, and subdials, limited edition of 300 pieces
• 103 St Sa wanted - Steel case, screw-down pushers, sapphire crystal, anthracite dial and bezel, yellow subdials
• 103 St Ty - Plain bezel, steel case, tachymeter and pulsometer scale, black dial and subdials
• 103 Ti Ar - Titanium case, Ar-Dehumidifying Technology, black dial, bezel, and subdials
• 103 Ti Ar - Edition Die Zeit - Titanium case, Ar-Dehumidifying Technology, sapphire crystal, black dial, bezel, and subdials, red hands
• 103 Ti Ar UTC - UTC hand, date only, titanium case, Ar-Dehumidifying Technology, black dial, bezel, and subdials
• 103 Ti DIAPAL - UTC hand, date only, titanium case, DIAPAL escapement, Ar-Dehumidifying Technology, sapphire crystal, anthracite dial and bezel, black subdials
• 103 Ti IFR - DIN 8330, 9-12 subdial arrangement, titanium case, Ar-Dehumidifying Technology, sapphire crystal, black dial, bezel, and subdials
• 103 Ti TESTAF - UTC hand, date only, titanium case, black dial, bezel, and subdials
• 103 Ti UTC IFR - DIN 8330, UTC hand, 9-12 subdial arrangement, date only, titanium case, Ar-Dehumidifying Technology, sapphire crystal, black dial, bezel, and subdials
• 103 Ti UTC TESTAF - UTC hand, date only, titanium case, black dial, bezel, and subdials