B737 captain reported takeoff with an unknown nose gear pin resulted in a return to the departure ai...

Attributes
ACN	1609858
Time
Date	201901
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Parked
Flight Plan	IFR
Component
Aircraft Component	Gear Extend/Retract Mechanism
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Ground Event / Encounter Other / Unknown

Narrative:

A 4th gear pin was discovered installed after takeoff in the nose gear. Performed return and landed uneventful. Pin was removed and flight resumed to destination. The aircraft had just returned from several days of maintenance. At some unknown point; someone installed a nose gear pin that had no ribbon or markings. Using standard gear pins with proper markings would have prevented this occurrence.

Original NASA ASRS Text

Title: B737 Captain reported takeoff with an unknown nose gear pin resulted in a return to the departure airport.

Narrative: A 4th gear pin was discovered installed after takeoff in the nose gear. Performed return and landed uneventful. Pin was removed and flight resumed to destination. The aircraft had just returned from several days of maintenance. At some unknown point; someone installed a nose gear pin that had no ribbon or markings. Using standard gear pins with proper markings would have prevented this occurrence.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

B737 captain reported takeoff with an unknown nose gear pin resulted in a return to the departure airport.