The captain of a cessna C550 reported that after takeoff the landing did not fully retract.

Attributes
ACN	1412253
Time
Date	201612
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	Citation II S2/Bravo (C550)
Operating Under FAR Part	Part 135
Flight Phase	Initial Climb
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Gear Up Lock
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 8450 Flight Crew Type 1600
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

Aircraft took off; as we retracted the gear; the air traffic control tower advised us that our gear appeared to not be up. We had the associated gear unlocked light on with the gear selected up. We asked to fly runway heading to our initial assigned altitude and restricted speed below 176 knots maximum gear extended speed and ran the checklist for the gear unlocked light illuminated.the checklist only made reference for extending the gear; but none for retraction so using my experience in the plane; and using the checklist as a guide; we followed the list up to the portion where we blow the nitrogen to lock the gear in place since we had three green lights and no unlock light. I cycled the rotary test to 'ldg gear' to verify the continuity of the gear unlocked light; and retarded the throttles below 70% N2 to verify there was no gear horn. We entered a holding pattern to dissipate fuel as to land below the 12;700 pound landing weight limit and then did a low pass over the air traffic control tower to have a visual confirmation of landing gear extension. The landing was successful with no further issues while taxiing to the FBO.

Original NASA ASRS Text

Title: The Captain of a Cessna C550 reported that after takeoff the landing did not fully retract.

Narrative: Aircraft took off; as we retracted the gear; the Air Traffic Control Tower advised us that our gear appeared to not be up. We had the associated gear unlocked light on with the gear selected up. We asked to fly runway heading to our initial assigned altitude and restricted speed below 176 knots maximum gear extended speed and ran the checklist for the gear unlocked light illuminated.The checklist only made reference for extending the gear; but none for retraction so using my experience in the plane; and using the checklist as a guide; we followed the list up to the portion where we blow the nitrogen to lock the gear in place since we had three green lights and no unlock light. I cycled the rotary test to 'LDG GEAR' to verify the continuity of the gear unlocked light; and retarded the throttles below 70% N2 to verify there was no gear horn. We entered a holding pattern to dissipate fuel as to land below the 12;700 pound landing weight limit and then did a low pass over the Air Traffic Control Tower to have a visual confirmation of landing gear extension. The landing was successful with no further issues while taxiing to the FBO.

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.