A cessna 172RG pilot had the right main gear fail on landing at mmu.

Attributes
ACN	438232
Time
Date	199905
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : mmu.airport
State Reference	NJ
Altitude	agl single value : 0
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : mmu.tower
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Navigation In Use	ils localizer & glide slope : 23
Flight Phase	landing : roll
Route In Use	approach : instrument precision
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : cfi pilot : instrument
Experience	flight time last 90 days : 45 flight time total : 590 flight time type : 110
ASRS Report	438232
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

I was being vectored to the ILS runway 23 approach at mmu. When told to descend from 3000 ft to 2000 ft (approach altitude), I did my pre-landing check, including lowering the landing gear. I had a green light and saw the left wheel. When we broke out and saw the runway, I added full flaps and reduced power to idle. The plane landed and then banked to the right, at which time the gear warning horn came on. The plane did a 180 degree left turn and came to rest. The nose and left wheel were down, the right gear was folded back. The damage to the plane was minor, and there were no injuries to myself or my passenger (my 5 yr old daughter, who slept through the whole incident). There was some turbulence on the approach and I did not double-check green light and wheel down on short final. The mechanic who inspected the plane said that the gear operated normally, but maybe got unlocked in the turbulence.

Original NASA ASRS Text

Title: A CESSNA 172RG PLT HAD THE R MAIN GEAR FAIL ON LNDG AT MMU.

Narrative: I WAS BEING VECTORED TO THE ILS RWY 23 APCH AT MMU. WHEN TOLD TO DSND FROM 3000 FT TO 2000 FT (APCH ALT), I DID MY PRE-LNDG CHK, INCLUDING LOWERING THE LNDG GEAR. I HAD A GREEN LIGHT AND SAW THE L WHEEL. WHEN WE BROKE OUT AND SAW THE RWY, I ADDED FULL FLAPS AND REDUCED PWR TO IDLE. THE PLANE LANDED AND THEN BANKED TO THE R, AT WHICH TIME THE GEAR WARNING HORN CAME ON. THE PLANE DID A 180 DEG L TURN AND CAME TO REST. THE NOSE AND L WHEEL WERE DOWN, THE R GEAR WAS FOLDED BACK. THE DAMAGE TO THE PLANE WAS MINOR, AND THERE WERE NO INJURIES TO MYSELF OR MY PAX (MY 5 YR OLD DAUGHTER, WHO SLEPT THROUGH THE WHOLE INCIDENT). THERE WAS SOME TURB ON THE APCH AND I DID NOT DOUBLE-CHK GREEN LIGHT AND WHEEL DOWN ON SHORT FINAL. THE MECH WHO INSPECTED THE PLANE SAID THAT THE GEAR OPERATED NORMALLY, BUT MAYBE GOT UNLOCKED IN THE TURB.

Data retrieved from NASA's ASRS site as of July 2007 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.