In a velocity rg, as the nose gear was lowered to the runway, a violent oscillation occurred and the...

Attributes
ACN	582782
Time
Date	200305
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Amateur (Home) Built
Operating Under FAR Part	Part 91
Flight Phase	landing : roll
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 30 flight time total : 1700
ASRS Report	582782
Person 2
Affiliation	other
Function	observation : passenger
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other other : person 1
Resolutory Action	none taken : detected after the fact
Consequence	other other
Factors
Maintenance	performance deficiency : inspection
Supplementary
Problem Areas	Maintenance Human Performance Chart Or Publication Aircraft
Primary Problem	Aircraft

Narrative:

As I lowered the nose to the runway a violent oscillation broke out in nose gear. It broke off at the fuselage. FSDO could not be reached to get permission to move aircraft. Oscillation had occurred in the past and reinforcement had been added to the nose gear bulkhead. Nose gear axle, wheel, fork and strut had been inspected. A crack in the heat treated strut was not visible until it broke completely. Having a passenger in the front seat apparently changed the caster angle enough to allow shimmy. Callback conversation with reporter revealed the following information: the reporter stated this nose gear had a slight noticeable vibration that resulted in the bulkhead supporting the landing gear strut to crack. The reporter said the bulkhead cracks were repaired and the bulkhead reinforced. The reporter stated that after the nose gear broke it was discovered the factory that made the chromalloy strut had bent the strut incorrectly causing the vibration and crack. The reporter said the error was admitted by the factory. The reporter stated inspection of the entire strut is difficult especially where it joins the bulkhead, the area where the failure occurred. The reporter said the manufacturer has alerted home builders of this kit of the problem with newer struts.

Original NASA ASRS Text

Title: IN A VELOCITY RG, AS THE NOSE GEAR WAS LOWERED TO THE RWY, A VIOLENT OSCILLATION OCCURRED AND THE NOSE GEAR BROKE OFF, CAUSED BY A CRACKED NOSE STRUT.

Narrative: AS I LOWERED THE NOSE TO THE RWY A VIOLENT OSCILLATION BROKE OUT IN NOSE GEAR. IT BROKE OFF AT THE FUSELAGE. FSDO COULD NOT BE REACHED TO GET PERMISSION TO MOVE ACFT. OSCILLATION HAD OCCURRED IN THE PAST AND REINFORCEMENT HAD BEEN ADDED TO THE NOSE GEAR BULKHEAD. NOSE GEAR AXLE, WHEEL, FORK AND STRUT HAD BEEN INSPECTED. A CRACK IN THE HEAT TREATED STRUT WAS NOT VISIBLE UNTIL IT BROKE COMPLETELY. HAVING A PAX IN THE FRONT SEAT APPARENTLY CHANGED THE CASTER ANGLE ENOUGH TO ALLOW SHIMMY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THIS NOSE GEAR HAD A SLIGHT NOTICEABLE VIBRATION THAT RESULTED IN THE BULKHEAD SUPPORTING THE LNDG GEAR STRUT TO CRACK. THE RPTR SAID THE BULKHEAD CRACKS WERE REPAIRED AND THE BULKHEAD REINFORCED. THE RPTR STATED THAT AFTER THE NOSE GEAR BROKE IT WAS DISCOVERED THE FACTORY THAT MADE THE CHROMALLOY STRUT HAD BENT THE STRUT INCORRECTLY CAUSING THE VIBRATION AND CRACK. THE RPTR SAID THE ERROR WAS ADMITTED BY THE FACTORY. THE RPTR STATED INSPECTION OF THE ENTIRE STRUT IS DIFFICULT ESPECIALLY WHERE IT JOINS THE BULKHEAD, THE AREA WHERE THE FAILURE OCCURRED. THE RPTR SAID THE MANUFACTURER HAS ALERTED HOME BUILDERS OF THIS KIT OF THE PROB WITH NEWER STRUTS.

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.

In a velocity rg, as the nose gear was lowered to the runway, a violent oscillation occurred and the nose gear broke off, caused by a cracked nose strut.