A cessna 208, on landing, pulled excessively to the right, and the main tires deflated.

Attributes
ACN	573797
Time
Date	200302
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : charter
Make Model Name	Caravan 1 208A
Operating Under FAR Part	Part 135
Flight Phase	landing : roll
Flight Plan	IFR
Person 1
Affiliation	company : charter
Function	flight crew : single pilot
Qualification	pilot : multi engine pilot : commercial pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 150 flight time total : 12500 flight time type : 3000
ASRS Report	573797
Person 2
Affiliation	government : faa
Function	controller : local
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : company policies non adherence : far non adherence : published procedure other anomaly
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	other other
Factors
Maintenance	performance deficiency : inspection performance deficiency : installation
Supplementary
Problem Areas	Maintenance Human Performance Flight Crew Human Performance Aircraft
Primary Problem	Maintenance Human Performance

Narrative:

The incident was at ZZZ. 2 blown tires. Clear day, dry runway. I was early and in no hurry. Touchdown seemed normal. As I started to brake, the airplane started a pulling motion to the right. The slower the speed of the aircraft, the more severe the right pulling motion. To compensate for that effect, I used differential rudder and braking. I brought the aircraft to a safe stop on the runway. The aircraft started to turn 180 degrees, and the left tire deflated. The aircraft was removed from the runway. After installing the tires, the mechanics noticed that the right tire would not tighten down and that the tire would shimmy left and right. So, they broke down the right tire and found that there was a bushing missing. They talked with our maintenance, and I went to aircraft to see if I could acquire the part. They did not have one in stock. When I returned, they informed me that they had the bushing. They then explained to me that when they took off the axle nut, it must have fallen inside the jack. As we talked further, they made me aware that the bushing would have to have been improperly installed to have fallen out. The bushing goes inside of the seal cover on the back side to push against the bearing to hold the tire assembly secure. To get the bushing out, you must remove the split ring, take the seal out, and take the bushing off of the back of the seal. It was their belief that the bushing was placed outside the seal, and when the axle nut was removed, it fell out. Their feeling was that being improperly installed would have allowed the tire to shimmy left and right, and could have contributed to the incident. They also said it could have broken the axle if conditions were right. They reinstalled the tire correctly, and I felt satisfied I could at least return the aircraft to our maintenance base safely. Callback conversation with reporter revealed the following: the reporter stated the installation of the tire and wheel assembly was improperly done. The reporter said the right main inner bearing was installed correctly behind the grease seal, but the support bushing was installed outside of the seal, causing the wheel to wobble, due to no bearing support. The reporter stated the major damage was to the 2 main gear wheel tires.

Original NASA ASRS Text

Title: A CESSNA 208, ON LNDG, PULLED EXCESSIVELY TO THE R, AND THE MAIN TIRES DEFLATED.

Narrative: THE INCIDENT WAS AT ZZZ. 2 BLOWN TIRES. CLR DAY, DRY RWY. I WAS EARLY AND IN NO HURRY. TOUCHDOWN SEEMED NORMAL. AS I STARTED TO BRAKE, THE AIRPLANE STARTED A PULLING MOTION TO THE R. THE SLOWER THE SPD OF THE ACFT, THE MORE SEVERE THE R PULLING MOTION. TO COMPENSATE FOR THAT EFFECT, I USED DIFFERENTIAL RUDDER AND BRAKING. I BROUGHT THE ACFT TO A SAFE STOP ON THE RWY. THE ACFT STARTED TO TURN 180 DEGS, AND THE L TIRE DEFLATED. THE ACFT WAS REMOVED FROM THE RWY. AFTER INSTALLING THE TIRES, THE MECHS NOTICED THAT THE R TIRE WOULD NOT TIGHTEN DOWN AND THAT THE TIRE WOULD SHIMMY L AND R. SO, THEY BROKE DOWN THE R TIRE AND FOUND THAT THERE WAS A BUSHING MISSING. THEY TALKED WITH OUR MAINT, AND I WENT TO ACFT TO SEE IF I COULD ACQUIRE THE PART. THEY DID NOT HAVE ONE IN STOCK. WHEN I RETURNED, THEY INFORMED ME THAT THEY HAD THE BUSHING. THEY THEN EXPLAINED TO ME THAT WHEN THEY TOOK OFF THE AXLE NUT, IT MUST HAVE FALLEN INSIDE THE JACK. AS WE TALKED FURTHER, THEY MADE ME AWARE THAT THE BUSHING WOULD HAVE TO HAVE BEEN IMPROPERLY INSTALLED TO HAVE FALLEN OUT. THE BUSHING GOES INSIDE OF THE SEAL COVER ON THE BACK SIDE TO PUSH AGAINST THE BEARING TO HOLD THE TIRE ASSEMBLY SECURE. TO GET THE BUSHING OUT, YOU MUST REMOVE THE SPLIT RING, TAKE THE SEAL OUT, AND TAKE THE BUSHING OFF OF THE BACK OF THE SEAL. IT WAS THEIR BELIEF THAT THE BUSHING WAS PLACED OUTSIDE THE SEAL, AND WHEN THE AXLE NUT WAS REMOVED, IT FELL OUT. THEIR FEELING WAS THAT BEING IMPROPERLY INSTALLED WOULD HAVE ALLOWED THE TIRE TO SHIMMY L AND R, AND COULD HAVE CONTRIBUTED TO THE INCIDENT. THEY ALSO SAID IT COULD HAVE BROKEN THE AXLE IF CONDITIONS WERE RIGHT. THEY REINSTALLED THE TIRE CORRECTLY, AND I FELT SATISFIED I COULD AT LEAST RETURN THE ACFT TO OUR MAINT BASE SAFELY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: THE RPTR STATED THE INSTALLATION OF THE TIRE AND WHEEL ASSEMBLY WAS IMPROPERLY DONE. THE RPTR SAID THE R MAIN INNER BEARING WAS INSTALLED CORRECTLY BEHIND THE GREASE SEAL, BUT THE SUPPORT BUSHING WAS INSTALLED OUTSIDE OF THE SEAL, CAUSING THE WHEEL TO WOBBLE, DUE TO NO BEARING SUPPORT. THE RPTR STATED THE MAJOR DAMAGE WAS TO THE 2 MAIN GEAR WHEEL TIRES.

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.