N769EA

On August 31, 2012, about 1630 eastern daylight time, a Cessna 402C, N769EA, registered to and operated by Hyannis Air Service, Inc., dba Cape Air, as Flight 775, experienced collapse of the nose landing gear during the landing roll at Nantucket Memorial Airport (ACK), Nantucket, Massachusetts. Visual meteorological conditions prevailed at the time and a visual flight rules flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 135, scheduled domestic passenger flight from Barnstable Municipal Airport-Boardman/Polando Field (HYA), Hyannis, Massachusetts, to ACK. The airplane sustained minor damage and there were no injuries to the airline transport pilot or 9 passengers. The flight originated from HYA about 1608.The pilot stated that on approach to ACK he extended the landing gears and performed the Before Landing Checklist with normal indications (3 Green, no red, no gear warning horn). He landed on the main landing gears, and as he lowered the nose, it continued down until contact with the runway. He notified air traffic control and evacuated the passengers.

Post incident inspection of the nose landing gear revealed the nose landing gear drag brace part number (P/N) 5142002-5, was fractured near the actuator attachment lug.

Examination of the nose landing gear drag brace was performed by the NTSB Materials Laboratory located in Washington, D.C. The results of the examination revealed the drag brace was fractured aft of the actuator attachment clevis. The rod end fitting for the actuator was also fractured, while the bearing end of the end fitting remained attached to the drag brace. The fracture features of the rod end fitting were matte gray and rough consistent with ductile overstress fracture. A portion of the fracture surface of the nose landing gear drag brace revealed the extent of the fatigue crack was approximately 40 percent of the cross section. The fatigue features originated from the upper inboard corner, which was in the area that was reworked during a repair made in July 2012; however, no tightly curving crack arrest features consistent with an origin were observed adjacent to the surface. The blend radius at the aft side of the lug measured 0.12 inch. Additionally, no evidence of paint was observed on the fracture surface. A copy of the NTSB Materials Laboratory Factual Report is contained in the NTSB public docket.

A representative of the airplane manufacturer reported the date of manufacture of nose landing gear drag brace part number (P/N) 5142002-5, could not be determined. The representative also reported the part is not serialized at manufacture, and the date and to whom the part was shipped after manufacture could not be determined.

According to the information provided by the operator, the first historical documentation associated with nose landing gear drag brace P/N 5142002-5 was Federal Aviation Administration (FAA) Form 8130-3, associated with a repair by a FAA Certificated Repair Station (FAA CRS) dated June 19, 2011.

Review of the FAA Form 8130-3 Form associated with the June 19, 2011, repair revealed the part was cleaned, repaired, inspected and was approved for return to service by the FAA CRS. The form also indicates that the nose landing gear drag brace was "… Inspected and Repaired [in accordance with] MEB 91-11 Rev 1 as supplied by customer. Replaced four bearings. Identified crack repaired I.A.W. Above MEB. Unit ID spotted to alert compliance with MEB. Painted and returned unit to service." At this repair the part was identified with serial number (S/N) T35119. A copy of the FAA Form 8130 is contained in the NTSB public docket.

Following the repair, the nose landing drag brace was installed in another airplane (N68391) on June 29, 2011, and removed from that airplane on November 11, 2011, after accruing 473.4 hours. On December 22, 2011, the drag brace was installed onto N26514, and was removed from that airplane on July 24, 2012, after accruing approximately 530 hours since installation, or a total of 1,003 hours since being reworked in June 2011. A copy of the installation and removal records is contained in the NTSB public docket.

The nose landing gear drag brace was then sent to the same FAA CRS that performed the repair in June 2011, and according to documents provided by the facility, a 1/8 inch long shallow crack was noted near the actuator attach lugs. The crack was blended in accordance with Cessna Service Bulletin MEB91-11, Revision 1, and a Fluorescent Dye Penetrant inspection of the area was then performed. No further crack was detected so the part was painted and returned to service on July 26, 2012. A copy of the records from the repair station is contained in the NTSB public docket.

According to the airplane maintenance records, during a routine Phase 5 inspection, on August 3, 2012, at airframe total time of 27,968.1 hours, nose landing gear drag brace P/N 5142002-5, T35119 was installed onto the incident airplane. Since installation, the nose landing gear drag brace was visually inspected in-situ twice during a special inspection of the rod end area for condition and security. The first occurred during a Phase 6 inspection performed on August 15, 2012, at airframe total time of 28,025.6 hours, and the second occurred during a Phase 1 inspection performed on August 27, 2012, at airframe total time of 28,074.6 hours. The airplane total time at the time of the incident was reported to be 28,098.6 hours.

The airplane had been operated for approximately 131 hours and approximately 218 cycles (based on the 2012 average utilization of 0.6 hour per cycle) since the repaired nose landing gear drag brace was installed. Since actual cycles is not tracked by the operator, they were asked by NTSB to determine the actual number of cycles since installation of the nose landing gear drag brace; they reported it was 286. The operator also reported that the nose landing gear drag brace total time since June 2011 was approximately 1,134 hours.

At the time of the incident, the operator was removing the nose landing gear drag brace every 400 hours to comply with Cessna Multi-Engine Service Bulletin MEB91-11R1.

Cessna Multi-Engine Service Bulletin MEB91-11, Revision 1, dated February 24, 2003, indicates reports of cracking of the nose landing gear drag brace near the actuator attach lugs, which could result in a drag brace failure and inability of the nose landing gear to lock in the down position. The bulletin indicates that airplanes that have a nose landing gear drag brace that was shipped from Cessna Parts distribution on or after July 2, 2002, are exempt from the bulletin. Additionally, the bulletin indicates that for airplanes with the P/N of drag brace installed (5142002-5), shall be inspected within the next 250 landings or 12 months whichever occurs first, and upon reaching 2,000 landings or for drag braces with over 2,000 landings, this inspection shall be repeated every 250 landings for drag braces that have been reworked to remove a crack per the requirements of this Service Bulletin.

On April 1, 2009, Cessna Aircraft Company incorporated Supplemental Inspection Number 32-20-00 (SI 32-20-00) into the maintenance manual. The supplemental inspection pertained to the nose landing gear drag brace and specified a visual and Fluorescent Liquid Penetrant Inspection, and if a repair for cracks(s), corrosion, or damage is required for a repair that is not available in the Model 402C maintenance manual, to contact Cessna Customer Service for possible repair instructions or replace the part. On September 30, 2011, SI 32-20-00 was revised indicating that the required inspection method of the nose landing gear drag braces is visual and eddy current, that repairs or modification of cracked nose landing gear drag braces was not allowed, and the document supersedes MEB91-11. The operator did not incorporate SI 32-22-00 into their maintenance program and were not complying with it; therefore, they were still complying with MEB91-11R1 at the time of the incident.

A review of FAA Service Difficult Reports (SDR's) pertaining to nose landing gear drag brace P/N 5142002-5 revealed that from 1995 to March 12, 2014, excluding the SDR submitted for the incident event, there were a total of 13 reported issues involving either cracking or failure of the nose landing gear drag brace (1 duplicate entry was noted). Of the 13 reports, 5 were submitted by the operator. Between 2002 and March 12, 2014 (SDR run date), excluding the SDR submitted for the incident event, there were 3 reports involving either cracking or failure of nose landing gear drag brace P/N 5142002-5, of which 2 were submitted by the operator. Of the 2 reports submitted by the operator, 1 related to finding the nose landing gear drag brace cracked at regular scheduled inspection and the other in May 2010, which was the only one submitted in 2010, related to collapse of the nose landing gear due to failure of the nose landing gear drag brace. In 2011, and in 2012 (excluding the incident event), the operator or the FAA CRS who was inspecting the nose landing gear drag braces for the operator did not submit any Malfunction or Defect Report concerning cracking of the nose landing gear drag braces. A copy of the SDR's is contained in the NTSB public docket.

According to records generated by the FAA CRS that last inspected the failed nose landing gear drag brace, between 2002 and 2012, the operator submitted to them a total of 1,216 nose landing gear drag braces for MEB91-11R1 inspection. Of those, a total of 1,102 were repaired and 114 were cracked beyond the allowable repair limit of MEB91-11R1. Specifically, in 2010, a total of 161 nose landing gear drag braces were inspected per MEB91-11R1, of which 24 were found to be cracked beyond the allowable repair limit of the bulletin. In 2011 and 2012, a total of 687 nose landing gear drag braces were

inspected per MEB91-11R1, of which 51 were found to be...