N769EACessna 402C · 1980

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 cracked beyond the allowable repair limit of the bulletin. A copy of the drag brace inspection list is contained in the NTSB public docket.

A review of 14 CFR Part 135.415 titled Service Difficulty Reports, revealed that each certificate holder is required to report the occurrence or detection of each failure, malfunction, or defect in an aircraft concerning in part an unwanted landing gear retraction. Additionally, each certificate holder shall report any other failure, malfunction, or defect in an aircraft that occurs or is detected at any time, if, in its opinion, the failure, malfunction, or defect has endangered or may endanger the safe operation of the aircraft.

A review of 14 CFR Part 145.221 titled Service Difficulty Reports, pertaining to FAA Certificated Repair Stations, revealed that a repair station must report to FAA within 96 hours after it discovers any serious failure, malfunction, or defect of an article. The regulation also indicates that a certificated repair station may submit a service difficult report for a 14 CFR Part 135 certificate holder, provided the report meets the requirements of Part 135. However, the certificated repair station and Part 135 certificate holder must not report the same failure, malfunction, or defect. If the certificated repair station submits a SDR, it is required to submit a copy to the certificate holder.

On April 27, 2009, at 0700 eastern daylight time, a Cessna 402C, N769EA, Cape Air flight 84, registered to Hyannis Air Service LLC, operated by Cape Air/Nantucket Airlines as a 14 Code of Federal regulations Part 135 scheduled domestic passenger flight, received minor damage when the left main landing gear collapsed during landing roll out at Nantucket Memorial Airport (ACK), Nantucket, Massachusetts. Visual meteorological conditions prevailed and a company visual flight rules flight plan was filed. The certificated airline transport pilot and eight passengers reported no injuries. The flight originated from Barnstable Municipal Airport (HYA), Hyannis, Massachusetts, at 0633.

The pilot stated he lowered the landing gear on final approach to runway 6 at ACK. The left main landing gear light did not illuminate and the landing gear unlock light and hydraulic pressure light remained illuminated. The pilot recycled the landing gear with negative results. He informed the Nantucket control tower of the malfunction and made a go-around. The pilot completed the "Gear Will Not Extend" checklist and activated the blow down bottle with negative results. He then completed the "Landing With Defective Main Gear" checklist and asked the tower operator to notify the airport rescue and firefighting. The pilot landed the airplane on runway 6 and the left main landing gear collapsed.

The captain, age 24, holds an airline transport pilot certificate with a rating for airplane multiengine land. He holds a commercial pilot certificate with a rating for airplane single-engine land, issued on August 13, 2008. In addition, he holds a flight instructor certificate with ratings for airplane single-engine, airplane multiengine, and instrument airplane, issued on May 29, 2008. He also holds a ground instructor certificate with ratings for advanced instruments issued on August 13, 2008.

The operator hired the captain on May 5, 2005, and he completed his initial operating experience (IOE) in the Cessna 402 on June 20, 2007. The pilot completed his initial Part 135 check ride as a second-in-command on July 14, 2005. He completed a pilot-in-command (PIC) checkride for mail and freight on June 13, 2006, and was qualified as a PIC in all company operations on June 19, 2007. His last Part 135 checkride was on January 18, 2009, and his last line check was on January 26, 2009. The captain has 3,525 total flight hours; of which, 2,750 hours are in the Cessna 402C and 3,111 hours as PIC. He holds a first-class medical certificate issued on April 15, 2009 with the limitation, "must wear corrective lenses." Review of the captain's training records revealed all pertinent aviation records pertaining to 14 CFR Part 135 airman competency and proficiency checks had been recorded as conducted.

The Cessna 402C, serial number 402C0303, is a twin-engine airplane with a tricycle landing gear manufactured in 1980. The airplane has a seating capacity of one flight crew, and nine passengers. Two Continental TSIO-520-VD fuel injected 325-horsepower engines power the airplane. Hyannis Air Service LLC purchased the airplane from Canyon leasing Inc., on January 8, 1999. The last approved aircraft inspection program (AAIP) inspection was completed on April 18, 2009.The total airframe time at the time of the incident was 24,161 hours. The left engine had 2,321.6 total flight hours at the time of the incident, and had flown 5.9 hours since the inspection. The right engine had 10.8 total flight hours at the time of the incident, and had flown 5.9 hours since the inspection. The last gear retraction test before the incident and emergency gear extension test was completed on April 16, 2009.

The 1628 ACK surface weather observation was: wind 120 degrees at 9 knots, visibility 10 miles, sky clear, temperature 10 degrees Celsius, dew point temperature 4 degrees Celsius, and altimeter 30.39 inches of mercury.

The airplane came to a stop in the grass off the left side of runway 6, and an emergency evacuation was completed. Initial inspection of the airplane by an Federal Aviation Administration (FAA) inspector revealed the left main landing gear collapsed during landing when the left gear did not lock in the down position. The left flap was scraped on the lower left surface and the left wing tip was damaged. A dent was present on the left wing about 8 feet inboard of the left engine, where it collided with a taxiway light. The left propeller was also damaged.

The airplane was lifted up with recovery equipment; maintenance personnel extended the left main landing gear by hand, and verified the landing gear was down and in the locked position. The airplane was towed to the ramp and inspected.

An FAA inspector issued a special flight permit on April 29, 2009, and the airplane was flown to HYA for further inspection and repair. A Landing gear retraction test was conducted and the failure of the left main landing gear to extend was duplicated. It was noted that hydraulic pressure was available at the extend inlet side of the up lock actuator, but not on the extend outlet side of the actuator. Although the up lock actuator properly retracted, the up lock hook allowed the landing gear to fall from the well. The extend inlet port was removed for inspection. It was discovered that one of the small ball bearings was in the wrong position with respect to the larger ball bearing. In addition, the ball bearing was smaller in diameter, allowing the smaller ball bearing to jump the larger ball bearing, causing a blockage. The up lock actuator and the main gear actuator were removed and placed in quarantine pending further examination.

Disassembly of the up lock actuator at an authorized repair facility found an improperly sized ball bearing installed, which controls the port opening to the actuator. The actuator housing was damaged in the area of the ball seat along with the ball spring and fitting assembly. The main gear actuator was tested and all functions of the lock, unlock, and all pressure limits were within manual limits.

The operator's Director of Maintenance stated, “The up lock actuators are on a condition item and we do not have them overhauled. All work on these actuators are performed in our in-house shop by 1 individual performing this work for over 10 years. This individual was questioned and indicated that he has never replaced the ball bearings in the actuator. The only work performed on these actuators is to replace the o rings on the fittings due to leaking, and if needed due to corrosion pitting, the internal shaft is replaced.” He further stated the actuators have not been added to the tracking system. “We have no way of properly tracking it to look at its history. Since this event was a latent failure, we have no idea who, when, or how long the ball in question was placed in the actuator.”

Toxicology specimens were taken from the captain. The specimens were sent to Mid Cape Medical Center, Hyannis, Massachusetts for analysis. The results were negative for amphetamines, opiates, marijuana, cocaine, and phencyclidine.

Review of FAA surveillance records for the Part 135 operation of Hyannis Air Service Inc., revealed the FAA conducted 81 maintenance or operation enroute inspections, 207 airworthiness surveillance inspections, 113 operations inspections, and 13 facility inspections, from April 27, 2008, through April 27, 2009.