Liberty XL-2 N550XL

Summary

On 21 February 2007 at about 15:57 local time, a Liberty XL-2 registered N550XL, operated by Ormond Beach Aviation, Inc., was involved in an incident near Ormond Beach, Florida, United States. 2 people were on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

21 February 2007 at 15:57

Classification

Incident

Location

Ormond Beach, Florida, United States

Nearest airport

Ormond Beach Municipal Airport (KOMN)

Coordinates

29.3006, -81.1136

Aircraft

Liberty XL-2

Registration

N550XL

Category

Airplane

Engines

1

Operator

Ormond Beach Aviation, Inc.

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Ormond Beach → Unknown

Aircraft damage

Minor

Weather

VMC

Light

Day

NTSB number

MIA07IA052

Nobody was injured.

The improper manufacturing of the nose undercarriage leg by the vendor, and the inadequate surveillance of the vendor by the airplane manufacturer.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

While landing during a personal flight, the airplane touched down, veered right, and bounced 3 to 4 feet. The pilot-in-command allowed the airspeed to bleed off, and heard the stall warning. The airplane landed hard, and the nose undercarriage leg failed near the 2 inch bend radius. National Transportation Safety Board examination of the nose undercarriage leg revealed overstress separation. Transverse parallel crack-like features were noted on the forward surface of the leg below the fracture. The crack-like features were established to be local transverse regions of oxidation, many of which also contained a transverse crack in the surface. A meandering crack network was also noted in the aft side of the leg adjacent to the fracture. The cracks intersected the fracture at several locations, and oxidation accompanied the cracks. A polished cross-section intersecting the cracks in the forward and aft surfaces revealed at least eight cracks in the forward surface, and one crack in the aft surface. Close examination revealed heavy oxidation of the crack surfaces and adjacent material consistent with high temperature exposure after crack formation. Hardness testing in several locations of the nose undercarriage leg was within limits. No fatigue cracks were noted. The cracks of the nose undercarriage leg were caused due to improper forming of the bend by the vendor. In addition, the airplane manufacturer did not specify forming procedures for the vendor to comply with, nor did they perform any sample testing. The vendor was responsible for performing sample testing. A failure of a nose undercarriage leg owned by the airplane manufacturer occurred 15 days before the incident date. Testing of the failed nose undercarriage leg from the occurrence 15 days earlier revealed it had similar cracks as the incident case investigated by the Safety Board. Further investigation of the manufacturing process of the nose undercarriage legs by the airplane manufacturer revealed the 2-inch bend radius was torch heated then manually bent; the torch heating caused the cracking noted. As a result of the 2 failed nose undercarriage legs, the airplane manufacturer changed vendors, modified the nose undercarriage leg drawing, wrote a specific technical document for future vendors pertaining to the forming procedure, prepared Service Information Letter SIL-07-006, and inspected the nose undercarriage legs of 60 aircraft. Of the 60 aircraft inspected, the nose undercarriage legs of 29 were found to be defective with cracks similar to cracks found in the nose undercarriage leg of N550XL.

Quoted verbatim from the NTSB record.