Boeing B-727-200 N770AT

Summary

On 9 July 1997 at about 13:40 local time, a Boeing B-727-200 registered N770AT was involved in an incident near Indianapolis, Indiana, United States. 11 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

9 July 1997 at 13:40

Classification

Incident

Location

Indianapolis, Indiana, United States

Nearest airport

Indianapolis Intl (IND)

Coordinates

39.7300, -86.2895

Aircraft

Boeing B-727-200

Registration

N770AT

Category

Airplane

Engines

3

Operator

Not recorded

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Las Vegas

Aircraft damage

Minor

Weather

IMC

Light

Day

NTSB number

CHI97IA205

Nobody was injured.

the improper installation of the incorrect spherical bearing by the company's maintenance personnel. A factor was the improper plating of the trunnion with chromium by the landing gear overhaul facility.

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

Read the full NTSB narrative

While the aircraft was being loaded with passengers, the flight engineer found that the right main landing gear had partially collapsed. The fractured right main landing gear had recently been overhauled and had accumulated 51 cycles and 126 hours since installation 21 days prior to the fracture. An examination was made of the aft portion of the upper and lower lugs of the trunnion. Chromium plating was apparent on sections of the trunnion where the overhaul manual stated that 'No Chrome' was to be applied. The spherical bearing assembly, locking bolt and anti-rotation washer were also examined. For normal assembly, the aft trunnion of the gear is inserted into the inner diameter of the wing mounted spherical bearing. The spherical bearing that contacted the trunnion journal had an inner diameter which measured approximately 3.50 inches. The aft trunnion journal of the failed landing gear had an outer diameter that measured approximately 3.25 inches. During landing gear replacement, the maintenance procedures require that the proper sized spherical bearings, either 3.50 inch or the 3.25 inch inner diameter, be matched with the appropriate outer cylinder aft trunnion outside diameter.

Quoted verbatim from the NTSB record.