What is an Aircraft Components Manufacturer
Automated Data Collection Saves Time, Improves ROI
Total Quality Management (TQM) had its first application at this Southwestern aircraft components manufacturing firm in 1981, and SPC became part of the program in 1989, with manual data collection and charting using paper and pencil.
The company’s Detail Fabrication department first investigated automated SPC in 1988, and eventually selected DataMyte 862 data collectors. The Production Technology Military Assembly department began to look at automated data collection in early 1993 and conducted an industry survey and data collector evaluation.
The company currently manufactures aircraft engine nacelles, vertical and horizontal stabilizers, fin cap, and refueling receptacle panels for the C-17 military transport.
Problem
The Military Assembly Department had a number of key characteristics which must be checked in final assembly of engine nacelles to ensure aerodynamic correctness. These characteristics included the inner and outer fan duct assemblies, core and fan reverser cowlings, and the engine pylon interfaces.
One of the toughest inspections is the 100% circumference joint inspection conducted on the nacelles. The circumference of the nacelle at intake is over 300 inches. An inspector had to move his gauge to each inspection point, manually take a measurement, write it down, and then perform manual charting when all points around the circumference had been measured.
Solution
Four different roving data collectors, including the DataMyte 3053, were evaluated. They were judged on features, versatility, and ease of use. The DataMyte 3053 more than met all of these requirements, and was best suited to the needs of the Military Assembly Department.
A cost benefit analysis for SPC also was conducted by the Detail Fabrication Department. This cost-of-quality analysis compared manual and automated SPC, and demonstrated the payback of each, showing that automated SPC would reduce personnel hours significantly. Detail Fabrication now uses the 3053 data collector for checking dimensional data in its flexible machining center. Items checked include diameter, thickness, length, and width of various machined parts.
Step and gap measurements, ensuring that adjoining panels have the correct gap and are flush with one another, are performed using the 3053 with a DataMyte 516 gap gauge. Other measurements are taken using calipers and dial indicators. Data is collected on aerodynamically critical key characteristics for every engine nacelle. Several parts of the nacelle are measured individually, and then the completed nacelle is assembled and measured as a unit.
The critical engine nacelle circumference measurement is now performed using a 3-point base and dial indicator connected directly to a 3053 data collector for the same operation. Time savings for this one operation are huge.
The 3053 is also used to gather data for process capability studies, including hole diameter, countersink diameter, and fastener head height. In addition, gauge reliability and repeatability studies (gauge R & R) are conducted on various parts using DataMyte data collectors, and sample data for design of experiments (DOE) is also gathered with the data collectors. This has eliminated manual data collection — and its inherent errors — for these processes.
The data is downloaded to DataMyte Quantum software directly from the 3000-series data collectors. A sorted data list is then prepared, and is very helpful in areas where a three-part specification is used. The sort produces a histogram that gives engineers a clear delineation of the ranges involved.
In addition, standard data reports are also prepared and sent with the product to the customer. This serves as statistical evidence of quality (SEQ), as required by military customers. Printed copies of charts and reports, including x-bar and R and histograms, are furnished to the individual manufacturing teams. Some customers also request x-bar and moving range data, but in most cases, individuals data is furnished.
Automated SPC has resulted in major time savings. Using manual SPC as a baseline, production engineers assigned a value of 100 to the time needed to verify a part. With automated SPC, this value is reduced to 25. The company is working toward complete implementation of automated SPC, which is expected to result in even greater savings from reduced scrap, rejection, and rework costs.
