Chem-tronics FYI Update 1998
News and Technical Information for
Engine Repair and Aircraft Maintenance Professionals
Contents:
Pratt Certifies HVOF
Coatings for JT8 in Tulsa
Approval Granted to
Repair Airbus CFM56-5C Fan Blades
OASIS Replaces Guillotine
Inspection Procedure
Service Bulletin Announcements
Pratt Certifies HVOF Coatings for JT8 in Tulsa
Tulsa, Oklahoma As a part of GKN Aerospace Chem-tronics Inc.'s efforts to
better serve the needs of its customers, a repair facility was established in, Tulsa,
Oklahoma, for performing all repairs and service bulletins for JT8D engine fan blades.
Today this facility serves the needs of over 35 airlines, overhaul centers, and parts
dealers in the repair and overhaul of fan blades for the JT8D, JT3D, RB211-535, Tay 650,
V2500, and the U.S. Air Force's TF33. In addition, it handles the overhaul of the RB211-535
fan disc and annulus fillers.
In 1990 Chem-tronics announced a major technical partnership with Metco and Pratt & Whitney that has resulted in the implementation of an HVOF (High Velocity Oxy Fuel) sprayed tungsten carbide coating to the mid-span faces of the JT8D. A flight test evaluation period, with two major airlines participating, subjected HVOF-applied coatings together with the baseline standard of PWA46 (D gun) in different model JT8D engines that included the JT8D-217A and 217C. With over 2,000 hours accumulated on each engine tested, Pratt & Whitney's evaluation resulted in the approval of an HVOF spray-applied hardface coating designated at PWA32306 as an equal to PWA46 and PWA256-4. This marks the first approval of a non-proprietary coating system for mid-span faces. Pratt &Whitney has now issued approval to Chem-tronics' Tulsa facility to apply PWA32306 to all JT3D and JT8D fan blade mid-spans. This is the first approval issued by Pratt & Whitney and covered under Chem-tronics' FAA station certificate. It is currently being used on a production basis for JT8D and JT3D fan blades that are repaired by Chem-tronics. This allows Chem-tronics to optimize its turn times on JT8D and JT3D fan blades. To assure consistent coating quality and thickness, robots are used to apply PWA32306. Chem-tronics is continuing in its technical efforts with Pratt & Whitney in flight test programs for Pratt's large thrust engines. By early 1997 it is expected that PWA32306 will be extended to such Pratt & Whitney engine types as the JT9D-3, JT9D-7R4, PW2037, and the PW4000. When this happens, Chem-tronics' El Cajon facility will be ready to provide this service.
Approval Granted to Repair Airbus CFM56-5C Fan Blades
The largest airplanes built by Airbus Industrie are the A340-200 and -300.
Both aircraft are powered by CFMI CFM56-5C engines. Currently there are 66 aircraft flying
with 17 operators and 150 planes on order. The A340 is a 4-engine aircraft with only this
engine option. Chem-tronics has received an approval from CFMI/SNECMA to refurbish the fan
blades and perform airfoil straightening on the bent FOD fan blades. This is the fifth
CFMI fan blade configuration for which Chem-tronics has received certification to perform
overhaul manual repair and restoration. As with previous CFMI models, CFM56-5C fan blades
will have a full range of repairs available for damaged hardware. These repairs will
include airfoil straightening, insert repairs to replace missing material, and shroud
welding to repair shingling. Chem-tronics' previous experience with CFMI components makes
the CFM56-5C fan blade a natural addition to our complete spectrum of fan repairs.
OASIS Replaces Guillotine Inspection Procedure
Chem-tronics has been qualified by CFMI/SNECMA to use our Optical Airfoil
Surface Inspection System (OASIS ) as a final airfoil inspection tool for CFM fan blades.
On our latest repair development program, CFM56-5C2 fan blades, the OASIS inspection
procedure will replace the typical guillotine gage inspection procedure that checks
airfoil contours and twist. The OASIS inspection application developed for the CFM56-5C2
will serve as the model for airfoil configurations in the future at Chem-tronics. Airfoil
inspection with OASIS is faster and makes record keeping for statistics process control
efficient and easy. On a typical fan blade approximately 50 airfoil characteristics are
inspected and a report generated all in 6 minutes, compared to a minimum of 25 minutes
with the conventional guillotine gage. Another benefit of the OASIS process is the
consistency and accuracy of the data recorded. Guillotine gages are now obsolete because,
in addition to their slowness, they rely on interpretation and produce greater variability
of results. OASIS is a video imaging system that uses high resolution digital cameras and
white light interferometry to generate a 3-dimensional map of the blade surface. OASIS
outperforms touch probe CMM inspection systems by gathering more data points and
processing them more quickly. At each airfoil section, OASIS typically collects and
processes 1550 data points. OASIS inspection is the latest technology used in the airfoil
repair industry. Accuracy and speed make OASIS the inspection tool for the future.
Service Bulletin Announcements
Service Bulletin 5625
Conversion of JT8D-209/217A Stage 1 fan blades to the configuration required for the JT8D-217C/219 by Service Bulletin 5625. Chem-tronics is Pratt & Whitney-approved for this source controlled modification. Modification work at our Tulsa, OK, facility has begun for several major airlines which are converting their engines. Chem-tronics has also received Pratt & Whitney approval to make the conversion of the JT8D-217C/219 to the JT8D-209/217A configuration at customer request. These conversions can incorporate the repairs of Service Bulletin 6174 and 6193 as required.
Service Bulletin 6174 & 6193
Leading Edge Cut Back and Mid Span Shroud Face Angle Modification. Pratt & Whitney approved Chem-tronics in January, 1995, to accomplish Service Bulletins 6174 and 6193 for the JT8D-209/217A/217C/219 Stage 1 Fan Blade. These two service bulletins require source substantiation by Pratt & Whitney. These service bulletins are performed at our Tulsa, OK, facility where dedicated equipment meets an increasing demand for these bulletins. Chem-tronics has completed thousands of fan blades for air carriers and overhaul centers that have incorporated Service Bulletins 6174 and 6193.