Jet-Care International has recently upgraded its corporate aircraft from a Piper Malibu piston single to a new Cessna CJ1. The UK-based specialist in aero-engine oil and debris analysis took delivery of the new aircraft in August and is keeping it busy with flights all around Europe, including to its new laboratory in Basel, Switzerland. The company also provides engine condition trend monitoring (ECTM) using gas path analysis (GPA).
The company’s main European laboratory is located in Odiham, 40 mi southwest of London. It also has a U.S. subsidiary operation in Cedar Knolls, N.J. In Europe, where it was founded in 1976, the company trades under the name Spectro Oil Analysis.
The CJ1 is largely based at Blackbushe Airport, seven miles north of its Odiham headquarters. However, the limitations of the airport’s landing aids, opening hours and 4,400-ft runway sometimes oblige the Jet-Care flight department to operate out of nearby Farnborough Airport. Jet-Care is currently seeking to sell its Malibu.
The company employs two full-time pilots, Keith Heron and Roger Frederiks. Heron previously flew Gulfstreams for another corporate operation. Frederiks had been flying Piper Navajos for an Exeter, UK-based air charter firm before joining Jet-Care.
During November the Citation was used for a three-week tour of European customer facilities. It gave company executives direct access to smaller airports with no airline service, such as Kassel, Germany, and made it possible for them to complete several visits in one day. The new jet is currently averaging about 30 hr per month and typically carries three or four passengers.
Early this year Jet-Care will take the CJ1 across the Atlantic to conduct a similar exercise around North America. Heron told AIN that the number of hours flown in the jet is likely to increase over the next 12 months. In his view, the relatively low number of flight hours logged to date has been due to the company making such effective use of the aircraft through careful planning of trips.
Heron manages the operation and is responsible for all logistics and budgets. He told AIN that the European operating environment is not as tough as it is sometimes portrayed, “except for occasional ATC holdups.”
According to Heron, the Citation has greatly enhanced the scope of Jet-Care’s flight operations. He said he can already envision a need for a larger business jet with greater range.
The CJ1 is registered in the U.S. It was not registered in the UK because when the aircraft was ordered the type had yet to complete certification by the British Civil Aviation Authority. However, to avoid legal problems Jet-Care has formally imported the Citation into the UK.
Jet-Care’s services are largely geared to turbine aircraft operators, both airline and corporate (including helicopters). The range of analysis provided by its three laboratories covers oil, hydraulic fluids, fuel, filters and engine debris. The operation runs around the clock and is currently monitoring the health of more than 10,000 aircraft engines in more than 50 countries using GPA.
For GPA, the Jet-Care technicians monitor the following key engine performance parameters and operating conditions for individual flights: outside air temperature; airspeed; flight level; N1 and N2 speeds; temperature of engine exhaust gas after the combustion process; and fuel flow. From the data gathered, the company calculates how a notional engine should perform in these conditions and plots any differences with the engine being monitored.
With the Honeywell ALF502 and LF507 engines, Jet-Care also checks vibration levels, as well as oil temperature and pressure. On the LF507 the data can be downloaded to a laptop by mechanics directly from the Fadec system and then e-mailed to Jet-Care. Data can also be collected digitally from Honeywell TFE731 turbofans.
By observing performance patterns, Jet-Care can identify problems ranging from gauge malfunctions to serious hot-end distress. Technicians are looking for factors such as a slowdown in the engine’s turbine stage combined with increased temperature, which could indicate distress.
Having identified symptoms of hot-end distress, the customer will be advised to conduct a borescope test. The GPA process has uncovered serious damage and wear in engines, such as damaged turbine discs and blades, and burnt trailing-edge stators caused by rubbing. By catching such problems early, operators can reduce repair costs for an incident by as much as 90 percent.
In all cases, the oil, fluids and engine debris tests are designed to uncover evidence of contamination or foreign objects in the oil or fluids. These can indicate excessive wear in the engine that needs to be remedied to head off more serious problems.
In some instances, the tests have uncovered symptoms of a potentially catastrophic failure, in which case Spectro staff will immediately contact the aircraft operator to advise that the engine be immediately removed from service. Senior technician George Hartgill said that on a number of occasions he had been called into the UK laboratory in the early hours of the morning to verify a test result before making calls that resulted in widebody airliners being withdrawn from service just a few hours before scheduled departure.
Oil analysis might, for example, reveal abnormal ferrous (iron) content, suggesting that the engine is shedding metal shavings. Spectro’s database includes extremely detailed baseline information on the metallurgical content of each engine. Similarly, the tests may uncover a sudden drop in a particular compound in an engine. This may well be explained by something as innocuous as the operator replacing a worn engine component without notifying Jet-Care.
The laboratories’ main tools are scanning electron microscopes and inductively coupled plasma spectrometers. These provide an accuracy of 0.1 percent and can pin down exactly which part of an engine the materials found come from. They can analyze materials as minute as one one-thousandth of a millimeter.
The Spectro technicians also use viscometers to test the viscosity of engine oil. These can reveal not only that oil is no longer doing its job properly but, more seriously, that it has deteriorated to the extent that it is actually harming the engine. “For example,” explained Hartgill, “if additives are diluted they can increase the viscosity of the oil and make it hotter due to increased friction–potentially resulting in a fire.”
Another machine is used to test for water content in oil. Condensation in oil is a common problem when engines have been stored or if gearbox fluids flow over the seals. Flash fuel tests are also conducted by Spectro to assess the temperature at which the oil will spark.
The cost of the tests varies from around $15 to $250, which many customers view as a modest investment compared with the expense of unforeseen maintenance or complete engine failure. Some regular customers, such as Crossair, send in samples from all their engines after every 80 to 120 flight hours.
Early in 2000, Spectro introduced its new engine condition health online (Echo) program. The proprietary software allows operator maintenance technicians to receive constant test updates via e-mail and to build an accurate, real-time overview of the status of any given engine in the fleet.
Echo can be customized to the requirements of individual maintenance departments.
For instance, the software could allow data to be networked between employees.
Customers can generate graphs and trend patterns to keep tabs on engine performance in their fleet.
Spectro sales and marketing manager Alan Baker said Echo is popular. The reporting service is provided at no extra charge, and customers are sent a single file for each engine analyzed.
Spectro’s services are recognized by engine manufacturers such as General Electric, Honeywell (nee AlliedSignal), Pratt & Whitney, Pratt & Whitney Canada, Turbomeca and Williams International. Airframers backing its program include Bombardier, BAE Systems, Dassault, Cessna and Raytheon. The regular customer list includes Executive Jet NetJets, Jet Aviation, TAG Aviation and several regional airlines.