The prognostics

Interesting about the F-35A AF-27 June fire that is being blamed on the PW F135 motor.

Why didn't the jet engines prognostic health monitoring systems (in the aircraft, engine and ground equipment) detect such serious problems?

These systems have been in use in the civil and military aerospace world for years. If an oil sample turns out bad or if any number of sensors detect an adverse trend while the motor is running, you would think there would be "prognostic" health warning.

And the mishap motor didn't have that many hours on it.

Here are the duties of a PW field rep:

Coordinate F135 propulsion system maintenance activities with the OT&E squadrons, Joint Operations Test Team maintenance planners, and P&W team

Perform Controls activities related to aircraft download processing and analysis, propulsion system software loads, activations and monitoring of propulsion system Prognostic Health Monitoring, Engine Health Reporting Codes, and Maintenance Built-In Test Systems

Advise and assist the Customer in performance of F135 propulsion system maintenance, ensuring activities are performed IAW technical data and safe engine operation and maintenance procedures. Activities include fault isolation/troubleshooting and F135 repair actions consistent with the F135 Unit Level Maintenance Concept

Support Government Property Management processes for program execution, to include but not limited to support equipment, tooling, material supply, and government processes

Work closely with P&W Customer Support Engineering to resolve technical and logistical problems involving F135 engine operation and maintenance through the use of the Autonomic Logistics Information System and MERLIN System

Use initiative and judgment to identify problems, conduct investigations to determine root causes, and implement corrective actions

Actively support ACE initiatives and ensure employee safety by complying with and supporting EH&S activities

Actively interface with local Edwards OT&E military personnel at all levels from senior leadership to the newest recruits.

Provide timely insight to PW management relative to emerging issues and relationship with the engine and the weapons system. Business Unit: Pratt & Whitney

OK, off to Canada:

F135 Engine Program Places US$48 Million Purchase Order with GasTOPS of Canada

EAST HARTFORD, Conn., May 27, 2009: Pratt & Whitney announced today that Hamilton Sundstrand , a key supplier on the F135 engine for the F-35 Lightning II, placed a purchase order with GasTOPS for the fan eddy current sensor for the F135. The agreement has a potential value of $48 million over the life of the program. Pratt & Whitney and Hamilton Sundstrand are United Technologies Corp . (NYSE:UTX) companies.

"Our company has worked closely with Pratt & Whitney and Hamilton Sundstrand for many years on the development and introduction of advanced sensors for engine health monitoring," said Dave Muir, chief executive officer of GasTOPS. "We are extremely pleased and proud to be selected for this new program and to have the opportunity to continue this successful partnership."

The fan eddy current system is part of the prognostic health monitoring system that monitors the structural health of the fan blades.

How about the F135 design theory?

The F135 integrates the F119 core, a six-stage HP compressor and single-stage HP turbine unit, with a new low-pressure spool featuring a very high pressure ratio fan driven by a two-stage LP turbine. In addition, the propulsion system features prognostic and on-condition management systems that provide maintenance awareness, autonomic logistic support, and automatic field data and test systems.

Propulsion system support and maintainability are further enhanced by the F135's maintenance-focused design. It has approximately 40 percent fewer parts, which also improves reliability. All line-replaceable components (LRCs) can be removed and replaced with a set of six common hand tools. And, the F135 has a 50 percent lower infrastructure support requirement compared to current engines.

Some thoughts from a small-mouth F-16 engine guy...

If you thought FADECs made motors smart; this is the next step to a true "intelligent engine."

The F135 team has also issued a contract of its own to Diagnostic software maker Qualtech Systems Inc. of Wethersfield, CT to provide real-time on-board diagnostics for its jet engines. The contract calls for Qualtech Systems to provide fault isolation development software tools and an an on-engine "diagnostic reasoner" as part of Pratt & Whitney's Joint Strike Fighter Engine Prognostics & Health Management (PHM) Program.

PHM will make use of electrostatic and other sensors to monitor such parameters as debris generation, vibration, blade health and lubricating-oil quality. The suite of sensors will constantly monitor approximately 500 data streams, which will be integrated with the F-35's own systems. The complete PHM system has been developed in partnership with NASA Ames, which created vital data-fusion algorithms, NASA Dryden and NASA Glenn, with flight development to be carried out with a C-17. As noted previously, the aim is to predict the need for inspection or parts-replacement, so that, via a satellite link, the airbase or aircraft carrier knows the engine health before the aircraft returns from its mission.

500 data streams!? ..and the engine will know when it's broke!? WOW!

How do you figure they're going to do these things? (Thoughts anyone?)

1. Debris Generation = Chip detectors?
2. Vibration = Vib Checks are done with sensors during testing now, they'll also be on board?
3. Blade Health? Pass an eddy-current through the blisk(s) to find FOD/Cracks?
4. Lubricating-oil quality = on board oil-analysis? Done with a small SOAP module?

I'm looking into NASA's C-17 testing now. I'll post more as I find it.

PW does however want to clear up some things. Their 'truth' of course... from 2010:

Following competition, the next most commonly heard refrain from the F136 camp constitutes myth number two: that a single engine supplier for the F-35 presents too much risk to the warfighter.

Supporters of the duplicative alternate engine argue that a second engine is necessary to mitigate the threat of a fleet-wide grounding. This is nothing but a scare tactic, and quite frankly, counter to GE’s own military engine business. There are more than 4,000 GE F404s powering the entire F/A-18 fleet and 14,000 GE T700s powering all the current and future Apache and Blackhawk/Seahawk fleets. These are massive fleets of aircraft, powered by a sole source engine provider, and neither has ever experienced a fleet-wide grounding. Nor has the F-22 powered solely by the Pratt & Whitney F119. The bottom line is that no military aircraft developed in the past three decades has been procured with multiple engine suppliers because it is unnecessary.

Why? Because advances in computer-based design and simulation applications, rigorous testing regimes, highly accurate, capable, and repeatable manufacturing processes, new durable materials and powerful digital electronics have dramatically improved the safety and reliability of modern jet engines.

Furthermore, technological advancements in risk management and mitigation processes have mitigated fleet-wide groundings resulting from propulsion system design, material or logistics failures. Improved inspection capabilities, as well as the increasing use of prognostic health and condition-monitoring systems, detect problems early and thus mitigate their potential impact on flight operations. In other words, this is fifth generation technology, not first, second or third generation.

This constant march of technological progress has yielded benefits across the aviation sector. For instance, in the commercial aviation sector, the Federal Aviation Administration and similar organizations abroad have lengthened the Extended-Range Twin-Engine Operation Performance Standards (ETOPS) to allow a 180-minute diversion period for twin-engine airliners.

As U.S. Air Force Chief of Staff Gen. Norton A. Schwartz said in March 2010, “We are not in the 1980s any longer, where high-performance engines had suspect reliability.”

LOL. The Schwartz quote is icing on a very ugly cake.