Story ID: 124Bell525HAI16
Bell 525 'Ahead of plan'
By: Mark Huber
Caption: Certification of the Bell 525 is scheduled for 2017.
Word Count: 827
Test flying of the new super-medium Bell 525 twin is “ahead of plan,” according to Larry Thimmesch, vice president of the 525 program. A second 525 flight test vehicle (FTV2) joined the program late last year and the program remains on track for certification in 2017, Thimmesch said, with five test aircraft eventually comprising the program. Through the end of the year Bell held 75 letters of intent from customers, the majority coming from the offshore energy services industry. Bell has yet to formally release a price for the aircraft.

“Getting into a production cadence is where we are focused right now,” Thimmesch said. “The good news about flight test is we spent a lot of time in the systems integration lab validating components integration, throwing faults in the system and seeing how the aircraft reacts. That has paid off. The things that you do in flight test are the things you want to do in flight test: aerodynamics and performance. It’s not systems integration and reliability issues. It’s the things you can only do in the air. You can only go so far with analytical predictions and then you have to go up there and do true flight test, and that is exactly what we are doing in terms of the test points we want to fly. In terms of July to now, we are way ahead of our plan so it has been a very efficient flight test plan so far. These other aircraft coming on board are going to dramatically increase the amount of learning. It is where we want to be in the flight test program. The aircraft has proven to be a solid platform that is hitting or exceeding all of our expectations, so it is extremely good news for us.”

FTV1 had flown 65 hours through the beginning of December and had validated the never-exceed speed of 165 knots, ceiling of 12,000 feet, much of the hover performance testing in and out of ground effect and initial autorotation testing. “We did a lot of hover performance testing and that came in extremely well, better than our predictions, so our performance guys were happy about that,” said Thimmesch said. “It gives us good margins on gross weight and Category A capabilities when we get to that testing. That aircraft, in the first part of 2016, will go up to Canada or Alaska to do cold weather testing. We are characterizing the damper so we want to get into some cold weather so we can get our production configuration pinned down for those dampers.”

He added, “Ship 1 is doing a lot of envelope expansion and gross weight configuration, different density altitudes and filling the corners of the [flight] envelope. The systems [in the lab are] very close to what we are seeing on the aircraft. Bell invested a lot in new design and analytical tools at the beginning of this program and it is paying off. We are not seeing anything that is a big surprise, and when we do see something like hover performance it is on the good side.

“The aircraft continues to be very stable and flies very well,” Thimmesch said, and that includes the aircraft's fly-by-wire flight control system. “The control laws are exceeding expectations and [we do not anticipate any] further tuning for the inner loops. [On] the outer loops, the fly-by-wire enhancements, we’ll do a fine-tuning tweak to that after we get through all our aerodynamic envelope expansion. But out of the box, it has been flying very well–really no surprises on the performance side. The aircraft has been very reliable in flight test, and they have been able to turn the aircraft very quickly. The things that typically keep us down are weather and instrumentation. The aircraft itself has typically been ready to go.”

FTV3 is in final build and Bell hopes to fly it in the first quarter of this year; FTV4 and FTV5 will be added to the program in August and September. With FTV1 off for cold weather testing, FTV2 will be used for development and envelop expansion and FTV3 will do low level survey work. FTV1 and FTV2 will begin certification flight testing in the second quarter, with FTV2 slated for artificial icing testing toward the end off the year and aircraft 3, 4 and 5 coming on line to fly certification testing. Full icing certification testing and function and reliability flight testing will continue into 2017.

Build began on the first customer production aircraft last November. Thimmesch sees customer aircraft coming on line at the rate of one a month. “We’re getting into the production phase of the build, working with early production customers to spec their aircraft, installing a lot of kits in the build, very integrated more than we have done in the past. We’re working with our customers to get those aircraft configured and get into the production flow,” he said.