The price of maintaining Rolls-Royce Spey engines, which power the Gulfstream II and III, has dropped dramatically over the last several years, according to MRO shops and operators. Gulfstream made 460 GIIs and GIIIs between 1966 and 1987, but operators increasingly are scrapping them in response to rising fuel prices and more stringent anti-noise requirements that will require the installation of hush kits or restrict operations.

This scrapping has resulted in an abundance of spare parts and even whole, mid-time engines finding their way to market and significant cost savings for those who continue to operate these aircraft.

The 1950s-designed Spey was one of the first turbofans to enter wide military and civilian service. A pair of Speys burns an average of 556 gallons per hour, or about 20 to 25 percent more than the Tay engines on a 1990s-vintage GIV. Speys have a time between overhaul (TBO) limit of 8,000 hours.

Because of scrapping, says Ben Brown, vice president of hush kit maker QTA, most parts for the GIII “cost less than half what they cost five years ago.”

Vann White, CEO of GIII operator Nonstop Aviation in Boca Raton, Fla., says that his overhaul costs have dropped significantly in the last few years. In December 2010, White sent out a single Spey for a 10-year, 4,000-hour mid-life inspection costing $692,000. Today, he says, he can do two engines with that same vendor for less than $800,000.

Spey MRO BBA Dallas Airmotive offers its Spey customers a wide variety of lower-cost options, according to Mike Snellgrove, senior director of Rolls-Royce programs for the company. Dallas offers its customers three levels of Spey service: silver, gold and gold plus. Gold plus includes a 10-year warranty and cosmetic and life-extending engine work, including a vibration-reduction package. That covers restoring the pins on the low-pressure compressor and putting Xylon coating on them to guard against build-up and debris, as well as remapping and rebalancing. The silver package has fewer features and a five-year warranty. All programs use overhaul condition parts if they are available, at the customer’s option, Snellgrove said. “The prices have gone down dramatically over the last six years, and that is a reflection of the value of the aircraft,” he said.

Spey owners also are opting for fewer services. Overhauls are rare and mid-life inspections are typically limited to the calendar portion of the requirement, 10 years, as opposed to the full 4,000 hours for the midlife inspection. They are also taking advantage of the new 5Y2K “reduced work scope 511-8” program for previously timed-out engines; a special set of inspections on these engines allows operation for another five years or 2,000 hours.

Used GIIs can trade for less than $500,000, while a well maintained GIII can be purchased for around $1 million, according to aircraft pricing service Vref. “Some years ago we realized that the market for these engines was going to get smaller and smaller and we wanted to try and find some way to extend the life of the airplanes as the cost of their airframes went down. So we developed the reduced work scope to keep them in the air longer,” said Chris Pratt, Dallas Airmotive’s director of marketing.

Pratt noted that some customers just want to get their airplanes to 2015, when Stage 3 anti-noise requirements become mandatory, before they scrap them.