Saturday, February 1, 2003
Cops and Choppers
With a tradition of racking up time on their aircraft and a new reality of tight budgets, Houston’s police aviators must find more efficient maintenance solutions.
A helicopter has been described as 10,000 parts moving in close formation, not flying as we know it but beating the air into submission. Keeping the parts in close formation demands first-rate maintenance.
Few operations illustrate the challenge of satisfying that demand better than the Helicopter Patrol Division of the Houston Police Department. Like law-enforcement aviation units around the world, the division in that Texas city flies a busy schedule of high-priority public-safety missions. Many of those units manage their maintenance challenges by replacing aircraft every three to five years or shifting older ones to less strenuous duties like training.
Houston’s helicopters seem to serve forever. The division’s fleet includes three MD-500Es, the oldest of which has been flying for 12 years and more than 15,500 hours. Only a handful of police units in the U.S. operate aircraft with that much time on them.
The division’s younger aircraft include two Schweizer 300Cs and two Schweizer 333s that, by Houston standards, are practically brand new. The division received the 333s at the start of 2001, at which point it retired several aircraft, including one MD-500C with roughly 23,000 flight hours. (It also flies a Cessna 182S.) Accumulation of hours like that "is a good index that their maintenance is the highest quality," said a MD Helicopters official.
Like many government and private-industry rotorcraft operators, however, the Houston division faces new challenges in maintaining its fleet. Major cuts in the municipal budget are prompting division officials to change the way they do business.
A longtime standard operating procedure, for instance, has been to have at least one spare on the shelf for every major component in the fleet. A part removed was immediately refurbished and returned to spares. The division has counted on that inventory to assure its ability to dispatch helicopters, and has avoided using parts exchanges.
With a tight budget, though, that practice is changing, according to the division’s Lt. John King. He is second-in-command to Capt. Debby Watkins. The division is drawing on its histories of times between major failures for certain components to help it decide whether to send a component out for overhaul immediately. So an engine overhaul may be delayed until the budget includes funds for it, he said, or until the replacement is likely to be needed.
This approach, which "preserves our budget as well as our cash flow without jeopardizing our parts requirements," King said, "is dramatically different from the way we’ve done it in the past."
He and others there said the focus of maintenance crews remains unchanged: to provide first-rate support to ensure helicopters are available when needed. "Given the kind of flying we do and the demands on our equipment," King said, "it’s absolutely non-negotiable."
The "Fox" units, as the aircraft are called, do fly. The division has flown as much as 7,700 hours in a year. Last year, a slumping economy led the Houston City Council to adopt cutbacks that resulted in the helicopter division’s budget being cut 40 percent. The division responded in part by reducing flight time. This year, King said, the division may schedule 6,500 hours and operate for 5,000. Roughly 85 percent, he said, is flown by the turbine helicopters, with the MD-500s flying slightly more than the 333s.
The division is squeezed even further by new missions to perform. In addition to its traditional ones of traffic patrol, pursuit, and anti-drug flights, the "Fox" units now perform homeland-security duties, such as patrolling refineries and fresh-water treatment plants.
Even at the lower projection of 5,000 hours for this year's operations, each turbine helicopter should average roughly 850 hours this year. By comparison, the Helicopter Association International figures the average utilization for all helicopter operators in 2001 was 545 hours.
Keeping the division’s helicopters on patrol with minimal down time requires that each ship undergo about 90 minutes of maintenance for every hour flown at a cost of about $150 per maintenance hour, King said. That cost is roughly on par with average industry maintenance costs for the aircraft in the division’s fleet.
"We’re always re-evaluating our maintenance operation," King said, "to ensure that we are getting the most bang for our buck."
A staff of eight full-time technicians, all with several years on the job, keep the aircraft ready for the division’s 27 line pilots. King said they follow factory and regulatory guidelines for periodic and major inspections, as well as those prompted by pilots’ write-ups.
Since its inception more than 20 years ago, the division generally has acquired new helicopters, in part because warranties and manufacturer support for the new equipment lowered maintenance costs. When it acquired the Schweizer 333s, for instance, Houston’s became just the second police department to operate that type. The department in San Antonio, Texas was the first, having traded in two 330SPs for 333s.
In the long run, buying new "actually saves us money," King said. The division won’t go out on the open market and buy a used helicopter whose pedigree is uncertain. "We’re not interested–and we can’t afford it because it’s taxpayers’ money that keeps us flying–in buying someone else’s problems."
A desire for a clean pedigree–and avoiding other people’s problems–also drives the division’s use of parts. When a removed part is repaired or overhauled, that same part is yellow-tagged and returned to the division’s in-house inventory. "We track each and every part and component as it comes in new, as it is overhauled, and returned to us," King said. "It’s important to us know the source of our parts as well as their history."
For that reason, the division does not exchange parts. "We want the original parts that came off our ships back once they are yellow-tagged," he said. "That maintains our continuity."
Citing the publicity in recent years over unapproved or unairworthy parts, King said the division’s recordkeeping will keep such parts from getting on helicopters pledged to public safety in Houston. "If any of our original parts come back with questions, the decision is really simple," he said. "They’re not going on our ships."
An advantage in dealing with the budget crunch is the division’s ability to forecast maintenance. "Unlike charter operators who never really know what their schedules are going to be, we do, in fact, know how much flying we’re going to do and when the maintenance issues are likely to occur," King said. This makes it easier to budget for that work. "Of course, there is a fair amount of unscheduled maintenance, as there is with any operation, but we are prepared for that and can handle it within the confines of our budget."
The maintenance problems confronting the division don’t necessarily come from the age and heavy use of its helicopters. "You’re going to have time- and life-limited parts in any helicopter," said the director of maintenance, Steve Cowan. What demands his attention are the electronics. "We fly so much–in the upper 5 percent of total hours flown by helicopters in these type missions–that all the vibration and heat in the summer works the radios over the most. That sort of thing just goes with the territory."
Given that the salt water of Galveston Bay and the Gulf of Mexico is 30 miles away, corrosion is a concern, too, Cowan said. "We’ve gotten pretty good at knowing where to expect corrosion to show up, so we are constantly looking in those areas," he said. Common problem areas are in the skids and their support structures. "When we find corrosion, it’s not a big surprise because we usually expect it sooner or later."