Upgrades for InterMountain Helicopter’s fire bird
InterMountain Helicopter is putting its only aircraft, a Bell 212 HP, through a retrofit involving airframe modification, an avionics upgrade and engine replacement in preparation for this year’s fire season.
InterMountain Helicopter, a California, US-based aerial firefighting specialist, has reported that it is putting its only aircraft, a Bell 212 HP, through a retrofit involving airframe modification, an avionics upgrade and engine replacement in preparation for this year’s fire season.
The estimated cost of the work is $450,000, of which some $70,000 will be spent to meet US Forest Service (USFS) contractual mandates. Rick Livingston, president of InterMountain Helicopter, commented: “It is very unusual for a company of our size to invest that kind of money into an ageing aircraft, but we had to for contract compliance, and operational safety.”
The helicopter is a 1975 model that was acquired by InterMountain in 2003 and has nearly 14,000 hours of flight time on the clock. With a capacity of nine passengers, plus the pilot, the machine is deployed by the company in an initial attack mode, ferrying ground-based firefighters and support equipment to where it’s needed. The helicopter is also used to drop water and retardant from an external bucket.
Livingston explained that one of the contract compliance modifications involves the installation of a BLR Aerospace FastFin and Dual Tailboom Strakes kit to enhance the helicopter's stability and improve out-of-ground-effect hover performance. He added: “It’s a labour-intensive and expensive modification at a cost of about $40,000. At the same time, we are mandated to install an air traffic advisory component, although the challenge is to find one for which we have room on our instrument panel – and [that is] affordable.” That, Livingston explained, would add another $25-30,000 in mandatory upgrades.
The most extensive modification, however, is the replacement of the helicopter’s two Pratt & Whitney Canada (PWC) PT6T-3 engines with the more powerful PWC PT6T-3B powerplants at a cost of around $380,000. “The PT6T-3B twin pack will give us better ‘one engine inoperative’ (OEI) performance for a greater margin of safety,” explained Fritz Bayer, InterMountain Helicopter’s chief pilot. The engine change decision, Bayer said, was not a contract mandate, but prompted by the fact that the PT6T-3s had reached their life limits: “One of the engines had just about hit its 4,000-hour limit, while the other was nearly 500 hours beyond the 4,000-hour limit, operating under an approved extension by the Federal Aviation Administration and PWC. We had the choice of overhauling them to zero-time, or spending the money for a more modern engine with greater supportability and available parts, since there are more PT6T-3Bs in the active Bell 212 and 412 fleets.”
In order to avoid any impact on the helicopter’s availability during the fire season, the modifications were timed to coincide with the normal, 12-month scheduled maintenance work, which includes component overhauls and replacement of parts which have reached their life-limits. Bayer commented that a lot of routine, heavy maintenance is performed during the winter, who added that this June, the helicopter will deploy to the USFS Shenango helicopter base near Bozeman, Montana, for a 120-day exclusive-use contract period.
Tom Eversole, executive director of the American Helicopter Services and Aerial Firefighting Association (AHSAFA), of which InterMountain Helicopter is a member, noted: “In today’s aerial firefighting business environment, private operators are being told by the USFS to do more, at their own expense, in order qualify for federal contracts for wildland firefighting. InterMountain Helicopter is a good example. This is why it is imperative that the private enterprise aerial firefighting infrastructure, typically made up of small to midsize companies, be maintained, and allowed to compete on a level playing field.”