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Sikorsky and the Doppler Effect

By By Lee Benson | May 1, 2016

Following my last article on the acquisition of surplus U.S. Army A-model Sikorsky Black Hawks by several commercial operators in the U.S., I saw three UH-60As on display by various operators at Heli-Expo in Louisville, Kentucky. All were impressive in their general appearance, and each Black Hawk had specific modifications related to their intended use in the marketplace.

Sikorsky hosted a meeting during the show. Attendees included operators; GE (which makes the Black Hawks’ T700 engines); members of the maintenance, repair and overhaul community; and firms developing equipment for the UH-60A.

Again GE stated that, within the limits of legacy issues on the 700-series motor, it will support that engine and eventual conversion to the 701 series.

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The folks from Sikorsky in the room were engaged and focused on presenting clarity to support issues going forward. They appeared to see the big picture and embrace this as an opportunity to continue founder Igor Sikorsky’s often-repeated vision of the helicopter as a tool for the betterment of mankind.

Years ago, a defining moment for me during all the visits and meetings with Sikorsky that led up to the L.A. County Fire Dept. buying and developing the Firehawk in 2001 was when I was taken to Igor Sikorsky’s office at the manufacturer’s Stratford, Connecticut, plant.

On his desk was the last thing he worked on: a letter congratulating an Argentine helicopter pilot on a rescue performed with a Sikorsky helicopter. “If you are in trouble anywhere in the world, an airplane can fly over and drop flowers, but a helicopter can land and save your life,” wrote Sikorsky. Maybe some of the folks at Sikorsky could learn a thing or two from this letter.

We all know that the Doppler effect is what causes a train to sound louder and higher pitched as it approaches and lower in intensity and pitch as it leaves. I suggest that the lower, quieter sound that Sikorsky is hearing is the Black Hawk market passing it by. Now is the time for the OEM to get on board or get left holding flowers at the station.

Smart men have put serious money into the acquisition of surplus Black Hawks. I, for one, have little doubt these operators will make a success out of their investment through parts manufacturer approval, cannibalization or Army surplus. On the other hand, Sikorsky is in a position to see this as an opportunity to provide good spares and product support at a reasonable cost and make a fair profit.

Other Black Hawk issues of interest to those using the aircraft for fire suppression include crew-hauling ability and water-delivery systems. Brainerd Helicopters out of Leesburg, Florida, has been successfully employing a bucket for firefighting with its S-70 Black Hawks since 1995. Firefighting efforts in the future will likely mirror this approach.

Some potential customers for fire-suppression Black Hawks have made a fixed-tank solution part of their requirement, driven by the dominance of urban or wildland interfaces in their regions.

Providing a fixed-tank solution largely depends on four areas.

One is the airframe modification needed to mount the tank, which is within the abilities of a good sheet metal shop once the hard point is supplied.

Another employed by the L.A. County is the landing gear modification that raises the aircraft 16 in to provide room for the tank. This modification might be easier to do than the hard points. But will Sikorsky supply the data for the manufacture of these two elements? That has not yet been defined.

Then you have the drop tank. Simplex Aerospace has the means to build the tank used on the L.A. County aircraft and several National Guard birds. But the 1,000-gal tank requires the landing gear mod. Simplex is now working on a 700-gal tank that would employ the standard Black Hawk gear, solving some of those problems.

The last point would be the cockpit display for the tank. The system used by L.A. County incorporates a separate screen display and has worked well for the department. The display shows the amount of water and foam on board and the status of the retractable snorkel-and-tank system. Some operators may opt for an electronic flight instrumentation system (EFIS) solution because of legacy issues with the current instrument package. With an EFIS, I would look for a utility page that would allow a tank status and next power exceeded display.

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