Pima Sheriff's second Helio Turboprop Conversion, Tricycle Gear was added later.While fixed wing aircraft are undeniably the first police aircraft to take to the air, the helicopter has long since taken over as the preferred law enforcement aircraft of choice, for obvious reasons. But is it smart to ignore the capabilities of some fixed wing aircraft as a primary patrol platform? You might be surprised at what one Arizona Sheriff’s Department has been able to accomplish.
In 1999 Sgt. Rick Pearson of the Pima County (AZ) Sheriff’s Department was tasked by his command to come up with a patrol support aircraft. The only caveat was that it had to be cheaper to procure and operate than a traditional helicopter.
Pearson almost immediately had an answer, a fixed wing Helio Courier STOL aircraft. Pearson had prior experience flying Helio airplanes and new that they had a stall speed in the high 20’s and could take off in 300’ with no head wind and at max gross weight. Sgt. Pearson also knew that the Helio Courier had been used as a forward observation aircraft during the Vietnam era, and that hard points could be installed under the wings to mount a FLIR camera. It was the perfect aircraft as far as he was concerned.
In 1999 the Pima County Sheriff’s Dept. purchased a 1974 model Helio Courier HT-295, and set about making the necessary upgrades to put it into service as a patrol support aircraft. By early 2000 “Survey One” took to the air with a fresh coat of paint and a fresh engine overhaul. It didn’t take long for the Pima County Sheriff’s Dept. to know that they had made the right decision going with the Helio Courier. The aircraft flew an average of 5.5 hours a night, required little maintenance and had an operational cost of approximately $100 per hour.
As great as this patrol aircraft was, the members of the Air Support Unit recognized that it could be better. Over the next several years the Pima Sheriff’s Air Support Unit would convert this aircraft to a turboprop, then acquire a second Helio Courier and convert it as well. This makes the Pima County Sheriff’s Department the owners of the only two Helio HT-420 aircraft in the entire country!
The turbine engine used for the conversion was the Rolls Royce C-20 with the B-17c turboprop conversion. Now this was not the first time a Helio Courier had been converted to a turboprop. A 1967 conversion “B-15” version of the engine resulted in 320 shaft horse power, but it actually underperformed the piston engine at higher altitudes. The B-17c conversion results in 420 shaft horse power.
R.R. C-20 Turboprop engine being installed.So what kind of performance do they get with their turboprop Helio Courier? How about a take off roll of 100’ at 87% torque, a landing roll of 50’, a minimum forward air speed of about 30 knots IAS, 20 gallons per hour at loiter speed, and the ability to loiter for several hours longer than any LE pilot wants to stay in the air. But there is more, at loiter speed (which is 70-80 kts) the prop only turns at about 1700 rpm resulting in little tip noise, and a very quiet aircraft above the city. No who could use less noise complaints right? Top speed for the aircraft is about 140-150 kias at 8500’ msl.
One of the first flights after the Turboprop Conversion.Both Helio Courier turboprops are outfitted with a FLIR Star Saffire III camera making them a true stand off “eye in the sky.” Deputies in the cockpit of one of these aircraft are capable of monitoring a police call from several miles away, often without the bad guy or even the general public even knowing they are there.
So what is the cost of such an aircraft? Here are some numbers provided by Sgt. Pearson for their second aircraft.
R.R. C-20 Turbine Engine: $250,000
Total Conversion: $450,000
FLIR Star Saffire Camera: $450,000
Aero Computers Moving Map: $100,000
Direct Operating Cost: About $170 an hour. (about 1/3 of a Bell 206B3)
Sgt. Pearson notes that their program has been so successful, the budget for the Pima County Sheriff’s Air Support Unit was actually increased this year. This is noteworthy in a time when many police air units are facing budget cuts.
The Pima County Sheriff’s Helio HT-420 aircraft are operated under “Public Use” aircraft rules.
While the aircraft may not be FAA certified, only factory parts were used in the conversion and FAA standards were followed as closely as possible.
Any department or agency interested in acquiring and converting their own Helio aircraft for patrol can contact Sgt. Pearson if they have further questions.
Police Helicopter Pilot.com would like to thank Sgt. Pearson for his cooperation, information and photos that made this article possible.
All Pima Sheriff pilots are IFR Certified, and benefit from this all glass panel.