2012 Reabe Spraying Service
THE MOTIVATION BEHIND REABE AIRCRAFT IMPROVEMENT
In 1945 my father, Roy W, started Reabe Flying Service using J-3’s and Stearmans modified to spray. I grew up in a world where making changes to aircraft to improve their usefulness was commonplace; longer wings, bigger hoppers, bigger engines, better spray systems. In 1979 my three brothers and I formed Reabe Spraying Service to specialize in our father’s crop spraying service. By then the Ag industry had aircraft designed to do the job. But we were still making changes to the aircraft as we worked them and identified short-comings. We were using the Field Approval process to get the paperwork completed. Our FAA PMI (Principal Maintenance Inspector) suggested we get STC’s to cover some of our work. In 1991 I started Reabe Aircraft Improvement as a hobby that specialized in creating STC’s. This hobby has created eight STCs, applicable to Air Tractor, Thrush, Bell Helicopter and Piper Twins. Each STC started as a short-coming identified by our pilots, a fix created for our pilots, then tested and refined in our fleet. The final step is the STC process. Over the past 25 years, I have seen the STC process take four times longer and cost a boatload more to get through. But as I work around an aircraft I still see things I want to improve. I never thought my hobby would affect over 2800 aircraft.
Jeff Reabe, President, Reabe Aircraft Improvement
FAA-approved Improvements Include:
Maintaining 7 Bell 47’s is motivation to reduce the number of moving parts. After counsel with Gifton McCurry of Texas Helicopters, I began the STC process to remove the elevator actuating system and hold the elevator in a stationary position. This modification removed 10 pounds from the helicopter. Note: This is a helicopter flight control change which required flight testing, yet from application (Feb. 25, 1992) to STC issuance (March 10, 1992) took 12 days. The Good Old Days! After modifying 121 helicopters, the STC was sold to Scott Churchill of Scott’s Helicopters.
In 1990 after consult with Jerry Beck, I installed the first geared R-1340 on an AT-301. Because the 301 used CAM-8 on it’s Type Certificate, I could use CAM-8 as Approved Data for the 337 major alteration. Turning a 10 ½ foot diameter prop yielded a 15% increase in performance. To increase prop ground clearance, 29×11-10 tires were installed on the 8.50×10 rim. Chuck Ebert of the Milwaukee FSDO issued 337 Field Approvals for the tire installations on the first few aircraft. I used the Field Approvals as supporting data for the Big Tire STC. Time from STC application to STC issuance was 70 days. Yes, still the good old days!
On one of my monthly phone calls to Leland Snow, I mentioned my concern that the FAA may someday change their interpretation of CAM8 relative to the geared R-1340 installation and I would have a grounded fleet. Leland suggested I write a step-by-step modification process and he would make it a Service Letter. Snow Engineering Service Letter #80S was typed on my typewriter. Yes, the Good Old Days!
Our pilots were getting stiff necks. They would duck down to peak under the canopy to see their next pass while in the turn. The turn windows were too far aft to be of use. When in the turn, the airplane’s path is hidden behind the fiberglass canopy forward of the turn window. Our senior pilot, Tom Hegy, suggested a bubble canopy like a P-51. Our solution was to have LP Aero Plastics make a plexiglass canopy. As cell phone towers and wind turbines populate the countryside visibility is very important. Ed Newberg told me, “If not for my canopy, he would have continued a turn into a tower. I do not know how many lives our canopy has saved. Time from STC application to STC issuance was 80 days. Yes, the Good Old Days!
With a family of 6, the Aztec is a good fit. But baggage space becomes tight, especially on a ski trip. Again the Milwaukee FSDO provided a 337 Field Approval for my Aztec. The Field Approval was used as Supporting Data. The STC took 2 years to complete as we were in no hurry.
The float arm and pointer quantity indicator of the older Air Tractors were very reliable but lacked precision. In one of my monthly talks with Leland Snow I inquired about a better indicator. Leland said they have a digital indicator but I would not like it. Leland transferred me to Jeff Dobbs for more information. Jeff Dobbs explained when it works it’s great but it is the most common warranty problem on the airplane. When the system arrived, we wired it on the bench to test, but when power came on, smoke came out. That was the moment I knew I had to build my own. My son Troy was working as an engineer for a paper machine manufacturer. He saw a probe bent by a forklift that continued to work. He passed that model information on to me. I purchased a magnetostrictive probe from Ametek and a programmable display from Red Lion. It worked flawlessly for the season. Everyone was very impressed with the “to-the-gallon accuracy”. However, the display was clunky, dim and too sensitive so I asked my son Troy to build a slim purpose-built display. I had been keeping Leland informed on what we were doing and in February 2010 Troy and I went to Onley to show it to Leland. We were proud of what we had made. Jim Hirsch spent the rest of the day with us explaining the features we needed to add and requirements to get the system ready for “Prime Time”. The features were added and a new display was made. The new system was installed in our 502 in April 2011 and STC application was filed. Seven months later the STC was issued. The “True Quantity Hopper Gauge” became standard Air Tractor equipment in 2013. After selling over 2800 systems, I sold the STC to Troy Reabe in 2026.
We could see the efficiency gain of a ram air inlet, so a new Air Tractor inlet was installed. We noticed the new filter was quickly contaminated as the contaminate particles had a straight-line path to the filter. Using a P-51 style scoop placed below the cowl in the high speed air flow, we gained good plenum pressure. Requiring the airflow to make a 90 degree turn to get to the filter and allowing the contaminant particles to continue straight out the back of the scoop, we had particle separation. The inlet was installed on our AT502 using 337 Field Approval with ACO concurrence in May 2012. The STC took 1 ½ years to complete as we were in no hurry.
We had been installing the PMA’d Reabe Hopper Quantity Gauge in our Bell 47 fleet for years. When the Bell 206 arrived, we installed the PMA’d airplane Reabe Hopper Quantity Gauge with deviations for the 1st season. The helicopter pitch changes effect on the long shallow belly tank presented some new problems that needed to be addressed. The STC took 9 months to complete. I sold the STC to Troy Reabe in 2026.
Reabe Spraying Service bought an AT-602 with a hydraulic gate. I saw all this stuff (electric motor, hydraulic pump, accumulator, regulator, valves, actuator) adding 200 pounds to the plane. I also noticed if the complex system failed, the airplane would be parked until it was fixed. I told my son Troy “there has got to be a better way”. In 2018 we installed this prototype on my nephew Damon’s AT802 via 337 Field Approval with ACO engineering concurrence. As the season progressed more features were added. The system grew for a power assist to the “Smart Gate”. It took 20 months from STC application to STC issuance, but it was the most complex STC we did. During this time the FSDO provided 337 Field Approvals with ACO concurrence. The “Smart Gate” is my son Troy’s creation, I just pointed him in the right direction. After selling 60 Smart Gates I gifted the STC to Troy.