Camarillo, California-based AKV, Inc., has received regulatory approval for a starter interrupt system that prevents any Robinson helicopter from suffering an engine overspeed during ground start-up.

“I used to teach in Robinsons, and I always knew it was a problem with students overspeeding the engine on startup,” said Jonathan Gunn, president of AKV, Inc. “It’s a common problem throughout the world, and it exists to this day — students get sidetracked, and even private pilots or commercial pilots, if you’re bouncing between helicopters, you get sidetracked — you forget to check the throttle is closed, and you crank the engine with no load on it and it goes through the roof.”

To address this problem, Gunn developed the Robinson Helicopter Starter Interrupt (RHSI) kit, which is an on-ground only prestart starter inhibitor. If a pilot has the throttle open, the system won’t allow the aircraft to engage the starter.

Correct operation of the system in the R22, R44 and R66 is verified by a push-to-test amber indicator lamp before and after the engine start. After the start is complete, the starter interrupt kit is automatically de-energized so that in-flight engine restarts are not affected.

“The benefit of this system is not just in preventing an actual engine overspeed on start-up, but also the peace of mind this capability brings to an owner/operator,” said Ken Obi, owner of Orbic Helicopters. “This system is very simple and works perfectly.”

The system has been adapted for the entire Robinson product line, and in the R66, it also monitors the fuel cutoff in addition to the throttle.

“The reason I added the fuel cutoff as part of the circuit is because there are a lot of pilots that move from the [R44] Raven I or Cadet into the 66, and the fuel cutoff knob on the panel is identical in its form and look —one you have to leave out, and one you have to push in before you start,” said Gunn. “You can hot-start a 66 pretty quickly if you forget what you’re sitting in.”

Gunn said the pre-assembled kit is “simple to install.” It weighs less than one pound, and is available for under $3,500.

The system has received regulatory approval in the U.S., with EASA certification expected shortly.

AKV is currently shipping kits for the R44 line (Raven I, Cadet, and Raven II), with kits for the R22 set to follow in a few months, followed by the R66.