One of the reasons the 60S replaced the 60H was because there were deficiencies in that airframe that caused mission impacts. And the 60H was getting old. Imagine if we hadn't have acquired the 60S and instead the 60H had been allowed to whither over the past 10 years like the USN Phrogs that were loosing an engine per day across the fleet. Tired iron is tired. There's only so much upgrading and strapping on cool new gadgets that can be done before the airframe and dynamic components give up.