Bront and Shy: The original limit for cabin door opening was 120 KIAS. We could have made it higher at the time, but just thought that speed would cover operations, and flight tested accordingly. There was no spec/US Army requirement in that area as I recall. Not being able to do this at all imposes unreasonable restriction, operationally speaking. There was discussion about how to handle the cockpit door on/off configuration, and quite honestly, the restriction had no basis with regard to structural intergrity etc*,but rather a judgment regarding the logistics about “ whose got, or where are “ my doors, once you take them off. You have probably seen a number of pics ( all USAF In my viewing experience ), of doorless UH-60’s from the Middle East of late. I know someone who might shed some light on the door transition restriction in forward flight. I’ll inquire.
* Anecdotal support: when we did the 12 ft/sec landings on a 9 degree concrete pad for the SH-60, I had to take the door off, as the USN had a budget issue and only built a 50 ft pad. In order to get the vertical speed nailed at 12 ft/sec, it was necessary to start at 100 ft and seeing the pad became a door problem.
The restriction on opening the sliding window is new to me, and (other than the map disposal functionality considerations ), baffles me. I can say that the original door design drawing did not have an openable window in it, which, after a few animated discussions, was rectified.
Rev 1 ( 2125 hrs lol ). Good friend said that door open/close restriction due to cracks in original aluminum tracks. However the USN MH-60S had a test done to provide a 120 KIAS open/close approval but Army wasn’t interested in the data. Going to have to look into this further.