if you fly the KC-135R, none of it matters because we got so much thrust.

 

The way I read this sentence (after reading it several times in the full paragraph) is...

just because your all-engine data says you can make the all-engine climb with all-engines it does not mean you'll be able to make OEI requirements with OEI, you have to run OEI data to ensure that.

Seems to make sense to me. Are you lawyering it differently?

 

fsuskypilot

Yeah, I see your take on it. I was reading it differently. I think your interpreation is correct as it makes sense.

 

Good - because I was confused at what the confusion was all about.

 

Navi,

When was the last time you departed MGW form a hot and/or high location? Rs beat the hell out of Es and As, but a "rotate" call at 1000' runway remaining still happens on occasion. We're under 200/nm and even 152/nm pretty often on operational sorties even with the CFMs.

 

That happened a lot with our EC-135N airplanes on max-weight takeoffs, but we got used to it. When we merged with the unit at Wright-Patterson, their guys said: "Something's not right here." A series of instrumented tests revealed that the "book" was off by as much as 15%, because the performance engineers had only estimated a drag penalty for the modified nose. Fortunately, nobody had lost an engine during a max-weight takeoff.

 

KC-135 climb performance (in actual feet per nautical mile) has always been a mysterious hocus pocus to me. Before this most recent change the performance manual defined "climb gradient" in three different ways in three consecutive sentences. So now, after decades of having nothing, we have SID compliance charts, from which we can derive a ft/nm value given the required variables. Why can't we just get simple tab data, like the T-1 has?

 

By the way, even though the climb performance is shown in ft/nm, it really is not an accurate ft/nm as the climb is non-linear - just to make it more nonsensical.

 

Ha!! Love it. It really does work.

 

Being former AF, it took me a while to get my arms around this topic. I try to keep things simple. TERPS deals with rules for laying out airspace during departures and arrivals. OEI data is specific to each aircraft. It would be cost prohibitive to build departures which guarantee obstacle clearance for every type of aircraft out there. SDPs are great but are normally not economically feasible unless an operators operates at an airfield on a regular basis. The AF doesn't want to pay for SDPs unless they have to.

Also, the USAF has been very gun-shy about TERPS issues and using Jepps since they lost the CT-43 in Dubrovnik and the C-130 in Jackson Hole. Problem with the Jepps for the AF is not so much that their database was out of date, but that the AF could not verify that it was--especially for some more out-of-the-way airfields overseas. The funny thing is that AMC's databases are probably more out of date than the Jepps, since they have to independently verify procedures overseas and do not have the manpower to do so. Result--a waiver to operate--many times using Jepps procedures. I'm retired now, but when I was flying in the AF, I found more mistakes in DoD books than in Jepps.