CV-580 Pilots

[CopilotDoug]

Quick question: Was pressurization "manually" controlled ?

 

[Rick1128]

It has been awhile, but if I remember right it can be controlled manually. It is a alternate type procedure though.

 

[A Squared]

Quick question: Was pressurization "manually" controlled ?

I haven't flown convairs, so I don't have any *direct* knowledge, but I do fly airplanes of the same vintage so I'm not speaking form a position of complete ignorance (partial, perhaps) Anyway, I would be *very* surprised if hte promary means of controlling pressurization was manual. Automatic pressurization control was standard in other aircraft of that vintage (DC-6 for example) and manually controlling pressurization would add significantly to the cockpit workload, particularly on an aircraft without a flight engineer.

I'm pretty sure that there would have been a means of controlling the pressurization manually, in the event that the automatic controls failed, but I'd be surprised if the pressurization was normally controlled manually.

 

[Donsa320]

Quick question: Was pressurization "manually" controlled ?

It has been a long while for me also but I have about 15,000 hrs in 340s,440s, and 580s. The only thing manual about the system was the dump valve as I recall. The rest was pneumatic but very reliable. Cigarette smoke residue on the outflow valve was the biggest maintenance problem. The valve would get sticky and cause "bumps" in the differential. Sometimes uncomfortable on the ears.

Why do you ask, may I ask?

DC

 

[CopilotDoug]

Thanks for the feedback. In discussing aviation with a friend, he was fairly certain that the 580's only means of control was through the cockpit window. I didn't think it was unplausable, but as A Squared stated, the workload would go through the roof with just a two man cockpit. Maybe certain operators did get approval to operate the aircraft in this manner?

 

[Donsa320]

Thanks for the feedback. In discussing aviation with a friend, he was fairly certain that the 580's only means of control was through the cockpit window. I didn't think it was unplausable, but as A Squared stated, the workload would go through the roof with just a two man cockpit. Maybe certain operators did get approval to operate the aircraft in this manner?

Yes, after engine start we would have had the copilot's side window cracked open and he would slowly close it to avoid a pressure bump. Reason: the outflow vave was not open enough to let all the incoming air from the EDC (engine driven compressor) out. This would take maybe 5 seconds, not a biggy while taxiing out. Conversely after landing the F/O would slowly crack that same window to get rid of the last little bit of pressurization while taxiing in. This was a procdure for on the ground only. In flight if you wanted to get unpressurized, the pressure dump handle would open the dump valve and that would do it. I think it had to be reset each time so we did not routinely use it.

I hope that helps.
DC

 

[JessMan]

I turn the EDC Cabin Pressure to "AUTO" and it maintains about 4.3 PSI through the outflow valve. The "REG" selection will pressurize about 1.5 PSI through ram air flow without having the EDC running, and "ALT AIR" opens the dump valve. As far as the pressure bump goes, there's no good way to avoid it in our planes, even with slowly closing the windows, but then again these old things leak air like a fat guy in a chili eating contest.

 

[CopilotDoug]

Yes, after engine start we would have had the copilot's side window cracked open and he would slowly close it to avoid a pressure bump. Reason: the outflow vave was not open enough to let all the incoming air from the EDC (engine driven compressor) out. This would take maybe 5 seconds, not a biggy while taxiing out. Conversely after landing the F/O would slowly crack that same window to get rid of the last little bit of pressurization while taxiing in. This was a procdure for on the ground only. In flight if you wanted to get unpressurized, the pressure dump handle would open the dump valve and that would do it. I think it had to be reset each time so we did not routinely use it.

I hope that helps.
DC

Thanks for clearing that up. It was my misunderstanding him that led to the confusion.