On Sun, 16 Feb 2003 22:13:38 -0500, Andrew Case <[EMAIL PROTECTED]>
wrote:

>to me the four man hours of on-pad effort is possible, but once you 
>take into account the time to install the payload on the pallet and 
>time in the hanger for periodic maintenance, a total of four man hours 
>per flight seems out of reach

I think a total four man-hours per flight is not so much out of reach
as out to lunch.  Where did this figure come from?  When I take my car
to Jiffy Lube for an oil change, it takes about a man hour to service
my car and do the paperwork.  Just refueling it takes over 1/10th of a
man hour - and this is a vehicle with a 3% mass fraction.

We talk a lot about wanting to emulate airline operations.  OK, how
many man hours does it take to turn around a 737?  Two flight crew and
two cabin crew * 15 minutes to clear the passengers is one man hour.
Two baggage handlers * 15 minutes to clear the cargo is half a man
hour.  A janitor and a fueler for 15 minutes each is half a man hour.
Two gate crew and two cabin crew for 30 minutes for passenger embark
is two man hours.  Two baggage handlers for 15 minutes to load the
cargo is half a man hour.  Two ground crew and two flight crew for 15
minutes to launch the plane is a man hour.  We're up to 5 1/2 man
hours, and we haven't even done any maintenance yet.

Granted, much of this time is spent unloading and loading passengers
and their bags, which is always time-consuming (baaaa).  But even if
we're dealing with fast turnaround cargo flights, prepping a (low
margin) SSTO or mating a (high margin) TSTO are both going to take
some minimum amount of time and effort, and I think that minimum will
be well over four man hours.

And so what?  The biggest driver of operations cost for a commercially
developed RLV is debt service on the R&D budget.  Four man hours per
flight is so lost in the noise that it's like looking for pennies at
Fort Knox.

-R

--
Every complex, difficult problem has a simple,
easy solution - which is wrong.
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