Well,
this way you get to fly it and get paid for it too :))
The 601 was piston or a turob conversion?
TJ
On 5/25/07, H & J Johnson <hjjohnson@sasktel.net> wrote:
Sounds good TJ, I've flown a fair few twin's over the last 10+yrs. I like the 414 as it's about like flying a 172, it basically flys itself. Yet its lots of fun, at the other end of the spectrum the A601P I flew.. now there was a fun bird.. was like a fighter more than a 6 seat light twin.
The 414 is a corporate job I do on the side.. Lots of long legs from Central Canada down to SoCal and Az etc.. I wish I could afford one. but the first time I filled up.. I'd be broke :-)
Jarrett
----- Original Message -----
From: Thomas Jakits <rotary.thjakits@gmail.com>
Date: Friday, May 25, 2007 11:27 am
Subject: [FlyRotary] Re: Marginal Cooling
> Jarrett,
>
> thanks again for the details! Very interesting!
> There is a RAM on the ramp down here sometimes....
>
> Agree on the first 2 points for change - just never imagined that
> one would
> have to endure more than a hour on the taxiway :((, so your RAM
> fits my
> initial requirements just fine (An hour or more is about "forever" or
> infinite)
>
> I still would want to be able to climb at any speed at full power
> for 5 min
> and indefinite at Vx/Vy at max power - whether I get there is a
> differentquestion, at this time I am still inthe wishful thinking
> phase.And the "thinking" changes nearly weekly as new systems show
> up on this
> list....
>
> Is the RAM your own mount or are you flying it for someone else?
>
> TJ
>
>
> On 5/25/07, H & J Johnson <hjjohnson@sasktel.net> wrote:
> >
> > *TJ, well I think the reality is, there will be a point where
> you have to
> > draw a line and say, if it will do this under this, this and
> this conditions
> > then I'm happy. The only reason I brought it up was because the
> way you'd
> > layed it out, my 414 wouldn't fit, nor would a very large
> percentage of
> > certified a/c. Yet I know my 414 to be an excellent aircraft,
> which in my
> > opinion, has never let me down due to some part of it having a
> poor design.
> > [well other than the water/oil seperator when flying in high
> humidity,> winter conditions but .. thats more to do w/ the
> engines system design than
> > the airframe, or its integration :-) ]*
> >
> > *Now I'll tell you why I had an oil temp problem. *
> >
> > *#1. I sat on the ground idling in Vegas [30dC outside] w/ a
> 27G37 tail
> > wind for 1 hour and 47 minutes. It took 1 hour and 20 minutes
> before the oil
> > temp got high, the last 27 minutes I was #1 for dept on
> Julite/hold Short on
> > 19R and could turn into the wind to cool it back down. The oil
> temp never
> > reached red line, and it may never have reached it, but it was
> high enough
> > that I wasn't comfortable w/ it.*
> >
> > *#2 I could climb at just over Vmca and it would overheat.. but
> I know of
> > NO REASON to do so. First of all, Vmca is like 79 knt's. My Vx
> and Vy are
> > both up around 120, at Vmca it's very possible that the a/c
> would hardly
> > climb at all, at gross weight, but I could still fly at that
> speed. It
> > would be a senseless act, but it still does fit your parameters.*
> >
> > **
> >
> > *The 414 I fly is a Ram IV, it has all the airflow do-dad's you
> could> imagine [ I think RAM has come out w/ a couple new
> conversion's since this
> > one but.. they only have a few more minor slow speed handling
> upgrades] It
> > has cowl flap's as well as the top-of-the-cowl gill. The gill
> is behind the
> > engine and allow's for cooling air to get to the turbo's during
> cool down
> > [after shut down] and allow's the hot air out. I don't think it
> has a whole
> > lot of effect while in flight.. [it must have some.. but I don't
> know how
> > much.. and at this point it's irrelevent] well other than
> freaking my
> > passengers out when they see the glowing turbo's through there
> at night.. It
> > freaked me out for the first couple hundred hour's I flew it..
> but after a
> > while you just get de-sensitised to it :-)*
> >
> > *There is nothing wrong w/ the cooling abilities of the airframe
> when> flying it properly. I get 120dF oil temp's during the summer
> at cruise and
> > climbout and 320dF cylinder head temp's as well. It is actually
> cooling too
> > well! We had to block off 1/3 of the oil coolers to get the oil
> temp's up to
> > where I was comfortable w/ them [over 150dF] and it had these in
> place when
> > I had the hot oil in Vegas.*
> >
> > *I guess the point I was trying to make is, there will always be
> a point
> > where something won't work the way you want it to, if you have
> to sit and
> > idle for just about 2hrs w/ a ~35knt tail wind in the desert,
> before the oil
> > overheats, I think you have a very good system. If you tried to
> improve on
> > it at this point, your just pushing yourself way down the efficentcy
> > ladder. There's a reason the old Jenny's of the 1920's were
> soooo slow..
> > [amoungst other things] they had a 4ft x 4ft rad right out on
> the front of
> > the airframe about 4" behind the prop.. I think they cooled good
> though..> :-)*
> >
> > *I would re-write your cooling requirements to be something like
> this:*>
> > *A) idle for more than 1hr on the ground w/ a outside air temp
> of up to
> > 35dC, with a maximun tail wind of 15knt's.*
> >
> > *B) Support 3 minutes of Run up into wind with zero ground
> speed at max
> > power.*
> >
> > *C) Support a max power climb for not less than 5 minutes at Vy
> or Vx [you
> > pick] w/ an outside Air temp of not greater than 35dC.*
> >
> > *Tempurature maximum's: Oil-225dF, coolant- 210dF [or whatever
> they might
> > be]*
> >
> > **
> >
> > *Honestly I think under the exact same conditions in a car it
> would have
> > overheated as well [that day I was in Vegas] It was #@#^$
> <%23@#%5E$> HOT
> > and the wind was like a furnace. *
> >
> > *Anyway, we all know that designing a cooling system is going to
> be a
> > compromise, I just don't think blanket spec's as open as what
> you'd listed
> > are going to get you the system you need. We already fly our
> planes to fit
> > parameters [ or in your case heli's :-)] we just have to
> continue in that
> > vein and write spec's of which we'd be happy w/ and then tweak
> the system
> > until we get there.*
> >
> > **
> >
> > *Not poking fun or trying to be facetious, I just wanted to shed
> some real
> > world experiance "light" to the conversation.*
> >
> > *Best*
> >
> > *Jarrett* > > > > ** > > >
|