X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 10 [X] Return-Path: Received: from an-out-0708.google.com ([209.85.132.245] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2067736 for flyrotary@lancaironline.net; Fri, 25 May 2007 16:51:48 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.132.245; envelope-from=rotary.thjakits@gmail.com Received: by an-out-0708.google.com with SMTP id b2so252745ana for ; Fri, 25 May 2007 13:51:11 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=eI8Vc1KZCOVPCshR5WghXGtBgCPPOGeU6ANfc0lovGRcBZ3EZDRvVoh8nrbeDQNmaRNXtlOrTrryOztBZjX7uUjx12gIe0wJk1d8LQGhLaAZ6jB40ZwpGBkga6faF6Ni6yoSQvXsQsYiC5XQg9o0VMHfvWkG2dvfgCQjuSoxjfw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=rd0FXgaRso45jQCRUM0dyHo//fpSNGVDa5kATal0McSm9MGS7AMbGQc1HMYuIdP+iy7br/0E4uQNswS3a8tPk8EFei8zNHGWQjRPmtX32IXhCOqbPtESssHET/EcC//g4PigAjdAjQskLizQYhja/PYuEZ6scaw3geUTbrrn7P0= Received: by 10.100.143.11 with SMTP id q11mr3007989and.1180126271025; Fri, 25 May 2007 13:51:11 -0700 (PDT) Received: by 10.100.96.15 with HTTP; Fri, 25 May 2007 13:51:10 -0700 (PDT) Message-ID: <63163d560705251351o217fb29fwfe60d57fcba67103@mail.gmail.com> Date: Fri, 25 May 2007 15:51:10 -0500 From: "Thomas Jakits" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Marginal Cooling In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_199034_5125129.1180126270954" References: ------=_Part_199034_5125129.1180126270954 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline 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 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 > > *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 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* > > > > > > ** > > > > > > > -- > > Homepage: http://www.flyrotary.com/ > > Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html > > ------=_Part_199034_5125129.1180126270954 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline
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*
> >
> > **
> >
>

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