X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 18 Oct 2013 10:32:47 -0400 Message-ID: X-Original-Return-Path: Received: from mail-qe0-f41.google.com ([209.85.128.41] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6545818 for lml@lancaironline.net; Fri, 18 Oct 2013 10:31:51 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.128.41; envelope-from=legacyl2k@gmail.com Received: by mail-qe0-f41.google.com with SMTP id x7so1859523qeu.0 for ; Fri, 18 Oct 2013 07:31:11 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.49.116.210 with SMTP id jy18mr4206470qeb.65.1382106671208; Fri, 18 Oct 2013 07:31:11 -0700 (PDT) Received: by 10.96.84.233 with HTTP; Fri, 18 Oct 2013 07:31:11 -0700 (PDT) In-Reply-To: References: X-Original-Date: Fri, 18 Oct 2013 07:31:11 -0700 X-Original-Message-ID: Subject: Re: [LML] MT prop fully reversible 1st report... From: Mike Larkin X-Original-To: Lancair Mailing List Content-Type: multipart/alternative; boundary=047d7b5dbfc82ddefc04e904c990 --047d7b5dbfc82ddefc04e904c990 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Ronald, I have spent many years flying a large variety of airplanes with reversible pitch props, both certified and experimental. Things to think about: Can YOUR airplane going into Beta in-flight? Do you have enough redundancy in the systems to prevent this. Second, blade flex! Low RPM reverse is very stressful on the prop blades and MT's are not very tolerant of this. You won't have to deal with a failure, but blade de-lamination is greatly accelerated vs time. Lastly, loss of tail effectiveness (rudder) at high power reverse which reduces and/or eliminates directional control with the rudder on deceleration. This can create problems on contaminated and narrow runways. The 4p Turbine suffers from this but is controllable. Food for thought! Mike Larkin 4LL ect... On Fri, Oct 18, 2013 at 4:55 AM, Ronald Stevens wrote: > Hello guys**** > > ** ** > > As I told many months ago, I planned to get *the 4 bladed MT prop fully > reversible and fully feathered.* Today it came finally together=85.**** > > ** ** > > The reason it took so long is that it took some adaptions on the plane, a > confused wire plan and off course the delay just getting the prop and the > governor.**** > > ** ** > > Today I had my first experiences and will report more once I can test it > without any wind conditions to see how it really performs, but so far it > did really well. The system has 2 switches, where 1 is to =91arm=92 the s= ystem, > and the other to use it as the =91beta=92 switch.**** > > ** ** > > Now my first fast taxi was very uneventful, as a matter of fact, I was > kind of disappointed not seeing a huge effect right away. I taxied at abo= ut > 30 knots and switched it on and =85.almost nothing happened. This actuall= y is > a good thing (I found out later), as the system is actually very smooth > going into beta without any =91wiggling=92 or any unease feeling of a pla= ne > suddenly going another way.**** > > ** ** > > My first faster taxi (at 60 knots) was at least more eventful, when I > switched it on, and had the prop was at about 700rpm, I just noticed that > it had a little extra drag, but than giving it some throttle it started t= o > give some nice braking action. But all very comfortable, nothing weird, > just simple.**** > > ** ** > > So I took it into the air, and landed with the system, and for sure with > some good practice I can land the plane between 1500-1800ft. (going with > 90knots over the numbers, today I was already within 2000ft). This is gre= at > when the gremlins are taking away some runway in the night going in to ho= t > J**** > > ** ** > > The system does have some safety features like it cannot go to reverse > above 70knots or when the prop is higher as 1200rpm. The feather works th= e > same as with the Hartzell (just pull the prop).**** > > ** ** > > So far it was working fine, and when I have some more experiences with it > (not doing crazy stuff) I can provide some real numbers of how much runwa= y > not it takes to land the 4p with this combination. I will not go extreme > with going full throttle once activated, throwing is dust and dirt all ov= er > the plane LOL **** > > ** ** > > The prop and installation is not cheap, but running of the runway is more > expensive J**** > > ** ** > > The installation was done by Matthew Collier from Fibercraft and Avionics > Instalations, here in Spruce Creek, Florida (7FL6). **** > > ** ** > > Ronald Stevens (400h LNC4p and some=85.) n45HL**** > > ** ** > --=20 Mike Larkin LarkinAviationConsulting LegacyL2K@gmail.com 602-770-6054 --047d7b5dbfc82ddefc04e904c990 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Ronald,

I have spent many year= s flying a large variety of airplanes with reversible pitch props, both cer= tified and experimental.=A0 Things to think about:=A0 Can YOUR airplane goi= ng into Beta in-flight?=A0 Do you have enough redundancy in the systems to = prevent this.=A0 Second, blade flex!=A0 Low RPM reverse is very stressful o= n the prop blades and MT's are not very tolerant of this.=A0 You won= 9;t have to deal with a failure, but blade de-lamination is greatly acceler= ated vs time.=A0 Lastly, loss of tail effectiveness (rudder) at high power = reverse which reduces and/or eliminates directional control with the rudder= on deceleration.=A0 This can create problems on contaminated and narrow ru= nways.=A0 The 4p Turbine suffers from this but is controllable.=A0 Food for= thought!

Mike Larkin
4LL ect...


On Fri, Oct 18, 2013 at 4:55 AM, Rona= ld Stevens <ronald@sdc.com> wrote:

Hello guys

=A0

As I told many months ago, I pl= anned to get the 4 bladed MT prop fully reversible and fully feathered.<= /b> Today it came finally together=85.

=A0

The reason it took so long is t= hat it took some adaptions on the plane, a confused wire plan and off cours= e the delay just getting the prop and the governor.

=A0

Today I had my first experience= s and will report more once I can test it without any wind conditions to se= e how it really performs, but so far it did really well. The system has 2 s= witches, where 1 is to =91arm=92 the system, and the other to use it as the= =91beta=92 switch.

=A0

Now my f= irst fast taxi was very uneventful, as a matter of fact, I was kind of disa= ppointed not seeing a huge effect right away. I taxied at about 30 knots an= d switched it on and =85.almost nothing happened. This actually is a good t= hing (I found out later), as the system is actually very smooth going into = beta without any =91wiggling=92 or any unease feeling of a plane suddenly g= oing another way.

=A0

My first= faster taxi (at 60 knots) was at least more eventful, when I switched it o= n, and had the prop was at about 700rpm, I just noticed that it had a littl= e extra drag, but than giving it some throttle it started to give some nice= braking action. But all very comfortable, nothing weird, just simple.

=A0

So I too= k it into the air, and landed with the system, and for sure with some good = practice I can land the plane between 1500-1800ft. (going with 90knots over= the numbers, today I was already within 2000ft). This is great when the gr= emlins are taking away some runway in the night going in to hot J

=A0

The syst= em does have some safety features like it cannot go to reverse above 70knot= s or when the prop is higher as 1200rpm. The feather works the same as with= the Hartzell (just pull the prop).

=A0

So far i= t was working fine, and when I have some more experiences with it (not doin= g crazy stuff) I can provide some real numbers of how much runway not it ta= kes to land the 4p with this combination. I will not go extreme with going = full throttle once activated, throwing is dust and dirt all over the plane = LOL

=A0

The prop= and installation is not cheap, but running of the runway is more expensive= J

=A0

The installation was done by Ma= tthew Collier from Fibercraft and Avionics Instalations, here in Spruce Cre= ek, Florida (7FL6).

=A0<= /u>

Ronald Stevens (400h LNC4p and some=85.) n45HL

=A0




--
Mike Larkin
LarkinAviationConsulting
LegacyL2K@gmail.com
602-770-6054
--047d7b5dbfc82ddefc04e904c990--