X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 18 Oct 2013 12:19:36 -0400 Message-ID: X-Original-Return-Path: Received: from mail-qa0-f53.google.com ([209.85.216.53] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6545957 for lml@lancaironline.net; Fri, 18 Oct 2013 11:49:05 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.216.53; envelope-from=legacyl2k@gmail.com Received: by mail-qa0-f53.google.com with SMTP id k15so785112qaq.5 for ; Fri, 18 Oct 2013 08:48:30 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.224.75.200 with SMTP id z8mr5455259qaj.71.1382111310213; Fri, 18 Oct 2013 08:48:30 -0700 (PDT) Received: by 10.96.84.233 with HTTP; Fri, 18 Oct 2013 08:48:30 -0700 (PDT) In-Reply-To: References: X-Original-Date: Fri, 18 Oct 2013 08:48:30 -0700 X-Original-Message-ID: Subject: Re: [LML] Re: MT prop fully reversible 1st report... From: Mike Larkin X-Original-To: Lancair Mailing List Content-Type: multipart/alternative; boundary=001a11c30c1eaf778e04e905ddd8 --001a11c30c1eaf778e04e905ddd8 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Ronald, Just offering up things to think about... One of my favorite sayings that has gone a long way with my experimental builder group is, "You Don't Know What You Don't Know. This is a learning process." I have been involved in a fair amount of work using beta/reverse props. From multi-engine reverse requirements to diving an airplane into the vertical then using reverse so skydivers can fly with the airplane. My Basic point, unexpected things can go wrong. When they do with experimental beta type prop setups, they usually go wrong in a big way. A few Lancair's have fallen victim to some of these issues. All the best and good luck, be safe.. Mike On Fri, Oct 18, 2013 at 8:23 AM, Ronald Stevens wrote: > Hi Mike**** > > ** ** > > The BETA in flight are prohibited with 2 safety features, the first is an > airspeed switch (so your plane needs to go less than 70knots, the second = is > RPM limited (<1200rpm).**** > > A loss of oil pressure will turn your blades into feather, not beta.**** > > ** ** > > The plane itself when switching to Beta on low RPM is doing nothing that > will make you wondering what it will do next (I did Beta on a p210 with > Allison conversion (Silver Eagle) and this had a much bigger effect on th= e > plane than this one does.**** > > ** ** > > So when I was going into Beta the tail already is about doing nothing > anymore (speed is below 70kts, actually 66kts), so the tail effect was no= t > noticeable at all. The plane was steering the same or even better now jus= t > using the brakes, which you now use less.**** > > ** ** > > About the delamination, this will have to show over time, I cannot commen= t > on this as I do not have this experience.**** > > ** ** > > But thanks for the tips, and yes the blades are ALWAYS on my preflight > check=85.and now even more J**** > > ** ** > > =3D=3D Ronald**** > > ** ** > > *From:* Lancair Mailing List [mailto:lml@lancaironline.net] *On Behalf Of > *Mike Larkin > *Sent:* Friday, October 18, 2013 10:33 AM > *To:* lml@lancaironline.net > *Subject:* [LML] Re: MT prop fully reversible 1st report...**** > > ** ** > > 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 tolera= nt > 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 contaminate= d > 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**** > > **** > > > > > -- > Mike Larkin > LarkinAviationConsulting > LegacyL2K@gmail.com > 602-770-6054 **** > --=20 Mike Larkin LarkinAviationConsulting LegacyL2K@gmail.com 602-770-6054 --001a11c30c1eaf778e04e905ddd8 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Ronald,

Just offering up thing= s to think about...=A0 One of my favorite sayings that has gone a long way = with my experimental builder group is, "You Don't Know What You Do= n't Know.=A0 This is a learning process."=A0 I have been involved = in a fair amount of work using beta/reverse props.=A0 From multi-engine rev= erse requirements to diving an airplane into the vertical then using revers= e so skydivers can fly with the airplane.=A0 My Basic point, unexpected thi= ngs can go wrong.=A0 When they do with experimental beta type prop setups, = they usually go wrong in a big way.=A0 A few Lancair's have fallen vict= im to some of these issues.

All the best and good luck, be safe..

Mike
=


On Fri, Oct 1= 8, 2013 at 8:23 AM, Ronald Stevens <ronald@sdc.com> wrote:

Hi Mike

=A0<= /p>

The BETA in flight are= prohibited with 2 safety features, the first is an airspeed switch (so you= r plane needs to go less than 70knots, the second is RPM limited (<1200r= pm).

A loss of oil pressure wi= ll turn your blades into feather, not beta.

=A0

The plane itself when switching to Beta on lo= w RPM is doing nothing that will make you wondering what it will do next (I= did Beta on a p210 with Allison conversion (Silver Eagle) and this had a m= uch bigger effect on the plane than this one does.

=A0<= /p>

So when I was going in= to Beta the tail already is about doing nothing anymore (speed is below 70k= ts, actually 66kts), so the tail effect was not noticeable at all. The plan= e was steering the same or even better now just using the brakes, which you= now use less.

=A0<= /p>

About the delamination= , this will have to show over time, I cannot comment on this as I do not ha= ve this experience.<= /u>

=A0<= /p>

But thanks for the tip= s, and yes the blades are ALWAYS on my preflight check=85.and now even more= J

=A0<= /p>

=3D=3D Ronald

=A0<= /p>

From: Lan= cair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Mike Larkin
Sent: Friday, October 18, 2013 10:33 AM
To: lml@lancaironline.net
<= b>Subject: [LML] Re: MT prop fully reversible 1st report...

=A0

Ronald,

I have spent many years flying a large variety of airplanes with reversibl= e pitch props, both certified and experimental.=A0 Things to think about:= =A0 Can YOUR airplane going into Beta in-flight?=A0 Do you have enough redu= ndancy in the systems to prevent this.=A0 Second, blade flex!=A0 Low RPM re= verse is very stressful on the prop blades and MT's are not very tolera= nt of this.=A0 You won't have to deal with a failure, but blade de-lami= nation is greatly accelerated vs time.=A0 Lastly, loss of tail effectivenes= s (rudder) at high power reverse which reduces and/or eliminates directiona= l control with the rudder on deceleration.=A0 This can create problems on c= ontaminated and narrow runways.=A0 The 4p Turbine suffers from this but is = controllable.=A0 Food for thought!

Mike Larkin

4LL ect...

=A0

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

Hello guys

=A0<= /u>

As I told many months ago, I planned to get the 4= bladed MT prop fully reversible and fully feathered. Today it came fin= ally together=85.

=A0=

The reason it took so long is that it took some adap= tions on the plane, a confused wire plan and off course the delay just gett= ing the prop and the governor.

=A0<= u>

Today I had my first experiences and will report mor= e once I can test it without any wind conditions to see how it really perfo= rms, but so far it did really well. The system has 2 switches, where 1 is t= o =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<= br> LegacyL2K@gmail.co= m
602-770-6054




--
Mike Larkin
LarkinAviation<= font style=3D"color:rgb(51,51,255)" size=3D"4">Consulting
LegacyL2K@gmail.com
602-770-6054
--001a11c30c1eaf778e04e905ddd8--