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Where did the 320 and 172 information come from ?
Fixed pitch props will continue to windmill but what about constant speed ?
- - I haven't tried this with a non-responsive, non seized engine.
The next question is what is the blade angle, resulting from a wind driven
constant speed propeller, for the "max" rpm and "min" rpm lever positions.
The control loop gain will be "adverse" in that scenario (wind driven
vs shaft driven).
. . . in the wind driven mode - as the rpm decreases - the pitch is
made to go flatter - making the rpm decrease more - - -
After consulting with H&S Prop Shop here in Michigan, the light goes
on.
It does not matter where the RPM lever is set.
With a non-responsive engine, the blades will go to the minimum pitch set
by the physical stop in the prop hub,
. . . typically 10-15 degrees depending on setup for the particular
installation.
Now a feathering prop is a different ball game . . .
Wolfgang
----- Original Message -----
Sent: Sunday, August 18, 2013 10:53
AM
Subject: Re: [LML] Fw: [LML] Re: FW:
[LML] Flaps on take-off?
Wolfgang,
See the diagram for drag from wind milling and fixed prop. Hartzell
CS prop for 320 flat pitch is 12 and coarse is 40 degrees.
Base diagram from Aeronautics for Naval Aviators.
Scott Krueger
In a message dated 8/18/2013 9:45:25 A.M. Central Daylight Time, Wolfgang@MiCom.net writes:
But . . . when you added power, didn't you also
increase the prop rpm ?
Makes me wonder . . . in gliders we modulate
drag with spoilers . . . how much drag off the propeller disk can be
modulated by using the prop rpm control ?
. . . but then again . . . if the engine is
ceased . . . the spring in the prop hub makes the blades go flat pitch . . .
maximum drag !
Wolfgang
----- Original Message -----
Sent: Thursday, August 15, 2013 9:39
PM
Subject: RE: [LML] Re: FW: [LML]
Flaps on take-off?
Robert,
I suppose you
could run out of gas, but I think the reason for the exercise was to teach
the pilot how far the plane would glide with power off in case he was
trying to make a farmers field in a real
emergency.
I think you would
be surprised about the feathered prop. I was trying to change my
landing technique the other day by changing the prop to a coarse setting
while in the pattern and locking it in that setting. I had to give
it up because when the plane got into ground effect, it just glided the
entire length of the runway and would not stop flying! Then when I
added power to do a go around, the plane didn’t want to fly because of the
lack of power from the coarse prop.
I was trying this
because I didn’t think I liked the fact that the plane would slow down so
fast with the prop in fine pitch when I pulled the power back. I
have now decided that I like it fine!
:>)
B2
From:
Lancair Mailing List
[mailto:lml@lancaironline.net] On
Behalf Of Lancair-ESP
Sent: Thursday, August 15, 2013 6:25
PM
To:
lml@lancaironline.net
Subject: [LML] Re: FW: [LML] Flaps on
take-off?
Bill,
What you
describe is certainly a possible scenario – actually that sounds like my
typical arrival. With the engine pulled back to 10-12” and a
windmilling prop the decent rate should be similar zero power and a
feathered prop.
But how
likely is an engine that fails in the close pattern after a cross-country
flight? More likely something would go afoul enroute, when the pilot
could select a landing spot and arrive 2000 ft above it. If not able
to arrive 2000 ft agl – choose an alternate
spot.
Just my
couple lira . . .
Robert
From:
Bill Bradburry [mailto:bbradburry@bellsouth.net]
Sent: Wednesday, August 14, 2013 2:06
PM
To:
lml@lancaironline.net
Subject: RE: [LML] FW: [LML] Flaps on
take-off?
Robert,
You should try it
under conditions that are more likely to be the case.
Descend to
pattern altitude, 1000 ft AGL, slow to pattern speed, and idle the engine
abeam the numbers and see if you can make it
I recommend you
idle the engine and not kill it, because I would be surprised if you do
make it. I also don’t recommend you coarse pitch the prop since you
may need to add power for the go around.
Bill
Bill,
I practiced
that maneuver with a Lancair company pilot flying my ES-P and found it a
non-event.
Overhead
upwind at 2000 ft agl and slowing to pattern speed in the
turn.
No flaps
until over the fence then deployed everything and aimed for 1/3 down the
runway.
I realize
the IV would take different speeds but it should still be do-able with a
little practice.
Robert
ES-P
N301ES
That seems a
scenario where you would be in better shape with the flaps up. You
very well might make the runway. With flaps down, you likely would
not and it would be very dangerous to try and retract them. With the
high wing loading that all the Lancairs have, they are flying bricks with
no power. I think almost nobody makes the approach to land with no
power.
Remember way back
in primary training when the instructor had you remove power abeam the
numbers and make the landing without having to add power? Does
anyone practice that maneuver with their
Lancair?
Bill
B
Matt, I agree
with the others that w's insults are inexcusable, but I must ask a
question.
What do you do if your low over the
departure end of the runway and the engine
quits?
1. Land at high speed flaps
up.
2. Lower the flaps and
deal with the big trim and pitch change while making all the other
decisions and actions required in
parallel.
-----
Forwarded Message -----
From: "marv@lancair.net" <marv@lancair.net>
To: lml <lml>
Sent: Monday, August 12, 2013 4:02
PM
Subject: [LML] Re:
Flaps on take-off?
Posted
for Matt losangeles <mattinlosangeles@yahoo.com>:
>
I feel much safer adding 5 knots or so on the ground before I lift off so
I
>don't have to mess with trim when I am low to the ground. I
could see a
>scenario where I take off IFR and I am immediately
handed off to departure
>control while I am putting the flaps up.
They tell me to do something the
>requires me to look at my map and
the next thing you know, while distracted,
> I am at an
unusual attitude really close to the ground. When I am down low
>like that I want to make sure if I am distracted it isn't a
problem, the
>plane just keeps on climbing along at Vy or
so.
>
> I also would guess if you use flaps on take
off, this adds drag and slows
>your rate of climb (I have not
tested this). I am able to be at Vy a couple
>seconds after
take off and I am going to get to a safer altitude before the
>guy
using flaps (again, this is my guess since I have not tested the two
>scenarios).
>
> Another thing. It is an
experimental aircraft. As it states on the
>EAA, "There
is no FAA approved flight manual or POH for experimental
>aircraft, nor is there a TC".
>
> Ohh, what about those reno racer Legacy aircraft that have just
bonded thier
>flaps in place so they can't go down in order to
eliminate the drag of the
>hindges. I guess they are not flying
those aircraft the way they were meant
>to be flown. You could
argue they are reno racers I suppose. It is also
>likely they are using those planes the other 51 weeks out of the
year to fly
>all over the place and those planes don't seem to be
crashing on takeoff.
>
> "I believe everyone would
agree that flaps do add a margin of safety"
> I personally
consider myself part of everyone and I don't agree that flaps
>do
in fact add a margin of safety on take off. I use them on landing so I can
>see out the window and out of habit I suppose. If the speed
you land at makes
>such a difference, then the best thing to be
doing is flying a plane that
>lands at a slower speed.
>
> Perhaps if we were all 100 hour pilots, blindly following
the POH makes
>sense. It is funny, I remember having this EXACT
same argument on a Mooney
>board. I used to take off without flaps
when I had a Mooney and I heard the
>same thing there. Follow the
POH explicitly or you are completely reckless
>and should have
your license taken away. At least those Mooney guys had a
>point.
That was a certified aircraft with a POH that said to take off with
>flaps.
>
> Something else to consider, if flaps
are so critical to flight on our
>planes, why on earth don't they
have a back up system to ensure they always
>go down when needed
like our landing gear has? My guess is because the plane
>will fly
just fine without them.
>
> Matt
>
>
> ________________________________
> From: Art Jensen <flycassutts@yahoo.com>
>
To: lml@lancaironline.net
>
Sent: Monday, August 12, 2013 1:46 PM
> Subject: [LML] Re: To
Marv
>
> Maybe Wolfgang was short on political
correctness, but the truth remains
>that if you cannot or do not
fly the plane as it was meant to be flown then
>you should not be
flying that plane.
>
> I believe everyone would agree that
flaps do add a margin of safety and
>should be used for take-off
and landing as per your POH and I believe every
>instructor giving
training in a Lancair would agree. If an instructor
>reading this disagrees, please share why you disagree with
me.
>
> Art
>
> Sent from Yahoo! Mail for
iPad
>
>
>
________________________________
> From: steve <n5276j@aol.com>; To: <lml@lancaironline.net>; Subject:
> [LML] Re: To Marv Sent: Mon, Aug 12, 2013
5:39:28 PM
> I second your post. I am
surprised by the comment.
>
> steve alderman
N25SA 360
>
> .
> -----Original Message-----
From: Claudette Colwell <colwell.ch@gmail.com>
>To: lml <lml@lancaironline.net> Sent:
Mon, Aug 12, 2013 5:43 am Subject:
>[LML] To
Marv
> It is very regretful the comment from Wolfgang
apparently directed to Matt
>appeared on the LML. This has
always been a constructive exchange of
>information and
ideas. That type of personal comment is not in keeping with
>the spirit of cooperative sharing of information.
>
> Claudette
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