|
|
Some good points, David, thanks.
I generally try to fly my patterns such that I could make an "engine out"
landing in a GA bird - this generally meant keeping a prop rpm of 1500-1700.
Yes, the RV flaps are not really much of lift producers as they are really
drag devices. I agree the "idle" pattern does result in a steeper angle of
approach, but with obstructions off both ends it puts you on the runway
sooner (in my hard landing case - MUCH sooner {:>)).
That approach worked fine with my smaller prop and 2.17 gear box, but going
all the way to idle with the new set up appears to add considerably to the
rate of descent - which if you plan for it from git go is undoubtedly
manageable - but, throwing it to idle when less than 200 ft altitude does
not appear to be prudent.
Energy management is what its is all about.
Ed
----- Original Message -----
From: "David Carter" <dcarter@datarecall.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Saturday, February 26, 2005 10:28 PM
Subject: [FlyRotary] Re: Monster Prop Air Brake
When I was 17 and just had my Private license, I'd been flying Cubs and
Aeronca Champs - no problem making idle patterns.
Then an older friend took me up in his Navion and let me fly a final. I
pulled the throttle back to idle (with gear down and FULL flaps) - looked
like a 20 degree dive bomb run!!! I tried to add power instinctively - he
wouldn't let me. It was VERY uncomfortable.
Later in life, flying T-33's, we set the RPM at something like 55% (idle
was
35% on those old engines) and flew the pattern that way.
Later, in swept wing fighters (much higher wing loading than the T-33),
you
NEVER turned from downwind to final at idle - always carried enough power
to
have a reasonable descent during the VFR turn to final.
Sounds like the RV-6 or whatever, must have draggy flaps, so it simply
isn't
comfortable to do the entire pattern at "idle" - carrying some power like
the "big boys" makes a lot of sense and is consistent with good practice
for
lots of other aircraft models. Not "being at idle" isn't "wimpy". Nor is
"being at idle" necessarily "smart" or "cool".
I've had my 1.4 dual with Mike Seeger (spelling?) in Oregon - we flew
"idle"
but it was a "steep pattern" with lots of talk about "being able to make
the
field if the engine quit". Seems to me that "being able to make the field
if the engine quits" (steep pattern) isn't consistent with a "comfortable
descent profile". In the "big iron" we didn't worry about making the
field
if the engine quit - that wasn't even a consideration. We had an ejection
handle, but, our engines never quit on turning final so it was a
non-issue.
- Flying airplanes is like designing them - lots of tradeoffs and
compromises for "best overall outcome".
David
----- Original Message -----
From: "Russell Duffy" <13brv3@bellsouth.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Saturday, February 26, 2005 8:56 PM
Subject: [FlyRotary] Re: Monster Prop Air Brake
Rusty, do you throttle back to idle in the pattern, base, final? My idle
is
around 1200-1500, but I seldom ever go below 2500rpm on final in flight.
If
may be that if you establish you minimum rpm as you are stabilized on
final,
then the drag factor is there and you are already compensating for it. If
you are stabilized on final and then drag it back to idle is when I find
the
effect.
Hi Ed,
I'm almost always at idle during the entire final. What I can't say is
what
my rpm really is during final, because I've never looked at it that I can
recall. I'm sure the airspeed raises it some from the 1600 that it would
be
on the ground, so maybe it is 2500. I should also add that I often don't
use flaps. When I do, I usually only use about half. Full flaps, slow
airspeed, and idle power will truly plummet.
Rusty
>> Homepage: http://www.flyrotary.com/
>> Archive: http://lancaironline.net/lists/flyrotary/List.html
|
|