Green Arc Red Zone

C-177B models also had a red zone range
you could feel the vibration in the floor if you were in the "red zone",
neat trick for instructors..
Instructor to student: "you feel that vibration"
Student: "yes"...
Instructor: "Then do something about it"
Student: "What should I do? I'm not flying to fast.."
Instructor: "You think maybe the engine or prop are trying to tell you
something?"
Student: "Oh yah.. That red arc"

BT

"john smith" wrote in message
...
Jack Allison's discussion of the Hartzell AD for his Arrow has gotten me
to thinking.
What aircraft do you fly/have you flown/do you have first hand knowledge
of which have a red zone somewhere in the green arc of the tachometer?

For example, I know there are/were certain models of Cessna 210's that had
such markings, but I cannot remember the specific models/engine/prop
combinations.

"john smith" wrote in message
...
Jack Allison's discussion of the Hartzell AD for his Arrow has gotten me
to thinking.
What aircraft do you fly/have you flown/do you have first hand knowledge
of which have a red zone somewhere in the green arc of the tachometer?

For example, I know there are/were certain models of Cessna 210's that had
such markings, but I cannot remember the specific models/engine/prop
combinations.

john smith wrote:
Jack Allison's discussion of the Hartzell AD for his Arrow has gotten me
to thinking.
What aircraft do you fly/have you flown/do you have first hand knowledge
of which have a red zone somewhere in the green arc of the tachometer?

For example, I know there are/were certain models of Cessna 210's that
had such markings, but I cannot remember the specific models/engine/prop
combinations.


I have a modified Cessna 172 with the Lycoming O-360-A1A engine and
Hartzel prop. I have a redline limitation between 2100 and 2250 rpm.
Really stinks.

--
Regards,

Ross
C-172F 180 hp
KSWI

Although there is red marking in the green arc, the POH for the 1979
Piper Turbo Arrow IV/PA28RT-201T, the LIMITATIONS SECTION lists the
following placards:

AVOID CONTINUOUS GROUND OPERATION 1700-2100 RPM IN CROSS/TAIL WIND OVER
10 KTS.

AVOID CONTINUOUS OPERATION 2000-2200 RPM ABOVE 32" MANIFOLD PRESSURE

I believe this applies to the two-bladed prop only and not the
three-bladed prop, but I can find nothing in the manual to support this
theory. I do not find the placards on the panel of the aircraft I fly
which has the three-bladed prop.

These two lines in the LIMITATIONS SECTION are the only place in the
POH which mention this condition.

Should read: "Although there is no red marking..."

Although there is red marking in the green arc, the POH for the 1979
Piper Turbo Arrow IV/PA28RT-201T, the LIMITATIONS SECTION lists the
following placards:

AVOID CONTINUOUS GROUND OPERATION 1700-2100 RPM IN CROSS/TAIL WIND OVER
10 KTS.

AVOID CONTINUOUS OPERATION 2000-2200 RPM ABOVE 32" MANIFOLD PRESSURE

I believe this applies to the two-bladed prop only and not the
three-bladed prop, but I can find nothing in the manual to support this
theory. I do not find the placards on the panel of the aircraft I fly
which has the three-bladed prop.

These two lines in the LIMITATIONS SECTION are the only place in the
POH which mention this condition.

john smith wrote:
Jack Allison's discussion of the Hartzell AD for his Arrow has gotten me
to thinking.
Wow...attribution and getting Mr. S to think. My work here is done :-)

What aircraft do you fly/have you flown/do you have first hand knowledge
of which have a red zone somewhere in the green arc of the tachometer?
Ours is a yellow arc that goes from...rats, I don't have it written down
anywhere. IIRC, the upper end of the yellow is 2300, maybe 2350. I'll
have to check tomorrow, make a note, and report back.

At any rate, it's really not much of a deal for our plane since,
basically, we use three prop settings:

1) Full forward for takeoff
2) 2500 rpm at 1000 AGL (and 25 inches MP)
3) 2400 rpm at cruise (and 21 inches MP...or, if you want to burn more
100ll for only a couple kt gain, go with 24 inches MP).


--
Jack Allison
PP-ASEL-Instrument Airplane

"To become a Jedi knight, you must master a single force. To become
a private pilot you must strive to master four of them"
- Rod Machado

(Remove the obvious from address to reply via e-mail)

Jack Allison wrote:

john smith wrote:

Jack Allison's discussion of the Hartzell AD for his Arrow has gotten
me to thinking.

Wow...attribution and getting Mr. S to think. My work here is done :-)

Should I respond to that?

Naw! I don't feed trolls. :-))

I don't think anyone mentioned the early Cherokee 180s. They have (or
should have) a red arc on the tach from 2150 to 2350 and a placard
stating that continuous operation should be avoided in that range.
The reason was harmonic vibrations developed between the Sensenich 76"
prop and the hollow cranked O-360-A3A. There were some prop tip
losses in the late 60s that prompted the restriction.

The restriction was removed in the '68 and later models, with the
introduction of the solid cranked O-360-A4A engine.

John Galban=====N4BQ (PA28-180)


--
JGalban
Posted at www.flight.org

john smith wrote:
Jack Allison's discussion of the Hartzell AD for his Arrow has gotten
me to thinking.

Wow...attribution and getting Mr. S to think. My work here is done :-)

Should I respond to that?

Too late, you just did! :-)

Naw! I don't feed trolls. :-))

Oh sure, break out the 'T' word. :-)


--
Jack Allison
PP-ASEL-Instrument Airplane

"To become a Jedi knight, you must master a single force. To become
a private pilot you must strive to master four of them"
- Rod Machado

(Remove the obvious from address to reply via e-mail)