Thread: Piper Seneca
View Single Post
  #11  
Old April 19th 06, 10:22 PM posted to rec.aviation.owning
external usenet poster
 
Posts: n/a
Default Piper Seneca

Hi!

Thanks to all the replies!

I'm going to seriously look into the Aztec.

How is the baggage loading compared to the Seneca?

Is it easy to get bukjy items into the plane?
Easy to remove seats if I need to carry something big?

I ask, because I am a double bass player......

:-)

Frode

"Jim Burns" skrev i melding
...
My real world '66 C, non turbo Aztec numbers are identical to Ronnie's.
Recent 25 hour round trip flight from WI to Las Vegas and back yielded an
average of 22 gph fuel burn at TAS between 160 and 165. I also flight
plan
on 160 TAS at 25gph.

Jim

"Ronnie" wrote in message
. com...
Frode,

For my 1964 C model, non-turbo Aztec:

Gross Weight: 5,200 lbs Empty Weight: 3,120 lbs Useful Load: 2,080

lbs
Payload w/ Full Fuel 1,240 lbs

Total Fuel: 144 gallons Usable Fuel: 140 gallons
Payload with full fuel: 1,240 lbs



Normal cruise Performance: 160 KTAS @ 7,000 MSL @ 24 GPH
Endurance: 5.8 hours
Range: 928 NM



The flight manual indicates that the maximum cruise speed is 178 knots at
7,000' to 8,000' and 75% power.

I have found this to be optimistic. I flight plan for 160 knots with a

fuel
burn of 25 GPH. In flight, I see

true airspeeds ranging from 160 to 165 knots and at the pumps the fuel
consumption normally turns out

to be around 22 GPH. Using 160 knots and 25 GPH is conservative and it
is
easy to do the math for fuel

burn in your head.



If you'd rather save fuel, extended your range and endurance, and log
more
multi-engine hours, just pull

the power back. On a recent flight at 3,500', I decided to use 2,000 RPM
and 18" of manifold pressure and

see what the speed and fuel flow would look like. The true airspeed was
around 135 knots and the fuel flow

was 15 gallons per hour. On a 425 NM trip, the calculated difference in
time en route was 30 minutes, turning

what would have been a 2 hour, 40 minute trip into a 3 hour, 10 minute

trip.
The difference in the calculated

fuel consumption was 58.4 gallons versus 47.2 gallons, or a savings of

11.2
gallons. An added benefit of lower

power settings is that the airplane is quieter and the engines are
loafing
along and running very cool.




Flight Speeds and Characteristics:



SPEED MPH
KTS

Vso 68
59

Vs 72
63

Vmc (Red radial line) 80 70

Vr (Vmc + 5) 85
74

Vxse 97
84

Vyse (Blue radial line) 102 89

Vx 107
93

Vy 120
104

Vfe 125
109

Va (@ 4800 lbs) 145

126

Vle 150
130

Vcruise 184
160

Vne 249
217




You have to look at the flight manual to get the various performance
figures, but on average

you will experience climb rates of between 1,400 to 1,900 FPM on a

standard
day from 4,000 lbs

up to full gross weight. With my normal load and on a hot summer day
leaving a 782' MSL field

using a cruise-climb airspeed of 130 MPH, I'll average 750 to 1,000 FPM
as
the initial rate of

climb. At light weights and under cool conditions, using Vyse, it is not
hard to peg the

+2,000 FPM limit on the vertical speed indicator. This is of course with
both engines running.

A healthy rate of climb provides a quicker trip up to the cooler,
smoother
air where you and

your passengers will be more comfortable.



The single-engine rate of climb is much less. Rate of climb is dependent

on
power in excess

of that necessary for level flight. When you lose an engine, you lose
50%
of your total power,

but in the order of 80% of your excess power. Therefore your climb
performance also suffers

by that same 80% figure. The flight manual shows a single-engine rate of
climb of between

225 and 625 FPM depending on weight for sea level, standard day

conditions.
Many people

are afraid of twins because of this poor single engine performance and
the
potential for loss

of control after an engine failure on take-off. But consider the climb
performance of a single

engine airplane after loosing one engine! I'll guarantee you it will be
less! The most critical

time period in a twin for losing an engine is the few seconds between
rotation and getting to

a safe maneuvering altitude. There is an elevated risk of losing control

of
the airplane during

these critical few seconds of flight. This risk it managed by good

initial
training, good recurrent

training, and by proper planning and preparation before each and every
take-off. If you are well

trained, well practiced and have thought through the possibilities before
each take-off, you

should have no difficulty executing the manufacturer's engine-out

checklist
procedures and

maintaining control of the airplane.



For other phases of flight, an engine failure is a non-event. Assume you
are cruising along at

8,000' and you lose one engine. Yes, it will get your attention, but

there
is no emergency.

Identify which engine failed, verify you have identified the correct

engine
as the failed one,

and then go through the steps to either fix the problem or to feather the
prop and secure the

engine. If you end up securing the failed engine, you continue to fly on
the remaining engine

and will only slowly drift down to the single-engine service ceiling.

This
is the altitude where

the rate of climb is less than 50 FPM. For the Aztec, the lowest
single-engine service ceiling is

5,000' and goes up to over 17,000' depending on initial take-off weight

and
remaining fuel load.

In short, unless you are in the mountains, the single-engine service

ceiling
will not likely be a

concern. Simply find an airport where repairs can be made and head that
way.



Similarly, a single-engine approach and landing is also a non-event. Fly
the airplane at Vyse

throughout the pattern, fly a bit wider than normal pattern to give

yourself
a little extra time,

and defer the use of full flaps until the landing is assured. Once full
flaps are deployed, don't

attempt a go around. If you need to go around, make the decision early
in
the approach. If you

attempt a "low and slow" go around, you've put yourself back into a
single
engine takeoff phase

of flight which should be avoided.



I am a firm believer that a twin-engine airplane is safer than a
single-engine airplane, hands-down,

assuming a well trained, competent pilot in command in each airplane.
The
benefit to you is that

you will fly safer as will your family and other passengers.



All the data above is for a non-turbo model. Turbo-charged Aztec are
also
common and will

of course post higher speeds up high and associated higher fuel burns.
Maybe Kyler will

post the data for his turbo Aztec.



Ronnie





"Frode Berg" wrote in message
...
hi!

Thanks for your input.

As I stated, this is not a short term consideration, as I do not

currently
hold an IR license, but will be getting one starting this summer.

My wife and I have been toying with the possibilities of getting a
vacational house in southern Europe, and I've been saying ok, but we'll
need a de-iced twin, and she agrees, so a lot of the job is done....

:-)

However, the Aztec idea is interesting.

What are the figures for this plane?

Loading capabilities? Speeds? Endurance/range?

Thanks,

Frode


"Ronnie" skrev i melding
. com...
Frode,

I know you asked specifically about a Seneca and if you
want a Seneca, a Seneca you should get. However, in the
meantime, you might consider another Piper twin, the Aztec.

Older versions can be had for much less and would let you
fly a twin and accumulate multi-engine time before ultimately
getting the Seneca that you want. I admit I'm a bit biased
since I've been flying 1964 C model Aztec for the last 7 years.
There was a very, very nice Seneca III hangared in the same
hangar as my Aztec and it made me conside trading for a Seneca,
stricly on apperances. However, when I began comparing useful
loads, single engine rate of climb, and over-all performance versus
cost to aquire, I decided the Aztec fit my needs much better. At
first, the blub seating and left side, low entry door looked like a

plus
for the Seneca that make getting passengers and big items in and out
easier
However, after taking a couple of trips the club seating turned out to
be problematic for my family with the kids bumping knees. In our
case,
we like the forward facing seats and two large cargo areas fore and

aft.
better.

Just food for thought.

Ronnie


"Frode Berg" wrote in message
...
hi all!

This might be a silly question, but I am dreaming of owning, or
co-owning a Piper Seneca.
Not this year or next, but maybe within the next 10 years.

I have been browsing the aircraft for sale sites, and found planes

from
the 70's (Seneca II) selling for as low as $139K with about half time
remaining on the engines and props.

Anyone care to share the pro's and con's of the different models?

(I-V)
Obviously, I will not be able to afford a V, so far, only the II's

seem
accessible sort of.
Anything worth knowing about this model? Bad things?

Also, I understand maintenance will be about double of what I have
now
(Arrow 180).
Any other traps to consider cost wise going for a twin?

Any other aircraft in the same price range that might be better

choices?

I'm looking for a piston certified for Icing conditions.
I also want a twin, as I'll be flying over mountains and have

nightmares
about engine out's in IMC and icing conditions over mountain
terrain.....

Thanks for any hints,

Frode