When I checked out in the Seneca II, (PA-34-200T) it was standard practice
to start on Main, go to X-Feed (for both sides) during taxi, and return to
Main for run up checks and take off. And then the check pilot said, "don't
mess with what is working", interesting statement, meaning, don't do the
x-feed check on the ground. Forget to go back to Main for take off and
you'll have bigger problems.

I checked my POH and found the reference you mention. And no explanation as
to why.
Long time on both to x-feed.. or take off with both on x-feed is not
recommended. A guess would be "Not able to maintain high fuel flow rates at
take off power across the x-feed line".

According to the manual, the only reason to x-feed is to maintain lateral
fuel balance when operating on one engine (emergency condition) and to have
the other fuel selector to the "off" position. So, right engine shut down,
right wing getting heavy from left engine draining fuel from left tank. So
Right tank goes to x-feed the left, and left tank is set to off.

I know this information does not answer your question.
BT

"Silvio Mecucci" wrote in message
om...
I've asked the following question to NewPiper Inc.

Sent: Tuesday, February 08, 2005 7:24 AM
To: Flynn, Kathy L.
Subject: PA34 200T question

Dear Mrs / Ms Flynn
I've called the italian dealer you gave my the number of.
They made me talk with the dirigent who answered my question in the way
I'll report

Since I'm not fully satisfied by his answer I would like also your
opinion.

In the P.O.H. of the PA-34-200T, Seneca II I'm flying with, Section 7 -
Description and operation, there is a NOTE which reports:
"Do not operate with both selectors on "X-FEED.""
Page 7-13 Issued August 23, 1976 Revised March 11, 1977

If such a note is present I suppose that something dangerous may happen
if the prescription wouldn't be followed .

It is straightforward that operating the airplane with both engines in
x-feed is meaningless,
but I would like to know which could be the consequence of operating
both engines on X-FEED on the ground, other than wasting some of the
returned fuel if the tanks are full.

The italian dealer answered:
"I don't know the answer but I think if you use both engines in x-feed
they will stop for lack of fuel. In any case you don't need to worry
about the x-feed pipeline integrity. It is checked yearly by mechanics,
and also you'll never use it in your life."

This was all his answer and it seems a little too generic to me and,
maybe I'm wrong, I'm not sure He's aware of the precise technical
consequence of the both engines x-feed operation.

Since I'm going to fly as instructor on this plane I would like to know
in deep detail all the consequences of the possible wrong actions.
Your help would be really useful to me.

Thank you for your attention,
Silvio Mecucci

Piper answer was:

I our technical support reviewed your message and responded with following
reply:

* All aircraft per certification must be operated using the most current
Pilot's Operating Handbook for their aircraft.
* The New Piper Aircraft, Inc. recommends the aircraft to be operated per
the approved current manual for the aircraft.
* The New Piper Aircraft, Inc. will not speculate on what may happen if
the
aircraft is not operated per the most current correct POH.

Thank you,
Kathy Flynn
THE NEW PIPER AIRCAFT, INC.

And this was my last reply...

Dear Mrs/Ms Flynn,
I do agree with all the point you made and for sure I will operate the
aircraft only according to the manual.
Having made this last point certain, what I would like to know is the
reason
why Piper put that note in the manual.
This doesn't mean I don't want to follow it....

The problem is that if I, as a flight instructor, say to someone "Never
use
it in this way." and that someone asks me "Why ?"
I should be able to answer him something more complete than "Since this is
what the manual says.".
That's the reason why I've asked You a support in this.

I can assure You that nothing of what You will write in the email (I hope
you will answer me again) has a legal
value here in Italy (yet), so could you please tell me the reason that
note
is present in the P.O.H. ?

Silvio Mecucci

No answer since then...
Can anybody help me, or should I unassemble my Seneca II to get an answer
?

Thank You all,
Silvio Mecucci