Both X-FEED on Seneca II

[Silvio Mecucci]

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

[kage]

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


You are simply wasting your time. Nobody is going to care about how you can
contort your airplane into an un-airworthy state. Be more concerned about
learning the proper way to operate the fuel system.

Follow the POH.

Karl

[jsmith]

Isn't that what he is trying to do?
I don't find his request extraordinary.
I find it perfectly reasonable to learn the consequences of an
inadvertant selector setting.
This is like turning the boost pump on while the engine driven pump on a
Bonanza is operating normally. It says don't do it, but it doesn't tell
you why.

kage wrote:
> You are simply wasting your time. Nobody is going to care about how you can
> contort your airplane into an un-airworthy state. Be more concerned about
> learning the proper way to operate the fuel system.
> Follow the POH.

[[email protected]]

Silvio Mecucci wrote:
> 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 ?"

And the reply is, because if you do that, then you are being a test
pilot.
At any rate, I would certainly not be willing to find out if it works.
But if you really need to know, can't you just look at the fuel system
diagram in the POH?

[Jose]

> Nobody is going to care about how you can
> contort your airplane into an un-airworthy state. Be more concerned about
> learning the proper way to operate the fuel system.

"VFR not reccomended"

This answer is exactly why people no longer understand the world
around them. I run into this mostly with computers ("Just tell me
what button to push") and the consequence is that
1: they don't really learn what button to push.
2: they have no idea what happens when they push it.

and as a further consequence, nobody who works in tech support will
tell you what happens when you push it.

Jose
--
Nothing is more powerful than a commercial interest.
for Email, make the obvious change in the address.

[Silvio Mecucci]

"kage" > wrote in message >...
> "Silvio Mecucci" > wrote in message
> om...
> > I've asked the following question to NewPiper Inc.
>
>
> You are simply wasting your time. Nobody is going to care about how you can
> contort your airplane into an un-airworthy state. Be more concerned about
> learning the proper way to operate the fuel system.
>
> Follow the POH.
>
> Karl

You and NewPiper seem to be on the same line :) CYA

I never said I want to operate the plane in ways different from those
reported in the POH. I just would like to know WHY the POH is that
way.
For those who know exactly how the fuel system works on the Seneca II
it shouldn't take that much time to answer my question.
POH like all the uman products can be wrong, even if I'm sure this is
not the case. Knowing how things works, beside "turn it on or off",
sometimes is useful.

Imagine you are a FI and your student asks you why you should not test
both X-FEED at the same time durign taxying. What are you gonna answer
him ? "Because it is written in the POH." ?! If your student is a good
one He would not be satisfied by this answer since it is an answer it
could find himself.

Thank you anyway...
Silvio

[kage]

>
> Imagine you are a FI and your student asks you why you should not test
> both X-FEED at the same time durign taxying. What are you gonna answer
> him ? "Because it is written in the POH." ?! If your student is a good
> one He would not be satisfied by this answer since it is an answer it
> could find himself.
>
> Thank you anyway...
> Silvio

Imagine you are a FI and your student asks you why you should not test
THE LANDING GEAR time durign taxying. What are you gonna answer
him ? "Because it is written in the POH." ?! If your student is a good
one He would not be satisfied by this answer since it is an answer it
could find himself.

Best,
Karl

[Silvio Mecucci]

> And the reply is, because if you do that, then you are being a test
> pilot.
Really nice answer ! :)
I'll use it meanwhile...

> At any rate, I would certainly not be willing to find out if it works.
> But if you really need to know, can't you just look at the fuel system
> diagram in the POH?

That's what I did. In the diagram, as it should be, there is no
connection between the two pipelines. So, as far as the diagram
reports, no problem should arise.
Also.. since in short taxying like those in small fields you don't
have enough time to test both X-FEED pipelines each at a time, I heard
is a common beheaviour to test both at the same time.

I am going to actually look at the valves operated by selectors.
Maybe the two valves are mounted nearby and there is no enough room
for them to operate properly at the same time... it's just a
supposition.
I'll tell you about.

Silvio

[Silvio Mecucci]

"kage" > wrote in message >...
> "Silvio Mecucci" > wrote in message
> om...
> > I've asked the following question to NewPiper Inc.
>
>
> You are simply wasting your time. Nobody is going to care about how you can
> contort your airplane into an un-airworthy state. Be more concerned about
> learning the proper way to operate the fuel system.
>
> Follow the POH.
>
> Karl

Just an example about why to ask such a question...

You take off with a PA19 (L18C), full tank(s), no special AC, after
leaving the ATZ you start a continuos turn with 30° bank. After 20
minutes (maybe less) your engine stops. As far as I know there is
nothing reported about this in the POH. And continuous turns are not
prohibited manouvers for a PA19.
In this case you follow the POH, performs a normal, even if unusual,
flight, and you get into trouble just because you don't know how one
of the simplest aircraft fuel system works.

Silvio

[Silvio Mecucci]

I'm sorry but I can't understand your observation:

First.
What you exactly mean by "test the landing gear" ?! What you want to
test ?
The green lights, the actuator, the switch, or what ?
But testing the X-FEED selector is very specific on the PA34.

Second.
I've never seen something like "Don't *test* the landing gear during
taxying."
in any P.O.H. I've read.
But I did see "Check the operation of the fuel management controls by
moving each fuel
selector to CROSSFED for a short time, while the other selector is in
the ON position."
(PA-34-200T P.O.H. Section 4 Normal Procedures 4.23-Taxiing)

Also the "short time" terms are questionable. Do you remember how long
it took to stop the
engine when your FI/CRI simulated an engine failure cutting your fuel
? And the engine was
(hopefully) at cruise power. How long would it take to use all the
fuel in the whole main
pipeline from the same side and let the X-tank fuel feed the engine ?
Making this test for 3-4-5 seconds is meaningless.


Third.
Should a student ask such a question every FI will know the answer:
"Because the safety valve may not work and your landing gear may
retract
while on the ground."
But I couldn't find any answer to my question yet.

Fourth.
The answer every FI should know (to your student's specific question)
is usually
reported in the P.O.H.s (At least in that of the PA23 Atzec).
But I couldn't find anything similar for the fuel selectors yet.
Maybe someone who reads the P.O.H. more carefully than me can
answer...


Silvio

"kage" > wrote in message >...
> >
> > Imagine you are a FI and your student asks you why you should not test
> > both X-FEED at the same time durign taxying. What are you gonna answer
> > him ? "Because it is written in the POH." ?! If your student is a good
> > one He would not be satisfied by this answer since it is an answer it
> > could find himself.
> >
> > Thank you anyway...
> > Silvio
>
> Imagine you are a FI and your student asks you why you should not test
> THE LANDING GEAR time durign taxying. What are you gonna answer
> him ? "Because it is written in the POH." ?! If your student is a good
> one He would not be satisfied by this answer since it is an answer it
> could find himself.
>
> Best,
> Karl

[Greg Esres]

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

I was told the same thing by a mechanic, but I'm skeptical he has any
idea.

I've had students put them both in cross feed on the ground, and the
engines didn't stop.

You might try a high power runup on the ground and do the test.

[BTIZ]

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

[[email protected]]

On 9 Feb 2005 11:02:02 -0800, (Silvio
Mecucci) wrote:


>I am going to actually look at the valves operated by selectors.
>Maybe the two valves are mounted nearby and there is no enough room
>for them to operate properly at the same time... it's just a
>supposition.
>I'll tell you about.
>
>Silvio

been a long time, but i think you will find the fuel selector valves
immediately outboard of the nacelles fwd of the spar. am thinking that
if you pull the wing panel that the fuel bowl quik drain comes thru
and look aft you will see them.

it really, really ****es me off that i've forgotten stuff like this.

TC

[Gig Giacona]

"kage" > wrote in message
...
> >
>> Imagine you are a FI and your student asks you why you should not test
>> both X-FEED at the same time durign taxying. What are you gonna answer
>> him ? "Because it is written in the POH." ?! If your student is a good
>> one He would not be satisfied by this answer since it is an answer it
>> could find himself.
>>
>> Thank you anyway...
>> Silvio
>
> Imagine you are a FI and your student asks you why you should not test
> THE LANDING GEAR time durign taxying. What are you gonna answer
> him ? "Because it is written in the POH." ?! If your student is a good
> one He would not be satisfied by this answer since it is an answer it
> could find himself.
>
> Best,
> Karl
>
>


Well the answer to the x-feed question may be "It was not tested by the
builder hence it is not allowed in the aircraft."

[Silvio Mecucci]

Yes...
The final answer is in the manteinance manual or in the aircraft
itself.
At the first inspection I'll try to be present and see what comes up.
Today I've flown the PA30. On this plane there is a physical
impossibility to use both X-feed at the same time. When you select one
X-feed the other selector is blocked. Nice and straight.

S.


wrote in message >...
> On 9 Feb 2005 11:02:02 -0800, (Silvio
> Mecucci) wrote:
>
>
> >I am going to actually look at the valves operated by selectors.
> >Maybe the two valves are mounted nearby and there is no enough room
> >for them to operate properly at the same time... it's just a
> >supposition.
> >I'll tell you about.
> >
> >Silvio
>
> been a long time, but i think you will find the fuel selector valves
> immediately outboard of the nacelles fwd of the spar. am thinking that
> if you pull the wing panel that the fuel bowl quik drain comes thru
> and look aft you will see them.
>
> it really, really ****es me off that i've forgotten stuff like this.
>
> TC

[Boliver]

Good Question Silvio, The answer is probably related to an accident
in the early 70's. A Piper Aerostar hit the ground with both fuel
selectors in crossfeed. I have no idea why he crashed, but the selctor
situation came out in the litigation, and some folks seemed to think it
was Piper's fault. This was during a time when Piper aircraft was about
to become "the new piper aircraft". I tried to check the NTSB reports,
but they only go back to 83 or so. Maybe someone here can remember
better than I. Al

[Capt.Doug]

>"Silvio Mecucci" wrote in message -
> 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
> 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.

Here is a link that adequately describes why both engines should not be in
the crossfeed position-
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20010716X01434&key=1

D.

[Scott D.]

On Fri, 11 Feb 2005 00:19:48 GMT, "Capt.Doug" >
wrote:


>Here is a link that adequately describes why both engines should not be in
>the crossfeed position-
>http://www.ntsb.gov/ntsb/brief.asp?ev_id=20010716X01434&key=1
>
>D.
>
How does that accident adequately describe why you shouldn't have both
engines on crossfeed? In the statement made by the pilot, he stated
that he placed the fuel selectors on crossfeed during his taxi but
prior to takeoff, he had them in the on position. Then after the plane
landed on the highway and on his exit of the plane, he flipped them
down missing the off position (which is very possible if you have ever
flown in a Seneca) The FAA's examine found them just as the pilot
stated. In the probable cause statement, all the FAA could do is
state that there was a loss of engine power in the left engine. There
is no other facts supporting the notion that he had taken off with
both on crossfeed.

Now you could make the assumption that the pilot was lying, but
because there was no other evidence to show that he was, you can not
say that this was the cause of the accident. The FAA sure didn't feel
comfortable saying it, because it wasn't even mentioned as a
possibility.

I am curious as well as why. I fly for a company part time that has a
Seneca II and I have also taught many students in a Seneca II and not
once has that question been poised to me nor have I really thought
about it. But it does make for an interesting question.



Scott D

To email remove spamcatcher

[Silvio Mecucci]

| 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".

Yes, I thought to this. But then I thought also that while using the
X-feed in real situation the engine still running is used at higher
than normal cruise settings.
So.. I still don't know..


A good answer to the original quetion could be
"Since it has happened that a take off with both X-FEED on has ended
in an accident, and nobody has still identified the cause".
But this accident has to be reported prior of March, 11, 1977, the
last revision for the manual I have.

S.

[Capt.Doug]

<Scott D. wrote in message > In the statement made by the pilot, he
stated...

Would you incriminate yourself? The costs of cleaning up the lead left from
the fuel on the highway and surrounding soil and sewer to EPA standards was
huge. The interstate was closed for most of the day which brought
repercussions from the DOT. Not to mention the airplane was totalled. What
is the incentive to admit liability?

> There is no other facts supporting the notion that he had taken off with
> both on crossfeed.
> Now you could make the assumption that the pilot was lying, but
> because there was no other evidence to show that he was, you can not
> say that this was the cause of the accident. The FAA sure didn't feel
> comfortable saying it, because it wasn't even mentioned as a
> possibility.

In a court of law, the evidence presented is weak. However, can you explain
why the aircraft failed to remain airborne? It wasn't an overweight issue. I
have flown Senecas, I through IV. The fuel selectors are not too hard to
manage effectively. One just has to remember to manage them.

If fatalities are not involved, the NTSB sometimes chooses to find an easy
way to finish the paperwork. I know this firsthand as do a select few others
in this group. Read between the lines of the report and you will know the
cause. Talk to a Piper engineer off the record and you will know the cause.
Ask the same engineer the same question in a courtroom and a different
answer will be elicited, something akin to the answer received by Mr.
Mecucci.

> I am curious as well as why. I fly for a company part time that has a
> Seneca II and I have also taught many students in a Seneca II and not
> once has that question been poised to me nor have I really thought
> about it. But it does make for an interesting question.

Here's some more interesting questions. Why do some single-engine Cessnas
equipped with bladder tanks run out of gas prematurely? Why do some Mooneys'
electric landing gears retract during the roll-out? The AFMs don't tell you.
Here's one for you to ponder- Why do Senecas have a preponderence for
nosegear failures? Piper won't tell you that they do, but they will sell you
a reinforced drag link bolt.

D.
D.

D.