337 Cross feed (2) engines at once!!!/CPA related comments

[Guy Paris]

This was on CPA this am. I was not aware of this, hope I am not getting sometimers. Guy.... old72driver....

Ok, In my 1977 POH 337 G It states:
Fuel cross-feeding: Cross-feeding is limited to level flight only. If operating both engines from a single tank, cease cross-feed when level is withen: 50 lbs. of empty tank in use, or 50 lbs. of full in tank not in use.... Guy

T337G CROSSFEED BOTH ENGINES...
Dear Tom,
I recently had a very interesting experience in my P337. I was
cruising at +/- 12,500 when the front tank ran dry (a fuel imbalance by
line crew). Upon switching to the rear tank, the rear engine began to
quit! I immediately switched the front engine back to its own tank and
the rear engine regained power. I then "caged" the front engine and
proceeded to the nearest available airport to investigate and change my
shorts! I refueled and proceeded to my home airport without further
incident. Have you ever heard of this kind of problem with the
Skymaster before? My only thought is that the crossfeed lines could be
reversed. Before I spend several hours of expensive investigative
stupidity, I thought I would pick your brains as I have found you to be
the absolute best resource in aviation. You have saved me several times
my membership dues over the years.
Sincerely,
Rick,

Rick
What you did was a big no no. In your owners manual in section 2 on
page 2-3 is the important note you need to read and thoroughly
understand. "Crossfeeding is authorized for single-engine operation
ONLY. OPERATION OF BOTH ENGINES FROM THE SAME TANK IS PROHIBITED.
Simultaneous operation of both engines from the same tank could lead to
a double engine failure because of inadequate fuel flow."
What you learned is the fuel system supply cannot feed both engines
and the end result is a proven. Both engines will quit. I do not know
of anyone that has discovered what the max power settings the single
tank operation might be possible. That would be Test Pilot stuff and
way outside my area, I do not have or want that hat.
Tom Carr, CPA Tech Rep mailto:tom.carr@cessna.org
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