Thursday, April 26, 2012


NOW AVAILABLE - FAA Approved paperwork for extended range (9-gallon) wing tanks for Taylorcraft L-2 / DC Tandem series aircraft.

C E R T I F I E D   A E R O N A U T I C A L    P R O D U C T S
$ 550.00 
CALL TODAY (254) 715-4773 
C.A.P. has collaborated with FAA Certified Repair Station operator, Craig Gunder of Gunder Restorations and Design, and L-2A owner Mark Watson, to develop details and installation drawings for this worthwhile upgrade.  Gunder and Watson teamed up to fabricate and install the upgrade in Watson's L-2A using FAA-DER approved paperwork from C.A.P.  They have each shared the following photos of their quality workmanship. 


RED LION, PA - (717) 246-1200

The 9-gallon tank design drawings specify 0.050t Aluminum 5052-H32.  All plumbing connections, including sight tube, are identical to the original 6-gallon factory tanks.  The weight of each aluminum 9-gallon tank assembly is within 1/2 lb. of the original steel/terneplate 6-gallon tanks.     


The installation requires that the #2 rib be cut between spars and re-located approx 3 inches outboard.  A false rib is attached to spars and bonded to tank top surface.  A false rib is also used at bottom. 

LH installaiton - note false rib bonded to tank

LH installation - note #2 rib re-located.

LH installation underside - note false rib at tank bottom
Optional aluminum leading edge skin section can be added for ease of access.  Although this modification could be accomplished with the wings still mounted on the airframe, it is recommended to remove wings for this job.
RH tank with 9-gallon tank and optional wing leading edge section installed

False ribs are used to maintain airfoil curvature and fabric attachment by rib-stitching. 

View inside RH wing of fabric attachment to false spar via rib-stitches

Mark finished modifying his airplane in March 2012.  We have not yet had a pilot report.  Perhaps he may be too busy flying.  We do hope to hear more feedback from Mark soon.

Both wings finished, ready for installation.
The modification is highly recommended for L-2 and DC-65 airplanes which have had engine upgrade to C-85, C-90, or O-200 per CAP's STC # SA02146LAWhen finished, the total fuel capacity is increased from 14 gallons to 20 gallons.    This means you can extend your aircraft's fuel endurance range by approximately 1 hour, considering the fuel consumption rate of an O-200, a logical trade-off for a fuel weight gain of only 36 pounds. 

Aircraft / People profile: N57504, L-2A is no stranger to this weblog.  Back in 2008, when owned by Mr. Ed O'Brien of Denver, CO, this airplane became one of the first to have a C.A.P. STC engine upgrade to C85-12 installed by Mr. Dave Wiebe in El Dorado, KS.  The airplane had been restored in 2004 by Mr. Jon Frasier in Idaho. Mark Watson acquired the aircraft from Ed sometime after 2008.  Then in 2011, tragedy struck.  While displaying the airplane at the annual Sun-N-Fun fly-in, the airplane was severely damaged in the infamous tornado.  Not letting this adversity get the best of him, Mark went to work repairing his airplane. He decided to install the 9-gallon tanks upgrade in the process.  Our hats are off to Mark, having the airplane airworthy again in less that a year after the tornado incident.

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Credit where credit is due:  C.A.P. can certainly take no credit for the concept employed in the L-2 fuel tank mods.  In fact, other one-off fuel tank installations have been accomplished in the past under various configurations to increase the fuel capacity of L-2's.  C.A.P. was involved in some of these to support individuals with their own designs.  We have seen everything from fiberglass to multiple inter-connected fuel cells.  We have studied all configurations and decided to take the best features from all and incorporate them into one design concept that could be standardized and cleanly packaged for ease of production and simple to install.  Design concept credit really comes from the combined lessons learned from projects by Lane Tufts, Mike Letrello, John Collier, and Jim Calcotte.  Credit for the detail design of the tank itself is rightfully due to the expertise of Craig Gunder.  And much of the details associated with installation design credit must go to Mark Watson.  The Taylorcraft community is indebted to these folks.  C.A.P. exists to help funnel this kind of expertise into the vintage airplane fleet at large, to help preserve these airplanes for years to come