FireDOC Search

Author
Buckson, W. | Schlegel, W. | Smith, I. R.
Title
Design, Development and Evaluation of a Crash-Resistant Fuel System Installation. Technical Report.
Coporate
All American Engineering Co., Wilmington, DE
Sponsor
Federal Aviation Administration, Washington, DC
Report
Technical Report; ADS-27, December 1965, 202 p.
Distribution
Available from Defense Technical Information Center
Contract
FA-WA-4580
Keywords
fuel systems | installing | design applications | evaluation | aircraft fuel systems | aircraft fuel tanks | fire tests | fuel cells
Identifiers
basic design considerations of crash resistant fuel system
Abstract
A crash-resistant fuel system, utilizing high-strength bladder fuel cells, breakaway fittings, crash-load-actuated shut-off valves, and fiber glass protective liners, was designed and installed in the center section of a DC-7 aircraft wing. The wing was mounted on a wheeled dolly and the No. 2 and No. 3 main fuel tanks were filled with water. The No. 2 tank was standard DC-7 configuration; the No. 3 tank was equipped with CFR components. A jet-propelled car was used to accelerate the wing and dolly to predetermined velocities prior to engaging a decelerator. The decelerator, especially designed for this project, imposed controlled decelerations on the wing ranging from 2 g's to 21 g's (28-g fuel equivalent). There were no failures in either standard or crash-resistant fuel (CRF) system fuel cells and no inadvertent valve closures in the CFR system during the tests. Hydraulic loads were nominal and were not additive from one cell to another through interconnections. A final destructive test was conducted wherein the wing, at a velocity of 77 knots, engaged two stationary vertical poles, positioned to shear the wing panels at the outboard nacelles. It was demonstrated that, with a more positive means of triggering shut-off valves, the CFR system has a potential for greater chances of fuel containment, with consequent less fire hazard, in case of survivable crashes. The CFR system, as installed in a DC-7, imposes a penalty of 6.97% fuel volume loss for a range loss of 7.6%, although it results in a weight decrease of about 1200 pounds.