Airworthiness Directive · Amendment 39-14295 · Boeing Model 707 Airplanes, and Boeing Model 720 and 720B Series Airplanes
Boeing Model 707 Airplanes, and Boeing Model 720 and 720B Series Airplanes
This AD applies to all Boeing Model 707-100 long body, -200, -100B long body, and -100B short body series airplanes; Model 707-300, -300B, -300C, and -400 series airplanes; and Model 720 and 720B series airplanes; certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 707 airplanes, and all Boeing Model 720 and 720B series airplanes. This AD requires revising the Limitations section of the airplane flight manual (AFM). The AFM revisions include instructions for monitoring the low pressure lights for the center tank fuel pumps, and a statement prohibiting the resetting of a tripped circuit breaker for a fuel pump in any tank. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent dry operation of the fuel pumps in the center fuel tank, which could result in high temperatures or sparks inside the fuel tank, ignition of fuel vapors, and consequent fire or explosion. We are also issuing this AD to prohibit the resetting of a tripped circuit breaker for a fuel pump in any tank, which could allow an electrical fault to override the protective features of the circuit breaker, and result in sparks inside the fuel tank, ignition of fuel vapors, and consequent fire or explosion.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 30 days after the effective date of this AD: Revise the Limitations section of the Boeing 707 AFM to include the following information. This may be done by inserting a copy of this AD into the AFM. Thereafter, operate the airplane in accordance with the limitations specified in these AFM revisions.
For ground and flight operations, a fuel pump circuit breaker which has tripped must not be reset.
Center tank fuel pumps must be ‘OFF’ unless personnel are available in the flight deck to monitor low pressure lights.
Each center tank fuel pump switch must be positioned to ‘OFF’ without delay when the respective center tank fuel pump low pressure light illuminates.”
Note 1: When information identical to that in paragraph (f) of this AD has been included in the general revision of the AFM, the general revision may be inserted into the AFM, and the copy of this AD may be removed from the AFM.
Incorporation of the information in Approval Reference Number 045151 of the Boeing Model 707 Airplane Flight Manual before the effective date of this AD is considered acceptable for compliance with the corresponding action specified in this AD.
