AD 60-23-01

60-23-01 BOEING: Amdt. 216 Part 507 Federal Register November 4, 1960. Applies to the following 707-100 Series aircraft: Serial Numbers 17586 through 17591, 17628 through 17651, 17658 through 17672, 17696 through 17702, and 17925 through 17927.

Compliance required within 2,500 hours' time in service after effective date.

Incidents have occurred of the engine start lever slipping toward the "OFF" position causing engine flame-out. One such incident occurred during takeoff. These incidents were caused by insecure placement of the start lever in the "idle" position. In addition, inspections have disclosed the presence of incorrect parts and improper installations on some airplanes.

Also, in the present starting ignition system, on some airplanes, the igniter plug fires during initial engine rotation. This has caused combustion chamber explosions when fuel vapors were present.

To correct the above unsatisfactory conditions, the following modifications or FAA approved equivalents and inspections are required:

I. Modify and inspect the start lever system as follows:

a. Machine an additional slot at the start position of the start lever latch in each of the start lever guides as shown in Fig. 1 of Boeing Service Bulletin 369 dated April 15, 1959.

b. Ascertain that the control stand start lever spacers, P/N 66-19067-1 and -2, and lever guide fillers P/N 66-9256-3, are correctly installed as follows:

(1) The two outboard spacers must be P/N 66-19067-1 and -2 and installed in accordance with Boeing Drawing 65-1795. (Boeing 707 Parts Catalog Fig. 25-2-11 is in error in calling for P/N 66-9256-1 and -2 for Items 28 and 33. Correct P/N's are 19067-1 and -2 as indicated above.)

(2) The middle lever guide filler, P/N 66-9256-3, must be installed with the wide section at the top and not at the bottom. (Item 17 in Fig. 75-2-11 of Boeing 707 Parts Catalog is incorrect in that it shows the wide section at the bottom.)

c.Ascertain that the start lever detents have a minimum distance of 0.53 inch between the stop strap and the idle detents in accordance with Bulletin 369.

d. After reinstallation of the start levers, ascertain that the start lever system is properly rigged as covered in Chapter 76 Boeing 707-100 Series Maintenance Manual. This applies only to airplanes which require removal of the start lever detents for machining the slot.

II. Modify the starting ignition system as follows:

a. Remove the jumper wire between the "COMMON" terminal and "NO" terminal of each engine start lever switch (S192, S193, S194, S195).

b. Install a wire from the "ON" contact flight start and control switches (S188, S189, S190 and S191) on the pilot's overhead panel to the corresponding engine ignition circuit breaker bus on the P6 circuit breaker panel. Remove the No. 18 jumper wire between the flight start and ground start terminals of the engine start and control switch. Boeing Service Bulletin No. 195 (R-1) dated July 8, 1959, and Supplement No. 195 (R-1)A dated August 4, 1959, covers these changes.

This directive shall become effective December 6, 1960.