66-13-02\tBOEING: Amdt. 39-236 Part 39 Federal Register May 13, 1966. Applies to Models 707 and 720 Series Airplanes Listed in Boeing Service Bulletin 1789, Revision 1. \n\n\tCompliance required as indicated, unless already accomplished.\n \n\t(a)\tWithin the next 125 hours' time in service after the effective date of this AD, incorporate the following operating limitation in either the Airplane Flight Manual or on a placard installed adjacent to the cabin dome light switch: \n\n\t"THE DOME LIGHT SWITCH MUST BE IN EITHER THE BLUE, LOW OR BRIGHT POSITION DURING \t\t\tTAKEOFF AND LANDING". \n\n\t(b)\tWithin the next 1,200 hours' time in service after the effective date of this AD, install a new relay in the emergency exit light circuit or rewire the circuit to use existing contacts on the essential a.c. power failure relay, so that the emergency exit lights will function automatically when power is lost on the essential a.c. bus in accordance with Boeing Service Bulletin 1789, Revision 1, or later FAA-approved revision or an equivalent approved by the Chief, Aircraft Engineering Division, FAA Western Region.\n \n\t(c)\tThe operating limitation imposed under (a) may be removed when the modification required in (b) has been accomplished.\n\n\tThis directive effective May 13, 1966.