AD 69-12-02

69-12-02 BOEING: Amendment 39-813: 707/720 and 727 series airplanes. Applies to all Boeing 707/720 and 727 series airplanes, as appropriate.

Compliance required within 1000 hours time in service after the effective date of this AD, unless previously accomplished.

To provide for (1) arming of the takeoff warning system at about 25 degrees of thrust lever advancement from the idle position, and (2) to advise flight crews of the characteristics of the system, accomplish the following:

A. For 707/720 series airplanes listed in Boeing S.B. No. 2384, dated January 31, 1967, or later FAA approved revisions, modify the takeoff warning actuating switch installation in accordance with Boeing Service Bulletin No. 2384, dated January 31, 1967, or later FAA approved revision, or by an equivalent modification approved by the Chief, Aircraft Engineering Division, FAA, Western Region.

B. For 727 series airplanes listed in Boeing S.B. 27-102, Revision 1, dated July 7, 1967, orlater FAA approved revisions, modify the takeoff warning actuating switch installation in accordance with Boeing Service Bulletin No. 27-102, Revision 1, dated July 7, 1967, or later FAA approved revision, or by an equivalent modification approved by the Chief, Aircraft Engineering Division, FAA, Western Region.

NOTE: Some operators have modified the throttle control system to incorporate automatic throttle controls using equipment not designed by Boeing. In such installations, the modification kits available from Boeing for compliance with Service Bulletin No 27-102 may not be applicable, and operators should submit their modification for FAA approval.

C. For all 707/720 and 727 airplanes listed in this paragraph, incorporate revisions in the FAA Approved Airplane Flight Manual as follows:

1. For models 707-100/-200/-400/-100B (except -123B and -138B) / -300B/- 300B (ADV)/ -300C, REVISE SECTION III, Existing Paragraph Headed "Warning Horn," to read:

WARNING HORNLANDING

The warning horn will sound when any thrust lever is retarded or the flap control lever is in the 40 degree or 50 degree detent with the landing gear in the "unsafe to land position." NOTE: (Applicable only for airplanes incorporating Boeing Service Bulletin 1891) When the landing gear warning horn circuit modification is installed, landing gear warning horn will not function with outboard flaps in the fully retracted position. However, landing gear warning lights will function when thrust levers are retarded to idle power.

TAKEOFF

Sounding of the warning horn, when the No. 3 thrust lever is advanced to takeoff thrust indicates one or more of the following:

(a) Speed brakes handle is not in the zero degree detent.

(b) Stabilizer trim is not within the green band range used for takeoffs.

(c) Wing flaps are not in the takeoff position.

CAUTION:

The warning horn will not:

1. Be armed for sounding at the lower ambient temperatures due to No. 3 thrust lever takeoff positioning not actuating the thrust lever quadrant switch, or

2. Indicate stabilizer trim is in the improper takeoff position specified for actual center of gravity location.

CABIN PRESSURIZATION

The warning horn will sound intermittently whenever the cabin altitude exceeds 10,000 feet.

2. For Models 707-300/720/720B/707-123B and -138B, REVISE SECTION III, Existing Paragraph Headed "Warning Horn," to read:

WARNING HORN LANDING

The warning horn will sound when any thrust lever is retarded or the flap control lever is in the 40 degree or 50 degree detent with the landing gear in the "unsafe to land position."

NOTE: (Applicable only for airplanes incorporating Service Bulletin No. 1891) When the landing gear warning horn circuit modification is installed, landing gear warning horn will not function with outboard flaps in the fully retracted position. However, landing gear warning lights will function when thrust levers are retarded to idle power.

TAKEOFF

Sounding of the warning horn when the No. 3 thrust lever is advanced to takeoff thrust indicates one or more of the following:

(a) Speed brakes handle is not in the zero degree detent.

(b) Stabilizer trim is not within the green band range used for takeoffs.

(c) Wing flaps are not in one of the approved takeoff flap setting positions.

(d) An essential A-C power failure has occurred during takeoff. (applicable only for Models 707-123B/ -138B/ 720-023B airplanes)

CAUTION:

The warning horn will not:

1. Be armed for sounding at the lower ambient temperatures due to No. 3 thrust lever takeoff positioning not actuating the thrust lever quadrant switch, or

2. Indicate stabilizer trim is in the improper takeoff position specified for actual center of gravity location.

3. Indicate wing flaps are in the improper takeoff position specified for actual takeoff speeds and performance limits.

CABIN PRESSURIZATION

The warning horn will sound intermittently whenever the cabin altitude exceeds 10,000 feet.

3. For Models 727/727C/727-200 ADD NEW PARAGRAPH HEADING "WARNING HORN" IN SECTION 3, to read:

WARNING HORN LANDING

The warning horn will sound when any thrust lever is retarded or the flap control lever is retarded or the flap control lever is in the 30 degree or 40 degree detent with the landing gear in an "unsafe to land position."

TAKEOFF

Sounding of the warning horn, when No. 3 thrust lever is advanced to takeoff thrust, indicates one or more of the following:

(a) Speed brakes handle is not in the zero degree detent.

(b) Stabilizer trim is not within the green band range used for takeoffs.

(c) Wing flaps are not in one of the approved takeoff flap setting positions.

(d) Auxiliary power unit door is not latched. (If APU installed)

CAUTION:

The warning horn will not:

1. Be armed for sounding at the lower ambient temperatures due to No. 3 thrust lever takeoff positioning not actuating the thrust lever quadrant switch, or

2. Indicate stabilizer trim is in the improper takeoff position specified for actual center of gravity location.

3. Indicate wing flaps are in the improper takeoff position specified for actual takeoff speeds and performance limits.

CABIN PRESSURIZATION

The warning horn will sound intermittently whenever the cabin altitude exceeds 10,000 feet.

NOTE: Due to modifications accomplished by Supplemental Type Certificate or by other FAA approvals, the AFM material may not, in all cases, apply. Notify the Chief, Aircraft Engineering Division, FAA Western Region, when changes in equipment indicate possible non- applicability.

Effective July 6, 1969.

Revised September 9, 1969.