AD 74-04-02

74-04-02 MCDONNELL DOUGLAS CORPORATION: Amendment 39-1784 as amended by Amendment 39-1994 is further amended by Amendment 39-2352. Applies to DC-8 series airplanes certificated in all categories.

Compliance required as indicated after the effective date of this AD, unless already accomplished.

To prevent the inadvertent deployment of ground spoilers inflight, accomplish the following:

(1) After the effective date of this AD all re-rigging of the spoiler system must be accomplished in accordance with the following McDonnell Douglas documents or equivalent approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(1) (a) DC-8 Maintenance Manual chapters: 27-35-0, Series 50 (Temporary Revision), dated October 9, 1973, or 27-60-0, Series 60, dated December 1, 1973, or later revisions.

(b) Service Bulletin 27-251, Revision 2, dated January 7, 1974, or later FAA-approved revisions.

(2) Within the next 100 hours' time in service, add to theLimitations Section of the FAA-approved Airplane Flight Manual, the following Ground Spoiler Operation Limitation:

ON THOSE AIRPLANES NOT MODIFIED BY SERVICE BULLETIN 27-251, DO NOT ATTEMPT TO ARM THE GROUND SPOILERS BELOW 1000 FEET ABOVE THE TERRAIN.

(3) Within the next 450 hours' time in service, unless Service Bulletin 27-251 has already been accomplished, perform the following inspections:

With the actuator hook extended (Ground condition), proceed as follows:

(a) (i) Measure the spoiler lever aft travel necessary to extend the spoilers (as measured at the pedestal cover). Travel minimum required is 7/8 inch. This measurement should be taken by moving the lever slowly aft from the full forward (hands off) position until the spoilers initiate movement. (Observe system Pressure Drop of 200 psi or more).

(ii) The lever should be capable of being moved full aft and armed in the spoiler deployed position.

(b) Jack the aircraft nose to extend the nosegear oleo. With the actuator hook retracted (flight position), the spoiler handle should be armed and the following conditions observed:

(i) The handle should be capable of being armed with an "up" motion only. No aft motion of the lever should be required.

(ii) After arming, the spoiler lever should be no further aft (measured at the pedestal cover) than 1/16 inch from the forward lever stop.

(c) In the event that any of the requirements of (a) or (b), above, are not met, re-rig the affected portion of, or the entire system, per the documents referenced in (1), above.

(4) Within the next 3600 hours' time in service, install the spoiler handle lockout in accordance with McDonnell Douglas Service Bulletin 27-251, Revision 2, or later FAA-approved revisions, or an equivalent installation approved by the Chief, Aircraft Engineering Division, FAA, Western Region.

(5) Upon completion of items (1) through (7) of this A.D., Amendment 39-1122, (35 F.R. 18454) AD70-25-2, is no longer mandatory. The placard and AFM limitation described in AD 70-25-2 may be removed.

(6) Prior to February 15, 1975, on those airplanes incorporating the Hydro-Aire Mark II antiskid system, unless already accomplished, modify the spoiler card in the antiskid control box in accordance with McDonnell Douglas Service Bulletin 27-251, Revision 5, dated October 3, 1974, or later FAA-approved revisions, or an equivalent installation approved by the Chief, Aircraft Engineering Division, FAA Western Region.

Amendment 39-1784 became effective February 15, 1974.

Amendment 39-1994 became effective October 23, 1974.

This amendment 39-2352 becomes effective September 2, 1975.