AD 62-06-03

62-06-03 HILLER: Amdt. 411 Part 507 Federal Register March 22, 1962. Applies to All Model UH-12D Helicopters and Model UH-12E Serial Numbers 942, 954, 2001 Through 2198 Inclusive.

Compliance required as indicated.

(a) Prior to next flight install placard in cockpit in full view of pilot to read as follows:

"Oil Warmup Procedure: 1. After Start Idle at 1,450 r.p.m. in Flat Pitch. A. If Oil Temperature is Less Than 20 degrees C. Idle Engine For a Minimum of Four Minutes. Continue Idle As Necessary Until Oil Temperature Reaches 20 degrees C. B. If Oil Temperature is Greater Than 20 degrees C. Idle Engine For Two Minutes. 2. Complete Warmup at 2,350 r.p.m. Until Oil Temperature Reaches 40 degrees C. ShutDown Procedure. After Main Rotor Blades Come to Rest Crank Engine 20-25 Seconds With Magneto Switch Off."

(b) Within 10 hours' time in service after effective date of this directive and every 25 hours' time in service thereafter until accomplishment ofparagraph (d), inspect the first and second stage planetary system in the transmission in accordance with Hiller Service Information Letter 3028 and at time of first inspection install ring gear spacer baffle P/N 23652 as described therein. Replace parts showing evidence of overheating or abnormal wear prior to further flight.

(c) Within 10 hours' time in service after effective date of this directive install placard in cockpit in full view of pilot to read as follows:

"Operation of Helicopter in Ambient Temperatures of -10 degrees F., -23 degrees C., or Colder is Prohibited."

This placard may be removed upon accomplishment of paragraph (d).

(d) Within 100 hours' time in service after effective date of this directive modify transmission and lubrication system to incorporate additional lubrication provisions for the transmission. Conduct modification in accordance with Hiller Service Bulletin 2026.

NOTE: The inspection and baffle installation specified in paragraph (b), are included in and required as part of Service Bulletin 2026.

(Hiller Service Information Letters 3027 dated January 19, 1962, 3028 dated February 2, 1962, 3029 dated February 14, 1962, and Service Bulletin 2026 dated February 26, 1962, cover this same subject.)

This directive effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated March 2, 1962.