NEWS | Feb. 18, 2021

Black Hawk: Two Types of Tail Rotor Retention Plate Bolts OK

Soldiers working on tail rotor
Photo by Paul Hughes
 
Mechanics, when it comes to the Black Hawk tail rotor retention plate bolts, the ones with and those without a hole are OK to use.

Some units ordered the tail rotor retention plate bolts and discovered the bolts had two different style head designs. One had an internal relief hole in the bolt head and the other did not. Based on Aviation Maintenance Information Message (MIM) H-60-MIM-17-003, both bolt configurations have been deemed acceptable by the Aviation Engineering Directorate (AED) because the relief hole is cosmetic in nature and can be used to secure the tail rotor retention plate.

Here are the bolts in question:
 
Item NSN PN
Machine bolt 5306-01-093-5096 70101-11209-101
Machine bolt 5306-01-093-5095 70101-11209-102
Machine bolt 5306-01-117-7398 70101-11209-103
 
Make a note that the bolts may come from the supply system with two different bolt head configurations, one with the relief valve and one without it. And note that both styles of bolts can be used in any combination to secure the tail rotor plate. 
 
Both bolt types OK to use on tail rotor
Both bolt types OK to use on tail rotor
 
You can download the MIM and its supplement from the AMCOM Safety and Maintenance Messages (ASM) website at (CAC-enabled):