Connector Counting with the Boeing AH-64D Apache Helicopter
By Scott Clay, Bishop & Associates Inc.

I was able to spend some time in the Boeing plant during a recent trip to the Southwest. Most of my time was devoted to the rotorcraft assembly plant 512 and the wire shop where they do wire harness assembly for not only the Apache but for other systems, including the C-17, F-18G, Boeing Vertrol, and the Minuteman III ICBM. The helicopters are built on a modified assembly line where six to eight craft are assembled, rolling by hand from one position to another, as workers at each station take days to complete each job. At these locations all the access panels are open, allowing the techs to assemble the wiring and hydraulics within the frame. Working with the wiring techs and systems people, I found the base number of connectors on the “A” model (the original military A version is also referred to as Block 1), is 684. However, with all the upgrades and electronics improvements and additions, the new connector count is 736, and even that number is not static.

After several hours of examination on the line, and seeing the various access sections on the fuselage, it is clear that the majority of connectors on the airframe are 38999-type circulars. There are also 26482s, MIL-C D-subs, and some 5015 power connectors for the main power bus in the engine, transmission, and controls sections. The surprise is the wire gauge that goes into many of the 38999s. While 22-26 is common, there is a large amount of 28 to 30 gauge, with some of the connectors only half-filled with crimped contacts. Part of this is for uniformity and the ability to purchase several sizes in quantity, thus lowering the prices. It also allowed their many system (avionics box) suppliers to standardize several sizes, for additional volume cost savings. The frame of the helicopter has eight key bulkheads, which have access holes for the wire bundles to pass through, and mount locations for the various boxes and systems, which all have panels with bulkhead mount connectors for the I/Os.

The constant modernization programs for the updated “D” model, and the addition of new systems from the Iraq war, have created new self defense systems, new and better chaff and decoy dispersal systems, better sensor and target tracking electronics, improved video and cockpit systems, and even new controls to monitor the flight paths and orbits of small aerial UAVs. There are new weapons improvements for the weapons control officer, and better guns and missiles systems, even a new laser guided 2.75 diameter rocket that used to be a unguided weapon, which required the pilot to line the helicopter up on the target, and fire multiple missiles. Now, the BAE Advanced Precision Kill Weapon System is due to become a standard armament replacing the unguided version, and this will mean a new target screen, laser aiming system, additional electronics (at least one new avionics box) and the associated wiring and harnesses. There are two under-wing pods that each hold 19 of these small missiles. Distributed from the pods to the boxes to cockpit screens and controls, this is where an additional 24 connectors will be located.

Remember, at least half of Boeing’s work at this plant is rebuilding more than 1,000 “A” model Apaches that have been built for the U.S. Army and at least a dozen other countries. What this location does is take a former A model and strip it down to the very base shell, and remove all the cockpit controls, engine, transmission, drive systems, etc. Everything is stripped out of the shell and the aircraft is rebuilt from the ground up to a “D” (Block II) model. They have already rebuilt over 500 of the older versions. Boeing also has over 55 orders from DoD for new helicopters, many to replace combat losses in Iraq and Afghanistan. They also have dozens of orders from at least six other countries, plus several hundred of the A models for rebuild from the National Guard, Army Reserves, and many of the countries that purchased A models; Korea, U.K., Egypt, etc. They are also working on a Block III upgrade for the U.S. only which will incorporate all the latest electronics and a better engine, transmission, better “fly-by-wire” controls, and other improvements.

Scott Clay, Director Military & Aerospace, Bishop & Associates Inc.
Scott Clay has worked for more than 25 years in the connector and wiring systems markets. He has held various positions in field applications and marketing for Molex, Tyco, Methode, and ITT. For the past 15 years, Clay has focused on the military/aerospace sector, and five years ago formed his own company for consulting and application engineering. He has worked on design-in and electronics on F/A-18E/F, F-22, F-35, C-130J, C-5M, C-27, P-8, A-10, and numerous other aircraft. Some of the Navy programs Clay has participated in are SSN-774 Virginia class subs, CVX, DDG-1000, and the Littoral Combat Ship class. He has extensive expertise in land vehicle systems, and has worked closely with the worldwide locations of GD, BAE, AM General, and other key manufacturers. He is currently working on variations of MRAP, JLTV, upgrades for the Bradley fighting vehicle, M-88 recovery vehicle, FMTV, and other platforms in the wiring and systems areas, plus portions of the future combat systems.