Surprising Support For Luggage Tractors

The Origin of the Problem

It raised its head in mid-2004, when a number of airline maintenance shops were surprised to find that an old mainstay of the luggage tractor business, the Ford F300 inline six cylinder engine, was no longer available. The engine had actually been discontinued eight years earlier, but as is common in the automotive engine business, Ford had put more than 40,000 F300s in inventory for future needs. In June of 2004, the last had shipped out of Ford’s warehouse.

The search for an alternative did not have much urgency because of the decline in airline traffic and revenues. After all, much of the tractor fleet was sitting idle. Tractors with run-out engines were parked, and others used. The large inventory in Ford’s warehouse also lulled many who would have otherwise been alarmed, but the supply was finite and the time for concern had arrived.

A few shops tried a conversion to Ford’s 4.2 liter V-6 which bolts directly to the same C-6 transmission. These conversions were only marginally successful. The V-6 is wider and the conversion is labor intensive, requiring extensive sheet metal modifications (keeping in mind that some of this “sheet metal” is as much as an inch thick). Routine maintenance is awkward, at best. One has to recognize that the industry standard luggage tractor was built around a single engine/transmission combination. Many discussions were had with Ford personnel, but the decision to discontinue the engine was not to be reversed and the tooling for the engine would not be made available to third parties.

Airlines have had a life cycle issue with the tractor for many years. The engines wear out long before the tractor frame and body. Over the life of a tractor, its estimated that the engine might be replaced as many as six times. The tractors may idle for hours, and heads are known to crack in about 20 percent of cases.

Another Industrial Concern Noted the Problem

Shortly after the last engine shipped, a little known company introduced a hydrogen fueled 4.9 liter engine. The engine was based on the same F300 block used by tractors, but everything else was different. HEC picked the engine because the sturdy block could absorb the sharp power spike delivered by hydrogen combustion. The engine was machined to much tighter tolerances and used .030-in oversized pistons and very tight oil control.

Now, it seemed that the airlines and HEC had a common problem. No longer could they obtain new F300 engines. With millions of the engines in use, remanufacturing them seemed to be the obvious choice, but the option had drawbacks. Entering the Hydrogen Age dependent on a steadily declining supply of old engines which could only be rebuilt so many times seemed too risky. Fortunately, HEC was already in the engine re-design business.

It was a short trip to the design table to see what would be necessary to guarantee a supply of critical parts. Most parts were relatively easy to source, but heads and blocks were a challenge. HEC had already forged a relationship with a supplier who agreed to cast new 4.9L (F300) heads modified to eliminate known issues. The head was heavier, but only in automotive and airborne applications are engine weights of serious concern.

Distributors Ask For Help

About this time, the industrial engine distribution chain became aware of HEC’s developments and began asking if the company had any interest in supplying gasoline fueled engines for luggage tractors. In reply, HEC delivered an engine in three weeks, asking if this was what was needed. To no one’s surprise, there were a few differences in engines, but all were easily remedied. Instead of fuel injected engines, they needed to be normally aspirated. Rear sump pans gave way to center sump pans (and dipsticks). Provision had to be made for a gasoline mechanical fuel pump because HEC’s initial dry-fuel design did not need one. Lastly, the damper had to be changed from serpentine to v-belt. Very little else needed changing.