By Tom Memering
There are many reasons why operators of TFE731-powered business jets perform engine removal and reinstallation in the field. Maybe you want to accomplish an airframe inspection in house and to minimize the aircraft's downtime, you simultaneously ship the engine out for scheduled maintenance. Or perhaps you want to minimize the costs associated with flying the aircraft to an engine service provider, and you remove the engine and ship it to the service provider. Possibly your aircraft is grounded due to Foreign Object Damage (FOD) or performance problems and you have no choice but to change the engine where the aircraft is located. Whatever the reason, there are many factors that need to be taken into consideration before you start. The following will provide some useful tips.
One of the first considerations that may appear obvious, but is often overlooked, is the need for an appropriate shipping container. Honeywell Authorized TFE731 service centers have standard shipping containers for these engines. These containers utilize a preformed, engine contoured, foam enclosure that the engine rests in, free-float style. If you are going to be installing a rental engine while yours is being serviced you'll just use the container that the rental arrived in for your engine. If you aren't using a rental, have your service center ship you a container.
If your engine service needs require access to the engine's compressor for repair or for core zone inspection, it will likely require approximately four to eight weeks to complete the repair process, depending on the workscope, method of shipment, etc. In these cases a rental engine can be utilized to keep the aircraft working during the engine service process. The service center you are working with can supply you with a rental engine from either Honeywell's or its own rental pool. You should make arrangements to secure the rental engine 30 to 60 days prior to the actual removal date to ensure its availability. This way you can utilize ground shipment to minimize costs.
After you confirm the availability and delivery of the rental engine, you must then make sure that you have the tooling and equipment that is needed for the engine change. Again, many of these items would appear to be obvious requirements, but are frequently overlooked. To remove an engine you will need some type of apparatus to lift the engine off of the airframe. This will require the use of a heavy-duty overhead crane system or forklift. Either of these should be capable of lifting a minimum of 1,200 pounds and be able to lift it up to 12 feet in the air. Another piece of equipment that you'll need is an engine sling. The engine sling attaches to the engine hard points that are located on the fore and aft parts of the engine. The overhead crane system or forklift will lift the engine off of the aircraft with the use of this sling. You will also need a place to put the engine once it is removed from the aircraft so that the engine can be "undressed" and prepared for shipment. An engine stand is recommended to perform this function. Your service center can provide you with the engine sling and stand. Appropriate forklifts can be rented in most parts of the world.
If using a rental engine, the first thing that you should do when it arrives is inspect it. Verify that you have received the correct model. Further inspect for any obvious damage and verify that the engine is configured per your needed airframe configuration. Honeywell TFE731 engines (especially rentals) have many configurations and applications so you should verify this at your earliest opportunity.