Pre-Buy Inspections

I am just finishing up a long trip to California and Oregon where I worked with 6 Rotorway pilots and students. Several of my clients hired me to teach them a different way of performing autorotations in the Rotorway helicopter that are quite different from any that they have been taught previously. This technique takes all of the fear and guesswork out of performing an auto and after several hours of practice my clients were nailing them one after the other. I also was hired to inspect several Rotorway helicopters, one that had just been purchased and one that a client was intending upon purchasing.

There is a huge difference in the quality of construction in the experimental helicopter world. I have seen some really poor work and also some excellent workmanship when inspecting Rotorway helicopters for my clients.

The first ship that I inspected was recently purchased by a high time helicopter CFI who hired me to provide his insurance qualification check ride. I traveled to his home figuring that I would spend several hours inspecting the ship for airworthiness and the rest of the 2 day stay would be spent flying. The new owner was told that the helicopter had a total of 12 hours on it, mostly just run ups and some hovering.

As I began my inspection I was surprised to see that the entire engine compartment was so greasy. The traditionally Rotorway engine compartment will progressively become coated with oil due to the oil vent cap that the factory sells with the kit. It has oil vent holes around the bottom of the cap that vent the oil vapors and smoke into the engine compartment where it coats everything including the drive belts. One of the modifications that I always suggest is to throw out the factory supplied oil vent cap and to install a sealed vent cap/dip stick that vents the oil mist and moisture overboard away from the engine and drive train.

This photo is of the oil vent cap with dip stick that Andrew Burr makes for the Rotorway helicopters.

It was obvious that this helicopter had many more hours on it than the 12 hours that was showing on the Hobbs meter and that the seller had told the new owner. I next removed one of the valve covers and noticed that the inside of the engine was black. It looked like someone had sprayed it with black spray paint. This indicated many hours running with dirty oil or a severe over temp while running.

At this point in my airworthiness inspection I was beginning to doubt the airworthiness of the engine. I continued my inspection and noticed that virtually none of the wiring was secured or properly routed. They way the builder had “installed” the wiring was some of the worst workmanship or lack there of that I have ever seen. The new owner was taking notes of my findings and we were starting the second page by this point.

During my inspection of the flight control system I found that the rotor system was totally rigged incorrectly. I re-rigged the swash plate and tail rotor controls and continued my inspection. During the control check I found six of the control linkage jamb nuts that were not tightened- very bad. One of the jamb nuts on the tail rotor control cable was tightened against cable shank instead of against the rod end fitting where it is supposed to be. By this point I was beginning to wonder how many other surprises were waiting to be discovered.

The pilot side engine exhaust shield was cutting into the fuel tank so we modified it’s placement. The engine alignment was so far off that we needed to adjust the entire engine placement to insure proper drive train alignment. This ship had one issue followed by another issue.

As I looked at the builder’s use of nut plates during the construction it was evident that this builder did not have a clue as to what he was doing. All of the nut plates on the helicopter were attached to the outside of the skin and or fiberglass instead of on the inside. His method of attachment caused the nut plate to be secured by only the flared ends of the two pop rivets on the inside of the skin. The proper way of installing nut plates in on the opposite side of the skin than the item that is attaching to it. That way when the screw is tightened into the nut plate it pulls the nut plate against the skin. On this ship every nut plate would be pulled away from the skin as the screws were tightened.

The photo below is of the rear vertical stabilizer attachment bolt nut plate on this helicopter.

When you look at this photo you can see that the only structure that would actually be holding the rear vertical stabilizer attach bolt in place would be the pop rivet ends that were through the tail boom skin. The nut plate is supposed to be on the other side of the skin. This ship was built to crash!

I encountered issue after issue as I continued my “Airworthiness become UNAIRWORTHINESS” inspection of this ship. When I got to the tail rotor area I immediately saw that one of the tail rotor blades was cracked between the attach bolts. See the photo below.

I removed the tail rotor and found that the blade attach bolts that were inserted into the holes shown in the photo above were damaged. See the photo below.

Both of the bolts were bent and one had sustained a severe strike to the end of the threads to the point that the nut threads stripped when I removed it.

The tail rotor clevis that provides the pitch inputs into the tail rotor swash plate was an example of the worst workmanship that I have ever seen on a helicopter. See the photo below.

Note the quality of the weld with the holes that you can see through. Also note the bolt hole on the bottom of the fitting has less than an eighth of an inch of metal to hold the bolt. If this unit fails in flight, all tail rotor control is lost.

The inspection continued and I found gouges and scratches in the main rotor blades that sent chills down my spine. I informed the new owner that he should tear the helicopter down to the frame and start over by inspecting every piece and component and replacing every damaged part.

This was one of the worst cases of a non-airworthy helicopter that I have ever seen and as such we were not able to complete the insurance check out flights. However, I am convinced that I saved the buyers life. When he first called me to provide the insurance qualification training, he said that we was tempted to fly it before I arrived. He told me that he had hired a well known person to provide a safety inspection and blade rigging so he thought he would hover it a bit before I arrived. I told him to keep it on the ground until I checked it out. I am still surprised that the fellow that was hired to first check the ship out did not notice any of the many crash-worthy issues that were so obvious.

The new owner has ordered parts and has begun the needed work to bring the helicopter up to airworthy condition. I then traveled to the Sierra foothills where I instructed another student for his private check ride. He will be taking that with Steve Foster once I transition him into the Bell 47 for the practical test.

The next stop was to meet the perspective buyer of a ship in the far north eastern corner of California. I drove from Placerville to Sacramento to pick up the buyer at the airport and we drove for four hours to near the Oregon-Nevada borders. This professional helicopter pilot had hired me to perform a pre-buy inspection for him on a Rotorway with only 9 hours on it.

We arrived and removed all of the covers on the 162F. I was amazed at the difference in the quality and workmanship displayed on this machine. It was nearly perfect! I made a few suggestions like adding the longer skids, oil tank vent cap, fuel tank outlet fitting mods, and securing a few wires but other than that it was one of the best built Rotorway helicopters that I had ever seen. The photo below is of the buyer and I following the inspection and successful sale of the ship.

An interesting note is that the nearly perfect ship sold for only $5000 more than the ship that was totally non-airworthy that I first discussed in this article. The buyer of this second ship had the ship inspected and knew exactly what he was getting and that he was getting a real bargain in the transaction.