Monday, April 17, 2006

The source of the problem!

Well, after speaking (err...typing)with my friend Mark Smith, of Posey County Indiana, the center of Quicksilver innovations these days at the famous Posey Patch, he determined that when I reassembled my fan shaft and bearings, I omitted installing the spacers that go between the two bearings. This causes the inner races to be pulled together when you tighten the nut that holds the fan to the shaft. This type of bearing is designed to carry a radial load only, not a thrust load, so under improper loading, they fail. Duh, and I call myself an engineer? Thanks Mark for your insight and the spare parts. I'll have the situation all cleared up before I fly next!

Saturday, April 15, 2006

The shit hits the fan....literally!

First off, I want to apologize that I don't have any pictures. When I went to the USAF Thunderbirds airshow at Maxwell AFB last weekend, I broke my camera. I'll post some of the pics I took at the airshow soon. I'm looking for another camera, so bear with me until I find one!

Good Friday turned out to be really good weather for my MX; she loves light winds and so do I. I arrived at the airport at about 9:00 and did a quick preflight inspection and rolled the airplane out of the hangar. My plans for the morning were to fly locally over fields because I'm still trying to access the reliability of the Rotax 503 that I recently rebuilt. I only have about 3 hours on the engine. It seems to be running well but has a quirk or two that I'm trying to work out. After flying, I was going back toward home and stop in Montgomery to have lunch with my wife. I topped off the tank and started her up, then strapped myself in.

As I taxi to the runway, I check twice for traffic in the pattern. When I get to the hold-short line at the runway, I look to my left and at the end of runway 33 is a Blackhawk helicopter and he is approaching to land. They frequently use our runway for all sorts of training. I sit idling, waiting patiently for the helicopter to take off again and free up the runway. After about two minutes, I killed the engine, and wouldn't you know, as soon as I did, the helicopter takes off! I unstrap and get out and start my engine back up. As I get back into the seat, the blackhawk flys by on the runway heading at about 50 feet. I continue to watch as the helicopter turns left to start a pattern. I don't have a radio (interference with the points-type ignition won't allow clear transmission or reception) so I can't communicate my intentions to the helicopter. I start to taxi on the runway and when I'm about at the midpoint of the runway, the helicopter makes his base pattern turn for landing. I pull off the runway to the left, onto the grass and wait. Apparently the chopper didn't see me and started his landing approach, but then saw me in the grass when he was about 50 feet above the ground and aborted his takeoff. When he was past me by a safe margin, I take the runway again and taxi to the end, and turn around. When I notice that the Blackhawk has cleared the runway to the left and made his downwind turn, I take off and fly the runway heading until the end of the runway, then start a normal left-hand pattern while climing. The UH-60 continues his landing pattern and as I'm leaving the area, I see the helicopter at mid-runway, just sitting there.

I fly over the large fields within about 5 miles of the airport, and just when I was starting to settle in and have some fun, I hear the engine sag a bit, but then go back to normal RPMs. I look at the gauges, and the Cylinder Head Temperatures are starting to rise above normal. I turn my head and look at the fan on the engine and it isn't turning. CHT's are climbing to 400+ degrees as I pull back on the throttle and decide where I'm going to land. Because I've been flying over fields the entire flight, I have multiple choices. I choose a pasture in front of a house that I've flown over and around many times. I have to use the engine for some final adjustments and the landing is smooth and uneventful, except for the fact that I AM landing in a cow pasture and it does have fresh cow patties in it! After the ground roll stopped, I get out to look at the plane. Imagine my surprise that there is a big piece of cow crap on my fan guard! The shit had literally hit the fan!

I pulled out my cell phone and called my wife to tell her I wasn't going to be making it for lunch. I walk to the house, but wouldn't you know, nobody was home. At least there weren't any mean dogs who felt it was their duty to keep me away from the house! I call my friend who lives about a two miles from where I've landed, and he comes and takes me to my car back at the airport. I drive right back to where my plane is and start disassembling my fan. It's apparent that the belt has broken because the fan shaft bearings have failed...again! This set of bearings had less than 2 hours on them. I'm confident that my belt was not too tight, so maybe the problem has been with my method of installation.

To make a long story shorter, I left a note for the owner to call me and made a trip to Motion Industries in Montgomery (Alabama) to get my bearings. They couldn't find a belt like what I needed and suggested an auto parts store. What a joke.
The belt said 10X610 on it. I assumed this was equal to an English size of 3/8 x 24". I went to two auto parts stores (O'Reily and Auto Zone) and the counter people at both stores played with my broken belt for about a minute before they did anything! Then they plugged the number on the belt into the computer and told me that the number didn't interchange. Idiots! I then went to a local lawnmower place, who at least knew what I was talking about when I told them I was looking for a 3/8 x 24" belt, but referred me to the Car Quest store two doors down. They had the belt. I bought it and went home and carefully installed the new bearings in the fan housing, ready to take my parts back to the airplane in the morning.

The next morning when I arrived at the field where my MX was parked, I started reassembling the pieces I remove the previous day. It was quickly apparent that the belt I spent several hours searching for was too short. Great. Now it's time to go looking for the next largest size in a town that was unfamiliar to me, Greenville, Alabama. To make another long story shorter, after 3 stops at different auto parts stores, I found a 3/8 x 25" belt. I wanted to also purchase a 3/8 X 26" belt just to be safe, but I couldn't find a place that had one. I returned back to the plane about two hours later and decided that the belt wasn't the correct one, but that I could make it work long enough to fly seven minutes back to the airport. I finished the installation and started up the engine, which behaved normally. After begging the property owner, I arranged a pickup from the airport to bring me back to my car, and I took off from the pasture and headed straight for the airport. The path I chose kept me over clear fields the entire way in case of unexpected problems, but I didn't encounter any. I landed and secured my plane in the hangar and waited for my ride to appear. They arrived about 15 minutes later and in a few more short minutes, I was back at my car and I drove home. Now, if I can just figure out what caused my bearings to fail prematurely...

Wednesday, April 05, 2006

Airborne at last!

I finally got to fly yesterday after work. It was really enjoyable. The air was relatively calm and even though it was 78 degrees on the ground, it was quite nippy up in the air. I didn't bring my GPS with me because I can't find it at the moment, but I did get up to what I estimate to be 2000 feet or so. I didn't stay that high too long. I was only wearing a flannel shirt over my T-shirt and I was starting to get cold, so I descended to about 800 feet and did some pattern work and some touch & gos. I practiced for about 30 minutes before I started to fly out over some of the field near the airport. I flew about 30 more minutes before heading back in. It was really great to get airborne for the first time this year!

Monday, April 03, 2006

It wasn't to be...

With all my preparation for flying this weekend, it wasn't to be. It was cloudy and foggy on Saturday early when the winds were supposed to be mild. I didn't leave my house until 9:00AM or so and the winds were already picking up. I arrived at the airport a bit before 10 and the windsock was blowing straight out. I figured that I would do some work on the MX. I greased the driveline bearings, switched out the crappy Harbor Freight wheels that I tried last year for the real wheels. I also removed my radio mount and antenna so that I could install it on my Phantom. It didn't work well at all on the points engine. After re-installing the prop after the shooting the grease to the bearings, I started the engine and taxied around the tarmac allowing the engine to warm up. Then I put it back in the hangar and topped off the tank with fresh gas and left to go home.

On Sunday, I didn't get out to the field until about 1:00. The wind wasn't blowing at all at my house, but at the airport, it was pretty breezy. When I got out of my car and glanced at the MX, it appeared that the tank was empty! As I got nearer, I could see the dark stain on the gravel underneath and my seat cover was wet. After investigation, I found that one of my primer lines was split at the plunger and 5 gallons of gas had dripped out overnight. I repaired the line and trotted off to the gas station for more fuel. By the time I got back and put the fuel in, the wind was gusting quite a bit. I used my Halls airspeed indicator to check the speed and I got more than a few gusts that were 15MPH, so reluctantly, I decided not to fly. I'm sure I could have, but it just wouldn't have been any fun. Now that daylight savings time is in effect, I'll be able to leave after work and get to the airport with about an hours worth of air time. I'm really itchin' to fly!