2007 Annual Inspection
(12 Jan - 05 Feb 2007)

As mentioned on the Fort Worth Trip page, I experienced two mechanical problems which, while not downing the plane, led to my decision to do the annual a little early at Don Maxwell Aviation in Longview, TX.  To sum up, when I landed in Fort Worth, I found that one of two brackets holding the left main inner gear door had sheared and that the minor fuel tank weepage was getting worse.  I had already talked to Don about taking advantage of his fuel tank repair techniques and the necessity to get a new bracket for the gear door and fact I was already in Texas just made the decision easier.  Per the trip report, I flew the plane to Longview, met Don and flew his pilot back to Dallas-Love Field (KDAL) in my plane.  The pilot drove me over to DFW for my flight back to Chicago and then flew my plane back to Longview to start the repairs and the annual inspection.

This was the first annual inspection I've had done by a Mooney Service Center and obviously Don Maxwell has a superb reputation in the Mooney community for doing quality work at a fair price.  Since I was up in Chicago throughout the inspection, this report won't contain all the picture's of last year's report but rather provide some insight into what was done and my experience with Don.

Let me start by saying how totally professional the entire experience was.  I provided Don with a squawk list of things I wanted looked at or repaired:

  1. Left main gear inner gear door (weld/replace bracket and reattach to plane).
  2. Fuel weeping from left wing tank (bottom)
  3. Fuel weeping from right wing tank (bottom) and sometimes a sheen on part of the upper surface winwalk just outboard of the door.
  4. Two rusted fuel tank panel screws on upper surface of right wing.
  5. Intermittent static on pilot headphones.  Sound goes away when I push in the panel section containing the intercom and suction gauge.  Suspect loose connection or intermittent ground there...possibly on pilot stereo/mono switch as static not heard on passenger headphones.
  6. Left wing speed brake intermittently fails to retract fully.  Possible need for overhaul by Precise Flight? 
  7. Engine appears to have a much lower critical altitude than other 231s on the mooney list.  Possible Intake or exhaust leak?
  8. Have been chasing oil leaks on belly for several months.  Poplar Grove Airmotive found and fixed leaks on two crank case throughbolts as well as on the prop/cranshaft seal.  Still am seeing wet oil on the belly and left nose gear door after landing.
  9. Plane is out of rig (ailerons and flaps?) and needs to be rigged.
  10. Marker beacon appears to be inop.
  11. A section of SCAT tubing (front left side of engine) used for cabin heat is wearing through and needs to be replaced.

Don took this list and his folks went to work.  I was more interested in a quality inspection and getting the repairs done right since the plan was for the plane to stay down there until I could return in about 3 weeks (first week of February) anyway.  By the end of the first week, Don's team had completed the annual inspection itself and I had a detailed list of discrepancies, estimates on repair costs (time and parts) and their severity (must fix, should fix, can wait).  Don and I then went through each item line by line.  Of note for other 231 owners, they found a failed fitting on the intake manifold that was robbing me of intake manifold pressure.  They also found some exhaust cracks that were causing high CHT temps as well as robbing the turbo of exhaust gases  -- both were robbing me of power at altitude and decreasing my critical altitude.  How much of a difference did this make?  Well before the annual my critical altitude (defined as highest alttitude I could maintain 40" of MP with throttle, RPM and mixture firewalled) was around 15,000 feet.  After the repairs, it was around 17,000 feet.  While I don't cruise at full power, the additional MP avaialable meant I could run higher power settings while LOP (higher MP, lower mixture) and I effectively saw about a 10 knot speed increase during high altitude cruise....a huge difference for a simple repair!

While doing the inspection, Done also found two things no one who had inspected the plane since I first saw it (pre-buy, other repairs and annual) ever noticed -- the plane had no TIT or fuel flow gauges!  Apparently when built the plane had both installed in the panel.  Near as we can figure, they were both removed when the JPI EDM-800 was installed.  Problem was that the EDM was approved as replacement for the stock gauges.  Consultation with Mooney determined that the TIT gauge was required but the fuel flow was not since there is no fuel flow parameter or mention of it anywhere in the POH.  The stock gauge was (and is) inaccurate and hideously expensive, but Don determined that the Electronics International digital TIT gauge is STC'd as a replacement, much cheaper than the stock unit and much more accurate, so I made the decision to have one installed.  The assumption is I would just have another TIT digital TIT gauge to go along with the one in the EDM-800...  Once installed, we learned something interesting -- the new gauge reads about 70 degrees cooler than the EDM -- despite the fact the probes are located right next to each other in the exhaust!  Further research determined that the probes fail "hot" and it appears the EDM probe is starting to go.  Since that probe was just starting to fail, not required equipment, and we didn't determine the delta until the annual was over, I made the decision to defer replacing the probe until a future annual.

So all told, there were only two real surprises -- the missing gauges and the exhaust cracks/intake leaks.  I already talked about the gauges and repairs to the leaks were minor in nature and cost.  All other repairs were as estimated in cost and time.  Result was that on Feburary 5th I got up at 0400 to drive to Midway airport for an ATA flight back down to DFW (cheapest fare I could find).  It was unbelievably cold...25 below zero with the wind chill.  As I arrived at the gate, I heard an announcement that a flight to New York at the gate next to mine was delayed indefinitely because the fuel pumping truck was frozen and they could not fuel the plane.  I boarded my flight feeling pretty good, until after the safety demonstration when the pilot announced we'd be delayed because the pushback tug was frozen...45 minutes later we pushed back and were in the air for Dallas.

Don's pilot picked me up at DFW again and drove me to DAL where we boarded the plane he normally flies -- a Cirrus SR-20G2 for the quick flight to Longview.  While I had seen Cirrus's (Cirri?) before, this was my first flight in one.  I was impressed with the fit and finish of the interior -- it really is just like a new, high-end car and my old Mooney does not compare favorably.  Engine management was much easier with just a single throttle lever and a mixture control that was "set it and forget it."  The plane was fast (as expected) but run at very high power settings to achieve the speed -- not sure how the engines will hold up in the long term -- I do know I wouldn't operate my engine that way, but he was operating it per the POH.

Arriving in Longview started out with a detailed review of all repairs conducted in Don's office.  There were no surprises and everythng was as expected.  Don and his lovely wife Jan then took me to lunch at the airport diner across the field (a great restaurant with friendly staff and customers) and then it was back to Don's for a detailed pre-flight.  The plane had already been test-flown by Don, but I was about to take it on a non-stop flight back to Chicago, and prudence demanded the preflight.  Only found one minor problem (which was quickly repaired) and I was soon on my way back North.  Return to Chicago Map

The plane flew much better now that it was in rig and the additional power (possibly combined with the better flight control surface rigging) generated the higher speeds I mentioned above.  The result was I made much better time than I had flight-planned for and realized I would have to re-do all my altitude/speed charts for the plane's new capabilties -- but this was a project I would love since the numbers would all be going up!

I won't go into details on the cost.  If you really want to know, feel free to email me.  What I will say is that the total cost of everything (including the repairs to the exhaust and both fuel tanks) was slightly less than last year's base annual cost (not including the additional money I spent on the upgrades performed during the annual last year), so I was pleasantly surprised.  Even more importantly, I knew even more about the plane's condition and was even more comfortable with taking it on all these long cross-country flights.   Bottome line:  I was completely satisfied with the service I got from Don and his team and will most likely take the plane back there for next year's annual!

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