Friday, 14 December 2018

Still No Cylinder

Still not flying.  I failed to follow up on questions from the engine rebuilder (Aero Recip in Winnipeg) and so it was sitting on a bench waiting.  They needed to know how many hours it had since new.

So, it is on its way now and we should be back up in a few weeks.  Might be a bit dodgy with clearing the runway at the farm of snow but we can probably get it to work.  No way to put skiis on a Comanche.

Wednesday, 14 November 2018

Waiting for a cylinder

It has been a very busy summer.  Quite a few trip reports to get ready.  Annual has started and I had a cylinder fail the compression test.  Bad exhaust valve guide at 500 hours.  Not much flying to do while we wait for it to come back.

Friday, 13 April 2018

International Comanche Society Report

I was reading the safety report (linked to below) regarding an accident where a DC-3 was destroyed, and two pilots killed, by controlled flight into terrain in the Georgia Straight. 
What I learned was that there was a CAR requirement for commercial VFR operations at night.  The requirement states that commercial VFR operations at night must be conducted at least 2000 feet above the closest obstacle within 5 NM.  I had no idea there was such a regulation or that it had been around for a long time.
This CAR does not apply to private operators but it does make sense.  I have flown in the area that the accident occurred and I just cannot imagine conducting the accident aircraft's flight plan under VFR at 900-800 feet AGL, in the dark, among scattered cloud at 800 feet.  Those scattered islands are steep, well over 1000 feet, and mostly uninhabited - no lights.

My temperature sender has bit the biscuit and a new one is on the way from Air Parts of Lockhaven.  The gauge was barely reading above 60 degrees and that bothered me.  I figured it was just cooler due to the cold weather this winter (compared to Langley!) but it didn't matter how much tape I put over the oil cooler the gauge wouldn't budge. 
The schematic from the service manual shows that it is a single wire resistive gauge where current flows from the bus through the gauge and to the sender where it grounds to the engine.  The higher the temperature of the oil, the lower the resistance of the sender, the more current flows through the gauge and the more the gauge deflects.
So there are a number of possibilities.  The gauge could be defective, the wire between the gauge and the sender could be faulty, the sender thermistor could be defective, or the ground was poor.
I measured the temperature of the oil after a flight by constructing an inexpensive temperature probe consisting of an inexpensive ($5) thermistor, a coat hanger with tape on it, and a cheap multi-meter to directly measure the resistance of the fabricated probe.  Went for a short flight and by the time I could get to the filler neck the oil was still at 160 degrees F.  I measured at the oil pan and it was around 180 degrees F.  Thus I was not worried about the vernatherm.  I did calibrate my homemade temperature probe with ice cubes and boiling water and it check out to within a degree.
I measured the resistance from the sender body to ground and it was zero.  So the ground connection to the sender was fine.  Apparently this can get iffy due to corrosion or more importantly insulating tape on the threads.
I briefly shorted the sender wire at the engine to ground and the gauge promptly went to full scale so the gauge works.  This also checks the wiring to and from the gauge and it checked out ok as well.
Last check was the resistance in the oil sender.  This should be high (1000 ohms when cold) to low (30 ohms when hot).  The results were confusing and contradictory.  Thus a new sender is on the way.  I ordered the Rochester sender with the STC for converting the gauge to calibrate properly.
Fly Ins
The fly in to Victoria is on and if there are any more takers for the end of July trip to Victoria plus a tour of Viking (fabricator of new Twin Otters) please let us know.  I will also be hosting a BBQ at my hanger at Richter Field on the weekend of the 25th of August.  The owner of Richter Field (Frank Richter) gave us all hangar numbers the other day - I am "C4" - very explosive!
We need to have an annual election of tribe chief and so forth.  Please let me know if you are interested in serving in this position - I'll gladly step down if someone else volunteers.  If no one steps up I'll continue to serve as best I can. 
The matter down in the states is not yet resolved but I figure time will heal most wounds and a new set of elections for executive officers will help.  In the meantime the business of the society is proceeding.
I have volunteered to serve on the technical committee.  There are so many people with so much experience.  I mostly seem to ask silly questions compared to the level of skill and good judgment available.

Tuesday, 20 March 2018

Technical Project - Bank Indicator

Took my daughter up for a flight last week to test her instrumentation project.  She has tied a micro-controller to a gyroscope chip and created a bank indicator.  It did work as intended.  It does have a tendency to accumulate negative errors slowly but certainly.  However, the she seemed quite pleased by the initial test.

It isn't often that my children call me up and ask if we can go flying.  Any reason is a good reason.

Wednesday, 7 February 2018


A friend sent me these links to a documentary on the Mosquito.  My first exposure to these was "Mosquito Squadron" as a kid.

Tuesday, 12 December 2017

Antiques in Action

Here we have a 1940's Ford 8N tractor pulling a 1960's Piper Comanche into the hangar, with a 1950's Edsel Pacer in the background.  Will resist joining the twenty first century for as long as practicable!