Remember the one about the NASA engineers that forgot to convert inches into centimeters and buried a Mars probe INTO Mars instead of landing it ON Mars? OR "We will OWN our mistakes!"

September 30, 1999

Web posted at: 1:46 p.m. EDT (1746 GMT)


(CNN) -- NASA lost a $125 million Mars orbiter because one engineering team used metric units while another used English units for a key spacecraft operation, according to a review finding released Thursday.

For that reason, information failed to transfer between the Mars Climate Orbiter spacecraft team at Lockheed Martin in Colorado and the mission navigation team in California. Lockheed Martin built the spacecraft.

"People sometimes make errors," said Edward Weiler, NASA's Associate Administrator for Space Science in a written statement.

"The problem here was not the error, it was the failure of NASA's systems engineering, and the checks and balances in our processes to detect the error. That's why we lost the spacecraft."

If you've read this blog since the beginning you know that we have had to replace the Trekker's radiator fan clutch and fan twice.  The first time was immediately after it was delivered to us in January of 2014.  The second time it broke we had to be towed 75 miles to Pharr, TX to have it replaced.  Here's the www.JITrekking.com blog postings about that menagerie: 

http://www.jitrekking.blogspot.com/2014/03/red-bay-we-have-problem.html
http://www.jitrekking.blogspot.com/2014/03/o-o-there-goes-my-baby-o-o.html
http://www.jitrekking.blogspot.com/2014/03/red-bay-we-have-problem-part-ii.html

The fan clutch originally put into the rig and the 2 that were installed each time it was previously replaced were a NEW type of fan - a "squirrel cage" type.  Here's picture of it:

You can see that it has about 30 blades.  It is about 10 inches high.  You can see that it is quite substantial in size and weight.  Below are 2 pictures of the fan clutch that turns the fan on and off as needed to keep the radiator coolant within an acceptable temperature range.  This top one shows the fan clutch with the pulley that turns the clutch when it engages.

 The one below is the fan clutch with the pulley removed (it was reused on our NEWLY installed fan and fan clutch assembly).

Now, WHY?  Why was there a constant breakdown in these fan and fan clutch assemblies.  I mean this is the newest "fan" technologies, right!  Why the high failure rate?  Well, it seems that the engineer(s) that designed it at Tiffin forgot to factor in the additional weight of the new fan, the clutch and the additional air weight that is compressed by the multiple blades and the additional torque by the new fan.  OOPS!

Now, before you say "You've got to be kidding me."  I think it's VERY IMPORTANT to reiterate something that Bob Tiffin (the founder of Tiffin Motorhomes) told Irene and I when we spoke to him personally BEFORE they started building the Trekker.

"All Motorhome manufacturers make mistakes.  The difference is we OWN ours and will replace any item, ANY TIME (in or OUT of warranty - JRG) that is OUR fault.

I was talking to the Parts Manager today at the repair facility and was saying that we were having our fan and fan clutch assembly replaced.  I made the statement to him that I'm sure there are other Allegro Buses out there."  His reply was "384 of them."  They intend to replace EVERY ONE OF THEM at NO COST to the owners as Warranty work.

So, here are pictures of the new fan and clutch:

As you can see they are significantly lighter.  We also have it on good authority (owners who already have the "fix" installed) that the new fan and fan clutch do an excellent job of keeping the rig's engine well cooled.

Below is a picture of he new fan installed into the Trekker I got before they lowered it to the ground again.

As an additional added touch to this post.  Below is a picture of the Trekker being "Prepped for surgery."  The rig is lifted up on 6 jacks (one on the outside wheel of each axle - front, drive and tag axles). These lifts are electronically connected to lift it in unison.