Very serious - please read

Today's USA Today newspaper (Wednesday, June 18) has a front page article about aviation safety.

Included is a long report of the float mechanism in many tow plane carburetors.

The original float has a serious defect which causes engine failures. (This happened to us.)

The plastic replacement float also has a defect.

Tom Knauff
Ridge Soaring Gliderport

On Wednesday, June 18, 2014 10:38:48 AM UTC-4, wrote:
Today's USA Today newspaper (Wednesday, June 18) has a front page article about aviation safety.



Included is a long report of the float mechanism in many tow plane carburetors.



The original float has a serious defect which causes engine failures. (This happened to us.)



The plastic replacement float also has a defect.



Tom Knauff

Ridge Soaring Gliderport

Find it at

http://www.usatoday.com/longform/new...rt-1/10405323/

On Wednesday, June 18, 2014 8:38:48 AM UTC-6, wrote:
Today's USA Today newspaper (Wednesday, June 18) has a front page article about aviation safety.



Included is a long report of the float mechanism in many tow plane carburetors.



The original float has a serious defect which causes engine failures. (This happened to us.)



The plastic replacement float also has a defect.



Tom Knauff

Ridge Soaring Gliderport

Just read it. Having owned a PA-28-181 Cherokee powered by a Lycoming with a troublesome carburettor, I pretty much have to agree with the article. To an engineer, there are some pretty damn weird aspects of light aircraft design.

For example, what engineer in their right mind would duct hot air from around a muffler (made from thin, crack-prone metal) into the cabin for heat? That's 1930's technology which is just begging for a CO poisoning accident.

Most engines already have little oil cooler radiators the same size as automotive heater cores which reject about 50% of the waste heat. Why not use the oil cooler as a heater core? The only objection I have heard is oil leaks might soil the carpet. If my oil cooler is leaking oil, I don't give a damn about the carpet. I want to know about it ASAP so I can land.

Carburettors were proven inferior to fuel injection in the Battle of Britain 75 years ago. Adding to the absurdity is old-school, constant-flow fuel injection is simpler and cheaper to manufacture than carburettors. Objections to FI come from those who never learned how to start hot, fuel injected engines. Direct cylinder injection, which is now appearing in car engines - and was standard on Battle of Britain ME-109's - eliminate hot-start issues. There's just no excuse for airplane engines using carburettors.

USA Today was a little off with ice protection. Ice detection with piston GA airplanes is simple - look outside - if there's ice on the airplane it's accumulating ice - duh! No GA anti-ice system can protect an airplane from the worst icing conditions. The solution is to stay out of icing conditions in the first place and if a pilot screws that up, he needs to get out of it ASAP. Anti-ice systems just give the pilot a little more time to do that.

On Wednesday, June 18, 2014 8:04:25 AM UTC-7, Charlie Papa wrote:

http://www.usatoday.com/longform/new...rt-1/10405323/

Those interested in data rather than sensationalism could check out this link:

http://msacarbs.com/Service_Bulletins.html

Andy (GY)

On Wednesday, June 18, 2014 10:20:51 AM UTC-7, Andy wrote:

This appears to be the latest SB on floats. I was not able to find a related airworthiness directive.

http://msacarbs.com/pdf/SB-2_B_RPLmn...ats_062209.pdf

Andy (GY)

Not a new subject - but it doesn't hurt to bring up again, and again. In my case the float sank on the PA20. Showed up when the engine flooded after I reduced power for landing. Didn't know it until I needed a bit of power. Ever see a procedure in The Book that suggests pulling the mixture to get the engine to go?
An AD note came out within a short time saying to replace those nasty tin floats with magic plastic floats. A year or 2 or so later they came out with another AD note to replace those nasty plastic floats with metal floats because they absorbed gas and would sink. Y'all be careful now. That all happened prior to 1962.

On Wednesday, June 18, 2014 7:38:48 AM UTC-7, wrote:
Today's USA Today newspaper (Wednesday, June 18) has a front page article about aviation safety.



Included is a long report of the float mechanism in many tow plane carburetors.



The original float has a serious defect which causes engine failures. (This happened to us.)



The plastic replacement float also has a defect.



Tom Knauff

Ridge Soaring Gliderport

I've got many thousands of hours in "light general aviation airplanes". I even owned a Beech Sport for many years while building time for my future airline career. I never had a smidgen bit of problems with any carburetor. As for the comment about the cabin heater system; Yes, there could be a problem with exhaust gas leakage into the cabin but that is why I had a simple detector inside the cabin on my Beech Sport.

I've got many thousands of hours in "light general aviation airplanes". I
even owned a Beech Sport for many years while building time for my future
airline career. I never had a smidgen bit of problems with any carburetor.
As for the comment about the cabin heater system; Yes, there could be a
problem with exhaust gas leakage into the cabin but that is why I had a
simple detector inside the cabin on my Beech Sport.


No offense intended, but more evidence that "Better is the enemy of good
enough" for many.

I tend to fall into that category in many things, but not generally those
which put my life at risk. Being "an airplane (and glider) nut" since
childhood, I remember being amazed, aghast and nearly speechless when I
learned how cabin heat systems for light planes were designed. Still am. So I
happened to be an engineer at the time - big deal; I'd learned long before how
effective CO was as a means of ending life. Yes, a CO detector should-oughta
be more-better than none, but as a defense of the design...really? Even though
the bulk of my cadged lightplane rides with buddies have been in summer, I
never really felt/feel comfortable with that aspect of riding in lightplanes,
detector or no detector. Personally, I'd rather fly in or own a lightplane
without a heat muff at all. Thankfully...never had to worry about it in gliders!

In a similar vein, being a long-time reader of online FAA/NTSB
preliminary/final accident reports, it didn't take long for me to begin to
wonder - insight gained from the prelims alone - about the seemingly high
proportion of "topple and burn" light helicopter crashes/fatalities. What was
wrong with that accident picture, given the high chances/proportion of
"toppled in training" accidents?

Likewise, flight into icing conditions in anything but "an overpowered,
hot-appendaged" turbojet, - a form of life russian roulette, in my view.

Self-education. In my view, definitely a good thing!

Bob W.

With no intention of minimizing the legitimate concerns raised by Tom, I would like to point to some overall criticisms of the article that was published in USA Today:

http://www.huffingtonpost.com/jeff-s...b_5509253.html

http://www.aopa.org/News-and-Video/A...AOPA-says.aspx