21 October 2009

21 October, '09

Doc Richard emails and asks "What did ya learn about carb ice? What were your impressions of the R66?" I'm beatin' my head against the wall tryin' to get my friend to just leave his comments here...
Gotta have a talk with the guy!

This is why I continue to come to this course after all these years. A Britisher named Rick Mornington-Sanford just happened by our classroom. He's an accident investigator, and in pursuit of doing that job has taken a personal interest in carburetor ice in Great Britain. Cool and damp much of the time, Rick feels many of the accidents that leave him scratching his head looking for a cause have carb ice as a big contributing factor. He felt so strongly about this, he petitioned several organizations to help him prove his theories, finally finding money and resources to actually put a camera in the carb throat of an R22 Beta and photograph what happens there.

Robinson helicopters are different than airplanes, obviously. But they're also different from other helicopters in that they are de-rated, meaning they have high-horsepower engines but the operator is limited in the use of that power. The reason for this is that the engines will continue to produce normal horsepower ratings at higher altitudes, making Robinsons the heliocpter of choice for many of us that know and love them.

But that presents an unintended consequence...
Partial power settings, particularly on takeoff, allow ice to form across the gap between the carb butterfly and the throat of the intake. In England, they have had many accidents where they find a smoking mess and dead pilot and can find no reason why the helicopter crashed. It's been Rick's theory that these accidents were caused because pilots typically don't use carb heat on takeoff, and the above mentioned throttle setting, (NOT WIDE OPEN) allows ice to close off the intake system, causing the engine to quit during one of the most critical times in a flight... takeoff.

The photos prove him correct. Using carb heat at all times carb ice is possible will prevent many accidents, all thanks to Rick's research.

The R66?
There were two of 'em on the flightline when we were allowed to look them over...
One with strain gauges and other test equipment all over it, the other looked like it could be started and flown away by a new customer. (I suspect it will be on the floor at HAI in Februrary, if you want to see it.)
It looks enough like an R44 that your average citizen won't discern the difference. The interior is JetRanger-like... two seats up front and three across in the back. My calibrated eye thinks interior room is slightly larger than the JetRanger, but I cannot swear to that... it's just an impression.
For R44 owners that want to move up to a 5 place machine, and for those that are wearing out their present JetRangers and now cannot replace them because the grand old bird is no longer in production, the R66 will be a natural choice.
I think it will sell well.

UPDATED, 1700 hours:
For those of you with an interest in the "Carb Ice" comments, go
here to view articles on that, and other subjects.

3 comments:

mark1fuller said...

Greybeard...I would be interested in reading more about the R22 carb ice research. The link doesn't appear to work...perhaps that can be fixed?

Mark

Greybeard said...

The link works for me Mark, using both IE and Firefox browsers, so I think the problem may be at your end. Search for "Morninginton-Sanford Aviation"...
That'll getcha there.

mark1fuller said...

Found it...thank you. Other great articles there too!