The International Cessna 170 Association

At Deming Convention Bob Edmondson presented a topic about new Continental requirements in the maintenance manual in which a Service Bulletin SB-03-3 is no longer.... NOW it is in the maintenance manual...M-0 which makes it a requirement to boroscope cylinders during inspections.

Here is a You Tube video explaining the process as presented in a Webinar:

https://www.youtube.com/watch?v=7R-dAmv9VZk

(For your convenience, here is the SB03-3)

This is great info George. We were just talking about borescopes in the shop. Thanks for posting.

There Youtube video "The EGT Myth" is also very interesting. https://www.youtube.com/watch?v=VvxeEQC-7p8

Amazon is out of stock on the VA-400 Borescope and does not have a re-supply date.

When we did my annual in January a friend brought his bore scope (same as the one discussed at the convention forum as well as Mike's) and we scoped my cylinders. As I had a low cylinder on # 3, we dropped the exhaust valve and lapped it. Compression came up from the 30's to the mid 60's. Just finished changing my oil & filter after 26.3 hours of convention flying plus another 16 hrs prior to the convention and we bore scoped each cylinder again + checking compressions again. #3 was up slightly and the other 5 were at or slightly above January's readings. January's were with cylinders cold and yesterdays hot. Pulled two bottom plugs to clean out lead deposits. Interesting to see the buildup of crud around one or two sparkplugs while others were pretty clear. All cylinders seem to have crud on the pistons, but that goes with leaded fuel, etc.
Good video. Thanks for posting it.

Frank

hilltop170 wrote:Amazon is out of stock on the VA-400 Borescope and does not have a re-supply date.

Looks like Amazon got some more in stock. Not Prime but is free shipping.
https://www.amazon.com/dp/B00GY7C9ZW/re ... f9ed58a1_S

I use a very expensive unit at work. Regardless of the unit, you will not be able to see everything. What you do see will be open to interpretation, must be judged and measured so really more information is better but good judgement is best.

Thanks for posting that George. The other place a boroscope would be handy is in checking for corrosion in the oil sump. ... would need to come up with some sort of U-shaped solvent sprayer to clean the area before inspection.

Bob Edmondson deserves the credit for prompting me to post it. He also deserves credit for stating the nomenclature of the mx manual reference correctly... ( I misspoke at convention). It IS M-ZERO... (not the M-OH I supposed.)

The VA-400 is available at the mfg, Oasis Scientific directly $199.98/free ground shipping...or go to eBay (sold by Oasis Scientific link below) ...same deal:

http://www.oasisscientific.com/vividia- ... amera.html

eBay listing:

http://www.ebay.com/itm/Vividia-AbleSco ... Sw~oFXDb6l

Thank you for the Boroscope Ascendancy post.

I am going to purchase and feel every owner/operator should now have this tool in possession. I really like tools.

Good boroscopes have always been very prohibitively expensive and deservedly so. Precision instrument.

The word ascendancy peaked my interest. That is a rather lofty term.

I had already purchased a lower cost boroscope a few years back. Did not perform as advertised/hyped. Low performance 30 to 40% of claims. Wasted my money on tools, again. So why should the VA 400 be different?

There has been a technology change . Surprising to me is what drove the change. It is the continued research and development of the camera in your Smartphone. Yes it is unrelenting. Why should your Smartphone have two (2) cameras on backside? Why two?

I reached out for an answer. Apparently the unsatisfactory video boroscopes relied on fiber optics where the actual camera reside in the hand held portion of device and it was trying to image from extended end of fiber optic cable: poorly imaged.. The change, improved camera in VA 400 is located right at the END of shaft not back at the device handheld. Eureka!

It is not mandatory for part 91.

mit wrote:It is not mandatory for part 91.

What's not mandatory for part 91? Following M-0 the engine maintenance manual? That is where the borescope inspection is required.

I believe Bruce is correct. The reason Continental killed the SB and moved the identical verbiage to the Maintenance Manual is in order to get rid of the SB which does not require compliance by Pt 91 operators. However, ALL operators must follow the approved Maintenance Manual which now incorporates the actions previously called for in the SB. (As tedious as Mike Busch's halting-presentation is in the video, if one goes to about minute 17 and listens for the next two minutes, he makes it fairly clear that the action is mandatory for all operators.)

So..bottom line... it appears we all must follow the M-0 instructions and, when a cylinder fails a compression test, the engine may be flown 45 mins to see if it will pass... and if it fails again,... the boroscope must be used to determine condition.

As much as we all hate change.... this is probably something we all should be doing anyway...and Continental has now made it mandatory by inclusion in the MX manual.

AOPA safety foundation provides a free color chart for reference of valve conditions. It is an excellent tool.