TBO and airworthiness

Does an engine past TBO make an aircraft
non-airworthy? I can't seem to find a
straight answer on the web.

Jim Stewart wrote:
Does an engine past TBO make an aircraft
non-airworthy? I can't seem to find a
straight answer on the web.

There have been articles on avweb on the subject; search there for
details.

Short answer, for Part 91, no.

--
Jim Pennino

Remove .spam.sux to reply.

"Jim Stewart" wrote in message
. ..
Does an engine past TBO make an aircraft
non-airworthy? I can't seem to find a
straight answer on the web.

TBO is a manufacturers recommendation, it has noting to do w ith
airworthiness. Some aircraft are not airworthy 100 hours after TBO, while
some run well past the number.

http://www.avweb.com/news/savvyaviator/187037-1.html
The Savvy Aviator #4: Debunking TBO

Engine TBO (time between overhauls) seems to be one of the most
misunderstood concepts in aviation maintenance. There are lots of
TBO-related old wives tales that are widely believed by owners and mechanic
alike, and they can cost owners a great deal of money. Mike Busch endeavors
to clear up these misconceptions, and explain what TBO really means.

Matt Barrow wrote:

"Jim Stewart" wrote in message
. ..

Does an engine past TBO make an aircraft
non-airworthy? I can't seem to find a
straight answer on the web.


TBO is a manufacturers recommendation, it has noting to do w ith
airworthiness. Some aircraft are not airworthy 100 hours after TBO, while
some run well past the number.

http://www.avweb.com/news/savvyaviator/187037-1.html
The Savvy Aviator #4: Debunking TBO

Engine TBO (time between overhauls) seems to be one of the most
misunderstood concepts in aviation maintenance. There are lots of
TBO-related old wives tales that are widely believed by owners and mechanic
alike, and they can cost owners a great deal of money. Mike Busch endeavors
to clear up these misconceptions, and explain what TBO really means.

Thanks. I really appreciate the link.

"Matt Barrow" wrote in message
...

"Jim Stewart" wrote in message
. ..
Does an engine past TBO make an aircraft
non-airworthy? I can't seem to find a
straight answer on the web.

TBO is a manufacturers recommendation, it has noting to do w ith
airworthiness. Some aircraft are not airworthy 100 hours after TBO, while
some run well past the number.
...

So, does anyone know if TBO is based on B-10, B-50, B-90, or - what???

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

What is B-10, B50 etc?


Karl
Always top post


"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
...
"Matt Barrow" wrote in message
...

"Jim Stewart" wrote in message
. ..
Does an engine past TBO make an aircraft
non-airworthy? I can't seem to find a
straight answer on the web.

TBO is a manufacturers recommendation, it has noting to do w ith
airworthiness. Some aircraft are not airworthy 100 hours after TBO, while
some run well past the number.
...

So, does anyone know if TBO is based on B-10, B-50, B-90, or - what???

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"karl gruber" wrote in message
...
What is B-10, B50 etc?


Karl
Always top post


B-10, B-50... are the expected hours at which 10%, 50%, etc. are expected
to fail. The "B" is from "bearing" - the orignal theorys were developed to
predict the life of ball bearings, but the termanology is now used for
everything. The Weibull distribution is usually used to "fit" durability
data and determine these values.

If TBO is B-10, then, in most cases, it would seem silly to overhaul at TBO,
if it is B-90, then it would be optimistic to expect to make TBO...

Or, TBO could be a number that some engineer pulled out of the air (to put
it politely).

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
...
"karl gruber" wrote in message
...
What is B-10, B50 etc?


Karl
Always top post


B-10, B-50... are the expected hours at which 10%, 50%, etc. are expected
to fail. The "B" is from "bearing" - the orignal theorys were developed
to predict the life of ball bearings, but the termanology is now used for
everything. The Weibull distribution is usually used to "fit" durability
data and determine these values.

If TBO is B-10, then, in most cases, it would seem silly to overhaul at
TBO, if it is B-90, then it would be optimistic to expect to make TBO...

Or, TBO could be a number that some engineer pulled out of the air (to put
it politely).


I don't think TBO is a projected or average expected "point of failure". I
believe they'd call that "Expect Life Expectancy".

On Wed, 11 Apr 2007 06:06:53 -0700, Matt Barrow wrote:

There are lots of
TBO-related old wives tales that are widely believed by owners and
mechanic alike, and they can cost owners a great deal of money.

What's amazing is that some owners are almost religious about this. That
is, it matters not what articles you put before them counting their
beliefs. They still believe.

- Andrew

On Apr 10, 9:12 pm, Jim Stewart wrote:
Does an engine past TBO make an aircraft
non-airworthy? I can't seem to find a
straight answer on the web.

Assuming you can find an IA willing to sign an annual then no.

-Robert