IO550 AD

[hais]

I got a notification today: https://wwwapps.tc.gc.ca/saf-sec-sur/2/awd-cn/documents/US2023-02-12.PDF

Affected components were shipped between Jan-March 2022. 

[Pinecone]

Got to love FAA/GOV accounting.  They include ALL known costs.

Hmm, they give the cost to remove and inspect one cylinder, except these are 6 cylinder engines.

Hmm, they give the cost to remove the cylinder, remove the valve, and replace the valve.  But not the cost to reinstall the cylinder.

Hmm, whose shop rate is $85?  Mine is over $100

 

[Fly Boomer]

6 hours ago, Pinecone said:

Got to love FAA/GOV accounting.  They include ALL known costs.

Hmm, they give the cost to remove and inspect one cylinder, except these are 6 cylinder engines.

Hmm, they give the cost to remove the cylinder, remove the valve, and replace the valve.  But not the cost to reinstall the cylinder.

Hmm, whose shop rate is $85?  Mine is over $100

 

And who weighs 170?  

[GeeBee]

A lot of people don't weigh 170, but on average the population is close to that but you certainly need a large enough population to achieve average weights which was the statistical error the FAA made with the original re-write of part 135. 

[Fly Boomer]

13 minutes ago, GeeBee said:

A lot of people don't weigh 170, but on average the population is close to that but you certainly need a large enough population to achieve average weights which was the statistical error the FAA made with the original re-write of part 135. 

I'm sure the population of the planet is close to that, but I don't know any "senior" men who weigh 170.  I just asked Alexa, and she says "average adult male in the United States weighs about 196 pounds".  Take that with a grain of salt; half the time that bi+ch won't even answer me.

[EricJ]

I'm 62 years old, 6'0", and weigh 170 lbs.   Seriously.   That's down about twenty from eight years ago or so, but that's where I am now.   And I'm not alone.

[FlyingScot]

15 minutes ago, EricJ said:

I'm 62 years old, 6'0", and weigh 170 lbs.   Seriously.   That's down about twenty from eight years ago or so, but that's where I am now.   And I'm not alone.

Nope, you're not. 6'0", 61, 167. The difference in UL I make up in fuel. 

I read yesterday that the average waist size for men in the US is 40"

[GeeBee]

3 hours ago, Fly Boomer said:

I'm sure the population of the planet is close to that, but I don't know any "senior" men who weigh 170.  I just asked Alexa, and she says "average adult male in the United States weighs about 196 pounds".  Take that with a grain of salt; half the time that bi+ch won't even answer me.

Yes but an airliner is not full of adult men. It has women, it has adolescents when you average them altogether, it is about 173 pounds summer weight. Winter weight is more due to weight. Airlines double check these averages all the time as does the FAA. It is amazingly accurate. As the airlines went to expanded overhead bins, they upped the weight to 190 because of the larger carry ons. None the less the passenger weight sans bags is 173 average summer.  You only get into trouble when you go below about 25-30 people because the sample is not large enough to meet the average. When revised Part 135 came out in the late 70's the FAA allowed planes down to 10 passengers to use averages. In the comment period I wrote this would lead to over loaded and out of CG airplanes. The FAA ignored these comments from me and others in part due to pressure from the light commuter industry and you guessed it, a 10 passenger Navajo Chieftain took off in AK and crashed due to overloading when it lost an engine. The upside of course is the larger the airliner, the more accurate because the sample size is so large.

I've been a part of a number of "load audits" and it is amazing when you roll the airplane on the scales they are generally within 1%.

[carusoam]

You guys just made we get on a scale….   
6’ 0”…

To get close 175… I’m going to need to fly without clothes…

Y’all must have good calorie control… run 26 miles each week… or smoke a lot of cigarettes…

I see several hours of gym time each week…

Best regards,

-a-
 

 

[larrynimmo]

5 hours ago, carusoam said:

You guys just made we get on a scale….   
6’ 0”…

To get close 175… I’m going to need to fly without clothes…

Y’all must have good calorie control… run 26 miles each week… or smoke a lot of cigarettes…

I see several hours of gym time each week…

Best regards,

-a-
 

 

As a matter of fact….

larry weighs in at 162…6’0” and everyday does 15+ miles on a recumbent bike …just turned 68 years old and hope I am never characterized as “an average American”

[BDPetersen]

At 77, 5’11”, 173#. Down 30# from year ago where I had been forever. Does wonder for bp and cholesterol. But I’m not an IO-550.

[Guest]

15 hours ago, EricJ said:

I'm 62 years old, 6'0", and weigh 170 lbs.   Seriously.   That's down about twenty from eight years ago or so, but that's where I am now.   And I'm not alone.

Pensioner meals will do that to you!

[aviatoreb]

12 hours ago, GeeBee said:

...The upside of course is the larger the airliner, the more accurate because the sample size is so large.

I've been a part of a number of "load audits" and it is amazing when you roll the airplane on the scales they are generally within 1%.

There's some mathematical principles underlying the idea that larger samples from a random variable are more and more likely to be close to the mean.  First in line for these is Chebyschev's inequality.

P(|X-E[x]|>=a) <= Var[X]/a^2

https://en.wikipedia.org/wiki/Chebyshev's_inequality

which is a Markov inequality and comes from a really area of analysis called concentration of measure that describes how data looks in high dimensions.

Then there's Chernoff's inequality that tells us about the tails (large deviations) of the mean, and Hoeffding's inequality, Bernstein's inequality, and so on.  This isn't so esoterica that I would be surprised if the FAA does not have some kind of actuary or someone who keeps tabs on all this mathematical underpinnings to match their full to some alpha small mandated value that the probability of being over weight with n seats filled is exceedingly small at a specified precision.

[EricJ]

1 hour ago, aviatoreb said:

There's some mathematical principles underlying the idea that larger samples from a random variable are more and more likely to be close to the mean.  First in line for these is Chebyschev's inequality.

P(|X-E[x]|>=a) <= Var[X]/a^2

https://en.wikipedia.org/wiki/Chebyshev's_inequality

which is a Markov inequality and comes from a really area of analysis called concentration of measure that describes how data looks in high dimensions.

Then there's Chernoff's inequality that tells us about the tails (large deviations) of the mean, and Hoeffding's inequality, Bernstein's inequality, and so on.  This isn't so esoterica that I would be surprised if the FAA does not have some kind of actuary or someone who keeps tabs on all this mathematical underpinnings to match their full to some alpha small mandated value that the probability of being over weight with n seats filled is exceedingly small at a specified precision.

They may be relying on the central limit theorem a little bit, too, but when you get booked by a couple football teams or are shuttling a crowd to a little people's conference it might break down a little. 

[ragedracer1977]

Not just 550s. Looks like basically all big bore continentals.

 All of the valves were delivered no more than about one year ago.  Jan 22-May 22.  Seems to me that superior should be paying for this. This isn’t an “oh that happened decades ago” kinda AD

[GeeBee]

17 minutes ago, EricJ said:

They may be relying on the central limit theorem a little bit, too, but when you get booked by a couple football teams or are shuttling a crowd to a little people's conference it might break down a little. 

Athletic teams are counted differently. I used to fly a lot of football charters we used "heavy athletic" averages. In addition if you have a lot of "little people" you use "child weights". I have had several instances where we are payload limited and the agent comes on board and starts counting the children so we can use child weights instead of adult average. In addition child weights are divided between "pre-adolescent" and adolescent. It works guys, get over it.

[Fly Boomer]

55 minutes ago, GeeBee said:

Athletic teams are counted differently. I used to fly a lot of football charters we used "heavy athletic" averages. In addition if you have a lot of "little people" you use "child weights". I have had several instances where we are payload limited and the agent comes on board and starts counting the children so we can use child weights instead of adult average. In addition child weights are divided between "pre-adolescent" and adolescent. It works guys, get over it.

In a 4-place airplane?

[GeeBee]

 

1 hour ago, Fly Boomer said:

In a 4-place airplane?

I think we already covered that issue.

 

[Guest]

On 2/4/2023 at 9:40 AM, ragedracer1977 said:

Not just 550s. Looks like basically all big bore continentals.

 All of the valves were delivered no more than about one year ago.  Jan 22-May 22.  Seems to me that superior should be paying for this. This isn’t an “oh that happened decades ago” kinda AD

They are just present the official FAA voucher to you maintenance shop, it covers a very attractive labour rate and minimal hours.  The shop will happily cover any overrun’s.

[A64Pilot]

On 2/4/2023 at 10:40 AM, ragedracer1977 said:

Not just 550s. Looks like basically all big bore continentals.

 All of the valves were delivered no more than about one year ago.  Jan 22-May 22.  Seems to me that superior should be paying for this. This isn’t an “oh that happened decades ago” kinda AD

Real quick explanation of the difference in a recall as in your car and an Aircraft AD.

Auto recall the manufacturer screws up and they pay to fix it, manufacturer loses money, recalls are not mandatory.

AD, manufacturer screwed up, and your going to pay for it, AD’s ARE mandatory, and often the manufacturer makes a profit from the AD.