How many hours is too many??

[gsxrpilot]

5 minutes ago, jaylw314 said:

OTOH, 5000 hours gives a lot of opportunity for corrosion and bad maintenance, which are probably the bigger issues, but these are more related to time, the environment, and the owner than it is airframe hours.  Anal record-keeping by previous owners would be reassuring, although not a guarantee.

Yes. The 5000 hours has much less to do with corrosion and lack of maintenance than does the 50 years that have likely gone by since it rolled off the line in Kerrville. 

In fact, the 5000 hours is a much better sign than 2000 hours on the same plane. If the plane is being flow regularly, it will likely be in much better maintenance shape and more likely that corrosion has been addressed and treated, than the hangar queen with 2000 hours since new.

[jetdriven]

I’ve seen this airplane a couple of times now and the belly of it is cleaner than the top of the wing on most airplanes and the rest looks like it was painted last week. In fact I stopped by on my way from the paint shop and besides the timeliness of the color scheme, you couldn’t guess who’s was just painted and who’s was painted in 1988.  That’s Imron and a meticulous owner for you. 

[mike_elliott]

On ‎3‎/‎18‎/‎2018 at 7:00 PM, Mooneymite said:

How and where an aircraft was when it was not flying is probably more important than flight hours.

An ad that says, "always hangared in AZ" would catch my interest before one that said, "low hours".

and if the ad said "always in AZ" and it was on a ramp the whole time, it would be skipped for one that said "low hours"

[Guest]

22 hours ago, bluehighwayflyer said:

I’m the one here with a 10,000 hour Mooney. A ‘78 J, actually with almost 10,500 hours TTAF now. I have owned it for 12 years and can only think of a couple of maintenance items having been required that I could say were directly attributable the airframe hours, and that is that the pilot’s seat back was pretty much shot and required rebuild both to the seat back itself and the shaft that it rotates on.  The leading edges of the nose gear doors are also wearing pretty thin, so I bought a new set in anticipation of replacing them, but haven’t felt the need to install them yet.  Yes, I have had to rebuild the nose gear steering horn, “tighten the tail” with new bolts, replace the gear actuator’s NBC spring, and replace the landing gear and engine Lord mounts, etc., etc., but at this point this is all routine maintenance for any vintage Mooney.

In mitigation of my Mooney’s high total time, most of those hours were acquired as an eye-in-the-sky traffic reporter for a San Francisco Bay radio station. So these would have been all day loitering missions that should have been very easy on the aircraft. It was cared for by leading MSC Top Gun Aviation for all of these years and has always been hangared.  Hangarage and doting maintenance are exponentially more important than total airframe hours for Mooneys, in my opinion.  

Mine is currently on it’s fourth engine which is right at TBO and doing great. The first three engines were each replaced well past TBO, always with factory remans.  I promise you on a ramp full of vintage Mooneys mine would stand out as one of the cleanest, and the only way you would know about the high time airframe would be by wading through it’s box full of logbooks.

Jim

Had the plane been flown at normal speeds versus loitering speeds the time might well have been 7000 hours.

Clarence

[bradp]

2 hours ago, M20Doc said:

Had the plane been flown at normal speeds versus loitering speeds the time might well have been 7000 hours.

Clarence

Clarence just invented maintenance time travel.  

[jlunseth]

On 3/19/2018 at 1:28 PM, bluehighwayflyer said:

I’m the one here with a 10,000 hour Mooney. A ‘78 J, actually with almost 10,500 hours TTAF now. I have owned it for 12 years and can only think of a couple of maintenance items having been required that I could say were directly attributable the airframe hours, and that is that the pilot’s seat back was pretty much shot and required rebuild both to the seat back itself and the shaft that it rotates on.  The leading edges of the nose gear doors are also wearing pretty thin, so I bought a new set in anticipation of replacing them, but haven’t felt the need to install them yet.  Yes, I have had to rebuild the nose gear steering horn, “tighten the tail” with new bolts, replace the gear actuator’s NBC spring, and replace the landing gear and engine Lord mounts, etc., etc., but at this point this is all routine maintenance for any vintage Mooney.

In mitigation of my Mooney’s high total time, most of those hours were acquired as an eye-in-the-sky traffic reporter for a San Francisco Bay radio station. So these would have been all day loitering missions that should have been very easy on the aircraft. It was cared for by leading MSC Top Gun Aviation for all of these years and has always been hangared.  Hangarage and doting maintenance are exponentially more important than total airframe hours for Mooneys, in my opinion.  

Mine is currently on it’s fourth engine which is right at TBO and doing great. The first three engines were each replaced well past TBO, always with factory remans.  I promise you on a ramp full of vintage Mooneys mine would stand out as one of the cleanest, and the only way you would know about the high time airframe would be by wading through it’s box full of logbooks.

Jim

I dropped my plane off a Willmar for the annual last week and got a ride back to KFCM with a J pilot from Anoka.  He bought the plane new in, I think he said '79 but might be wrong on that.  He is on his fifth engine and has high 8,000's for pilot hours.  That was a really pretty plane, well maintained, he has a 750GTN in it now and several other delicious things on the panel. The engine hummed.  I have to say, it never dawned on me to worry about the wings coming off due to fatigue. I was too interested in enjoying the pilot's obvious skill in that plane.  The only things I could see in that aircraft that were in danger of coming apart due to age and materials fatigue, were the 82 year old pilot and his 68 year old passenger, each of which had also had a couple of overhauls.

Edited March 29, 2018 by jlunseth

[RobertE]

I once owned a Piper Cherokee and, as such, became familiar with what I believe was the largest grounding of GA aircraft ever (glad to say that grounding preceded my ownership).  In any event, a wing departed a Cherokee that caused the grounding.  Why I’m telling this story is that I’m told NASA thought it a good idea then to try to assess the life limit of GA aircraft in normal use, using the Cherokee as the proxy aircraft.  Their conclusion? 70,000 hours.

 

[Bob_Belville]

7 hours ago, RobertE said:

NASA thought it a good idea then to try to assess the life limit of GA aircraft in normal use, using the Cherokee as the proxy aircraft.  Their conclusion? 70,000 hours.

 

Well that's special. Do you know if it is in writing somewhere?

[One Whiskey Hotel]

On the topic of high TTAF, I was casually browsing Controller yesterday and saw a K model with 25,000 hours on it in South Africa. Still asking more than a couple of dollars for that one....will see if it sells sooner or later.

[aviatoreb]

49 minutes ago, One Whiskey Hotel said:

On the topic of high TTAF, I was casually browsing Controller yesterday and saw a K model with 25,000 hours on it in South Africa. Still asking more than a couple of dollars for that one....will see if it sells sooner or later.

Wow that’s more than typical.

i saw an embry riddle m20j for sale once we 12k on it.

dont some of those 75 year old dc3s still in service have like 250k hours on them?

[Marcopolo]

 

1 hour ago, One Whiskey Hotel said:

On the topic of high TTAF, I was casually browsing Controller yesterday and saw a K model with 25,000 hours on it in South Africa. Still asking more than a couple of dollars for that one....will see if it sells sooner or later.

I think the TTAF listed on that bird is a typo, in the description under Airframe it states "low total time - no damage history".  Also it shows as having the original (rebuilt 724 hrs ago) GB engine, I would guess if the air-frame had 25,000 hrs it would definitely be an LB by now.

 

FWIW,

Ron

 

 

[aviatoreb]

42 minutes ago, Marcopolo said:

 

I think the TTAF listed on that bird is a typo, in the description under Airframe it states "low total time - no damage history".  Also it shows as having the original (rebuilt 724 hrs ago) GB engine, I would guess if the air-frame had 25,000 hrs it would definitely be an LB by now.

 

FWIW,

Ron

 

 

I’m a math prof - I misplace the decimal point all the time and the students laugh at me...

[Hank]

34 minutes ago, aviatoreb said:

I’m a math prof - I misplace the decimal point all the time and the students laugh at me...

One of my Engineering profs gave no partial credit on tests for math errors. His reasoning was that if you're doing an estimate for a five story hotel where each floor is the same layout, forgetting to multiply by 5 may bankrupt the company but will certainly cost you your job.

In the real world, transposed numbers and shufted decimals are quite common . . . . . 

[Bob_Belville]

I went to college working with a slide rule (and a pocket liner). A slide rule will train its operator how to place the decimal point.

[DonMuncy]

2 hours ago, Bob_Belville said:

I went to college working with a slide rule (and a pocket liner). A slide rule will train its operator how to place the decimal point.

Bob, Don't you realize that a significant number of people here have never seen a slide rule. I probably should be sorry for the hours I have invested in learning to use a slide rule; but I'm not.

[aviatoreb]

1 hour ago, Hank said:

One of my Engineering profs gave no partial credit on tests for math errors. His reasoning was that if you're doing an estimate for a five story hotel where each floor is the same layout, forgetting to multiply by 5 may bankrupt the company but will certainly cost you your job.

In the real world, transposed numbers and shufted decimals are quite common . . . . . 

I agree completely and I was mostly just kidding.  I just said that because I thought it was funny .  I don’t actually do much computing with numbers when I’m lecturing - usually I’m presenting theorems or algorithms and proving them and describing how it all fits together logically. The funny thing is math profs don’t handle numbers much.  You should see the comedy scene at a conference when 3 or 4 math profs are splitting the dinner check.

I agree with your engineering prof / that one should know the order of magnitude of an answer that makes sense to back check a computed answer and I do that all the time when the occasion of working with numbers.

in flying if you compute your fuel reserves and you come up with 275 hours ... check your computation.

 

[jlunseth]

Well, I thought it was funny, and human.  My brain works the same way.  I can do the math in my head, but getting the commas and the decimal point in the right place is a chore.  Easiest to just mentally step back and say, what should it be, 10,000 or 1,000,000.  If I do it with a calculator or computer or even on paper, it’s not ever wrong, which is what I do when there is time and it matters. In all seriousness, this is an important pilot skill, knowing in what operations the pilot is prone to error more than in others, and knowing that when it matters, the pilot needs to check his work in those areas

[aviatoreb]

4 hours ago, jlunseth said:

Well, I thought it was funny, and human.  My brain works the same way.  I can do the math in my head, but getting the commas and the decimal point in the right place is a chore.  Easiest to just mentally step back and say, what should it be, 10,000 or 1,000,000.  If I do it with a calculator or computer or even on paper, it’s not ever wrong, which is what I do when there is time and it matters. In all seriousness, this is an important pilot skill, knowing in what operations the pilot is prone to error more than in others, and knowing that when it matters, the pilot needs to check his work in those areas

EXACTLY and perfectly said!  A+!

[thekubiaks]

21 hours ago, DonMuncy said:

Bob, Don't you realize that a significant number of people here have never seen a slide rule. I probably should be sorry for the hours I have invested in learning to use a slide rule; but I'm not.

And, the slide rule took project Mercury, Gemini, and Apollo into space....

[jlunseth]

I thought it was “computers” that did that.  See e.g. the movie “Hidden Figures.”  I didn’t see the computers operating any slide rules, it looked like pencil, paper, and a mechanical adding machine to me.

[EricJ]

2 hours ago, thekubiaks said:

And, the slide rule took project Mercury, Gemini, and Apollo into space....

 

19 minutes ago, jlunseth said:

I thought it was “computers” that did that.  See e.g. the movie “Hidden Figures.”  I didn’t see the computers operating any slide rules, it looked like pencil, paper, and a mechanical adding machine to me.

Yes, and the Apollo program did include on-board digital guidance computers:

https://en.wikipedia.org/wiki/Apollo_Guidance_Computer

You can buy a functional replica.   They're pretty cool if you're that type of nerd.

https://opendsky.com/

 

[jlunseth]

I put “computers” in quotes for a reason.  You need to see the movie.  These “computers” were binary and digital, but not in the way we know computers today.

[EricJ]

12 hours ago, jlunseth said:

I put “computers” in quotes for a reason.  You need to see the movie.  These “computers” were binary and digital, but not in the way we know computers today.

I saw it, good movie.   I was mostly adding to your comment addressing thekubiaks statement about slide rules.   Digital computers were used quite a bit in the Apollo program, both on the ground and in the spacecraft, and on the ground in the previous programs.   Since software tools weren't so great back then, a lot of hand analysis and modelling was done to figure out what software to write.

I'm sure slide rules were still used a lot throughout, since the computing resources were scarce, but they did exist.