[BillL]

No guesses, please, just calculate TT / years of service.

During the long SB thread for the HS on the 6-7-8 there was a lot of information presented about TT-airframe. This poll is to carry the data a little further and define a distribution on the number of hour per year RVer's fly. I did come collection on the thread, but hopefully more people will answer the poll as it is easy!

Just take the first flight date, compute number of years in service and divide into your TT on the aircraft.

We can use this data to determine possible failures in the future should any of interest occur.

Thanks,

 

[RV6_flyer]

No guesses, please, just calculate TT / years of service.

Most in a 12-month period was over 200. Lowest in 12-month period was 80-100. Using your formula of TT / years of service, I came up with 2,820/16.5 = 170.9 and posted accordingly.

 

[Vlad]

I guess you should exclude RV9 from your poll Bill ask those models affected by SB. Total time on 9 doesn't matter much. I could drone at altitude for 5-6 hours a day at 2300 rpm which doesn't put any stress on the airframe.

 

[BillL]

I guess you should exclude RV9 from your poll Bill ask those models affected by SB. Total time on 9 doesn't matter much. I could drone at altitude for 5-6 hours a day at 2300 rpm which doesn't put any stress on the airframe.

Good thought, Vlad, but the information can be used for more that just heavy structural issues. It could be for anything that one wishes to understand.

The 9 is not used for aerobatics but may well be used to the same % of limits as the 6-7-8.

I did several hours of collection off the SB thread and was a little surprised at the numbers. The median was about 70 hrs per year, but since the distribution is not normal, then the mathematical average was about 100 hrs/yr. I just added the 9 since it seems to be a similar use plane with 2 places. I did want to leave you and SCard out!

It seems like the typical non-RV/EAB aircraft only flies about 35 hours per year according to an article I found. It cost twice as much and flies half as much!.

Fun fact, the RV fleet above @100hrs/yr burns 4.5 million gallons of fuel at a cost of $22 mil! Maybe we should have a (strong) voice in fuels?

 

[flytoboat]

There was no poll choice for me. The RV6A I purchased last fall had flown an average of 18 hours per year over 12 years. I've flown 50 hours since last September and have a budget to fly 100 hours per year.

 

[BillL]

There was no poll choice for me. The RV6A I purchased last fall had flown an average of 18 hours per year over 12 years. I've flown 50 hours since last September and have a budget to fly 100 hours per year.

Thanks for the post, I will add you in the 0-20 range. I already had another PM with the same dilemma. I only had 10 poll selections max and I already knew there were a number above 200, so had to limit.

I hope this will be useful to vendors and analysts alike. I had to guess for a reliability analysis of the HS, SB and it was luckily close.

 

[rvbuilder2002]

I could drone at altitude for 5-6 hours a day at 2300 rpm which doesn't put any stress on the airframe.

It all depends on what you consider Stress Vlad.

Even in economy cruise level flight there are loads induced in the horizontal stabilizer (and the rest of the airframe)... it is constantly pushing the tail downward to counteract the natural nose down pitching moment produced by the wing.
There are a lot of different things that influence the loads on the airframe (turb. induced gust loads, etc.) but one that is constantly happening to some degree or another regardless of the flight condition is pilot input. Every time you move the stick to induce some nose up or down pitch change, the load on the horizontal stabilizer changes. This changing load is what over an extended period of time can cause an airplane to show its age.

A simpler explanation... if we take a small piece of thin aluminum and bend it a small amount (just enough that it will still spring back to original if released) and hold it in that position without changing the applied force, it could probably stay that way indefinitely.
If you take the same piece, but instead of holding the force, you keep applying and releasing it, it would eventually crack. It would take a lot of cycles (probably 10s maybe even 100's of thousands), but it would crack.
Each movement of the stick is cycling the loads on the airframe in the same way. The hope is that the design margins will allow for many thousands of hours of these cycles without any issues.

This is not meant to say that the longevity of an aircraft flow hard wont be any different than one that is not, just that flying easy doesn't remove the factors that can effect longevity.

 

[catmandu]

Another 0-20 airplane. Already changing that, re-poll in a year and I can do my own selection.

 

[Vlad]

It all depends on what you consider Stress Vlad.

Even in economy cruise level flight there are loads induced in the horizontal stabilizer (and the rest of the airframe)... it is constantly pushing the tail downward to counteract the natural nose down pitching moment produced by the wing.
There are a lot of different things that influence the loads on the airframe (turb. induced gust loads, etc.) but one that is constantly happening to some degree or another regardless of the flight condition is pilot input. Every time you move the stick to induce some nose up or down pitch change, the load on the horizontal stabilizer changes. This changing load is what over an extended period of time can cause an airplane to show its age.

A simpler explanation... if we take a small piece of thin aluminum and bend it a small amount (just enough that it will still spring back to original if released) and hold it in that position without changing the applied force, it could probably stay that way indefinitely.
If you take the same piece, but instead of holding the force, you keep applying and releasing it, it would eventually crack. It would take a lot of cycles (probably 10s maybe even 100's of thousands), but it would crack.
Each movement of the stick is cycling the loads on the airframe in the same way. The hope is that the design margins will allow for many thousands of hours of these cycles without any issues.

This is not meant to say that the longevity of an aircraft flow hard wont be any different than one that is not, just that flying easy doesn't remove the factors that can effect longevity.

Great explanation on stress, cycle and aging thanks Scott.

 

[Clarkie]

We've flown our -6 just over 100 hours in the past 12 months.

 

[RV6_flyer]

Translation Russan to English

Не имей сто рублей, а имей сто друзей.

Translation to English:
Do not have a hundred rubles, have a hundred friends.

My comments:
Yes my friend, you do have more than 100 friends.

 

[jsharkey]

Some of us have a living to earn

 

[Vlad]

Translation to English:
Do not have a hundred rubles, have a hundred friends.

My comments:
Yes my friend, you do have more than 100 friends.

Thanks Gary. Today I looked into my wallet and didn't see any roubles left. That's why no fresh track

Some of us have a living to earn

Jim, judging from aircraft paint and groomed hangar that's some good living earned

 

[49clipper]

hours flown

55 avg/yr flown since 2007

 

[Rosie]

3800 hours / 13.5 years = ~280 hours per year Rosie

 

[Jaypratt]

RV8 Borrowed Horse

"Borrowed Horse"
RV8
No cracks !
50 hours per year
550 hours TT
First Flight July 17, 2007

 

[pmccoy]

I had to estimate based on my first 9 months of flight. What fun, being able to add to this thread. It a blast to finally be flying.

 

[BillL]

Thanks for the participation. It seems to be reaching a stable distribution. It is turning out a little different that expected, like there are really three types of usage that are combined. Further detail is probably not needed, though. I am looking forward to being able to participate in future usage polls.

The RV owners/builders community is a powerful group taken all together!