The International Cessna^® 170 Association

Hello I have been contacted by a gentleman with a '53 170B that is for the most part everything I am looking for. The thing that cocerns me the most is the airframe time. It has nearly 5000 hrs. Should this be a concern. I understand useage is key here. Plane appears very nice so maybe/hopefully you can assume it has had reasonable care??? No recorded damage history. Are there things That I should look for because of hours? My last 170 was a 1952 model. I had a rudder problem. Seems that it was a fairly common one possibly something with the rudder horn. Whatever the problem was, I replaced the rudder. These are probably getting pretty hard to find. Thanks for any help/advice. Gary

A 1953 C-170 with 5000 airframe hours amounts to less than an average of 100 hours per year. That's certainly not excessive. If the plane has been properly maintained it certainly doesn't have excessive time on the airframe. You didn't mention the time on the engine. Still, you need to get a full blown annual done by a disinterested mechanic to ck it out before you purchase. IMHO

Thanks ole pokey I understand it's not may hours per year but it is still 5000 hours. No matter what year it is, there is a point where fatigue becomes a factor. Hard useage would accelerate this process. But even with average useage there is a point where some parts will start to fail.

The helicopter I fly every day at work has 7079 TTAF. The highest time airframe I ever flew was a UH-1H Huey at flight school with over 11,000 TTAF. My 170 as well as my Cub have around 4500 TTAF. All the aircraft where/are inspected and repaired as necessary. To be honest I don't give it a second thought.

If I had two otherwise identical 170s for the same price I guess I'd buy the one with less TTAF. Other wise engine TSMOH, installed equipment and the paint scheme are more important to me once I've determined the airframe is airworthy.

Hi Bruce and thanks for your input. I realize that there are a lot of planes out there with over 10000 hrs. that seem to be fine. I think these early 170's were probably built a little lighter, which also makes the more desireable to me, than newer planes and therefore would have metal fatigue issues sooner. I guess that there seems to be no AD's on the airframe with regards to parts fatigueing and therefore, possably nothing to be concerned about with the hours. I have always tried to buy planes with less than 3000 hrs. Hard to do when you are looking at planes from back in the early '50's. But I also know they are out there. I would like to find the best plane for the best price before the end of April. With this one, everything else is good, appearence, mods, avionics and engine time. Thanks Gary

Don't lose this otherwise good airplane looking for the perfect airplane. You'll only find that elusive perfect airplane just AFTER taking possession of the airplane you settle on.

Yes Bruce that is true also. Don't want to shoot myself in the foot here. Just wanted to feel comfortable about buying a plane with 5000 hrs. on it. As I said, I had always tried to stay under 3000 hrs. 5000 hrs. maybe fine, I just needed to hear it from people with more experience than me. Thanks again form your input. Gary

When I bought my 48 model 8 years ago it had about 3400 hours on the airframe. It now has about 4800-- no big deal. I know guys who have real low time airframes, they always worry about flying it too much and running the airframe time up. What fun is that? I just fly the hell out of mine, have fun, and don't worry about it. When you start getting up around 8 or 10 thousand hours it might be a different story. But the lower value of the high-time airplane is the price you pay for having fun and really getting familiar with it. My two cents...

Eric

That is one of my reasons for wanting a low time plane. I can fly the hell out of it and it is still pretty low time. I generally fly 150-200hrs/yr. If you buy one with 5-6000 hrs. you may have enough hours on it when you go to sell it that there aren't too many interested in it. I guess that becomes the price you pay for the fun of flying. You either pay more when you buy one with low time or you get less when you sell for one with hightime. My biggest concern was mostly higher maintenance costs with a higher time airframe having to fix things cracking from the hours of vibration, or even worse, having something fail in flight. No one seems to think that is an issue, so we will just see were the negotiations go. Thanks again Gary

zero.one.victor wrote: When you start getting up around 8 or 10 thousand hours it might be a different story.
Eric

Not so sure the 10,000 hour mark is as meaningful with your ragwing Eric. I know for a fact your wings will not experience any skin fatigue.

By the time I put another 5,000 hours on my ragwing, Dave, I think I"ll be the one with skin fatigue!

The 170 fleet actually averages pretty low airframe hours for their age, considering that most 172s you look seem like they spent time in a flight school and have A LOT more hours than that on them, with likely some pretty rough landings in there. When looking for my plane, I got caught up in the TTAF thing too, until I realized that 3000-5000 hrs on an airframe is actually fairly low.

Question: Do a lot of 170's not come equipped with a Hobbs, and all airframe hours are tabulated from tach hours? If so, it seems a little bit of an inaccurate way of meauring airframe time.

Z

170s don't come with a Hobbs meter unless someone installed one. The same is true for most airplanes built from the 60s back. My Cub doesn't even have a tach that keeps time.

Bruce,

Do you just keep an operating log for the Cub and tabulate the hours at annual? It just makes me think that the reported airframe hours for any older aircraft is going to be fairly understated. If my 170 has 3750 TT, but only a tach to record hours, then that airframe has to have a bit more than that, right?

Zane

Yes Zane that is exactly what I do. The Cub has a log book in it and every flight is logged in that flight to the closest 10th of an hour. A running total is keep so we know when to change the oil and comply with other inspections which may come before the annual. And yes total airframe hours specially on these older aircraft have to be taken with a grain of salt.

A tach only keeps correct time at a specific RPM. If you fly at a lower or higher RPM it's not correct either.

Most of the aircraft I've flown for a living don't have a hobbs meter. The FAA only requires that flight time in the air be keeped for maintenance. We keep the actual time we are in the air and never count the time sitting with the engine and rotor turning.

My current employer converts the actual time to tenths at the end of a flight which normally includes several legs. One employer only converted the time to tenths at the end of the day which might have been sixty or seventy legs.

Lets see the difference. Flight one is 3 minutes or .1. Flight two is 3 minutes or .1. We have a total of .2 but only 6 minutes of actual total flight which would only be .1 under the second employers rules.