TTAF useful life pressurized airplane

texasag93

texasag93

Line Up and Wait
Joined
Jun 23, 2012
Messages
759
Location
Denton, TX
Display Name
Display name:
texasag93
I read somewhere that the useful time TTAF for pressurized airplanes is 10,000 hours.

After that they are to be flown non pressurized.

Is that correct?
 
texasag93 said:
I read somewhere that the useful time TTAF for pressurized airplanes is 10,000 hours.

After that they are to be flown non pressurized.

Is that correct?
Click to expand...
I don't think it's hours, but rather cycles.
 
Actually I believe the PBaron does have an airframe life limit of 10,000 hours. But that's an anomaly.
 
Lance F said:
Actually I believe the PBaron does have an airframe life limit of 10,000 hours. But that's an anomaly.
Click to expand...

The 58P is a part 23 airplane, all of which have a life limitation if I'm not mistaken. That limitation exists for both pressurized and unpressurized airplanes.
 
Airliners have gone more than 100,000 hours flight time before retiring.
 
All aircraft structure has life limits. In the past, it was based on flight cycles or hours and generally was a hard limit requiring retiring the airframe. Modern aircraft are designed using the method of Fracture Mechanics which theoretically can mean an essentially infinite life as long as inspections do not find cracking beyond limits. Inspection intervals are set to find cracks prior to them being dangerous.

One reason the B-52 is still flying is the original design was reanalyzed using Fracture Mechanics and inspection intervals setup to find any critical cracks.

Cheers
 
Last edited:
MauleSkinner said:
Got access to the maintenance manual for the Cub Crafters CC19?
Click to expand...

Nope. That was one I wondered about, with the way the TC references the current MM for its life limitations. But the TC does still have a life limitation section, which is something different with the part 23 airplanes compared to the old CAR3 planes.
 
I forgot to add paying a FE.
 
Yeah, I know. They made big money.

727's were paid for, many times over.

And I'm pretty sure the 727 was faster than it's replacements, which could account for some of its higher fuel consumption.... but, what's the purchase cost comparison for 3, JT8D's verses 2, RB211 or PW2037/40 for thr 757?
 
Last edited:
GlennAB1 said:
Yeah, I know. They made big money.

727's were paid for, many times over.

And I'm pretty sure the 727 was faster than it's replacements, which could account for some of its higher fuel consumption.... but, what's the purchase cost comparison for 3, JT8D's verses 2, RB211 or PW2037/40 for thr 757?
Click to expand...
And how many times did they have to buy a JT8D compared to a newer design?
 
GlennAB1 said:
? We change "newer design" engines all the time.

JT8D fan blades were robust and cheap compared to new design.

ETOPS operating cost increase probably offsets FE pay.
Click to expand...
Didn't say anything about FE's, ETOPS, or the supposed robust blade design. I didn't even say anything like newer engines aren't changed.

I did ask how many about the life of a JT8D compared to newer engines. You did not address that question so it is clear that the answer does not support your position. Thanks for playing and HAND.
 
I Did address the question with "?" and, newer engines get changed all the time. They cost multiples of a JT8D. The fact that you needed it explained is not my fault.
 
Last edited:
It was my understanding the prevalence of trimotors was just a market response to the industry's unwillingness to certify twins over those long thin routes, in the pre ETOPS days. With ETOPS, the tri motor wonkyness went back to the history books.
 
There is no life limit that I'm aware of on the pressurized Twin Cessnas (such as the 414).

Cessna has published SIDs (not currently mandatory in the US, hope it stay that way) which do add inspections as hours increase. However they do not result in a set retirement life of the aircraft.
 
hindsight2020 said:
It was my understanding the prevalence of trimotors was just a market response to the industry's unwillingness to certify twins over those long thin routes, in the pre ETOPS days. With ETOPS, the tri motor wonkyness went back to the history books.
Click to expand...
The CF6-6 powerplants on the DC-10 produced about 40k lb. thrust X 3 and the CF6-80C2 on the B767 produces about 60k X 2. Yeah, the 80C2 is more reliable, but a double engine failure on either aircraft is practically an impossibility. A lot of people are still more comfortable on a three-holer.
 
GlennAB1 said:
Yeah, the 80C2 is more reliable, but a double engine failure on either aircraft is practically an impossibility.
Click to expand...
I know pilots who can beat me at a rousing game of "What are the odds of that?", but not many. ;)
 
You must log in or register to reply here.
Back
Top