A little rant about engines on condition

[Just another driver]

A lot of companies fly around with engines on condition, they have to pass “tests” (sorry I forgot the technical name for it) to keep it certified commercially.

But, when I can't make full power on T/O, can't even pull red line torque with the power levers fire-walled or temped out on the runway, NG at max through 1000’ AGL – basically what you see on the take off roll is all you get, I have to ask myself how valid are these tests.

Then it comes down to legality. Are the performance charts now valid? I don't think so, or at least I don’t see how they can be accurate. On every performance graph pertaining to any kind of T/O, climb, single engine performance ETC, it states “full power”. I’m not making full power but my plane(s) don't have it written anywhere in the manual that the engines must show a min power for T/O, technically there is no min requirement. Other planes in our fleet that run the same type of engine do have this limitation plainly stated, these one's don't. I don’t get it.

When I bring it up to the mechanics they again mention the “test” and how the engine is still passing; cold comfort. I feel like taking them on a flight, fully loaded and pull an engine at 200’ and see what happens. It might get my point across.

So I will keep on flying full loads of whatever to wherever, happy in the knowledge that because the engine passes the “test”, it’s safe.

End of rant.

[KISS_MY_TCAS]

Well, if the engines are meeting thier performance data sheets that the engineers use, they are serviceable as per the manufacturer as well as TC through thier approval of the on-condition program, not all engine's performance data runs are conducted at full power. Did you ever consider that perhaps the maintenance guys are rigging the engines incorrectly?

[oldtimer]

I wish I could quote chapter and verse where I read it but the manufacturer has to establish performance parameters the aircraft engine is required to demonstrate during certification trials. This is the level of performance used during certification of the aircraft engine. The manufacturer then has to establish when the engine is worn out and when the performance drops below certification standards.
It is in the best interest of the manufacturer to degrade the certified performance parameters as much as possible to allow as much performance degradation as possible. It is this degraded performance the the airframe manufacturer uses to establish performance data in the AFM. As long as the aircraft will meet the MINIMUM performance standards for the category of airplane, the airplane/engine can be certified. Check your AFM and CAREFULLY determine the performance the airplane is capable of and then compare your aircraft actual performance. Expect at least a 2% degradation. But you may be surprised. With a lot of aircraft, especially British, the charts give MINIMUM performance. When I flew the RR Dart powered Gulfstream, the engines were rated at 1910 HP per but in actuality, one engine was producing over 2100 HP and the other 2050 HP. 1910 was the minimum.

[COCO THE MONKEY]

I flew TPE331 Garretts for a company who admitted they fudged the ITT compensations to save engines. The torques fell well below the POH "assured takeoff" torques to the point some takeoffs barely cleared the fence at as little as 75% torque where mins off the chart were 98%. The compensations were set at up to 70 degrees overindication. As long as no one snagged them the company filled their boots. When one the guys did it was just signed off as checked out OK. Total denial.
When the crews started complaining about the low torques they declared at a meeting that they were going to fudge the torque indications up as well.
I know it sounds incredible but TC didn't seem to be interested when someone wrote it up to them. There was a significant exodus of senior guys but no change in policy. I can't believe someone hasn't been killed yet, not making it off the runway with both fans turning let alone when one quits and the only way is straight down.
I found a general ignorance among the pilots at the next company I worked for regarding minimum torques as well. Takeoff power checks are another term found in the POH and these are MINIMUM figures.
The ops manual for these companies calls for the crew to be responsible to assure both takeoff obstacle clearance and departure climb gradient with one engine out but clearly this can't determined if the performance figures no longer apply and you can bet that if you can barely make it at minimum torque figures you don't have a chance at 20%-30% less.
These min powers are generally included in the performance section of the POH and the charts simply don't apply without them.
Know your POH!

[2low]

Ya Navair doesn't really care about the performance of the engines. The pilots were told by the Ops manager that he could make the engines guages read whatever he wanted them too. With much bitching, still nothing done and there are people out there content to fly these pieces of shit because if you don't there are more people lined up to do it. Really sucks.

[Legacy]

I flew TPE331 Garretts for a company who admitted they fudged the ITT compensations to save engines. The torques fell well below the POH "assured takeoff" torques to the point some takeoffs barely cleared the fence at as little as 75% torque where mins off the chart were 98%. The compensations were set at up to 70 degrees overindication. As long as no one snagged them the company filled their boots. When one the guys did it was just signed off as checked out OK. Total denial.
When the crews started complaining about the low torques they declared at a meeting that they were going to fudge the torque indications up as well.
I know it sounds incredible but TC didn't seem to be interested when someone wrote it up to them. There was a significant exodus of senior guys but no change in policy. I can't believe someone hasn't been killed yet, not making it off the runway with both fans turning let alone when one quits and the only way is straight down.
I found a general ignorance among the pilots at the next company I worked for regarding minimum torques as well. Takeoff power checks are another term found in the POH and these are MINIMUM figures.
The ops manual for these companies calls for the crew to be responsible to assure both takeoff obstacle clearance and departure climb gradient with one engine out but clearly this can't determined if the performance figures no longer apply and you can bet that if you can barely make it at minimum torque figures you don't have a chance at 20%-30% less.
These min powers are generally included in the performance section of the POH and the charts simply don't apply without them.
Know your POH!

Any engineer that does that knowingly to my plane will be answering the the front of my boot. They are risking YOUR life for what? a few bucks int he OWNERS pocket?

[Turkey]

The pilots were told by the Ops manager that he could make the engines guages read whatever he wanted them too.

To which the pilots should reply, "Well, you better 'make them' read minimum torque prior to the next takeoff, or the airplane won't be going anywhere."

[Westrules]

Maybe it's not the engineers maybe its also the pilots loading the plane to the nuts. Maybe the next time you think about laying the boots to the engineer fixing your bus you should think about who really knows more about the aircraft you're flying. Do you think you are god or something?

[Turkey]

maybe its also the pilots loading the plane to the nuts

Those damnded pilots... causing the engines to indicate less than full power by loading the aircraft... Friggin' Pilots... "Another round of raises to the engineers!"

[Legacy]

double post

[Legacy]

Maybe it's not the engineers maybe its also the pilots loading the plane to the nuts. Maybe the next time you think about laying the boots to the engineer fixing your bus you should think about who really knows more about the aircraft you're flying. Do you think you are god or something?

Read the remark. I said if i found out if the engineers KNOWINGLY did that to the engines.......so what is the debate here. Read the remark properly next time.....if it was MY post you are referring to. That is like saying if an engineer KNOWINGLY didn't tighten the engine mount bolts on. All this aside, most turbine engines will have a minimum torque setting that you NEED to fulfill the performance spec in the book. If you do not get these min torques, snag the plane. Dont fly it. Simple

[xsbank]

What Legacy said. Snag it with numbers so it is in the permanent record - if it is below specs it is unserviceable and if you fly it YOU carry the can for any accidents. Try a bowl of dog food for breakfast tomorrow - that's what your family will be eating after your estate is sued...

I flew with a company a century ago where the owner had the waste-gates on the Navajos all dialled back (39"? Are they supposed to be 43? Memory is getting bad.) Eventually one engine on one of the Ho's kakked and there wasn't enough power on the good side to stay airborne and he ditched it off Port Hardy. Luckily, minor injuries as the junk settled on a reef and didn't sink. Company went to the wall about six months later so nobody had to take those risks anyway as it did dick for the bottom line. We don't fly 'em like that anymore, do we?

[KISS_MY_TCAS]

Aloow me to drag you all back to the second post on this thread, made by me....

Did you ever consider that perhaps the maintenance guys are rigging the engines incorrectly?

Far more common perhaps than pilots like to admit? It does happen...

Garretts are an interesting animal and it takes a very sharp engineer to understand and rig them as per the AMM, anyone who knowingly takes off in one with the compensators doctored (since we all know the numbers shown to the pilot are BS anyway) is just as guilty as the engineer that dialed the compensators back. Same deal with the 'Ho, you want 42 inches, get it. Once you accept the airplane and cannot make full rated power on takeoff and commit, YOU are liable and nobody else, simple as that. If the brass in your company decides to call you names and shun you for not taking it, good on you. You will fly another day hopefully on a well maintained aircraft. As per the original post, on-condition is approved based on material TC gets from the engine manufacturer and if the engine cannot make said power after xxxx hours beyond TBO, it needs to go to overhaul, you did your part and it went xxx hours past TBO under approval, beyond that it is overhaul time. Garrets and PT6s are different animals, and rigging is VERY different, like I stated earlier if the engineers say it makes rated power as per the performance charts and you cannot make T/O rated power question it, could be rigging, could point engineers to a problem they weren't aware of, or it could mean your Garrett is shot. Engineering data runs and takeoff performance are 2 very different things, some engines they are the same, some they aren't (PT6s are tested well below T/O power and charted based on a power setting well below T/O power). As a pilot, you accept it or you don't, you can always reject a takeoff before you become a statistic.

[KISS_MY_TCAS]

When I flew the RR Dart powered Gulfstream, the engines were rated at 1910 HP per but in actuality, one engine was producing over 2100 HP and the other 2050 HP. 1910 was the minimum.

Obviously water injected, cheater.

[rigpiggy]

after many late nights working with the AME, and picking his brain as all low time pilots should do, I came to understand that AWI on the Darts were just to bring you to sea level ISA performance w/ a very slight boost when cooler. Yea or Nay

[oldtimer]

The Darts were not W/M injectedwhen the power ratings wetre determined. We had a problem in the fact that the right engine was running hot. EGT was higher than the left. A Rolls Royce Tech Rep came out from Montreal with test equipment and more expertise than us. He claimed the right engine was OK and well within limits, the left engine was far better than specs and we compared the right to the left.
It is interesting in that the company sold the airplane and the next flight with the new owner, the left engine failed and the airplane crashed, killing both the pilot and co-pilot.

[Siddley Hawker]

Correct ot, the G1 and F-27F both had RDa 529's which were restored, as opposed to boosted power, engines. There was one Mark, the 532's I believe, that was boosted power. I seem to recall that water meth gave about an extra 150 hp a side.

You mention the different torque and TGT values to obtain min guaranteed power on these engines. When RR began supplying engines to Grumman for the Gulfstream, most of the operators had just come off the DC-3. On the Pratts, all the needles lined up on t/o - 2300 RPM and 42 inches or whatever it was - and the pilots couldn't believe they were getting the full 1910 hp with one engine reading 15,000 RPM and 385 torque, and the other the same RPM and 405 torque, even with equal TGT's. What Rolls did, was to pair engines off the test bed that had roughly the same torque values at t/o power and give them serial numbers in sequence. Our G1 had engine snrs 13857 and 13858, and the take-off figures were almost identical. Rolls did the same for the Fairchild F-27F, the one designed from the git-go for corporate operators. Ours had snrs 16116 and 16117. When we began to switch engines back and forth between the G1 and F-27 no one could believe the engines were putting out rated power because the torque values were so different.

[J31]

I flew with a company a century ago where the owner had the waste-gates on the Navajos all dialled back (39"? Are they supposed to be 43? Memory is getting bad.) Eventually one engine on one of the Ho's kakked and there wasn't enough power on the good side to stay airborne and he ditched it off Port Hardy. Luckily, minor injuries as the junk settled on a reef and didn't sink. Company went to the wall about six months later so nobody had to take those risks anyway as it did dick for the bottom line. We don't fly 'em like that anymore, do we?

Yes the engine should get the min power settings for the aircraft installation as per the manual. If it does not than it should be snagged and the problem rectified. But let’s get something strait…check those Navajo manuals again! In the Navajo engine you should never get redline (43”) unless you are at about 17000 ft and 30 C. The charts will tell you that about 39” is rated power depending on the temperature and altitude!

Now the Continental engine in the Cessna twins is a different story and you should see redline for rated power regardless of the altitude and temperature.

[oldtimer]

The RR Dart was the very first propeller turbine engine ever certified for civilian use (1948). Since then, we have learned better ways to monitor power output. The RR Dart had Min Guaranteed Dry Power which simply measured torque meter oil pressure which varied with each engine. The red line was minimum, not maximum power. Then you had W/M Check Pressure which was the minimum with W/M power restoration. The problem of different readings was taken care of with a paint brush applied red line on the face of the instrument or a stickon label maker. The EGT compensator in the TPE 331's compensate for differences simply so any engine can be installed in any airframe without any special procedures and they will all read the same. If a RR Dart was not run and declared prior to removal, it had to be sent to England for dynomometer runs to redeclare the engine.
J31 brought up a very good point. Check the AFM to see if what you are seeing is in fact correct. You may be surprised at what you find out.