Juice is correct.

From an engineering standpoint, "power," = Force x Velocity. The traditional method to rate this in the US is Horsepower, which is 550 ft-lbs/second.

It's been a while since I've flown a turboprop, and I don't know the particulars of your engine, but here's a hypothetical example:

Torque: 1800 ft-lbs
RPM: 2400
"Average" Prop radius (To calculate average "speed" of the blade): 4 ft

Math:

1800 ft-lbs x 2400 rpm x 4 ft / 60 sec per minute (to convert RPM to RPS); then /550 to change ft-lbs/sec to horsepower

Answer: 523 hp.

How the engine develops that torque or rpm is irrelevant. Doesn't matter if the ITT split is 100 degrees: power is determined by ft-lbs/sec.

A way to prove it: if your turn coordinator is sensitive enough, the ball will move towards the higher-powered engine if the guy is matching ITT. ("Step on the good engine;" just like in engine-out practice)

 

I have never heard of matching ITT and to me it is silly. The airplane will not fly straight if one side is producing less torque.

 

Ask him if jet pilots sync ITTs or N1s. Then ask him if when he got his multi, he matched CHTs or MF then props. Then tell him he is wrong and everybody is making fun of him.

 

Thanks for all the replies guys! I flew BE-1900's before this and EMB-120's and we always matched torque as to not exceed ITT limitations. His reasoning was so that fuel flow would be the same and prevent an imbalance and therefore the need to crossfeed.

Me: "then we are flying sideways".

Him: "just trim it out".

Me: "we could pull the power out all the way on one engine and center the ball, but we would still be flying sideways".

Him: "we are not flying sideways that much".

Me: "Okay if that is the way you want it done then that is the way I'll do it"

He was obviously the captain.

 

haha good point.

 

In the Convair 640 (RR Dart) we matched engine RPM and ITT. First we would set and match engine RPM to 14,200 and then use fuel trimmers (toggle switches) to set the ITTs to 770. This method maintained a set RPM but reduced power output and temps. This is a pretty ancient airplane and the other TPs I've flown do not do things this way. The other one I've flown had P&Ws on it and we matched Torque.

 

[QUOTE=Flex81;628023]

Him: "we are not flying sideways that much".
[QUOTE]

Me: You are not a bonehead that much.

 

we match tq too.

Sounds like you found a weirdo, if he's concerned about uneven fuel flow on turboprop length flights is he monitoring where the fat people sit too?

 

I see guys do this all the time! Matching ITT is not smart.

Look at this scenario: (R=Right, L=Left engine)

………… L ……….. R
ITT…. 640 …… 640
TQ…… 70 ….... 75

What’s wrong with this:
a. It increases yaw, one side is pulling harder than the other.
b. It increases drag, as you have to trim that yaw out in order to stay coordinated.
c. It decreases your a/c's total performance
d. It Increases your fuel consumption.
e. You’re more than likely operating the R engine much hotter than the L seeing that 1 bad thermocoupler can usually decrease your temperature reading by 15 degrees. Remember these things can't last forever; after all they are located in the heart of the engine and are exposed to its hottest temperatures.

So which side is right? I’m betting on the L side being correct. So I’d limit my L side to the recommended temperature and match the R side torque.

In the EMB we’re temperature limited to 800 T6 (ITT) and we get a Master Caution T6 (ITT) warning at 816. We climb limit ourselves to 720 unless we need the extra power (Wx, Terrain, etc). Let’s say that your CA wants to get home quick and is running the example below:

…………. L ……….. R
ITT…. 790 …… 790
TQ…… 82 ….... 86

There is a really good possibility he’s frying his R engine and doesn’t even know. He probably has 1 or 2 bad thermocouplers and his R engine is showing 15-30 degrees cooler than it actually is (790+30=820).

On the E120 each bad thermocoupler accounts for about 15 degrees of temperature change, the question is what do yours account for?

Bottom line, match the torques to the most restrictive ITT and you'll always be safe.

 

That's too funny!

Flex, tell him to kindly step out of the drivers seat, clap both hands so you know he isn't touching anything because you just took his turboprop card.