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350 Power Graph Magic


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B3 and 407 have within 5 engine horsepower of oneanother, the poor old B2 you like to put down has 115 less horsepower than your mighty 407. The 407 should be able to beat it hands down.

 

A little comparison, the B2 has 90 more horsepower that the B and look how much better it performs, the B3 has approx 110 more horsepower than a B2(200 more than the B). The B3 is a performer, no question.

 

But would still love to fly the 407 for awhile, what little I did was very impressive.

 

sc

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Skull, I hate to argue with someone as knowledgeable and talented as you, but......

 

 

My research says...

 

B3 - 847 Hp Takeoff- 728 Hp MCP

407 - 813 HP -BUT Derated to 674 Takeoff - 630 Hp MCP (Transmission Limits)

B2 - 732 Hp - 625 MCP

 

The EC site doesn't give the transmission derating limits on the 2 or 3 ?

 

Where did you get the 5 HP spread from???

 

----------------------------------------------------

 

You'd like the 407, a couple of noteable jobs it's done for me.....

 

* 6 pass and gear, 1.0 fuel on board, SnowDome last year (11,550') (X 5 trips).

*1,400 Lbs + generator INTO the bowl on the Cathedral Glacier, 9500'

*1,800 lb Snow guns moved at Lk Louise, approx 8500'

* 2,000 lb Measured load to the top station KHMR ski hill +10C, 7,800 (with HOGE) August 2000. OK, the doors, seats, and basket were stripped off, 250 lb fuel (.2 remaining) even left my Wallet at home for that one :blink:

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MGB rating for the B2 is 655HP, 30HP higher than MCP.

 

When does the 407 start temping out (alt/temp) on those hot days?

 

By the way 407D - looks like quite the article in Vertical - haven't read it yet - you and your bird in it?

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"left my wallet at home" yep, that saved you more weight then the average line driver out there can imagin'.................I here carrying a stack of 100 bills around can get pretty heavy :up: :up:

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Nomex, I respond to your question (Re 407 Temp limited) with another question, when does a B2 become Ng limited at altitude and temp? :D We all get focused on Torque, who says that it has to be the defining limit, is it not acceptable to be Ng limited, or Temp limited?

I've seen a huge range of C47 engines out there. Some are great, others :stupid: :down: are not. In our 7 C-47's, we have about 4 "great's" a couple of average ones, and 2 dogs. I've been told that Standard (or Acro or ?) can do a much better job of building a good engine if they have all the components Vs ..just a turbine?

 

The question should be...does the aircraft perform to the manufacturers published data? They all do !

 

I haven't seen the article from Vertical yet, it was shot in the Canmore area, so I doubt that our covert little western-slope operation is featured :(

 

Re: the B2's MGB limits, so what you're saying is that the B2 and 407 are quite close in available power? The 407 with a few % edge.

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Back to the original question.....sorry!!!

 

Hey leaner...I'm not sure which model of Astar you are using, but I believe ( and I'm sure that I will be corrected if I speak in error) you need to reach an operating limit to get an accurate power check

 

"set engine speed to the maximum compatible with the mechanical limitation. (TQ or Ng). The bleed valve flag should not be visable in these conditions"..out of the flight manual

 

I know a couple of instances where not pulling to a limit has caused some moments of confusion.

 

Good luck :up:

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Morning 407D - No, I'm not starting an astar/bell war here, only trying to learn a bit more. Just a question as it was actually one of your drivers that lamented about the temping out of the 407 (maybe it was one of those dogs you referred to on the other side of the mountains) - and as I haven't flown one, was curious about when temps get high and combined with altitude if there is a significant performance deterioration from what is in the AFM charts. The HOGE for the 407 is according to Bell 9650ft at 4500 lbs and +20. From your post it appears as if you can attain that figure without T4 difficulty?

 

Yes, its well known the B2's NG limit out first, the AFM gives the best correlation for T4 & NG:

 

-if T4 indicator fails, follow NG limits

-if NG fails, Max T4 750c above 15c OAT and 730c below 15c OAT

(Max Cont is 795c, so you are looking at 45-65c less than Max Cont T4 to remain within NG limits)

 

And yes, I guess according to your 407 figures about 19hp different in MGB limits -it appears as if the 407 can pull MCP right up to the MGB rating whereas the B2's engine is permitted to pull only within 30HP of its MGB rating.

 

What is the usual Empty weight for the 407 by the way (without your wallet) - 2600-2700?

 

Sorry to have strayed off-topic here, and going back to the Power Graph, does anyone know if there is a computer program available to chart astar power checks, similar to the one, I believe Acro has for the Bell/Augusta products. Even with a power chart as simple as the Bells, a dull pencil can easily make the difference between a + or - engine.

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You're going to have to try and stay on topic Nomex, after all ..here at Caaviation we ALWAYS stay on topic :D:D:D

 

The 407 airframe tends to weigh in at approx 2900, plus another 80 lbs for the basket (always attached !) Similar to the 350 performance graphs, I have found the 407 graphs to be accurate, regardless of Ng limitations or MGT (TOT) limitations.

 

Our (ex) 350B2's also weighed in at around 2900 lbs, given one squirrel cheek, a sliding door, and dual LF seat provisions. I've heard of B2's down to 2700 but never have seen one?

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Gentlemen, I have what you've all been looking for!!! :up: :up: :up:

There's a computer engineer in Montreal who happens to be Denis Robitaille's brother (for those of you who don't know Denis, he was the long time D.O.M. with Abitibi Helicopters in La Sarre and is now working for Eurocopter in Fort Erie).

Anyway, this guy's name is Paul Andre Robitaille and he sold me a program that calculates power checks on JetRangers and AS350D. This program takes into acount snow baffles, particle seperators etc. Very slick!!!

All I had to do was send him a copy of whatever powercheck charts I wanted and he converted each chart into computer lingo and voila! Instant power check!!!

 

If any of you are familiar with the Standard Aero power check program, his are almost identical except they are more user friendly. ( apparently, he didn't have a copyright for his program and S.A. copied it, put their name on it and went to town)

 

Like I said, he can make the program work for any type of engine provided he has a current copy of the flight manual power check chart.

 

Anybody interested can P.M. me for his number.

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