5 bladed props on a King Air 90
- Thread starter JDP
- Start date
Not sure. I saw one in a hangar up at TOL one night when a student had a tire go flat and we were waiting to be "rescued". Looked pretty cool, but I didn't get a lot of specifics on it. I'll see what I can find.
-mini
...I can't believe I found it.
http://www.nationalflight.com/services/airframe_services/beechcraft_king_air_services/1.htm
It is TPE331-10s with 5 blade props. Looks like a 7000 hour TBO and aft strakes with the engines derated to 715shp. Neat conversion, but certainly not cheap.
-mini
http://www.nationalflight.com/services/airframe_services/beechcraft_king_air_services/1.htm
It is TPE331-10s with 5 blade props. Looks like a 7000 hour TBO and aft strakes with the engines derated to 715shp. Neat conversion, but certainly not cheap.
-mini
juxtapilot
Snowflake
What's the benefit of having 5 blades vs. 4 blades?
I know the B100 has Garretts. Flew one once with the -10 conversion. Absolute rocket in the climb. Other than that, it was a typical B100...it sucked. I think the A100s have the PT6s...
Noise.
-mini
meritflyer
Well-Known Member
Wow I got contracted to fly one for a day trip last week and they said it was a 5 bladed 90. Like most of you I had seen this before on a couple 100s w/ Garrett engines. I couldn't take the trip, because I'm current/schooled in 200s but didn't get the differences school for the 90 even with 100hrs in type. I've never flown a garrett engine so I would have shown up going, huh??? we could have a small problem.
Luckily dodged a bullet there
Luckily dodged a bullet there
higney85
Property of Scheduling
Its called a "lonestar" conversion and they use walters with 5-blade props. Flat rated to the same shp as the stock BE90 but holds full rated to FL250. Something along those lines.... I worked at the FBO where they did the conversions so the mechanics had good specs and also complaints about the setup.
I agree the 90 vs. 200 diff. is a joke after about 100hrs in a 90GT and 250 in B200 the only main differences are the fuel pump and triple bus fuel system. Now when your talking Garretts to P&W I'm lost; the only thing I know about a garrett besides being loud is you have to remove the pin locks after startup and on shut down and you don't have any lag time when making power changes.
Boris Badenov
Fortis Leader
From the other side, I've only flown garrets, and not on a kingair, but my understanding is that aside from all the fixed/free differences, Garrets' power falls off more rapidly with altitude, so you'll see them rocket off the ground but wind up cruising in the mid-teens instead of the mid-twenties. This is subject to correction, just what I've heard. I know it's a rare night I'm over 20k.
LOGS
Well-Known Member
Have time in both (PT6A-42 and TPE-331)
Short TO or overweight - garrett, gotta love CAWI
Short LD - Pratt, props high is a huge brake
Starting in hot wx/high altitude - pratt, or just the garretts I flew where crap, idk was a crappy cargo company
passenger comfort - pratts, so much quieter
Garretts were easier to operate, less gauges to look at. Also just remember reverse before you taxi to take it off the locks and reverse which shutting down to put them back on. Hated having to spin them though after shutting down
Pratts, pretty much worry free starts, torque bleeds off pretty quick, fun to be able to feather them in flight, hated the lag
=Jason-
Short TO or overweight - garrett, gotta love CAWI
Short LD - Pratt, props high is a huge brake
Starting in hot wx/high altitude - pratt, or just the garretts I flew where crap, idk was a crappy cargo company
passenger comfort - pratts, so much quieter
Garretts were easier to operate, less gauges to look at. Also just remember reverse before you taxi to take it off the locks and reverse which shutting down to put them back on. Hated having to spin them though after shutting down
Pratts, pretty much worry free starts, torque bleeds off pretty quick, fun to be able to feather them in flight, hated the lag
=Jason-
KLB
Well-Known Member
Comparing the 1900(pratts) to the Metro(Garretts):
The metro is faster at low altitudes and far more fuel efficient. We're talking 150lbs - 200lbs an hour more fuel efficient!
It would take a lot of fuel for the Hondo to keep up with the metro under 200.
Around FL250. I don't know. It would be tough for me to keep the metro up that high.
One of the 1900 hundred drivers and lurkers took off out of BED 20 minutes before me one day. I had to deviate up and down and around for icing and still passed him half way through the flight....overtaking him by 30kts! Plus I was at a higher altitude with more headwind!
The metro is faster at low altitudes and far more fuel efficient. We're talking 150lbs - 200lbs an hour more fuel efficient!
It would take a lot of fuel for the Hondo to keep up with the metro under 200.
Around FL250. I don't know. It would be tough for me to keep the metro up that high.
One of the 1900 hundred drivers and lurkers took off out of BED 20 minutes before me one day. I had to deviate up and down and around for icing and still passed him half way through the flight....overtaking him by 30kts! Plus I was at a higher altitude with more headwind!
Tazjet
New Member
Well same reason they kept putting more blades on the Spitfire during WW2. Started life with two blades, then three and four going to five.
The clue is that the Spitfire's engines kept getting more powerful and the only way to translate horsepower to thrust within the same prop diameter was to add more blades.
The Jetstream J.41 had five bladed Carbon Fibre props. It made the aircraft quieter at take off, but gave it an awful low frequency clatter on the ramp. Incidentally I understand BAe no longer support the J.41 props so who provides the five bladed props for this conversion ?
