About aircraft engines...

Date 01-14-2009 22:42 Edited 01-14-2009 22:44

What kind of propeller engine sounds like a jet turbine as it passes over head?
I was just outside succumbing to my bad habit (I'm working on quitting but it's rough...) when a rather odd plane flew over head. As it approached it sounded like the usual C-130's that inhabit the air around here, but as it passed over head and flew on it sounded like a jet engine. The outline looked to be around the size and shape of a C-130 but I've never heard one sound like that before. The light pattern was different from the usual ones too, for whatever that's worth...

Ill drive by the airbase tomorrow and see if I can spot the odd ball. One of my air craft reference books mentions that the newer version of the C-130 has a 6 bladed swept prop over the 4 bladed older versions, so that should be easy to spot.

Have a good night,
-Clif

By Tommyjoking (****)

Date 01-15-2009 01:52

Well I don't know the exact plane you saw (some of my former AF buddies might). But more then likely it was a turboprop equipped plane. All C130's use turboprop engines. A turboprop is a prop driven plane that uses a small jet/turbine engine to generate power vs. a piston engine. I know that sounds funny, why not just make it a jet but thats what they are. They can sound real funny flying because you will hear the sound change dramatically when throttle is applied because they are varying the pitch of the blades significantly. On the ramp and on start up you hear that jet whine but usually the prop noise gets far louder. Maybe they are trying out a different exhaust or something......

Tommy

By PlasmaHead2 (***)

Date 01-15-2009 22:26

It might have been in the exhaust then, because it had a very distinct jet roar to it. Sounded just like the little lear (sp?) jets that fly around here after it passed by which is something the normal c-130s dont do.

Mabye they were toying around with the sync on the engines? Ive heard about the AC-130s in vietnam and how they would de-sync the engines to make the plane sound like a dragon.

By FixaLinc (****)

Date 01-15-2009 06:00

Don't know what you heard but we may have some of the same flying into the base near here soon since they are changing it up. Already got MC-130W flying around but they don't sound like a jet.

http://www.af.mil/factsheets/factsheet.asp?fsID=4887

I'm waiting for the unmanned ones to come flying around they are suppose to get in too.

http://www.af.mil/factsheets/factsheet.asp?fsID=122

Some of these coming too but don't know what they are?

http://www.cannon.af.mil/shared/images/Intro-Photo.gif

By Ringo

Date 01-15-2009 13:11

It was probably an Osprey.The Marine Corps fly's them,they have Rolls-Royce AE2100 turbo fan engines with no by-pass.

By PlasmaHead2 (***)

Date 01-15-2009 22:32

As cool as it would be, I doubt it was an Osprey. :(
I have an Air National Guard base in my back yard so all that's around are the C-130's and on rare occasions a C-5A. I gather the c-130's around here are the arctic ones that fly to the north and south poles.
Its amazing how fast such a big plane can get into the air with those JATO rockets they strap on them. :)

By Ringo

Date 01-16-2009 12:31

You outta see them land on a carrier.

By FixaLinc (****)

Date 01-16-2009 20:04

Yeah Osprey just hear the different pop noise but it's different than a big helicopter. I know the sound of them now as we see them out flying on tests after they are built near here. I bet he heard the whine from those turbine engines in still cold air as I could hear new sounds from the MC-130Ws the other day when wind finally quit blowing and was so cold and still out. Those only been around here a few months.

By Kix

Date 02-03-2009 17:39

Probably a C-17. Did it kind of look like this http://www.military-aircraft.org.uk/transport-aircraft/boeing-c-17-globemaster-iii.htm

By PlasmaHead2 (***)

Date 02-03-2009 21:55

It was too dark to see the tail that night, however i did hear the same thing from a diffrent C-130 a few nights later. The second time it was at a diffrent angle and i could tell it was a c-130 but it still had that weird jet whine to it. The engines sounded weaker the second time so it must have something to do with the power level they are using. I never heard them sound like this until these grey planes started poping up, so it must be something with their engines that makes the noise diffrent (the planes im used to are painted silver with orange tails and wing tips).