Aircraft overhead?

[Ed W]

I've heard multi-engine piston aircraft several times this morning, but I haven't managed to spot them. Is there some event going on in the area?

[dbacksfan 2.0]

Have you heard someone ringing a bell and this guy running around?

[Red Arrow]

I've heard multi-engine piston aircraft several times this morning, but I haven't managed to spot them. Is there some event going on in the area?

I am not aware of anything in particular.  Did they sound like round engines?

[dbacksfan 2.0]

I found this from TW. Sounds like it's the last one.

http://www.tulsaworld.com/business/aerospace/a-thing-of-the-past-oklahoma-air-shows-trying-to/article_be7bad85-0d90-5d6a-9a36-0bcdc050ff31.html

[Hoss]

I found this from TW. Sounds like it's the last one.

http://www.tulsaworld.com/business/aerospace/a-thing-of-the-past-oklahoma-air-shows-trying-to/article_be7bad85-0d90-5d6a-9a36-0bcdc050ff31.html

Been to a few airshows myself.  My goal before I shuffle off this mortal coil, however, is to attend, just one time, the shindig that happens every year in Oshkosh, WI.  A friend and I ALMOST did it one year, but the FBO renting the plane out wouldn't let him keep it overnight, and that was the only way we were going to be able to go in a plane.

[Ed W]

I am not aware of anything in particular.  Did they sound like round engines?

Dunno the difference between the sound of radial piston engines and in-line ones. Multi-engine props, though, have an almost subsonic rise and fall in volume, I assume because props cannot be perfectly synchronized.

[Conan71]

Dunno the difference between the sound of radial piston engines and in-line ones. Multi-engine props, though, have an almost subsonic rise and fall in volume, I assume because props cannot be perfectly synchronized.

Big difference in sound from a radial vs. boxer style piston engine.  Wish I could describe it, but it's very distinct.

[dbacksfan 2.0]

Big difference in sound from a radial vs. boxer style piston engine.  Wish I could describe it, but it's very distinct.

To me, a radial has a deeper roar to it almost coarse sounding, the V12 Merlins have a smooth deep sound, and the boxers have a higher sounding whine to them.

Think big block V8 with a radical cam, a V12 Jag, and a Porsche 911.

[Conan71]

To me, a radial has a deeper roar to it almost coarse sounding, the V12 Merlins have a smooth deep sound, and the boxers have a higher sounding whine to them.

Exactly.

[Red Arrow]

Dunno the difference between the sound of radial piston engines and in-line ones. Multi-engine props, though, have an almost subsonic rise and fall in volume, I assume because props cannot be perfectly synchronized.

The beat of out of rpm sync props is a kind of throbing sound.  It's a beat frequency.  Get the engines/props at the same rpm and the beat goes away.  

Find almost any WWII movie and listen to the bombers with round looking engine cowls.  A lot of fighters had round engines too. The radials are typically large displacement and slower revving compared to inline or opposed engines.  Cruise rpm may be less than 2000 rpm.

Keep in mind that most opposed engines like in a Cessna 172 red line at 2700 rpm with cruise rpm maybe 2000 to 2400.  A few go to a little over 3000.  Some of the new light sport airplanes use high revving (5000?) rpm engines with a reduction drive for the propellor.  They are very different sounding too because of the high rpm.  They kind of sound like a big angry sewing machine.  

Come over to RVS on almost any nice Saturday and watch the warbird guys. There are lot of AT-6s and some T-28s, a few Stearmans and a few others. There is one P51 that lives at RVS if you want to hear that too.  I don't know if they have any schedule but since I am frequently there, I get to see them playing.

Looks like the Merlin was a bit higher revving too at 3000 rpm for rated power:
Performance
Power output: * 1,290 hp (962 kW) at 3,000 rpm at take-off.
1,565 hp (1,167 kW) at 3,000 rpm at 12,250 ft (3,740 m, MS gear)[nb 17]
1,580 hp (1,178 kW) at 3,000 rpm at 23,500 ft (7,200 m, FS gear)
Specific power: 0.96 hp/cu in (43.6 kW/L)
Compression ratio: 6:1
Fuel consumption: Minimum 39 Imp gal/h (177 L/h), maximum 88 Imp gal/h (400 L/h)[nb 18]
Power-to-weight ratio: 0.96 hp/lb (1.58 kW/kg) at maximum power.

http://en.wikipedia.org/wiki/Rolls-Royce_Merlin

Looking at some of the higher horsepower radials, like in the DC-3, the rpm could be similar to today's opposed engines.  They still sound different.  Maybe it's the way the exhaust is collected.

[Ed W]

RVS?

Ed W

[Red Arrow]

RVS?

Ed W

The airport next to Jenks.  There is an observation area on 91st just east of Elwood.  The airport is actually in Tulsa.

[Hoss]

To me, a radial has a deeper roar to it almost coarse sounding, the V12 Merlins have a smooth deep sound, and the boxers have a higher sounding whine to them.

Think big block V8 with a radical cam, a V12 Jag, and a Porsche 911.

To me, it sounds like a VW Beetle on steroids.

[sgrizzle]

Been to a few airshows myself.  My goal before I shuffle off this mortal coil, however, is to attend, just one time, the shindig that happens every year in Oshkosh, WI.  A friend and I ALMOST did it one year, but the FBO renting the plane out wouldn't let him keep it overnight, and that was the only way we were going to be able to go in a plane.

I went in 2000. It was amazing.

I drove and stayed in Green Bay. The drive from here to Green Bay and back isn't bad.

[Vision 2025]

My goal before I shuffle off this mortal coil, however, is to attend, just one time, the shindig that happens every year in Oshkosh, WI.  A friend and I ALMOST did it one year, but the FBO renting the plane out wouldn't let him keep it overnight, and that was the only way we were going to be able to go in a plane.

I've been 6 times, you need check that one off the list...