Aero Commander 500, 560

[Tom Goodrick]

The Aero Commanders were designed in the 1950's by Ted Smith to have good general usage and good performance. They are also known as pilots' planes. enjoyed more by pilots for their flying qualities than passengers for their not-so-quiet cabins.

Milton Shupe and his team have done a very fine job of developing the designs for the Flight Simulator. Several of us on this Forum have flown these designs in FS. I have had the 560 for a couple of years. Its twin 295 hp engines with geared props give it plenty of power to crry a full load at about 190 knots. The quickest of the Aero Commanders is the turbocharged 680 that gets about 210 knots using high altitudes. It was sometimes pressurized by installing a pump in the cargo area.

I recently heard about the Aero Commander 500 model for FS. I confused it with an "AC500s" model I had obtained a few years ago that is a model of the 1978 Rockwell Shrike variant with a poiinted nose and a forward door for the pilot. But I knew there was a 500 model that was considered under-powered. It was the first of Smith's designs to fly. I found it Wednesday on avsim.com and downloaded it. From habit I took the version without the VC. I may go back and get the bigger file since it took very little time to download it.

Today I flew it. It needed one simple change to be right on the specs. I flew it with my own Aero Commander panel which showed 120% power on takeoff. (I had set the proper 250hp power gauge before takeoff.) Changing the power scalar from 1.0 to 0.8 took care of that extra 20% power. with just twin 250 hp engines it does fly okay but demands a little care during takeoff and climb with a full load. But it does cruise at 167 KTAS at the optimum altitudes (from 5000 ft to 8500ft). Landings are very easy. It has effective flaps. I found clean stall was 65 KIAS and stall with full flaps was at about 52 KIAS.

It's a very nice model of an aircraft that has a very good role in aviation. It is an economical twin that can carry 6 people with baggage at a fairly good speed for just about 900 nm.

[Ed Burke]

I hate to nit pick Tom but he AC680 series had supercharged engines. The F series had supercharged, fuel-injected Lycoming IGSO-540's with a max MP of 48" for take off. An old favourite of mine was the 680FL in which I spent many hundreds of hours as navigator/camera op and got to fly the old girl often.

[Tom Goodrick]

Sorry. I guess we had this discussion before. I thought turbocharged was same as supercharged except for the marketing input.

[dirtydog1006]

While I am building time in the def 172 (which seems to be paying off: Great advice, guys!), I cheat once in a while with Milton's AC560. I like it a lot, but the panel drives me nuts. I finally got the radios the way I want them, but there's a lot of 'customizing' yet to do. I would rather spend the time flying. Can anyone recommend some substitute panel?

Thanks, as always

[louross]

Turbocharger and supercharger, although many times used interchangeably, are actually 2 different things. Same idea with throttles an power levers.

I think I have a panel, and an interesting plane, let me check it out.
lr.

[Tom Goodrick]

Dirtydog, if I had your email address, I'd send you a photo of the panel I use in the Commanders. Then if you wanted it, I'd send you the files. It works fine for modern GPS navigation (it has no VOR or ADF).

[louross]

dirtydog,
here are 2 photos of what I've used- are these the ones your using?

PAX:


Cargo:


I haven't made any panel mods, so I'm curious as to what mods you're making. If you have any problems with using the panels, let me know and maybe I can give you some pointers. Never flew this in real life, so don'r know how accurate the FDEs are.
lr.

[Tom Goodrick]

I have a good set of FD's for the 560 and for the 500. I prefer the 500 because I am bothered by looking at the high rpms for the geared engines of the 560. The speed difference is only a few knots. I also have FD's for the Shrike which does not have geared engines and has the forward pilot's door. That's on my old computer. I have not found a recent version to download. The payload is better on the 500 and 560.

Edit: Unfortunately, my FD for the AC 500 won't start. The FD for the AC560 does start and I can't see the difference in the files.

Here are some cruise figures for the AC500, using the max continuous level of 2400 rpm and full throttle:

At 6500 ft, 177 kt with 75.31%, 22.6 in (less than full throt)
At 7500 ft, 177 kt with 73.81%, (full throt)
At 8500 ft, 175 kt with 70.55%, 21.32 in (full throt)

This is with a full load of fuel and 2x200 crew + 4x170 pax and 150 lb bags.

[louross]

Well, I'd like the FDE for the 500!
lr.

[Allan_Lowson]

For essentially the same end effect, superchargers operate by a direct engine drive pressurising the air flow into the engine while turbochargers use the exhaust gases to spin the pressurising fan.

The difference in end effect is that turbochargers have a lag in response at low engine revs, as only a low volume of exhaust gas is available and then they generate maximum pressure at high revs.

As superchargers have a mechanical drive they have essentially the same pressure output, so not so much lag.

Turbocharged cars are pretty common this side of the pond, mostly being diesels like my last Accord and current Passat. Car manufacturers should fit superchargers as that would better suit day-to-day driving, but turbochargers are simpler/cheaper and they have a marketing link to turbocharged rally cars/racers who spend far more time at high revs than road users. But why spoil a marketing hype?

For aircraft use, the main problem with turbocharged engines might be waiting for the pressure to rise when you want to go round on a missed approach.

But then it is essentially the same issue with jets and turboprops. A jet engine is basically a turbocharged recip with the pistons and valves removed. (Don't tell Frank Whittle I said that.)

[Tom Goodrick]

I don't think the extra power of turbocharged engines means much on takeoff or go-around since these are at relatively low altitude where plenty of power is available. The primary benefit is at high altitude where substantially more power becomes available with the turbocharger than with normal aspiration.

On this side of the pond we fear the extra maintenance costs of the turbo in a car engine. The main purpose of the turbo in a car is to make a line of cars beat the EPA restraints on mileage versus horsepower. But the fear is that it shortens engine life and is an extra thing prone to malfunction.