Turbo Commander

Here’s a little video from my first trip in Steve’s 980. I didn’t record much as I was busy picking my tongue up off the floor, so it’s a little truncated. But perhaps the most impressive thing is his golfcart/tug in the end with the gangster rims?

AdamFrisch wrote:

But perhaps the most impressive thing is his golfcart/tug in the end with the gangster rims?

That little machine appears to be the coolest thing on the airfield coupled with his skill in getting the aeroplane in the hanger, first time, without taking the tips off. Seriously, nice set up, and his 980 looks immaculate. What airfield is that?

That’s Camarillo, KCMA. Very active field as it catches all the Malibu rich kids, plus the more blue collar Camarillo, Ventura and Simi Valley people. So a good mix between G550’s and Piper Cubs. Doesn’t hurt that they have one of the best airside diners/restaurants in all of LA. It’s also the TBM delivery field for the west coast, as the distributor is based there, so always at least 5-10 TBM’s milling about.

I thought I’d just, for posterity, add the full range of Turbo Commander models (although I’m sure you’re all sick of hearing about them from me).

680T
Speed: 217kts
Ceiling: FL250
Press. diff: 4.2psi
HP: 575hp
Engine: TPE331-43A
MTOW: 8950lbs
Range: 956nm

680V
Speed: 217kts
Ceiling: FL250
Press. diff: 4.2psi
HP: 575hp
Engine: TPE331-43A
MTOW: 9400lbs
Range: 956nm
Biggest difference between this and earlier 680T model is that it has the big picture window at back of cabin and no eyebrow windows.

680W
Speed: 217kts
Ceiling: FL250
Press. diff: 4.2psi
HP: 575hp
Engine: TPE331-43BL
MTOW: 9400lbs
Range: 956nm
Just a minor engine improvement no real other differences. Landing lights are now retractable into wing and not on landing gear.

681
Speed: 242kts
Ceiling: FL250
Press. diff: 4.2psi
HP: 575hp
Engine: TPE331-43BL
MTOW: 9400lbs
Range: 1296nm
Identical to the 680W, except for the first time now cabin has bleed air pressurization, not hydraulic pressurization. Most of these got upgraded with the -151K engine, also called the “Century upgrade” that gave it more hp and better performance at altitude. Eyebrow windows are back for good.

690
Speed: 284kts
Ceiling: FL250
Press. diff: 4.2psi
HP: 776hp
Engine: TPE331-5-251K aka Dash 5’s
MTOW: 9850lbs
Range: 1555nm
Similar to 681, but now with 30in extended wing box, bigger props, new engine and larger rudder.

690A
Speed: 284kts
Ceiling: FL280
Press. diff: 5.2psi
HP: 776hp
Engine: TPE331-5-251K aka Dash 5’s
MTOW: 9850lbs
Range: 1471nm
Similar to 690, but now with heated windshield, full de-ice, higher press diff and certified to FL310 (before RSVM rules).

690B
Speed: 284kts
Ceiling: FL280
Press. diff: 5.2psi
HP: 776hp
Engine: TPE331-5-251K aka Dash 5’s
MTOW: 10325lbs
Range: 1471nm
identical to 690, but now with slightly increased MTOW.

690C, aka Jetprop 840
Speed: 287kts
Ceiling: FL280
Press. diff: 5.2psi
HP: 776hp
Engine: TPE331-5-254K aka Dash 5’s
MTOW: 10325lbs
Range: 2040nm
Completely new extended wing (another 30in at tips), upgraded engines, new Dowty Rotol props, wet wing fuel, increased fuel capacity to 425 or 484gal (LR). No dorsal fillet.

690D aka Jetprop 900
Speed: 286kts
Ceiling: FL280 (FL320 with a mod)
Press. diff: 6.7psi
HP: 776hp
Engine: TPE331-5-254K aka Dash 5’s
MTOW: 10700lbs
Range: 1966nm
Similar to 840, but higher diff press and higher MTOW. Certified to FL320, so can with a modification be RSVMed to go there, but probably not worth it. Has smaller cabin windows due to higher press diff.

695 aka Jetprop 980
Speed: 286kts
Ceiling: FL280
Press. diff: 5.2psi
HP: 940hp
Engine: TPE331-10-501K aka Dash 10’s
MTOW: 10325lbs
Range: 2041nm
Identical to 840, but Dash 10 engines from factory. Probably the fastest model they made (at FL280) as it has the higher powered engines and is still light like the 840. No dorsal fillet.

695A aka Jetprop 1000
Speed: 302kts
Ceiling: FL350
Press. diff: 6.7psi
HP: 940hp
Engine: TPE331-10-501K aka Dash 10’s
MTOW: 11200lbs
Range: 2080nm
Identical to 900, but now RSVMed to FL350 and has higher MTOW. At max ceiling prob the fastest overall at max altitude.

Which one to get? Depends a little bit on your mission. If you want to go far, above weather, with high press differential in cabin and don’t mind paying for it, the 1000 is the one to get. It can go 2080nm direct. If you want to climb and fly really fast and go very far slightly lower down, the 980 is the one to get. If you’re on a budget and don’t need extreme range, the 690A/B are good choices, especially with the Dash 5 engines. If you’re an unwashed cheapskate, get one of the older pre-690 models.

Adam how does the hydraulic pressurisation system work? Is it using the same hydraulic pumps as the gear and flaps? Presumably unlike the PA-23 you have dual pumps. The pumps must be quite robust.

AdamFrisch wrote:

680W
Speed: 217kts
HP: 575hp

681
Speed: 242kts
HP: 575hp

690
Speed: 284kts
HP: 575hp

How can you get first 35kts then another 42kts out of the same airframe and same engine hp? all at FL250 and the last one with 450lbs higher MTOW on top.

Arne am guessing that the earlier turbines were quite temperature limited as you climbed into thinner air, the later versions presumably were able to produce a lot more power at optimum cruise flight levels. I believe the later model had increased wing span which may have allowed less induced drag (lower AofA) and higher MAUM?

Sorry, that’s a typo. The 690 should have 776hp. Can’t change it now as it’s locked (one of my least favorite features on this forum). BTW, 776hp is continuous, during takeoff they can produce 840hp and are sometimes referred to as 840hp engines.

@Arne, don’t know why that is but I assume it has to do with better thermodynamic rating of the 43BL engine.

@RobertL18C, the hydraulic pressurization was a leftover from the early pressurized pistons. It basically bolted a huge 3000psi pump to the engine, piped the fluid into the cabin and then had a hydraulic motor on the pressure bulkhead run a compressor that pressurized the cabin. It was part of the general hydraulic system, but ran a fluid called Skydrol. Horrible stuff that can strip paint. Not a very good system, but that’s how they did it then. Early King Airs etc also had similar systems (if I recall correctly).

Interestingly, turbine engines were seen as just an alternative to pistons, not as a performance booster like we tend to expect today. You can see that in the early models – they have just marginally better performance than the piston equivalents. And for years to come, they sold piston and turbine version of same airframe side by side.

AdamFrisch wrote:

but ran a fluid called Skydrol.

I have never come across any other hydraulic fluid than Skydrol in all aircraft I have flown so far. It may be nasty to paint, but it is flame resistant and has some other properties which make it hard to replace. Avoid stepping into puddles of Skydrol on the floor though… a colleague once accidentally got his foot into one and after half a minute of walking, the sole just fell of his shoe.