That's all true, but there is actually a way to have a right-side locker tank on the 340 even with the air conditioning pump in the nacelle:



The wing locker can be converted to a tank, and it holds about the same quantity as the nacelle tank on the other side. When we installed that tank, we had the other side converted to the O&N system (automatically shuts off, no need to monitor it, and the light works backward of the factory system). Having had it both ways, each for years, the O&N approach is IMHO better and safer. And having a locker tank on both sides eliminates the usual need to crossfeed at some point during the flight.

I loved the 340--flew it 17 years--but I wouldn't be all that comfortable with somebody flying it a few times a year like we're discussing. It's a fact that the plane can bite you badly--and has bitten plenty of people--when something goes wrong if you're not really current in it. It's a complex plane in many ways, unforgiving of mistakes, and like other planes of the era, it lacks some important pilot protections built into more modern designs.

Ken

All,

Thanks so much for all the feedback and advice. I received lots of tips and documentation which is helping greatly with the training. I flew the C340 on Saturday after a couple hours of ground instruction. Larry at T&G is great and a wealth of knowledge. With 40,000 flight hours, you pick up quite a bit!

I loved flying the airplane. It's rock solid, very steady and stable and a joy to fly. I felt like I needed to give very little input to get it to do what I wanted. Most of the work was involved in finding the best combination of airspeed, FF and power settings to maintain CHTs on the climb. CHTs seem to be the limiting factor and requires a higher airspeed (roughly 140 KIAS) to keep the engines happy. At that airspeed we still climbed at about 800 fpm with two on board and full tanks.

The Cessna autopilot, although old, was surprisingly stable and worked very well. The landings are an area I definitely need to work on yet as the sight picture is quite different compared to everything else I've flown. You're up in the air MUCH higher in the cockpit which gives a different view on touchdown. Like any other type, I'm sure with a few more landings I'll get it down.

Some questions came into my head afterwards that I'm sure someone here will know immediately:

- What is the 2nd smaller exhaust pipe coming out of each engine compartment? There's a large one, which I assume is the main exhaust and there's a 2nd, much smaller one. Both of them have carbon on the inside walls.
- What are the tubes which extend out of the bottom side of the leading edge wing roots? They are about 1.5" in diameter and appear to have a butterfly valve in them.
- We didn't spend a great deal of time on pressurization yet, which we are going to cover at our next sessions. However, what would happen in the C340 if the cabin was still pressurized upon landing? Is there a squat switch which would dump the cabin pressure? Would the turbos no longer be able to hold cabin pressure and would the remaining pressure bleed off during taxi?

Also, I'm not entirely straight on the high altitude endorsement rules. Are you required to have the high altitude endorsement to be PIC to operate any airplane with a service ceiling above 25K ft? Am I reading the rule correctly?

More to come as I complete my next training flights this week...

Ports at the wing root are vents after dump valves with controls near the cowl flaps down low.
Small exhaust pipes are auto-waste gate exhaust pipes for turbos.

Wastegate exhaust is the hot one under the engine.

At the wing root are the pressurization dump valves. if you divert bleed air to not come inside to create pressure, it dumps out there. On my plane those controls are directly under the yoke, on the panel. there's a left and right.

pressure is dumped when the squat switch closes- probably not the best technique though.

Don - first of all, congratulations. You will be spoiled for sure. Post more pictures when you can. Regarding your questions:

Username Protected wrote:
Also, I'm not entirely straight on the high altitude endorsement rules. Are you required to have the high altitude endorsement to be PIC to operate any airplane with a service ceiling above 25K ft? Am I reading the rule correctly?

You need a high altitude endorsement (and training) from a qualified instructor. You don't want to be figuring out what to do or looking for checklists if you lose pressurization in the flight levels.

Thanks Allan, Gary and Alex for the clarifications.

Alex - the RH engine was happy as could be at 130 KIAS (It was recently overhauled) but the LH engine wasn't. The owner mentioned that they've noted low compressions on the LH engine recently and they are going to replace a couple of cylinders on that side in the next week or so. Perhaps this is responsible for the higher CHTs on that side?

BTW, I was using your method of using high boost pumps (I read that in your SOP manual beforehand!) in order to deliver more fuel and still had to use 140 KIAS to keep CHTs at or below 410 on the LH side.

Understood about the squat switch and pressurization. I wasn't asking as a means of operation. I just wanted to understand how the system functioned.

I fly again tomorrow. I'll write more and post more pics after tomorrow's flight...

So I completed my transition training earlier this week in the C340. We did an actual trip to Chicago for our last instruction flight. It was nice to use it on an actual trip, especially this day (Wed) as there was some potential weather that day and I got some actual lessons using the weather radar, which was quite helpful. The wx ended up being a non factor, thankfully.

For the trip back, we had to complete the high altitude endorsement, which requires a flight to 25K ft and simulated rapid decompression and emergency descent. I practiced the drill as though it was real, including doning the O2 mask prior to descent. It was quite a ride. The C340 has lots of green arc, allowing rapid descent rates with plenty of airspeed to work with.

I really like flying the airplane. It's rock solid very smooth. During the trip, I took the headsets off in the pilot's seat and then also went in the back of the cabin with headsets off to sample the noise levels inside. The pilot / co-pilots seats require headsets IMO and is probably a little louder when compared to the Seneca. However, the back of the cabin is much quieter and I think you could ditch the headsets when sitting in the back.

The one aspect of flying the C340 that I found not to be intuitive is the site picture and airspeed when in the pattern and especially base & final. You maintain roughly 130 kts abeam, downwind and initial final, slowing to about 100-110 only on short final. The site picture feels like you're pointing the nose at the ground and is definitely different from what I'm used to in the Seneca. More than one C340 driver has gotten too slow and too nose up in the pattern and ended with bad results - see here (http://www.ntsb.gov/_layouts/ntsb.aviat ... 061&akey=1). So, I made it a point to absolutely trim for 130 kts when in the pattern. I was greasing the landings every time after I planted this in my brain.

For those not all that familiar with C340's, this model is equipped with (1) nacelle tank (20 gal) and has a total fuel capacity of 183 gallons. There are (2) wing lockers (see pics below). The RH wing locker has a 120 lbs capacity and the LH wing locker has a 40lbs capacity (since that's the side with the nacelle fuel tank). The nose baggage space is very roomy with a 350lbs weight capacity. The internal baggage space is located behind the 3rd row of seats and is rather small. Overall baggage capacity is quite good with (4) places to put bags.

There are some squawks on this bird that are being addressed now (tweaks to press system, couple of jugs being replaced, etc) and repairs should be complete in a couple of weeks. I'm really looking forward to flying her some more!

Pics or it didn't happen, I know...

Don how well does the 2 vent air conditioning system work in that 340? Thanks for sharing your experience.

Don:
The 340 is a cool aircraft. I’ve always liked it. It’s nice to read about a guy enjoying the various phases of stepping up to a new class of aircraft. Keep after it hombre!

I agree about the nose-down sight picture. But like all things, it just requires getting used to it.
I love ours- You should buy one.

Steve, the a/c works very well. The lousy part of it is that it cannot be used on the ground, which is when you need it the most. My understanding is that the Keith a/c is electric and can be run on the ground for pre-cooling. If I were buying a C340, I'd be looking for one with the Keith system.

I may in the future Gary. However, for the moment, I'm quite satisfied with the stable I have access to now, especially since my financial exposure is greatly limited.

Our plane had the the Keith system. You can run it with a GPU to precool and it will freeze you out. Much better than the factory system. Only downside is that you cannot have it on during takeoff. The limitation was due to the total load on the electrical system was upward to 80amps when it was turned on so if you lost an engine, it would hit the limits of the remaining alternator quickly. However, on VFR 100 degree days that item might have been missed on the checklist.

Personally I think the 340 is the best one of the Cessna twins to fly ..training shouldn't be a huge issue...useful load quite limited.. At gross, climbs to 25 k easily, no need to step climb..flies like a sports car ....you might not go back to Seneca...go for it and have fun!

Our plane had the the Keith system. You can run it with a GPU to precool and it will freeze you out. Much better than the factory system. Only downside is that you cannot have it on during takeoff. The limitation was due to the total load on the electrical system was upward to 80amps when it was turned on so if you lost an engine, it would hit the limits of the remaining alternator quickly. However, on VFR 100 degree days that item might have been missed on the checklist.