414 Engine Beam Replacement

Ted

Ted

The pilot formerly known as Twin Engine Ted
Joined
Oct 9, 2007
Messages
30,006
Display Name
Display name:
iFlyNothing
When replacing the turbo on the left engine of the 414, we ended up finding additional problems. Unfortunately the problems ended up being needing an engine beam on the left engine.

On Twin Cessnas, the engines are supported by beams that connect to the wing spar. It's a rather complex structural arrangement with lots of rivets and it's a real pain to do. These beams are lightweight. One of the primary issues that exists is that the exhaust coming out of the turbo stays very close to the beam, and that heat exposure can cause corrosion. That is what happened in this case.

We are now at the point of the beam fully removed. This requires removing the propeller, engine, and drilling out a bunch of rivets. See the attached picture for what it looks like now.

IMG_0932.JPG
 
you would think application of some type of thermal wrap would solve that issue.
 
Sorry you're having to deal with this, but I appreciate you posting the picture - it's really interesting to see.
 
  • Like
Reactions: Ted
AggieMike88 said:
Sorta wondering if you're really trying to Johnny Cash your way to a new aircraft....
Click to expand...

Not trying to, but that's part of the deal with an old plane, and especially an old twin. This is a known trouble spot on these planes. When I looked over the plane I didn't see the corrosion in this spot, but it would've been very difficult to see without taking the turbo off.

It's worth noting that the big issues thus far were all known risk areas that were taken into account with purchase. I can honestly say that nothing so far has surprised me.

The props were old threaded hub McCauleys. We knew they might start leaking. They did.

The left turbo was stuck when we got it, so we didn't know how long it would last. We ended up getting about 100 hours out of it before it became time that we needed to replace it. Can't complain.

Engine beams are known problems on these airplanes. Although they looked good and no problems were noted at the time of prebuy, like I said this was hidden in an area you really couldn't see.

On the plus side, another risk factor was the nacelle areas where the nacelle fuel tanks are kept. I just saw a 340 with an incredible amount of corrosion in this area. We replaced the fuel bladders at initial annual and those areas looked brand new. With the interior out, all the metal looked great, etc. Those are really the most important things.

The price was appropriate for the risks taken, and was still the only way we were able to make it happen. The plane will get back in the sky.
 
kayoh190 said:
Sorry you're having to deal with this, but I appreciate you posting the picture - it's really interesting to see.
Click to expand...

Thanks. It's not the sort of thing that most of us see every day (including me) so I thought it would be of interest.

Plus, the realities that these things will have big dollar, big labor repairs. A lot of people go into this blind. To some extent you're playing a game of Russian Roulette with a Glock.
 
Ted,

Ive seen that form of corrosion before but it was in the very early stages and a heat shield solved the problem for a time. Thankfully, the plane was sold before I had to repair that. Sorry to hear you got stuck with the problem.
 
Norman said:
Ted,

Ive seen that form of corrosion before but it was in the very early stages and a heat shield solved the problem for a time. Thankfully, the plane was sold before I had to repair that. Sorry to hear you got stuck with the problem.
Click to expand...

That probably would have done the job if it was caught earlier.
 
bnt83 said:
Since you are already down for an extended time what other work you gonna do?
Click to expand...

I'm working on the LED light project for it, and we're probably going to do an annual as well. The exhaust for the left engine is going to at least be looked at but I expect replacement of certain items, perhaps repair in some cases.
 
Ted DuPuis said:
I'm working on the LED light project for it, and we're probably going to do an annual as well. The exhaust for the left engine is going to at least be looked at but I expect replacement of certain items, perhaps repair in some cases.
Click to expand...
So what do you think the total bill is gonna be for this "down time"? :D
 
Since there's apparently some interest in Twin Cessna with missing engines, here's mine in its current state. Both my beams are ok fortunately. Spent time cleaning things up while waiting and waiting and waiting for engine to come back. For reference the silver thing at the bottom is the intercooler which I reinstalled this afternoon. I have the turbo back and it will sit in the Vee and connects to the intercooler. Have to wait for the exhaust to come back before installing the turbo. More waiting. Fun stuff (insert sarcastic emoticon here)IMG_9274.JPG
 
This is such an old (and $$) problem; sorry to hear a long term solution has not been arrived at.
 
Having just finished a 2 day trip in a king air I can confirm that pressurization, flight levels etc... are worth it!


Sent from my iPhone using Tapatalk
 
Let'sgoflying! said:
This is such an old (and $$) problem; sorry to hear a long term solution has not been arrived at.
Click to expand...

Unfortunately the basic problem is hard to solve in any other way, both because of the FAA and basic structure. Because of how integrated this engine beam is in the overall structure of the aircraft, there's just not a whole lot you can do without major changes.

dell30rb said:
Having just finished a 2 day trip in a king air I can confirm that pressurization, flight levels etc... are worth it!
Click to expand...

I maintain that this was absolutely the right decision. Not because the dogs like pressurization and the flight levels (although they do - it's less bumpy which means fewer messes for me to clean up), but really the plane is a much more efficient hauler than the 310 for $/dog.

But, the bills are hard when they come.
 
Ted DuPuis said:
Already have my second job:

www.cloudninerescueflights.org

;)



A lot. :(
Click to expand...

If it wasn't for people like us pouring money into these old birds, especially piston twins, they would all be scrapped.

Step by step you'll get the airframe and systems lined out and she will be a good and trustworthy partner at altitude. :thumbsup:
 
GRG55 said:
If it wasn't for people like us pouring money into these old birds, especially piston twins, they would all be scrapped.

Step by step you'll get the airframe and systems lined out and she will be a good and trustworthy partner at altitude. :thumbsup:
Click to expand...

Going in, this was expected to be a 5-year project. We're basically one year in, and I think the progress is more or less expected for that timeframe. New props, new fuel and oil hoses, new fuel systems, new left turbo, will end up having the new engine beam and some new exhaust bits, plus some airframe upgrades and weight reduction. Really that's more or less what I had hoped for on the first year. I did want to put strakes on (an upgrade but one that improves efficiency) however that won't happen this year because of the engine beam.

Hopefully next year can be at least some avionics, but I think it's more realistic to expect an engine. Of course, at least some avionics will be required at some point prior to 2020 for ADS-B.
 
GRG55 said:
If it wasn't for people like us pouring money into these old birds, especially piston twins, they would all be scrapped.

Step by step you'll get the airframe and systems lined out and she will be a good and trustworthy partner at altitude. :thumbsup:
Click to expand...

They do make sense from a financial perspective when you compare them to a similar turboprop, so they'll probably be around awhile.
 
dell30rb said:
They do make sense from a financial perspective when you compare them to a similar turboprop, so they'll probably be around awhile.
Click to expand...

I believe the only cost difference between a 421 and a 425 is the cost of capital assuming part 91 and 40,000+ miles flown per year. A 414 is probably slightly less.
 
Thanks for sharing, gents. Sucks that these projects seem to do little more than drain a bank account, but as long as that is accepted going in, I suppose it's worth it in the end.

I've never seen under the cowling of a light twin, let alone the engine removed. @Lance F , is the "V" in your picture the beam @Ted DuPuis is referring to?

Good luck guys, and I'll be sticking to the light singles for quite a while longer!
 
dell30rb said:
They do make sense from a financial perspective when you compare them to a similar turboprop, so they'll probably be around awhile.
Click to expand...

As Eggman alluded, most people who go turboprop say their operating costs go down due to higher reliability and lower fuel cost. I know for us a turboprop would not be cheaper, but I do a lot of work on the plane and know how to operate piston aircraft as efficiently as possible from an ownership perspective. Frankly many, if not most, cabin class twin owners don't know or don't care so the equation shifts.

It also depends heavily on mission. For many the piston birds make sense where a turboprop would not. I agree - these planes will be around for a while to come. They still represent an unmatched value on purchase price and fill a need no other plane fills. Plus there are enough lower time examples to satisfy needs for years to come.
 
IMG_9276.JPG The Vee supports the turbo. Here's a wider view where you see the two parallel rails that come straight out. On each rail there are two doughnut looking things that support the engine mounts.
 
Ah, thanks for the explanation. Looks like a pretty involved repair. Just the price of doing business, I suppose!
 
Years ago, I rejected Richard Karl's C340 based on head damage to the sleds. Apparently the slip joints had not been well maintained and they were cooked. Very expensive repair.

But, you will prevail!
 
AWACSEng said:
Ah, thanks for the explanation. Looks like a pretty involved repair. Just the price of doing business, I suppose!
Click to expand...

bbchien said:
Years ago, I rejected Richard Karl's C340 based on head damage to the sleds. Apparently the slip joints had not been well maintained and they were cooked. Very expensive repair.

But, you will prevail!
Click to expand...

Unfortunately these planes have gotten to the point where if they haven't had beams done, they'll need them done soon. This was a bit unexpected since the beams otherwise looked perfect and the damage was very isolated. In this case it was just due to cooking from the turbo's exhaust, which was in good shape but may not have been at some point. I believe it was the left side that also had suffered some cooking of the insulation between the firewall and the nacelle baggage tank. So the other side may not have. However, I was hoping to avoid this expense.

As the #1 Twin Cessna guru says "We are in a continual state of restoration" [regarding these planes]
 
Ted DuPuis said:
As the #1 Twin Cessna guru says "We are in a continual state of restoration" [regarding these planes]
Click to expand...

That's true of every airplane!

Got any pictures of the damaged beam? That might be of educational value to viewers as well.
 
mondtster said:
That's true of every airplane!

Got any pictures of the damaged beam? That might be of educational value to viewers as well.
Click to expand...

Here's a close-up of the damaged area. It looks worse in person.

IMG_0799.JPG
 
Thanks for posting that Ted! That's pretty bad, and no question it needs replacing.
 
mondtster said:
Thanks for posting that Ted! That's pretty bad, and no question it needs replacing.
Click to expand...

Yeah it was pretty obvious once we uncovered it.
 
You know, it sucks to find something like that - and I agree, that one is not even close to being questionable - but I believe (and I know you agree) that the only thing worse than finding something wrong with the airplane, is NOT finding it!
 
I remember doing that job on a 340 many years ago. Not too bad a job as long as it is only the top plate that needs replacing, just lots of labour and cursing!

Cost of owning a 1970's twin Cessna in 2017.
 
bbchien said:
Years ago, I rejected Richard Karl's C340 based on head damage to the sleds. Apparently the slip joints had not been well maintained and they were cooked. Very expensive repair.

But, you will prevail!
Click to expand...


Dr Chien!

Do you still fly your Seneca?

i haven't seen you post here in a while!

Those inter-coolers look like horrible designs!

Without having run any calculations, they seem to be:
* Air mal distribution issues
* Undersized/Under-surfaced

i bet the outlet temperature is very high on them...ugh.
 
Tx_Flyboy said:
Those inter-coolers look like horrible designs!

Without having run any calculations, they seem to be:
* Air mal distribution issues
* Undersized/Under-surfaced

i bet the outlet temperature is very high on them...ugh.
Click to expand...

I assume that you're referring to the intercoolers on the Seneca, but the 340/414 don't have a great design, either.

That said, the compromise makes sense to me having spent more time flying them for the 414. On the 340/414 if you get "better" intercoolers (American Aviation, RAM VI, or RAM VII) they have scoops on the bottom which improve intercooler flow, but also increase drag. That helps you in climb rate, but hurts you in cruise efficiency. If you want max speed cruise, then sure, they're great. But if you want efficiency, they hurt you. They also add weight and reduce your useful load.

I had originally wanted AA intercoolers on the 414, and I may decide at some point to go for them, but at this point I have decided not to. Yes, it takes a bit longer to get to FL 190 with the stock intercoolers, but for the 3+ hour legs that I normally fly, the extra time in climb is inconsequential and ultimately you have equal or faster block times with the higher cruise speed at altitude. They also hurt you more at lower altitudes when you're flying low to stay below headwinds (which is one of the nicest features of a pressurized piston twin - the large range of altitudes you can use) since you're carrying around the drag but the intercoolers aren't doing anything to help performance at all.

When I compare fuel burns and speeds with people who have some form of improved intercoolers, the efficiency ends up being noticeably better with the stock setup. Cessna really did a decent job designing it.
 
Ted,

I'm referring to the Cessna inter-coolers...they are horrible designs.

just looking at it, i could improve the design without external modifications to the aircraft...
 
Tx_Flyboy said:
Ted,

I'm referring to the Cessna inter-coolers...they are horrible designs.

just looking at it, i could improve the design without external modifications to the aircraft...
Click to expand...

I'd agree, so could I. My point was that the compromise Cessna made compared to the other commercially available options is actually pretty decent.
 
You must log in or register to reply here.
Back
Top