Dear Lancair Drivers, I've never been a part of the LML or the Lancair community at all, I guess I'm kind of an outsider in that regard, so this will be my first real contract with everyone on the list. I hope it's as friendly of a group as it seams to be as I read back on
the history. I don't know proper forum posting or internet chat procedures, so I hope I don't do or say something tabu.
Some great questions and comments have come up on this discussion. I'll do my best to add some additional info on my engine failure. Lynn Farnsworth had a couple good questions I thought I could address as well as some other questions I've been asked.
1. Why "big bang" instead of a "poof" like Lynn's plane at Reno? This one is simple. My aluminum turbo pipe is bent at a 90 right after the turbo clamp. That 90 is 2 inches away from my engine mount. When the hose blew off, it hit the engine mount... hard!!! It actually dented the aluminum pipe. To me it felt like
someone hit the plane with a sledge hammer, the vibration transferred all the way through the airframe.
2. Why did it fail when Lynn's plane didn't fail or foul plugs? This is a multi part answer. First, there is big difference between going from boost to 26 inches MP like Lynn did, and going from boost to 14 inch MP like I did. It comes down to fuel-to-air parts-per-million. If you're fuel-to-air ratio is outside of the combustion parameters you will go from "bang" in the cylinders to only "burn". I recently did some experiments at altitude to see if I could duplicate the results of my emergency. I went to 20,000 feet leveled off and set mixture and power to high cruse power, 29in 21gph. I then pulled the turbos off (manual waist-gates), and the engine dropped to about 13inch MP. It lost a
TON of power but it did NOT quit running. EGT's where all still hot and engine was reasonably smooth. Leaning engine helped gain a little power but not much. Certainly not an emergency, it would just scare you good if you weren't expecting it, some descent would be required, and you would probably fly to the nearest airport to fix things. I then tried it a little different. I pushed power up to climb settings, 38inch MP, full rich 44gph. I pulled the turbos off again and dead engine. All EGT's around 200 and dropping fast. It was interesting to me that the EGT's where colder then my CHT's. I instantly pulled mixture to get engine running again and it was shocking how long it took to fire. Almost like when you over prime you're engine before starting it and have to pull mixture to cutoff and crank it for a while before it fires. However, when you do that on the ground you have LOTS of air in those
cylinders, unlike doing it up high. Even though the RPMs were higher then a starter could ever do, it still took so much time to fire that I started to wonder if it would fire again at all. It eventually did, and ran smooth, just little power. When my engine quit during the emergency I did not instantly pull mixture, there was at least 30 seconds before I was trying to get the engine running again. I had to get the situation under control first. Several things happened all at once when the engine quit. The autopilot was set to climb at 180KIAS so when the big fan stopped pulling and started acting like a 4 bladed air-brake, the plane pitched hard forward and left me floating up against my seatbelt. There is nothing like watching your cell phone slowly floating up toward the canopy as you quickly round out a climb into a dive you weren't planning on. The plane was also trimmed with lots of rudder for a high power
climb, so now the plane was yawing hard to the side leaving me with only one hand to fly as the other was against the canopy pushing me upright in my seat. By the time I declared my emergency, trimmed out the plane, evaluated surrounding airport weather, looked for alternate airports to the east, and made some tough decisions, the engine was as flooded and fouled as a plane can get. Lots of "burn" in the cylinders and no "bang"! It's like when someone taxi's at a high altitude airport with the mixture full and the plugs foul up on that short trip to the runway, and that's WITH "bang" in the cylinders. My situation was like that only minus the bang that keeps plugs clean, and then multiply the fuel flow by 19 and reduce the air in the cylinders by half.
3. What might be different between the Continental and Lycoming in this
situation? Well one big thing might be the electric fuel pumps. On my Cirrus (Turbo Contintinal 550) and on my Continental powered Legacy (Also turbo), I have a "High Boost/Prime" and "Low Boost" settings on the pump. High to prime and low for the climb. On the Lycoming you have one pump setting and it is "High/Prime" and you leave it on for the climb. So when my failure happened, I was Power Lever Full, Mixture Full, Boost/Prime pump ON and very little air in the cylinders. Would a Continental quit at altitude? I don't know; I would only guess not, unless you had the fuel pump on high/prime but that is not the normal engine management procedures so I doubt anyone would find themselves in that situation. My other legacy has automatic waist gates so I can't take that one to altitude and pull the turbos out to test that theory. I also don't know if there is any difference between how the
servos meter fuel. It may be that the Continental will just push the extra fuel back to the wing, the Lycoming can't do that, there is no fuel return to the wing.
4. Why didn't you pull the mixture immediately to keep engine from flooding and fouling? Two reasons. One, I was alway told when you have an engine failure you first AVIATE - best-glide KIAS, trim and configure... NAVIGATE - Pick a field and turn toward it... then INVESTIGATE and COMMUNICATE. Also recognize I had no reason to think that engine was ever coming back to life. Imagine yourself in the same spot not knowing what you know now. Loud bang heard and FELT through the plane, all EGT'S and OIL PRESSURE instantly go into the red and set off alarms. Unless this has happened before, your first assumption probably will not be to pull the
mixture to within a quarter inch of full off to get the engine to run. You just might think, like I did, that something just went through the case. It wasn't until later that I got a chance to work on getting the engine to run. It was only then that I realized the oil was only red because it went from 60PSI to bellow 30PSI (red alarm is at 30PSI and below). When I saw I had 26PSI on my oil, I thought "well that's a good sign, what else might be the problem." My next step was to pull mixture until the engine started to run. Only 3 cylinders would fire. As I continued pulling the mixture in hopes the others cylinders would fire, I eventually got to the mixture cut off, and no surprise, the 3 hot cylinders shut off too. So I pushed it in and set it to the smoothest possible setting, about 1,300 EGT on the three cylinders.
5. Why as you got lower didn't you advance the power beyond 14inch MP? Well as the power increased in only three cylinders the vibration was frightening. I made one attempt to push the power up and it started "kicking" I don't really know why the "kick", my only guess is that one or more of the dead cylinders where somehow trying to fire as the piston was on the upstroke. I knew I had 700FPM required to hit my target and I was descending at around 600-650FPM. So if I could keep the engine from blowing itself apart I would make the field.
6. How is the turbo system set up? Standard twin turbo setup other then manual waist-gates (they are coming off, don't like 'em) The boost lines "Y" together before the servo, the exhaust pipes are separate, 3 cylinders to each turbo,
two waist-gates.
I'm interested to learn more about the new and improved hoses and clamps Charlie talked about. I have had the same hoses and clamps on my other Legacy and after 450 hours now I've never had a failure, I fly usually between 16,000 and 25,000 feet between 25 and 30 inch MP and I have never had one blow off, but like most I have heard of it happening to other pilots on several occasions. My newer Legacy, N913MP, now has about 200 hours with no failure but the one, and in this case the clamp simply wasn't tightened, I put the hose and clamp back on the turbo without having to loosen it . All that being said, if there is something
better, I want it on my planes yesterday. I must admit, I have never seen anyone use a T-bar clamp on the exhaust side of the turbo like Charlie mentioned earlier on this discussion email, seems like everyone uses the standard V-band clamps on the exhaust side. If there is something better then the T-bar clamps, then Charlie is right about getting the word out; the engine builder put these hoses and clamps on and I understand Andy Chioveta did the engine install on this plane before I purchased the project. If it was the wrong setup you would think one of those two would have been aware of the problem and changed them out. Has anyone tried the new "Constant Tension Turbo Clamps"? I'm told the Road Track race guys push those to 100inch MP equivalent for entire races without any troubles. Charlie mentioned the new hoses are red. I looked
at my Cirrus and the boost hoses on the induction are black. So... if anyone has a definitive "best-practices" I'm all ears and eager to upgrade.
Charlie, I wish you the best of luck selling your IVP, it is a beautiful plane!!!!!!! It's a tough/sad time to sell. I sold my last Cirrus when my new Cirrus came in and I took HUGE hit on it! I kinda wonder if I would have been better off to hold on to it and see if the market would come back a bit first. Seems like your plane is really under priced for what it is. The other challenge I had with mine was I had put just over 800 hours on it in one year and all the other 08's had around 100-200 hours. I guess lower depreciation with hours is another nice thing about Experimental aircraft, most people feel better about a "proven" experimental then they do about
a low time one. Seems like I lost nothing when I sold my RV6, I had 1,200 hours on it and the buyer LOVED that fact, and said that it made him feel good about the plane.
Anyways. Take care and safe flying to all.
Tailwinds,
Mark Patey