PDA

View Full Version : Skymaster Arctic Circle Ditching.


Paul462
12-09-08, 03:21 PM
Amigos,

A 337 apparently just ditched south of the Anctic circle when both engines stopped turning. Both occupants survived, according to the BBC article at the following address:

http://news.bbc.co.uk/1/hi/world/americas/7773046.stm

Does anybody know what happened to cause both engines to stop?

larry bowdish
12-09-08, 06:36 PM
purely speculation, and dependent on altitude, but Brian Von Herzon has said that if the temp is below -34, fuel does not flow. There is apparently a placard on Malibu Mirages limiting operations due to temp. That is because the Mirages don't have fuel heaters. Neither do Skymasters.

JeffAxel
12-09-08, 11:48 PM
Larry,
I am not sure about that, only because I flew my P210 at FL230 at -40 ( C of F, your choice!) for 3 hours and had no problems. The P210 has no fuel heating either. I have read of dissolved water in fuel crystalizing out at very cold temps and clogging fuel systems though. That is why Cessna suggested Prist or Isopropyl Alcohol be added to the fuel if operations in very cold temps were anticipated. There were a few paragraphs about this in the P210 POH, as well as a graph showing how much Prist or Isopropyl Alcohol to add. The other Cessna P twins have oil heated fuel spiders I think.

larry bowdish
12-10-08, 05:45 AM
As i said, it's speculation.
it's been so long since I heard Brian talk about that, my memory is hazy.
Maybe a brain cloud :D

hharney
12-10-08, 05:18 PM
This is really ironic because I sold a dozen or so SOAPA t-shirts from the 2008 fly in to Troels Hansen. The Skymaster was in Ohio having a major avionics upgrade. Troels had told me that he was going to be flying the aircraft back to Sweden. I assumed it was his Slymaster but appearently not. Nice guy, I am really glad to hear they are alive. They are really lucky. Too bad about the aircraft though.

http://www.theglobeandmail.com/servlet/story/RTGAM.20081209.wcrash09/BNStory/National/home

http://www.avweb.com/eletter/archives/bizav/1272-full.html#199361

That just made my heart stop when I read his name.

larry bowdish
12-11-08, 11:39 AM
The photo is just incredible

Maybe they will be in the states next year, and will come and talk about it.

Dave Underwood
12-11-08, 03:26 PM
They are two very lucky fellows. God was smiling on them that day for sure.

Daev

JeffAxel
12-11-08, 04:59 PM
I agree they were so fortunate!!! Yikes!! I can't imagine a worse place to have to land, except the freezing water with no ice. It is too bad we will never know what really stopped both engines. Good comments on a lot of sites about being prepared for this sort of situation though.

Diamond Service
12-12-08, 12:44 PM
I agree they were so fortunate!!! Yikes!! I can't imagine a worse place to have to land, except the freezing water with no ice. It is too bad we will never know what really stopped both engines. Good comments on a lot of sites about being prepared for this sort of situation though.

Hello all Skymaster freinds.
I am presently in Iqaluit. I only have minor injuries. I will write my story in this forum when I get home to Sweden. Thank you for all the kind words and thoughts. I sure leaned about survival from this.
Regard Troels Hansen (former Skymaster owner)

larry bowdish
12-12-08, 12:56 PM
we are all thankful you are alive.

Skymaster337B
12-13-08, 12:58 AM
From AOPA Online:



Arctic rescue saves ferry pilots
Skymaster makes forced landing on ice floe

By AOPA Publications staff

A Cessna 337 Skymaster on a transatlantic ferry flight made a forced landing on an ice floe near remote Baffin Island on Dec. 7, and the two pilots survived 18 hours in sub-zero temperatures by walking.

The twin-engine, centerline-thrust airplane reportedly lost power in both engines and went down on an ice floe. But the ice was less than a foot thick, and the plane broke through and sank, taking the pilots life raft and survival gear with it.

With no food, shelter, or fuel for a fire, pilots Oliver Edwards and Troels Hansen, who both live in Sweden, paced through the night as temperatures dropped to minus 20 C and into the next day before a shrimp trawler located them Monday. A Canadian military helicopter brought them to Iqaluit, a small town on the southern tip of Baffin Island, where they were reported in good condition.

They were very healthy, Bo Mortensen, captain of the Atlantic Enterprise, the trawler that located them, told the Canadian Globe and Mail newspaper. One of them was frostbitten on his feet. They were smiling and crying.

The pilots wore survival suits designed for water landings. They had taken off from Labrador for what they expected to be a two-to-three-hour leg on their overwater journey to Europe. When both engines failed, they made emergency radio calls, and a Canadian rescue center in Halifax coordinated the search. The Atlantic Enterprise was about 180 miles away from the place where the airplane touched down.

Both pilots escaped the sinking airplane through the side windows.

D

brianvon
12-13-08, 04:22 AM
Greetings fellow SkyMaster pilots:

Thinking about the double engine failure of the SkyMaster recently off Baffin Island, several thoughts come to mind.

The sort of things that commonly cause double engine failures include:

1. fuel contamination
2. fuel system icing
3. induction air icing
4. dual-engine vapor lock
5. fuel starvation

The distance from Wabush NL to Iqaluit is 652 nautical miles. According to Wunderground, surface winds were 10 knots out of the south or east, resulting in a tailwind or cross wind, not much to worry about. With 7-8 minutes to landing, they could have been at about 4500 feet when the engines stopped (the MEA for the region).

The weather at Wabush was light snow and -10 to -8 celcius. Assuming dry adiabatic lapse rate of 3C per 1000 feet, at 4000 feet they would have had temperatures of -22C, not low enough to gel the fuel. Minimum temperature at Iqaluit was -17C that day, or -29C at 4000 feet, probably still not quite enough to gel the fuel. Conditions were probably warmer than that, given the high level of moisture (enough for it to snow most of the afternoon). So gelling the fuel is improbable given the temperatures.

Cessna says to add 1% anhydrous isopropyl alcohol if the aircraft will spend much time at minus 30C or colder. Note that there is a lot of heat capacity in the fuel, so it takes a few hours to cold soak the fuel enough for it to gel.

The light snow for several hours before departure suggests the hypothesis that ice could have accumulated on the air induction system. I have never had a problem of this sort, even when flying for over an hour in ice accumulation regions (not recommended). Also it would seem improbable that the two engines would ice over at nearly the same time, especially given the assymetric configuration.

Fuel contamination would seem to be ruled out unless they had just started drawing fuel from alternate tanks, but even then you would imagine that all tanks were filled from the same source in Wabush, so the main tanks should have failed much earlier unless the contaminant was much more concentrated in the aux tanks than in the main tanks.

One other possibility is that of vapor lock. In the T337G modified that I fly, it is very common to have fuel interruption in one engine as we climb through 11,000 to 13,000 feet, especially at low fuel flows. The fuel seems to vaporize in the injector lines, even more so when the fuel flow is low as the fuel has more time in the line to vaporize due to the lower flow rate. Did the pilots turn on the low pressure fuel boost when the first engine lost power? Still, these heating effects tend to be assymetric on the front and rear engine, and would not typically result in both the front and rear engines quitting within minutes of each other after 3-4 hours of operation. The best timer of this sort are the fuel tanks themselves.

Pilots go to great lengths to match the fuel flows of front and rear engines. The fact that the two engines quit within minutes of each other provides a lot of useful information. Some SkyMasters have electromagnetic wiggle pumps for transferring fuel from aux to main tanks. I often have these freeze up on me in cold weather, especially if there is a bit of moisture in the fuel. Ice may accumulate in the pump itself (or water that freezes on takeoff). The net result is that it is common for these pumps to freeze within the first hour of operation (when you can't pump the fuel because the main tanks are too full). By the time the second hour rolls around, the wiggle pumps may be already frozen, resulting in dead fuel in the aux tanks.

Skymasters have so many tank configurations that it can be hard to determine how much fuel these main tanks had. However, based on where the engines quit, they were airborne for approximately 3 hours and 42 minutes. We should probably hear from the pilots themselves about their fuel management approach and what they observed.

Given that pilots tend to actively manage their fuel flows to keep them nearly equal, and given the short amount of time between the first and the second engine quitting, and given that fuel contamination, dual-engine vapor lock, fuel icing and induction icing seem improbable (and produce different symptoms), we should consider the possibility of fuel starvation more carefully. Such fuel starvation could of course be caused by the inability to transfer fuel from one tank to another. The pilots may be able to tell us in detail what fuel management they used, what tanks were available, and what the state of their fuel was on takeoff. From that information we might be able to learn more about the nature of the problems they encountered.

By the way, one thing I learned from reading about this experience was the essential need for good waterproof lighting around your neck (to signal the helicopter!). The best one I have found is a green laser flare from Greatland Laser. 30 mile range signaling to an aircraft at night! I am just blown away that you can actually see this pen laser from 30 miles away with the naked eye, but I believe it! Equipped has a good article:

http://www.equipped.org/rescuelaser.htm

https://www.greatlandlaser.com/index.php?productID=162

I haven't tried it yet and have no affiliation with the company.

Weather at Wabush NL(departure) the day of the ditching:

10:53 AM 14.0 F / -10.0 C 10.4 F / -12.0 C 86% 29.75 in / 1007.3 hPa 1.5 miles / 2.4 kilometers ESE 6.9 mph / 11.1 km/h / 3.1 m/s - N/A Snow Light Snow

11:00 AM 14.0 F / -10.0 C 10.4 F / -12.0 C 86% 29.86 in / 1011.1 hPa 1.4 miles / 2.2 kilometers ESE 6.9 mph / 11.1 km/h / 3.1 m/s - N/A Snow Light Snow

12:00 PM 15.8 F / -9.0 C 12.2 F / -11.0 C 86% 29.84 in / 1010.3 hPa 2.0 miles / 3.2 kilometers SE 8.1 mph / 13.0 km/h / 3.6 m/s - N/A Overcast
12:05 PM 15.8 F / -9.0 C 12.2 F / -11.0 C 86% 29.72 in / 1006.3 hPa 2.0 miles / 3.2 kilometers ESE 6.9 mph / 11.1 km/h / 3.1 m/s - N/A Snow Light Snow

1:00 PM 15.8 F / -9.0 C 12.2 F / -11.0 C 86% 29.81 in / 1009.4 hPa 1.2 miles / 2.0 kilometers ESE 9.2 mph / 14.8 km/h / 4.1 m/s - N/A Snow Light Snow

2:00 PM 15.8 F / -9.0 C 12.2 F / -11.0 C 86% 29.79 in / 1008.6 hPa 1.1 miles / 1.8 kilometers ESE 9.2 mph / 14.8 km/h / 4.1 m/s - N/A Snow Light Snow

3:00 PM 17.6 F / -8.0 C 14.0 F / -10.0 C 86% 29.77 in / 1008.0 hPa 2.1 miles / 3.4 kilometers ESE 10.4 mph / 16.7 km/h / 4.6 m/s - N/A Snow Light Snow

4:00 PM 17.6 F / -8.0 C 14.0 F / -10.0 C 86% 29.76 in / 1007.8 hPa 0.6 miles / 1.0 kilometers ESE 10.4 mph / 16.7 km/h / 4.6 m/s - N/A Snow Light Snow

4:19 PM 17.6 F / -8.0 C 14.0 F / -10.0 C 86% 29.65 in / 1003.9 hPa 3.0 miles / 4.8 kilometers ESE 10.4 mph / 16.7 km/h / 4.6 m/s - N/A Snow Light Snow

John Hoffman
12-13-08, 11:22 AM
Brian - thanks for the work. Interesting to me in that Im not used to flying in such cold weather and have wondered what could happen in bitter cold weather. Encounter low temps over Rocky mts occasionally but its usually bone dry and not up there all that long. Also interesting to read the AOPA post that they exited the side windows. Side window exit has been my plan for a long time cause its pretty clear that a bunch of people and stuff just arnt going out the one door very fast - glad to hear it works.

Ernie Martin
12-13-08, 12:21 PM
For those relatively new to this forum, Brian von Herzen has been a member for many years, has crossed the Atlantic in his Skymaster via the northern route many times, and we were fortunate to have him speak of his crossings at the 2004 Skymaster Meeting and Fly-in held in Oklahoma City. An annotated group picture of that meeting may be found below, which allows you to put faces to names.

Ernie

brianvon
12-13-08, 12:27 PM
John, I have actually encountered -32C in California of all places in the spring! It was just a cold day with a norther jet stream coming straight down from Alaska! I was only up there for 45 minutes so did not worry about cold-soaking the fuel, but 2-3 hours in that weather would be enough to increase my pucker factor and consider using isopropyl! So you could definitely encounter such cold winter temperatures in the central US at altitude.

Side window exits in unpressurized craft are a good idea. Sadly, in my P337G the only solution is to jam the clamshell door open before landing using the door handle as the jamming mechanism. Any racking of the doorframe after landing would otherwise jam the clamshell shut. While this would result in a lot more float time, the exits would be highly problematic.

Ironically, it may have been the side windows that caused the skymaster to sink so quickly. (although there was some mention of window breakage on this ditching). Most planes float at the level of their wings. for a low wing, this is no problem. For a high wing, it means that most if not all of the cockpit may be underwater. We should get the story from the pilots as to where the cockpit floats. Open the windows and the water will fill the cockpit in seconds. So we are left with a real tradeoff. Windows open, you can get out but you will only have seconds to do so. Windows closed, you will have minutes to ponder a watery death, but with 1 pound per square inch covering all 300 square inches of your window, you are unlikely to get that window open with anything less than a hydraulic press.

Given the importance of the life raft and the water bag, I am considering modifying my procedures to have the copilot hold the life raft in his lap before ditching, and have the waterbag in my lap before reaching the surface. Downside is that the life raft will hit the yoke and force a nose first second impact after first bounce. Upside is that the life raft will be with you when you egress, like it or not.

Green laser flare around my neck is the other modification to my procedures. There are just too many ways of not being found out there to not have one!

Cheers,

Brian

Diamond Service
12-13-08, 01:21 PM
Fellow aviators.
I am in a Hotel in Ottawa waiting for my flight to Europe. Flight of SE-MBT started in New Philadelphia on the 6 of December. We had been waiting several days for a waiver from TSA allowing us to start our flight.Just in time we got the waiver and we started a 3 hrs 20 min flight to KPYM. This was the first flight with new avionics so a lot of time was spend on trying all the new functions of the recently installed equipment. The flight went well with only a few snags on all the new electronics.

I will continue my story later because my internet time is running out.

Rgds Troels.

Diamond Service
12-16-08, 09:08 AM
I am now at home and that sure feels good.

On Saturday the 6 we flew from KPYM via KBGR to CYQB. Both these legs were uneventful and without problems. We parked the aircraft overnight in Quebec City with the fuselage/window cover on and the electrical engine heaters hooked up. The next morning it was snowing and I cleared the aircraft from snow when Oliver submitted the flightplans for our two leg flight to CYFB. The aircraft started instantly and all systems were operating. We flew for 2 hrs and 30 min at 11000 feet before landing in CYWK. Refueled 172 liters and checked the aircraft for next leg. We climbed to 11000 on this last flight of SE-MBT. The weather improved and we soon enjoyed the most beautyful sunset. About 3 hrs and 40 min into the flight we went from heaven to hell. We first noticed a decrease in oil temp. on the forward.Soon followed by low oil pressure. I moved the prop lever to test the response of the propeller system. While doing that the engine failed with a loud metallic scream and smoke entered the cockpit through the heating system. Mayday call transmitted on 121.5 and a KLM aircraft responded. Decend to single engine cruising altitude initiated. The rear engine oil temp and pressure decreased just like the forward and the engine failed with a loud bang. Back on 121.5 to tell the KLM that we were now gliding all engines out. Position report transmitted as well.
I will be back soon with the rest of the story.

Troels.

larry bowdish
12-16-08, 09:38 AM
WOW

We are all glad you are safe, but that had to be the scariest moment in life.
Whay year was/is SE-MBT??

Diamond Service
12-16-08, 10:13 AM
Hi Larry.
It was a 1966 model. I will be back with the rest of the story soon. I also feel that I have a good idea about what went wrong and I feel this forum is full of very experienced people to discuss my theory with.

Troels.

Ernie Martin
12-16-08, 11:53 AM
Any work done on both engines recently? Both engines overhauled at the same time, by the same shop?

Ernie

Diamond Service
12-16-08, 02:09 PM
Hello Ernie.
The forward engine was factory new in 2000 and the rear overhauled in 1996.
FWD 462 TSN
REAR 900 TSO

I had the props,governors and all mags overhauled at the same time the avionics was done.

Troels.

Diamond Service
12-16-08, 03:06 PM
It was some busy minutes during the glide towards the cold below. Survival suit completely prepared and life vest put on and ready. Oliver sitting with life raft and some other equipment in his lap. I attempted to restart engines but of course without success. I drained the batttery trying to start engines so instrument lights were very weak. At about 3000 feet we decided to put the plane on the water just beside the ice. It was fairly easy to see the edge of the ice in the moonlight. Close to the water I selected full flaps and we hit the water with apprx 70 MPH. The nose went under and big chunks of ice crushed both windshields and the left side window. I put my right hand on the glareshield to brace myself. The aircraft stopped very rapidly and the water was up to our chest. Within seconds the cabin was completely under water. Oliver had the door open prior to impact but was now struggling to get it open. I got out through the left side window.Once out I pulled the inflate handle on my life vest and I was on the surface instantly. The left wingtip was resting on the ice and I used the wing to push myself up onto the ice. I looked back and saw Oliver in the water trying to get up on the wing. I was extremely worryed that the ice would carry our weight because it was moving and flexing a lot. Oliver boarded the ice crawling on the left wing. We talked about if we suffered any injuries and realized that the raft and other equipment was still in the aircraft. I started to crawl on the wing but the aircraft nosed down and went under. I got back on the ice and watched my company logo on the tailfin disappear into the dark water.

Last part of story to follow.

Troels.

gwengler
12-16-08, 05:27 PM
Wow! You guys are amazing! The fact that both of you made it out of there alive and almost unhurt is a total success story! I've been flying my Skylane to Iqaluit four times in the last three years, on two occasions going to/coming from Europe. Another crossing is planned for next year. I will take every word you wrote into serious consideration, as far as survival goes. When my wife who was with me on all of the above flights, heard your interview on CBC Radio, she cried because she knew from first hand experience how it is to fly in the Arctic and what a feel of relief it is to reach dry ground after a long water crossing.
I used to own a Skymaster myself, so our thoughts are now to find out if you are able to share with us your ideas on what went wrong with the engines. I think we all understand that you must have some concerns to share some information that could be used by various agencies; however, we all want to be able to avoid what you went through.
All the best, go flying soon,
Gerd

Ernie Martin
12-17-08, 12:43 AM
Good post from Gmas, and the arguments for partial refueling with jet fuel sound persuasive. One point I want to make is that in a standard Skymaster, without after-market engine monitoring instruments, the EGT guage isn't very informative. If you look, you will notice that there is no scale; it says 25 deg/div, so you can use it lo lean in cruise, but it doesn't tell you actual EGT. And although you might remember where it typically is, a lower reading can easily be attributed to the lower outside temperature.

Ernie

Skymaster337B
12-17-08, 02:30 AM
I put diesel fuel in a regular cars once. It only ran for about 5 mins. So I wonder how the airplane was able to fly 3+ hours on Jet A?

Diamond Service
12-17-08, 04:55 AM
We refueled in CYQB saturday late afternoon. All four tanks were refueled at that point.I dont recall the quantity but close to 200 liters. On Sunday we flew to CYWK without using fuel from the AUX tanks. The flight was 2 hrs 30 minutes. The MAIN tanks were refueled in wabush with 174 liters. I was up on a latter and checked that the AUX tanks were full. This means that if they refueled the MAINS with jet fuel the mixture in the mains would be about 50/50. About 1 hour 30 minutes into our last flight I selected AUX tanks on both engines simultaneously and flew for 1 hour before selecting back to MAINS. I noticed a slightly lower EGT on this last leg than on the previous legs. All magnetos were overhauled during the time the aircraft was in the shop for avionic work. I never heard any misfiring and the mag checks were always good. Starting performance was also very good both hot and cold engine.

Troels

Paul462
12-17-08, 08:20 AM
The classic JetA mis-fueling scenario is: take-off, and then the engine(s) quit at about 200 feet AGL.

Is it possible to run 1.5 hours on one set of tanks, then 1 hour on another set of tanks, and then after all that time have a mis-fueling engine failure?

Diamond Service
12-17-08, 05:46 PM
Today the Canadian NTSB send me a copy of my fuel slip from Wabush. It stated that I uplifted 174 liters of 100LL.

I want to finish my story so here it comes.

Standing on the 10 times 5 meter big piece of ice we started our 18 hour struggle to survive.
Time is hard to tell when you dont have a clock but about 1-2 hours later the first aircraft appeared and we got our hopes up that we would be found very soon. We were not able to show ourself in any way since we did not get this equipment with us from the aircraft. Most unfortunately the small lights on our life vests did not work. Several other aircraft and helicopters searched for us during the night and they were very close about three times.
I blamed myself that I did not have any signalling equipment. I think they called of the search when the ceiling got too low. I dont know how to describe it but it is extremely cold and the wind is blowing the cold air right through your bones. We worked hard for a long time to fight the cold and finally the daylight came.Now they will come back and find us we told ourselves,but nothing happened. We saw the shoreline in the distance and decided to jump
from one peice of ice to the other in order to reach dry land. After doing this for about 1 hour a light flashed in the horizon. We stared in that direction for a long time wondering what that couldt have been.We continued our walk on the ice for some time but then the light appeared again,and a little closer. We realized that the light must come from a ship so we turned around on the ice and walked towards the ship waving our life vests over our heads.Suddenly the light was pointed directly at us and after a while we heard the signal horn from the ship. WE ARE BEING RESCUED. The feeling of relief is hard to describe.

I am trying to figure out what happened to my engines and I have a few ideas. I want to share my ideas with you folks in this forum but it is getting late now so I will be back tomorrow.

brianvon
12-17-08, 08:09 PM
By the way, I spoke this week with my sailing friend in New England who does a lot of work in freezing salt water, and he said that it is _very_ fortunate that the wing was lying on the ice. Without the wing on the ice, it could have been nearly impossible to get up on the ice from the water even in a survival suit. Congratulations to the pilot at managing to keep the wing on the ice through the ditching process!

Best regards,

Brian

skymstr02
12-17-08, 08:17 PM
Is it possible to run 1.5 hours on one set of tanks, then 1 hour on another set of tanks, and then after all that time have a mis-fueling engine failure?

No, it is not possible. Jet fuel weighs more than avgas and the jet will settle to the bottom or near the outlet pipe. Jet fuel and avgas will not mix.

This is not a misfueling case.

brianvon
12-17-08, 09:44 PM
Dear Troels:

Thank you for your description of the flight. I was wondering if you read the outside air temperature at 11,000 feet during the cruise portion of the flight. The absolute minimum I would calculate would be -10C at Wabush minus 3C per 1000 ft = -43C assuming dry adiabatic lapse rate. Given the moisture at the departure, the actual ambient temperature could have been higher, perhaps between -28C and -43C at 11,000 ft altitude.

Did you see any variations in fuel flow before failure?

Regards,

Brian

larry bowdish
12-17-08, 11:08 PM
Patricia Bell, of CBC News sent me a link to a story she did on this. It includes an audio of Troels speaking to Patricia.

Of note, there are comments by two different crews who spoke to them when they declared their Mayday.

http://www.cbc.ca/canada/north/story/2008/12/09/crash-survivor.html

The comments are located here, and linked to in the above story

http://www.cbc.ca/news/yourbeststuff/2008/12/your_stories_mayday_mayday_rep.html

Diamond Service
12-18-08, 12:08 PM
The indicated OAT at 11000 feet was -31 C. I did not see anu variation in fuel flow. The engine never misfired or vibrated up until the point of failure.

Troels.

Diamond Service
12-18-08, 01:00 PM
The way I see it we must have lost the engine oil. The decreasing oil temperature followed by loss of oil pressure means no more oil to me. I know that the breather lines from the outlet to the rear baffle was not insulated. I still have pictures showing that. Maybe the breather line was blocked due to the low outside temperature and the oil pumped out somewhere because of that. I was not aware that it is a good idea to insulate the breather line. I have previously owned two Aztecs and the breather line on a Lycoming are behind the baffle on the rear part of the engine. This is pure speculation but maybe some of you have some experience on the subject.

Troels.

larry bowdish
12-18-08, 04:03 PM
Advisory Circular AC 91-13C covers cold weather operation of aircraft.

Section 4, d. says the Oil Breather requires special consideration. Frozen breather lines can create numerous problems.

My Skymaster had baffles that attached inside the front engine cowling, to reduce the amount of air flowing over the engine, during cold weather operations. Unfortunately, I don't have access to the POH anymore, but I seem to think these were for operations below 20 degrees F.

The whole AC is interesting reading for those who operate in cold weather.

skymstr02
12-18-08, 08:39 PM
I've seen an aircraft that the breather line froze over, the crankcase pressure built up, and blew the crankshaft seal out, then the mess began.

billsheila
12-18-08, 09:44 PM
So is all that is required to have some insulation over the line to prevent this problem?

Skymaster337B
12-19-08, 02:15 AM
The oil breather line should have a knoch cut into it about an inch or two above the end to counter a frozen line. If the engines were recently overhauled perhaps the shop replaced that line but didn't read the maintenance manual about ensuring that knock was there. That knoch is why most Skymaster belly's are dirty. It's a necessary evil.

larry bowdish
12-19-08, 11:54 AM
What about the rear engine??
My memory is that the rear vapor line goes up and out the rear of the cowling, adjacent to the prop. Would that line also get frozen up??

Frank Benvin
12-19-08, 02:27 PM
What was the time lapse between engine failures???

hharney
12-19-08, 11:40 PM
The rear engine would generate enough heat to keep the rear breather from freezing

After inspecting the rear engine area with Larry, I retract the statement above. We think that the rear breather could freeze.

Diamond Service
12-20-08, 05:49 AM
The forward engine failed first. This engine was factory new in 2000 and had been running 470 hrs since then. 5 minutes later the rear failed. The rear engine was Mattituck overhauled in 1996 and had a little more than 800 hrs running time since the overhaul.The rear has breather outlet just behind the prop. I saw no oil on the windshield.

I know that Continental is now working with The Canadian NTSB on the subject.

Troels.

CO_Skymaster
12-20-08, 08:36 PM
I bought my 1966 Skymaster 2 year ago, and with all used machine there were some repair to be done. I notice that when the aircraft sat after flying, small pools of oil would appear under the front wheel well and also when dropping my gear doors, oil was in there also. I asked my A&P about it and his response was that the seals on Continental engines tended to leak and there wasn't much I could do about it except to keep adding oil. My engines have about 2200 hours each, so at the time I took him at his word. Besides, I had other repair to work on.

Last Christmas, I flew from Colorado to California to test the aircraft after my repair had been made. The trip out to California was uneventful as was the scenic flight for my friends around the San Francisco bay area. On the way back to Colorado, I landed in Nevada for refueling. Didn't notice anything out of the ordinary. It was already cold (about 25 degree F on the ground) when I took off again. Over the Utah/Colorado boarder I passed through a cold air mass I was expecting and my OAT drop from 20 deg F to below -15 deg F in about 20 minutes. It was so cold, my heater could keep me warm and I had to put on my winter coat, which was in reach (I couldn't reach the gloves which were way in the back). By the time I landed in Colorado Springs I found my rear spinner cone and broke off and there was oil all over my horizontal stabilizer.

Besides the spinner cone being a pain (I mention it somewhere in the messages), it turns out those seal used on my valve covers started leaking and my oil just passed out past the propeller and out the back. I lost 4 quarts of oil during that flight. If I continued the flight, I would have lost it all. After fixing the seals, I have had any pools of oil leaking anywhere.

I wonder if flying into very cold weather with degraded valve cover gaskets allows oil to leak out of the engine and it just flow along with the airflow out the bottom of the aircraft on the front engine and out past the propeller for the rear engine. There would be no visual confirmation. You won't see an oil pressure drop until your almost out of oil and you never see a temperature rise in the oil (because there is less of it to absorb heat) or Cylinder head temperature rise due to the extremely cold weather. When all the oil is gone, your engine seizes.

Just my opinion at this point. I've included a picture my friend took of my front nose wheel and you can see the oil around the chocks. It doesn't do this anymore.

Karl

John Hoffman
12-20-08, 10:52 PM
I have had the Skymaster 10 yrs now and engine leaks have mostly been the gaskets under the valve covers. At some point they were discovered to be poorly installed and old so I had them all replaced. Leakage has been nearly zero. The new ones did require some retightening a couple of times, probably due for a check agin. Have had some minor leaks of the gaskets you describe but not a problem.

Skymaster337B
12-21-08, 02:09 AM
If the valve covers required safetywire to lock the nuts down, then we wouldn't have this discussion. I've used RTV on these gaskets and find that helps alot.

Diamond Service
12-21-08, 05:44 AM
Hello Karl.
Thank you very much for sharing your expirience. All information like this help me to find answers and to heal my wounds. I am quite sure that my engines had the red silicone seals under the valve covers. I need to look in a computer in my maintenance shop for the pictures.

Rgds Troels.

ipasgas1
12-21-08, 10:48 PM
I, too, had an engine failure but in a single engine aircraft. It had a Rotax 912ULS engine. But, I have often wondered if the cold had something to do with the failure. The NTSB and Rotax said it was due to oil starvation due to a "collapse" of an oil hose. It was MLK day, 4 years ago, and happened to be the coldest day of the year, around 0 degrees F on the ground. I had no warning of the impending failure, it was sudden and finite. The extreme cold sounds like a very likely culprit. I now fly a skymaster for the added engine but I still, and moreso after this, will not fly in extreme cold.

Dave Underwood
12-23-08, 07:46 AM
A thought on being prepared.

When I used to fly in Northern Ontario I was always reminded to be prepared and to make sure I could survive with only what I had on me as I got out of the plane. The reasons were simple. The float plane could sink or the aircraft could go up in flames.

These days with portable transceivers, Personal Locator Beacons, cell phones and multitools with powerful LED lights it is much easier.

Perhaps we should all consider what we need to have on us in that very worst case.

Can I also wish everyone a Very Merry Christmas and a Great New Year with bright blue skies and more reasonable gas prices.

Warm regards - Dave

JeffAxel
12-27-08, 01:11 AM
just looking at stuff and came across Cessna Service Bulletin ME79-2 which may have a bearing on this accident. It addresses use of Prist or Isopropyl Alcohol as a fuel additive in very cold conditions.

atsiii
12-28-08, 11:54 PM
The pilot's observed decline in oil temps followed by loss of pressure, caught my attention; as has the resulting discussion of possible oil loss. I'll offer my two-cents worth: one for each engine.

I had an oil separator installed on the rear engine of my '69 T337. Twice during long (3+ hour), high altitude, winter-cold cross-country legs, I lost four quarts of oil from the rear engine. The oil was literally everywhere. I finally determined that the probable cause was the breather running from the separator to where it vents by the prop had frozen, pressurizing the case and forcing oil out every available seal, gasket and orifice. It seems like there is or should be an alternate vent to atmosphere, but perhaps it was covered or plugged. At any rate, because it happened twice, I removed the oil separator, insulated the breather line and never had the problem again. I can't swear, however, that I again flew in as cold of temps.

The only oil anomaly I've ever had with the front engine was the result of the oil fill cap not being reinstalled properly after adding oil. The cap came off in flight (retained by its chain), and the engine proceeded to dump three-plus quarts of oil out the breather tube, completely coating the belly of the a/c. This occurred during a high altitude three-plus hour cross-country leg, but it was not particularly cold.

Like everyone else, I was relieved to hear that all were safe.

Allen

billsheila
12-29-08, 08:20 AM
I was speaking to my mechanic about this failure, so these are really his two cents: he suggests it is oil flow problem due to congealing (at the cooler, presumably?). Seems to make some sense given the temp indication followed by the pressure indication (followed by the failures)

Dale Campbell
12-29-08, 10:24 AM
I to installed M-20 air/oil seperators on my 337H 6 years ago. This was due to a oil slick found on the belly and tail area. I also insulated the breather line from engine to M-20 including M-20 down the exit pipe on both engines. My rear engine always ran much hotter than the front engine, which is normal for 337. In summer I fly with cowl flap door partially open when tempature above 85 degree. In winter rear runs about 180-200 degree. The front engine runs 180-200 in summer but ran 160-170 in winter. I now install a plate above front engine oil cooler for winter to get the engine above 180 degree. Without the plate I was holding water in oil and could see droplets on dip stick. No problem now with plate installed. My bird is normally asperated so anything above 13,000 feet is out of the question and I live and fly in Pennsylvania and mostly fly 500 mile radius of Pa, so I do not experiance any super cold air.

sunnysky
01-07-09, 06:21 AM
BILLSHEILA is on the right lines I think.
Several years ago I was flying my 337G from France to the UK. It was a much much colder than ISA day. Seem to remember something like minus 20c at 12000feet. We had been in the cruise for over two hours when I noticed the rear engine oil temp gauge "going off the clock". The problem was confirmed by low oil pressure. I reduced power on the rear and started a descent. The intention was to divert to Cardiff in Wales. At about 7000feet the oil temp started to reduce together with an increase in pressure. Power was gradually increased and the engine ran normally and the flight continued to Leeds Bradford.
I reported the problem to the Chief Engineer at Knight Air ( who were very "au fait" with the 337 ) and we concluded that there is a thermo valve in the oil cooler which stops oil going thro' the cooler when cold. In this instance because ambient was minus 20 or so, the cooler had shut off, then causing the oil to overheat then the low pressue. If there is then congealed cold oil in the cooler, the valve will not open to let the hot oil through. Then overheating. The only reason oil started to flow thro' the cooler again was due the the rise in ambient temperature.
Hope all this makes sense.!! It's my input for what its worth !!
Sunnysky

Ernie Martin
01-07-09, 11:19 AM
The report, however, is that they had a decrease (not increase) in oil temperature, which differs from your experience. Might be the same issue if oil temp was measured at the cooler in their aircraft and in the engine in yours.

Ernie

sunnysky
01-07-09, 11:39 AM
Hmm. Must say I didn't understand the bit about decreasing oil temperature in their report. Usually when you have decreasing OIL PRESSURE (as they state) you have a high oil temp ?
Maybe some clarifacation on the oil temp situation would help.
Your point Ernie on on where the oil temp is sensed. Surely its the same in all 337s ? Apart from the turbo ones maybe ?

Ernie Martin
01-07-09, 03:34 PM
I assumed the same, that all 337s measure oil temp at the same location, BUT a different measuring point seems the only way that your experience and theirs has the same cause. Also, is it possible that electronic engine monitors put the probe at a different point than the stock gauges?

Ernie

Skymaster337B
01-10-09, 10:35 PM
I'm starting to like the oil cooler theory. My question is, what type of oil was used? Straight weight or multi-viscosity synthetic oil? Personally, I only use synthetic oil and it makes a big difference how fast the oil pressure rises on a very cold day.

I also find it rather odd that the operator and maintenance manuals dont establish a cold weather limitationthey both generally discuss colder weather starting procedures. There is an option for an oil dilution system, but that is for starting during cold weather and not while operating at altitude. The operator's manual says to watch engine temps during a cold weather descenti.e, dont chop the throttle. But the big paradox is I remember seeing optional cold weather plates the restrict airflow thru the front cowl and also out the rear cowlbut cant find any info about it in either the operator or maintenance manual. It makes me wonder if Cessna really didnt even want to mention cold weather flying for some reason.

sunnysky
01-11-09, 03:23 AM
Yes. I;ve heard about "winterisation" kits, but can't find out much about them.
Sunnysky

Diamond Service
01-11-09, 05:41 AM
The aircraft just had an annual done. The DAR can not issue an export C of A unless the annual is no more than 30 days old. The magnetos,prop governor and propeller were overhauled on both engines. The engines was serviced with Aeroshell 15W50.

During the cruise at 11000 feet the oil temperature was pretty much in the middle of the green arc. I was not concerned with the OAT being -30C since I have flown several pressurized twin Cessnas and Malibu 310 in colder conditions.

I did two test flights in Ohio. Some oil was noticed on the prop blades and I discussed it with the owner of the maintenance shop but we both considered it to be normal for a newly overhauled prop. We agreed that the seals in the props need some hours of operation and they will stop leaking. I did not notice any major oil leaks on the blades later on. I monitored the oil consumption on the engines very closely and they were not using much.

It feels to me like there was no oil left in the engines. The oil temperature decreased because there was no oil flowing past the sensor,but just enough to hold the pressure up a little while longer. There is a lot of ways to lose engine oil and I can only speculate. Why this happened to both engines within such a short period of time is also hard to answer.

I have more than 12000 hrs in the air. I have flown a lot of piston powered aircraft. I got my aircraft mechanic license in 1984. I am the owner of an aircraft maintenance shop that serves light aircraft. I search hard for some answers on what happened to my engines that night over the Hudson Strait. I am thankfull for all your comments but I also accept that I will probably never know for sure what happened. I want to buy another Skymaster but my family has suffered enough and for them the aircraft is a symbol of misfortune. I learned a lot from this accident. The equipment we had and the skills we had saved our life. My advise to pilots that fly over remote areas is to have the right equipment and use it. I also learned that what you have inside your suit is what you have left after a ditching. I know that the people that searched for me that night and the people that took care of me after I was saved is probably not in this forum but I want to thank them anyway. I am touched and lost for words on what they have done for me.

Troels.

hharney
01-11-09, 04:00 PM
In the POH of my 1968 Super Skymaster (lots of emphasis on the SUPER) Section VII on Optional Systems contains "Cold Weather Equipment" and says:

WINTERIZATION KIT.
"For continuous operation in temperatures consistently below 20 degrees F, the Cessna winterization kit, available from your Cessna Dealer, should be installed to improve engine operation. The kit consists of two baffles for the front engine, one baffle for the rear engine, and crankcase breather insulation for both engines. Once installed, the crankcase breather insulation is approved for permanent use in both cold and hot weather."

Attached is a photo of the front baffles but I have never seen the rear engine baffle. The rear engine baffle is attached to the lower outside ring below the prop on the exit end of the airflow. This statement is pretty standard in most all the Cessna piston Pilot handbooks except for the Turbo models. Maybe the Turbo models generate enough heat and do not require this?

tropical
01-11-09, 04:48 PM
My advise to pilots that fly over remote areas is to have the right equipment and use it. I also learned that what you have inside your suit is what you have left after a ditching. I know that the people that searched for me that night and the people that took care of me after I was saved is probably not in this forum but I want to thank them anyway. I am touched and lost for words on what they have done for me.

Troels.

I'm just curious about one thing, why did you choose that time of year to make the trip? It seems to me making the trip in the middle of summer would far outweigh making it in the winter.

Skymaster337B
01-12-09, 04:44 AM
hharney, thanks for the info. It seems like there should be a limitation of -20C posted in the operator's manual unless the winterization kit is installed. But now that I know the nomenclature it is figure 83A in the maintenance manual for 65-69' models. There is also a placard figure 1 for "remove winterization kit for temps above -20C." It seems to me like the placare should say "install winterization kit for operations below -20C". What's everyone else's thoughts? Perhaps a new AD is required!


================================================== ================
"In the POH of my 1968 Super Skymaster (lots of emphasis on the SUPER) Section VII on Optional Systems contains "Cold Weather Equipment" and says:

WINTERIZATION KIT.
"For continuous operation in temperatures consistently below 20 degrees F, the Cessna winterization kit, available from your Cessna Dealer, should be installed to improve engine operation. The kit consists of two baffles for the front engine, one baffle for the rear engine, and crankcase breather insulation for both engines. Once installed, the crankcase breather insulation is approved for permanent use in both cold and hot weather."

Attached is a photo of the front baffles but I have never seen the rear engine baffle. This statement is pretty standard in most all the Cessna piston Pilot handbooks except for the Turbo models. Maybe the Turbo models generate enough heat and do not require this?"

Skymaster337B
01-12-09, 05:00 AM
hharney, thanks for the info. It seems like there should be a limitation of -20C posted in the operator's manual unless the winterization kit is installed. But now that I know the nomenclature it is figure 83A in the maintenance manual for 65-69' models. There is also a placard figure 1 to "remove winterization kit for temps above -20C." It seems to me like the placard should say "install winterization kit for operations below -20C". What are everyone elses thoughts? Perhaps a new AD is required!

One final thought, Cessna called it a winterization kit...but I'm flying in the winter without it. So perhaps it should be call the extreme cold weather kit...-20C is extreme cold weather. I really think Cessna went out of their way to ignore the whole -20C operation.


================================================== ================
"In the POH of my 1968 Super Skymaster (lots of emphasis on the SUPER) Section VII on Optional Systems contains "Cold Weather Equipment" and says:

WINTERIZATION KIT.
"For continuous operation in temperatures consistently below 20 degrees F, the Cessna winterization kit, available from your Cessna Dealer, should be installed to improve engine operation. The kit consists of two baffles for the front engine, one baffle for the rear engine, and crankcase breather insulation for both engines. Once installed, the crankcase breather insulation is approved for permanent use in both cold and hot weather."

Attached is a photo of the front baffles but I have never seen the rear engine baffle. This statement is pretty standard in most all the Cessna piston Pilot handbooks except for the Turbo models. Maybe the Turbo models generate enough heat and do not require this?"

Diamond Service
01-12-09, 05:44 PM
I'm just curious about one thing, why did you choose that time of year to make the trip? It seems to me making the trip in the middle of summer would far outweigh making it in the winter.

I purchased the aircraft in June. I planned the crossing for the end of august.Unfortunately the work on the aircraft took much longer than expected. I know that it is serious business to perform this flight during the winter and that you can easily be on the ground waiting for a weather improvement. If you are planning a flight like this make sure that you got th right gear.I hope this answers your question.

Troels.

Roger
01-13-09, 06:39 PM
Great story, and an absolutley great piece of survival flying and ditching. You should certainly write it up in either short story format, or talk to somebody about a book. Make up a couple Eskimo chicks and an igloo, and you could probably pay for the plane.

I would however not jump to any conclusion about oil loss being the cause of the engine failures. It is far to much of a coincidence to have both engines fail that close to each other from a oil problem, especially in a Skymaster. The whole dynamics of the engine compartment temperatures, and subsequent temperature variations encoutered by the oil systems is too diverse to have them both encounter the same error within minutes of each other.

It sounds like plain old fuel starvation which wound down the oil pressure , which cooled down the temps, which then caused some form of noise form the prop once there was no oil pressure in the system. Maybe the big noise was the blade kicking back to feather , and that was caused by it being frozen once the rpm's starting bleeding off.

Regardless, congratulations on getting through it.

Ernie Martin
01-14-09, 12:12 AM
Three times I have had an engine quit in mid-flight due to fuel starvation. Ignoring the first time, when I had zero experience with the aircraft*, the indications are immediately obvious as fuel starvation. Given Troels familiarity with this aircraft and his experience, I very much doubt that this was fuel starvation.


Ernie

______________
* It was my first Skymaster flight and, while climbing, the instructor turned the fuel selector valve to off without my knowledge to demonstrate the docile behavior after a lost engine.

CO_Skymaster
01-15-09, 12:13 AM
Does Cessna still sell the winterization kit or does anyone know where I can get an aftermarket version of it? I definatly need it flying around the Colorado Rockies in the winter.

Karl

Diamond Service
01-15-09, 02:28 AM
I never forget the sounds that my engines made before they stopped.Sounds of metal against metal and great friction followed by a loud bang. I saw the low oil pressure indication before they made these sounds.To me it is very clear why they stopped.

Troels.

Roger
01-20-09, 10:30 AM
I don't mean to be contentious giiven your extensive experience, personal observations, and expertiese, I am only concerned that because this is an "infomrmation sharing website" that we should all be cautious about what we profess to "know for sure" when it may affect other pilots safety.

I would think that because we don't "know" what happneded to your engines, that we should keep an open mind about other possibilities such as vapor lock and/or fuel stavation, gelling, fuel pumped outboard through the vents, frozen/cracked cork fuel tank seals, etc...

I didn't notice if you ever mentioned cross feeding the tanks, before or after the engine failure. For example when the rear failed, did it make the same loud noise, and/or did it just go out for an entirely different reason, and because the front failed from perhaps an oil problem, did you assume the rear had the same problem, and there was no reason or time to try a cross feed and restart?

Not picking on you : It must have been a nightmare. Just want to make sure nonone else encounters a like scenerio and has the wrong assumptions.

Diamond Service
01-20-09, 01:25 PM
Dear Roger.
I totally agree with you. For the same reason I try not to speculate or draw conclusions and just write exactly what happened and what I observed. I told my story in this forum because I was very thrilled about being a Skymaster owner and pilot. I am not trying to say that the Skymaster is a bad and unsafe aircraft. More than anybody I would like some answers to what happened to my engines,but unless the aircraft is salvaged I will probably never get any answers.I have been told that the Hudson Strait is 113 meters deep at the position we were picked up and since there is nobody in the plane it will not be raised.

Troels

Skymaster337B
01-20-09, 09:33 PM
Well said, but since this is an information web site, the info we've discussed is very valuable and should be taken to heart by all of us. For me personally, the -20C is a big red alarm if I'm ever flying in weather that cold...let's hope not.

Paul462
01-21-09, 03:17 PM
So Troels, when are you buying the replacement 337? There are some great deals around!

If you can pick one up during the next couple of months, you can meet us at the 2010 SOAPA Fly-In in Branson! :-)

Diamond Service
01-25-09, 05:52 PM
Paul
Do you know any good ones. I need the following.

Non turbo VAR crankshaft engines with some time left.Deicer boots.Preferably with some new garmin avionic including mode S transponder and a 406 ELT. ADF and DME is still a requirement in my country .Propellers and governors within their calender lifetime of 6 years. Magnetos within their calender lifetime of 4 years. Engine and airframe hoses within their lifetime as stated in the maintenance manual.

These are all EASA requirements and I know that finding one that meets all of them is hard since you normally dont do overhauls based on calender time in the US and so on.

I hope that I can go to one of your meetings some day and see your Skymasters.

Troels.

Paul462
01-26-09, 09:40 AM
Troels,

It sounds like a normally aspirated 337 with engines having been overhauled within the last 10 or 15 years should do - VAR cranks should have been installed at that time.

To get a panel still equipped with ADF/DME you'll probably want an older, non-updated panel (updated panels would have removed at least the ADF), and install a 406 ELT and S XPDR. If you don't require a panel-mounted IFR GPS (and even if you do), a Garmin 496 provides amazing functionalities.

Are there life limits stated on engines? I've only heard of TBO's. Replacing the engine hoses and airframe flexible hoses isn't that big a deal, and would start you on a new 5-year cycle.

Happy hunting!

gwengler
11-19-12, 06:46 PM
Here is the link to a CBC documentary. As good as it gets, I guess.

http://www.cbc.ca/player/Shows/Shows/ID/2305885459/

Gerd

larry bowdish
11-19-12, 07:33 PM
Not available. I guess not available to US computers.