downed CTs in the news

[shiny.ice]

Starting a thread for stories about CT incidents that are just in the news, not  personally witnessed or people we know.

[shiny.ice]

9/20/2023, Germany, Suhl Grossenhain Airfield (EDAK), single fatality.

https://aviation-safety.net/wikibase/345758

translated from the Bilt article:

Quote

 

He is said to have filmed looping
Pilot (62) dies in plane crash in Saxony .. crashed into a warehouse near the Textima Bridge south of the center of the large district town north of Dresden. "plane did a circle beforehand and did a loop directly in front of me. I was amazed at how low the plane flew - it only whizzed briefly over the savings bank building and then there was a crash. A thick, black cloud of smoke rose."

BFU (NTSB): "The person in Großenhain did not jump out with the parachute, but remained in the aircraft and tried to pull the rescue system. Initially there was initial information that the person was said to have left the plane with a parachute.”

 

radiolausitz:

Quote

According to media reports, the plane took off from the city airfield. According to eyewitnesses, it then made unusual circles before finally plunging steeply into the Karpinski warehouse.

tag24 is a little more explicit about the deceased.

[shiny.ice]

Nov 18 2023, N924RD, crash into a lake (Hungry Horse Reservior), Montana. Two occupants, minor injuries. 2016 CTLS.

https://nbcmontana.com/news/local/crews-remove-plane-that-crashed-into-hungry-horse-reservoir

https://www.krtv.com/news/montana-and-regional-news/small-plane-crashes-on-the-shore-of-hungry-horse-reservoir

https://www.kpax.com/airplane-crashes-into-hungry-horse-reservoir

https://www.flightaware.com/live/flight/N924RD/history/20231118/1439Z/KGTF/L 48.37816 -114.06858

Some good FLIR vid in the first link KRTV story.

 

 

[GrassStripFlyBoy]

Flightaware shows 4hours and 3 minutes then track ends, circled area around airport in Kalispell.  That is some beautiful and mountainous country.  ADSB track may have simply ended if they had landed at Kalispell, took fuel, and then departed later.  But no departure flight registered. 

Going purely on ATSB track, appears could not make it in Kalispell, and ran out of fuel.

[EricB]

Doesn't look like he deployed the BRS.  The good news for the rest of us is the quote that 2 occupants only had minor injuries.  

[FlyingMonkey]

3 minutes ago, EricB said:

Doesn't look like he deployed the BRS.  The good news for the rest of us is the quote that 2 occupants only had minor injuries.  

I'm a big BRS fan, but I have some mixed feelings on it.  It seems if you can get it on the ground without it like in this case, that's a good thing.  If there is a deployment problem like the chute wrapping around the tail (happened to a Cirrus) rocket failure, fire from rocket, etc the airplane might be unflyable.  But on the other hand statistically you're much more likely to walk away from a chute deployment than an off-airport landing.

I think it's really a game-time call based on the exact circumstances.

[kinoons]

In my off airport landing (N378CT) the other pilot and I discussed if we wanted to use the chute. We decided that if we felt we could safely land that we wanted to do so, and only use the chute if we were not confident about the landing. 
 

The owner did tell me after the fact he was informed by the insurance that if we had deployed the chute the plane would be totaled regardless of any other damage. 
 

The aircraft was totaled anyways, and the aircraft being usable shouldnt factor into decision making, but it’s interesting to know. 

[shiny.ice]

Cirrus uses the phrase “if landing is assured” in the parachute decision. Something like 10-15% get repaired and returned to flight.

[FlyingMonkey]

10 hours ago, kinoons said:

In my off airport landing (N378CT) the other pilot and I discussed if we wanted to use the chute. We decided that if we felt we could safely land that we wanted to do so, and only use the chute if we were not confident about the landing. 
 

I recently had an incident of two very quick engine hesitations on climb out, due to vapor in the fuel lines (I believe caused by a hot day and the ethanol fuel blend in Florida).  It did not recur and we elected to continue the flight.  Thankfully I had Bill Ince with me, and we talked through what we'd do if the engine quit.  We were at about 1000ft AGL and decided that we'd attempt a restart down to 400ft and if unsuccessful then deploy just off the beach in the shallow water.

After that I put 100LL in the airplane for the flight home to Georgia, and have since had no further issues with 100LL or Georgia gas, which is why I believe there was either a blend issue or just bad gas from the station.  I did sump the fuel prior to the incident flight and saw no particles or water.

[Anticept]

A recommendation too, morden: pick a higher climb speed to lower the nose if it hesitates.

[FlyingMonkey]

45 minutes ago, Anticept said:

A recommendation too, morden: pick a higher climb speed to lower the nose if it hesitates.

That happened immediately on the hesitation, I lowered the nose immediately to almost level.  That's about the time it stopped.

I knew instantly what it was, as right after my teflon hose conversion I had this happen a couple of times.  I replaced the upper hose aft of the firewall to make a straight run and eliminate a curved vapor trap, and replaced my 5 year old fuel pump.  I since had no more issues for three months in the heat of Georgia summer using ethanol mogas until it happened in Florida. 

I think when traveling long distances I'll stick to 100LL or ethanol-free mogas to try to mitigate any future occurrences.  My normal local BP station's 93 octane pump gas in Georgia seems good to go, but variances in blends and storage could cause this again.   

[Anticept]

You're e-lsa. Consider installing one of these:

https://www.leadingedgeairfoils.com/facet-electric-fuel-pump.html (i believe this is the Facet 40105, there is no 2.5 - 4.5 from their catalog but there is a 3.0 - 4.5)

Facet 477060E has an integrated fuel filter (installation kit # is FEP60SV) and the E means it's solid state controls. (PS: This profile of fuel pump leads me to believe variants of this pump are being installed as a relabel by PMA Products Inc for pipers etc).

There are many many facet fuel pumps, and lots of specs in each, but the ones I linked are the ones that should fit our applications. The important thing is they DO NOT have a positive shut off (they will flow fuel even when off), you have to dig through the specs to find which ones do and which ones don't. If you have a fuel flow transducer and it's the flowscan type, you have to keep your fuel filter or use a pump with an integrated filter, but if you don't have one, or have the red cube fuel flow transducer, you can remove that fuel filter completely in the center console. You could replace it with that pump, or find a place out on the firewall for it.

Facet fuel pumps work by electromagnetically slinging a hollow slug back and forth that has valves on it. It's the tick tick tick tick tick type of fuel pump.

[Madhatter]

When changing to different fuel pump systems, now that is experimental.  Basically you become the "A" model. Fuel systems can have hidden unforeseen problems, aviation is littered with them. I have done a lot of changes to certfied engines, fuel systems,  and airframes, legally. Even with lots of research, unanticipated things happen, I've been there. So be careful, nothing is assured to work as planned.

[Anticept]

Absolutely agree, but we also currently have edge case issues where morden and I have experienced power loss on takeoff (and I know of this event occuring with another carb flight designs) and I am pretty sure it's vapor.

I also noticed that the aircraft this is occuring on are those with e-props and unleaded car fuel. A theory that I have is that they already climb hard, but the e-props edge out the extra performance that the nose is lifted even higher for climb out, further reducing pressure feeding the engine fuel pump. Testing by climbing out at a higher than recommended airspeed showed that fuel pressure issues were far less, and haven't experienced the power loss again.

A fuel pump, even if were one of the lower pressure ones that only push a couple PSI max (the engine pump would boost from there to operating pressure), would make a difference. Just something that gets a little more positive pressure and flow going if vapor does form.

[Madhatter]

I have been using the EProp for years and have never had an issue and I use ethanol fuel. I was the first one in the US to have it on a CT. I do not see a correllation with fuel issues. The Rotax RPM is based on manifold pressure and the engine load is the same regardless of what prop is used. If angle of attack were an issue then power on stalls would be a problem. There is another reason, carbs, fuel line restriction, heat, etc. I have found several issues in the fuel system. One in particular is that the original fuel shutoff valve was not fully opening, and the size is quite small to begin with. Something else is going on and the only way to solve it is to start at one end and evaluate everything until you get to the last part. I find that many will jump into the middle of the system they are evaluating which doesn't always work. It will just take time.

[Anticept]

I've already posted a long report on the things I've done over the years, madhatter, with these fuel systems short of installing a fuel pump (due to regulation).

The correlation is what I said it is: you pitch higher on a climb, because the prop is more efficient. The fuel pump, being all the way in the front of the engine, means it's raised higher by the pitch, and the fuel already has to travel a long distance through snaking and undulating hoses before it reaches the pump. If you're already on the edge with issues, that can be just enough to present the issues.

Back when these aircraft were designed, the original pierburg pumps had a different internal design and never presented these fuel pressure warnings. The pumps we have now don't tolerate air very well, and doubly so since the inlet is *above* the outlet on them, and valves that don't fully close. That's why Rotax has that service bulletin about tolerating low fuel pressure warnings for limited times.

Add in long runups, high vapor pressure fuels, and just the right combination of other factors and you can start seeing the issues where some flight designs, filled with gas from certain states with different fuel standards, it might show these issues where others have none. Drop the nose just a little bit and many of these issues go away. Been there, done that, tested it, on more than one of these birds. If it wasn't vapor lock, you would very likely see issues in LEVEL flight at full power and I've never seen that. Only on high pitch scenarios at high power settings.

Add in 2 gallons of avgas for every 10 gallons of mogas, and suddenly it's a non issue. Did that too on FIVE birds including my own when I flew down to South Carolina with Ohio winter blend in the tanks.

A boost pump's the answer at this point, full stop.

I'm sorry that I'm coming off a little terse, but I'm really sick and tired of people arguing this with me assuming that I haven't torn these fuel systems ALL the way down, and constantly trying to say it has to be something else, it has to be something else! Short of using larger fuel hoses, I've torn down my fuel system and snaked a freaking borescope through the hoses trying to find issues and found NONE, replaced my fuel pump, installed springs in the system where it's prone to kinking, ensured the fuel inlets and filters are all clean... what HAVEN'T I done at this point.

I mean for real, if using avgas is what makes the issue stop I really don't know what else to say to the non-believers about vapor pressure.

And madhatter, you should know more than anyone, just because you don't experience the issue doesn't mean that it isn't affecting others.

[GrassStripFlyBoy]

6 hours ago, Madhatter said:

fuel line restriction

I've never had issue of power loss, the fuel line size (7.5mm or 5/16") and resulting GPM flow would be an interesting data point.  And sort of on that topic, this summer when I had a slight carb overflow issue I became aware of how sensitive the setting on carb float bowls are.

Andy, what fuel flow rate are you seeing at the gascolator?  Stab the drain port open, time for 6 minutes, then multiply the amount of fuel in jug by 10, is the technique I use.  My SW is typically around 2.25 -2.5 gallons or so / ~24 GPH.  Doing wing pull last weekend I had limited fuel in plane, around 7 gallons, and it was still solid 23+ gallons an hour flow.

Regarding carb floats, I recall you had a fuel overflow situation.  That is scary stuff and believe that was the carb float pin hole leaking on bottom and long corrected.  But that got me thinking if floats are set too low would a bit extra of "G force" on climb out tend to cause them to limit flow into bowl, one side carb more than other perhaps, and there's some roughness?  I'd double check float lever arm is nominal and not low tolerance or even too low.

Lastly on the fuel line size.  I'm just at point of 5 year rubber coming due, but have changed hoses within panel and lately the wing roots.  When I did the Y in cabin I selected 7.5mm as I didn't like anything less than a snug fit, and was in the camp of staying with 7.5mm.  When I did wing root, I took a section of both sizes and slipped on.  Both the pillar and the tank barb were snug on 5/16 hose, so opted to use Gates 5/16. That is a small section of hose, but the whole system being 5/16 would flow more, how much...  I see argument for either selection, but fuel flow could be the tiebreaker?  I'll likely go with 5/16 when replacing lines.

[GrassStripFlyBoy]

Thinking further about the G factor on floats, that would add fuel to bowls not the other way around, but if they are riding high maybe the point is the same?

[Anticept]

The gascolator drain port varies aircraft to aircraft. Mine originally could only drain about 6-8 gph through it, while another flowed very freely. Mine wasn't tapped very deep.

Take the gascolator bowl off cup off and do the test. It will do something in the vicinity of 30-35 gallons per minute.

[Madhatter]

7 hours ago, Anticept said:

I've already posted a long report on the things I've done over the years, madhatter, with these fuel systems short of installing a fuel pump (due to regulation).

The correlation is what I said it is: you pitch higher on a climb, because the prop is more efficient. The fuel pump, being all the way in the front of the engine, means it's raised higher by the pitch, and the fuel already has to travel a long distance through snaking and undulating hoses before it reaches the pump. If you're already on the edge with issues, that can be just enough to present the issues.

Back when these aircraft were designed, the original pierburg pumps had a different internal design and never presented these fuel pressure warnings. The pumps we have now don't tolerate air very well, and doubly so since the inlet is *above* the outlet on them, and valves that don't fully close. That's why Rotax has that service bulletin about tolerating low fuel pressure warnings for limited times.

Add in long runups, high vapor pressure fuels, and just the right combination of other factors and you can start seeing the issues where some flight designs, filled with gas from certain states with different fuel standards, it might show these issues where others have none. Drop the nose just a little bit and many of these issues go away. Been there, done that, tested it, on more than one of these birds. If it wasn't vapor lock, you would very likely see issues in LEVEL flight at full power and I've never seen that. Only on high pitch scenarios at high power settings.

Add in 2 gallons of avgas for every 10 gallons of mogas, and suddenly it's a non issue full stop. Did that too on FIVE birds including my own when I flew down to South Carolina with Ohio winter blend in the tanks.

A boost pump's the answer at this point, full stop.

I'm sorry that I'm coming off a little terse, but I'm really sick and tired of people arguing this with me assuming that I haven't torn these fuel systems ALL the way down, and constantly trying to say it has to be something else, it has to be something else! Short of using larger fuel hoses, I've torn down my fuel system and snaked a freaking borescope through the hoses trying to find issues and found NONE, replaced my fuel pump, installed springs in the system where it's prone to kinking, ensured the fuel inlets and filters are all clean... what HAVEN'T I done at this point.

I mean for real, if using avgas is what makes the issue stop I really don't know what else to say to the non-believers about vapor pressure.

And madhatter, you should know more than anyone, just because you don't experience the issue doesn't mean that it isn't affecting others.

I guess you have it all figured out. Hope it works for you. There are hundreds of CT's flying in Europe with the E-Prop for the last 6 or seven years and so far no issues. All I'm trying to say is that fuel systems can be complex in ways that may elude someone initially.  After 51 years of changing things on aircraft I have found surprising reasons for something not working as planned. The main issue is if you are in the air when you find this out. I never ever think I have it all figured out until I can prove definitely that the issue is resolved and other professional interested parties agree with the results and are able to duplicate these results.

[FredG]

Regarding the level of the fuel in the bowl under conditions of greater or lesser G-forces - I do not think there would be a change in the fuel level.  The reason is that the G-forces would be the same on the float and on the fuel simultaneously.  Since the float level is dependent on (i) the weight of the floats and (ii) the amount of fuel that must be displaced to equal the float weight, a change in G-forces will result in no change in the displacement (the height of the float in fuel when it is floating) since both factor change by the same amount.

[kinoons]

On 11/22/2023 at 6:29 AM, FlyingMonkey said:

I recently had an incident of two very quick engine hesitations on climb out, due to vapor in the fuel lines (I believe caused by a hot day and the ethanol fuel blend in Florida).  It did not recur and we elected to continue the flight.  Thankfully I had Bill Ince with me, and we talked through what we'd do if the engine quit.  We were at about 1000ft AGL and decided that we'd attempt a restart down to 400ft and if unsuccessful then deploy just off the beach in the shallow water.

After that I put 100LL in the airplane for the flight home to Georgia, and have since had no further issues with 100LL or Georgia gas, which is why I believe there was either a blend issue or just bad gas from the station.  I did sump the fuel prior to the incident flight and saw no particles or water.

In my incident I noticed the oil pressure level dropping several minutes prior to the stoppage, which gave us time to make a plan prior to the engine out situation. 
 

I have no doubt that having a little warning and making a plan prior to the actual emergency resulted in a much more “controlled” reaction vs a sudden unplanned engine out. 

[Jim Meade]

But FredG, you forget:  Correlation is Causation.  Or is it correlation is not causation.  Or is it....oh, I don't remember.  Darn.  I'll just stay confused.

[Mike Koerner]

The following statement is wrong and should be disregarded:

FredG,

You're right, you and Archimedes both, when you say that the weight of a floating object is equal to the weight of the liquid it displaces. However, whereas the weight of the floats is equal to their mass times the acceleration due to gravity (F=MA), and gravity is also acting on the fuel, the fuel is largely incompressible.

Under increased G loads the floats will sink further in the fuel bowl displacing a larger volume and weight of fuel.

[FredG]

Mike, the same force that acts on the floats also acts on the gas in which they are floating.  So, if the weight of the floats goes up due to increased G-forces then the per volume weight of the fuel also goes up (according to the same formula).  It does not need to be compressible for that to happen, it simply has to be acted on by a force (after all, the floats are not compressible, either).