I've been in aviation since the early 1970s, owned several aircraft, and even built one, but I never knew the difference in types of ducting. I vaguely knew about SCAT, but not the others. In fact, I called them hoses. Now, I know the difference, so I wanna thank you John 😉
It is very important the SCEET is not used in negative pressure such as between a air filter and throttle body. The inside will collapse and plug up the intake causing the engine to stop.This caused a Piper Aerostar to crash shortly after take of at a airport near me.
These are amazing videos !!!! Being a non-builder (and have purchased an RV6A) the learning curve on maintenance and materials are pretty steep - even with community help I am still lost from time to time - but your videos are super helpful to me. Thank you !!
Hi sir, its great what you do , thank you for sharing information and especially the practical knowledge and tips [you have remarkable experience,als a good method too]. Thanks a lot . Best regards
Other videos say to remove the wire for the first inch or so, instead of leaving it to be crushed under the clamp and indenting it into your ali flange.
Interesting that you suggest two-layer sceet/ceet for intake. Those are negative pressure applications, and not recommended for these products by the manufacturer, as the inner layer can collapse from the vacuum. That would block the air intake and stop the engine. What's your take on this?
Certainly NOT negative pressure on my airplane! It is the POSITIVE pressure of the air that is being rammed in from the outside feeding the engine! Do you see? Same principle for the cooling intakes.. high pressure from the aircraft flying thru the air that pushes air for cooling or combustion...
That may be true to some extent for the hose from your air intake to the filter, but not behind the air filter. There's negative pressure between your air filter and your carburettor or intake manifold. The engine is a huge suction pump. Especially at low speed and full power (eg takeoff) the engine will suck a lot harder than your air is being rammed in. If you search for NPRM 0011CS you will find a proposal for an airworthyness directive from Australian authorities explaining this, after 4 engine power loss events. Especially section 1.2.1: "1.2.1 Negative pressure: Induction airflow combined with the slight restriction of airflow across an air filter results in a negative pressure between the carburettor and the air intake filter: Any loss of bonding between the hose material and the supporting helix wire can result in the wire being displaced, exposing the material to a level where the hose can collapse blocking intake air flow. "
Many Jabirus would fit that picture, but also VWs, Subaru, BMW and any other installation that uses an external filter/air box with a connecting hose. Not trying to argue, just trying to add information that may make your viewers think about their specific installation before they get into trouble.
You could reticle this as “Ducting for the complete idiot”, which is EXACTLY what I needed. Thank you!
I've been in aviation since the early 1970s, owned several aircraft, and even built one, but I never knew the difference in types of ducting. I vaguely knew about SCAT, but not the others. In fact, I called them hoses. Now, I know the difference, so I wanna thank you John 😉
It is very important the SCEET is not used in negative pressure such as between a air filter and throttle body. The inside will collapse and plug up the intake causing the engine to stop.This caused a Piper Aerostar to crash shortly after take of at a airport near me.
These are amazing videos !!!! Being a non-builder (and have purchased an RV6A) the learning curve on maintenance and materials are pretty steep - even with community help I am still lost from time to time - but your videos are super helpful to me. Thank you !!
I was wondering if you are a pilot or regular airliner?
The cord on the duct is to help the duct flex. I make these at my job.
Thank you 😊 learn something every time I watch
What a great video. I love your delivery. Very clear and precise. Thanks for sharing this. I learned a lot.
Hi sir, its great what you do , thank you for sharing information and especially the practical knowledge and tips [you have remarkable experience,als a good method too]. Thanks a lot .
Best regards
Other videos say to remove the wire for the first inch or so, instead of leaving it to be crushed under the clamp and indenting it into your ali flange.
Thank you!
Thanks u r my best teacher #HomebulitHelp
Great info, Jon. Thank you!
Interesting that you suggest two-layer sceet/ceet for intake. Those are negative pressure applications, and not recommended for these products by the manufacturer, as the inner layer can collapse from the vacuum. That would block the air intake and stop the engine. What's your take on this?
Certainly NOT negative pressure on my airplane! It is the POSITIVE pressure of the air that is being rammed in from the outside feeding the engine! Do you see? Same principle for the cooling intakes.. high pressure from the aircraft flying thru the air that pushes air for cooling or combustion...
That may be true to some extent for the hose from your air intake to the filter, but not behind the air filter. There's negative pressure between your air filter and your carburettor or intake manifold. The engine is a huge suction pump. Especially at low speed and full power (eg takeoff) the engine will suck a lot harder than your air is being rammed in.
If you search for NPRM 0011CS you will find a proposal for an airworthyness directive from Australian authorities explaining this, after 4 engine power loss events. Especially section 1.2.1:
"1.2.1 Negative pressure: Induction airflow combined with the slight restriction of airflow
across an air filter results in a negative pressure between the carburettor and the air intake filter:
Any loss of bonding between the hose material and the supporting helix wire can result in the
wire being displaced, exposing the material to a level where the hose can collapse blocking
intake air flow. "
Sounds like good advice for engines that dont have their air cleaners mounted on the engine. Are those the Jabirus?
Many Jabirus would fit that picture, but also VWs, Subaru, BMW and any other installation that uses an external filter/air box with a connecting hose.
Not trying to argue, just trying to add information that may make your viewers think about their specific installation before they get into trouble.
Yes, and many thanks for adding to the knowledge! We all can use info like this. I appreciate your comments.
What's mean temp ?
Oh wow look at you, its called ducts not tubes lol. Good video tho