# Enstrom closes doors

### Help Support Homebuilt Aircraft & Kit Plane Forum:

#### Pilot-34

##### Well-Known Member
Well that makes sense but I thought the idea was that the 360 engine was somewhat unreliable because it was straining to make the same horsepower while the 435 engine could make easily and reliably?
Would the transmission care Which engine it was as long as the horsepower is the same?

#### D Hillberg

##### Well-Known Member
Well that makes sense but I thought the idea was that the 360 engine was somewhat unreliable because it was straining to make the same horsepower while the 435 engine could make easily and reliably?
Would the transmission care Which engine it was as long as the horsepower is the same?
Weight, Enstrom started with a normally aspirated 360 when more power was needed they added a turbo.
We'd usually replace the jugs as needed the bottom end was ok.

#### Martin W

##### Well-Known Member
Well that makes sense but I thought the idea was that the 360 engine was somewhat unreliable because it was straining to make the same horsepower while the 435 engine could make easily and reliably?
Would the transmission care Which engine it was as long as the horsepower is the same?
.

Nothing wrong with the 360 (great engine)

(Generally speaking) a typical Lycoming will have a TBO of say 2200 hours in a fixed wing

That same engine in a helicopter works much harder and at a higher rpm (3100) than in a fixed wing thus TBO is 1200 hrs or less.

Helicopter transmission (gearbox) is a critical component built as strong as possible and light as possible ... engineers select appropriate gears to horsepower .... more horsepower would require stronger gears and beefier gearbox and stronger rotor mast and so on .... one thing chase another.

The gearbox itself does not care what the source of power is .... as long as limitations are not exceeded ..... Robinson helicopter has a clever strategy by using a slightly overpowered engine ... (doesn't have to work so hard) ... but limits it by manifold pressure to protect the gearbox .... end result the Lycoming is not overworked and can make 2200 hrs TBO .

#### TFF

##### Well-Known Member
The lite shafts are fine if they are the big radius ones. The Kevlar was for cosmetics and damage resistants. The big problem was you couldn’t see the crack in the small radius shafts and they would crack. A rotor head flew off completely during a fair ride because of this. They were lucky. The helicopter was only 5-10 ft off the ground coming in for a landing and it plopped down with no rollover. Everything rotor went out and then started coming back like a boomerang and landed next to the helicopter. It’s still out there flying today. They had already designed the larger radius shafts, but there were a lot of old helicopters nursing them. I found two on recent prebuys.

#### EzyBuildWing

##### Well-Known Member
Just watched Youtube vid "HAI Heli Expo 2019 ENSTROM HELICOPTER Whats New?"........
280FX mast-shaft looks so thin, it looks "Mickey Mouse"...also it looks old and grey and tired and scrappy.
Mast-shaft needs a cosmetic cylindrical painted-cylinder clamped(attached) to it so it rotates with the shaft. Cylinder could be carbon fibre.
Of course, whole heli and rotating-mast must be painted same color.....bright-orange/yellow! See my artwork below.
( Orange is recognized as the "friendly-colour" )
In the above vid, the Enstrom chap extols the great "new-design super-large cabin-entry doors", whilst the short interviewer shows clearly he has to struggle to climb through the door into the right-hand seat......! Hmmmmmm....!!!!

#### Attachments

• Enstrom yellow mast.jpg
52.6 KB · Views: 1

Hmmmm!

#### Attachments

• Bell thicker mast.jpg
73.6 KB · Views: 0

#### BBerson

##### Light Plane Philosopher
Supporting Member

#### EzyBuildWing

##### Well-Known Member
Thin masts smake Enstroms look like a wind-up clockwork-toys.......mast needs to look thicker for psychological comfort of passengers(customers).
Cessna found that out when they tried removing some wing-struts and passengers said they felt more "secure" if they could see struts....sort of belt and braces!
Marketing guys should immediately do a mock-up, then get some focus groups to say which heli they'd prefer to be a passenger in.
I'll bet 100% say " the thick-mast version"!

#### TFF

##### Well-Known Member
Enstrom masts are three times bigger than a Jetranger. The control tubes are inside protecting them. Enstrom always had examples in the booth at HAI. They seem long but the Brantley people were always loosing their heads standing up next to them so I will pick the taller ones.
Friday, the judge might award the sale. I heard it might be a surprise.

#### EzyBuildWing

##### Well-Known Member
Interesting that Enstrom always had mast-examples in their booth at HAI, presumably so their engineers could convince the "doubting-Thomases" that the long masts could cope and that masts were properly engineered and there there were no problems.
How many others exhibiting at HAI had mast-examples in their booths?
I like the height of the long Enstrom mast, but it needs to be cosmetically dressed-up to look more psychologically substantial, for the peace of mind of passengers.
Like I said.....Enstrom should do a mockup and get some focus-groups opinions.
Will be interesting to see what the Judge finds.....

#### TFF

##### Well-Known Member
It’s not really that long if everything is side by side. It is longer than some but it’s not 3 ft longer. If you look at the turbine helicopter version, it’s the same general gearbox, which shows how strong the original was, but you have big fuel tanks and air cleaner hiding half of it. Most helicopters are hiding stuff behind the outside.

I think most people visually see the control rods on a Jetranger as structure. When it spins it looks like there is more meat. One of the local guys took a bird on one of those tubes. Scary how bad it flew and his company reprimanded him because he flew it back to the airport instead of putting it on the ground right away.

Just another note. The faster you go in a helicopter, that shaft has to bend. Because tailrotors will thrust a helicopter sideways, the whole rotor is tilted to counter. It is also tilted forward because all helicopters are biased to fly forward best. The faster you go the more the rotor head levels out. A long shaft doesn’t really notice the bending because the bend radius is small over the length. A short shaft has to practically kink comparatively.

Anyway flying in a helicopter makes you believe in engineering. Noway you can guess your way into one.

#### Pops

##### Well-Known Member
Supporting Member
It’s not really that long if everything is side by side. It is longer than some but it’s not 3 ft longer. If you look at the turbine helicopter version, it’s the same general gearbox, which shows how strong the original was, but you have big fuel tanks and air cleaner hiding half of it. Most helicopters are hiding stuff behind the outside.

I think most people visually see the control rods on a Jetranger as structure. When it spins it looks like there is more meat. One of the local guys took a bird on one of those tubes. Scary how bad it flew and his company reprimanded him because he flew it back to the airport instead of putting it on the ground right away.

Just another note. The faster you go in a helicopter, that shaft has to bend. Because tailrotors will thrust a helicopter sideways, the whole rotor is tilted to counter. It is also tilted forward because all helicopters are biased to fly forward best. The faster you go the more the rotor head levels out. A long shaft doesn’t really notice the bending because the bend radius is small over the length. A short shaft has to practically kink comparatively.

Anyway flying in a helicopter makes you believe in engineering. Noway you can guess your way into one.

Why I never really cared for helicopters. One time my wife's company was ask to bid on a large pipeline patrol for a large NA company and was looking to buy a couple. I do have my helicoper commercial written passed but I wasn't going to do any of the flying. She decided against it. Good.

#### TFF

##### Well-Known Member
That’s what my company did. You would probably have taken a to it once you got the hours in. Profitability wise is a different game.

#### EzyBuildWing

##### Well-Known Member
Anyone know what is going to happen to Enstrom?...........shame if they're kaput!
Thicker mast is purely cosmetic, but is definitely needed.

#### Attachments

• Enstrom battery start Mar 2022.jpg
55.5 KB · Views: 1