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-   -   The Scariest Helicopter Ever (https://www.pprune.org/rotorheads/502336-scariest-helicopter-ever.html)

Fareastdriver 28th Jan 2013 08:57

Story going around the Paris Air Show when the Mi 12 was there.

US and Russian pilots talking about it and the question was raised on how its certification was going. The reply was that one thing that was remaining was the landing without engines.
The Boeing pilots were amazed. "You've got four engines and you're going to dead stick it?"
"Yes, our government has got stupid rules as well."

Whether this ever happened is uncertain but the vibration harmonics was the problem that killed it off.

SASless 28th Jan 2013 11:30

Overheard just before we started the engines every single time I flew with a certain fellow in Nigeria as he bowed his head and held his two hands pressed together in supplication: "Lord! Please don't me die in this Bristow maintained piece of **** today!"

I laughed at him for a long while....then saw the Light!

Sikpilot 28th Jan 2013 13:51

Back in 1985....teaching students in an R22 A model. The A models had NO tip weights. Talk about low inertia rotors. Touchdown autos were NOT fun.

Dennis Kenyon 28th Jan 2013 16:37

Dangeroos (not the zoo kind)
 
Please gents ... as a long time supporter of the Menominee product can I offer two pennorth.

Yes the Enstrom can be a mongrel to start. Put that down to the 'shower of sparks' system which heralded the cold & hot start problems circa 1978 plus poor maintenance of the ignition and mixture systems.

Yes, the Enstrom can give a 'bouncy ride.' Put that down to the legion of engineers who don't have type experience or don't understand type RB tracking.

Yes, a ridiculous clutch engagement system. Put that down to a poor design. Hughes and Robinson use an almost identical system but with multiple drive belts that give few problems. Fragrant 'French Chalk' will solve the noise aspect!

Yes, a poor hover performance that can require max permitted power just to hold a hover at 15 degrees OAT. Mainly due to poor maintenance again in getting the operating mixture correct. The PFM requires pilots to lean the mixture to 1550 degrees for maximum power* (not over 29 map) ... something that I've found few pilots will practice. (*or if fuel flow exceeds 130 pph)

And an item not mentioned is the rpm correlation. OK once a pilot has been instructed well and a proficient RPM aware pilot should be able to cope ... but the factory could sure do with something better. Like copying the Hughes/Schweizer/Sikorsky 300 system for a start.

BUT. BUT ... In forty years operations in the UK, there has never been a single fatal accident.

With some 6.500 type hours I've never had an engine failure and my log book tells me while instructing I've completed around 5000 full engine-off landings to the ground without a hint of difficulty.

The 225 BHP version has a ROC of 1475 fpm at max gross standard ISA. Please nominate another piston type that matches that.

The Enstrom has a seven cubic feet luggage locker. (100lbs weight capacity on 28F or FX) Please nominate another three-seat design that can beat that.

The Enstrom can be trimmed to fly 'hands & feet off' for as long as one wishes. Please nominate another type that can better that.

Properly electronically tracked, the Enstrom can be brought down to .1 IPS in the hover. With forward flight vibration level dittoed, the type can be as smooth as any type, piston or turbine, I've flown in 14,000 hours.

VNE is 117 on the 280 version. If leaned to 1650 degrees in the cruise the Enstrom turbo versions will give an 85 pph (11.75 gph) fuel-flow giving an average 240 sm still-air safe range.

The type has won a WHC 'freestyle' event three times. Nominate another type that has done that.

In fact, like owning a classic Ferrari, if one can accept the shortcomings or get them put right, Enstrom ownership can be a total delight and one might be forgiven for wondering why anyone would buy any other type in the price range! I've sold exactly 148 of the blighters. Well someone had to speak up!

Dennis K (head down again!)

Thomas coupling 28th Jan 2013 23:06

Any shares in Enstrom Dennis?

Yes - but apart from all that, what has Enstrom done to prove itself? :E

Cracking post - best in years.:D

RPM AWARE 29th Jan 2013 11:51

Hey Den

"a proficient RPM aware pilot"

Something in that sentence rings a bell, but I can't put my finger on it ;)

Of course, you are the UK's Enstrom sage, as is well known :ok:------------------------------------------------------------------------

"A rotorway on the other hand?!?"

And I see someone's had a pop, most likely without substance...fancy defending the type too ?

From 1m 06s

chevvron 29th Jan 2013 12:48

I'm not a qualified helicopter pilot, just fixed wing, but I've scrounged rides in many types.
The first one I flew in (passenger only) hasn't been mentioned yet, the Brantly B2B. On startup, I could feel the engine pounding at my back, and it seemed grossly underpowered.

jim63 8th Mar 2014 17:41

Who tried inventing this contraption
 
Looks to me like a scary situation,
http://www.liveleak.com/view?i=c64_1279412306

krohmie 8th Mar 2014 17:57

Piasecki invented it with US Navy money for the US Forrest Service Piasecki PA-97 - Wikipedia, the free encyclopedia

defizr 8th Mar 2014 18:17

Paul Ludwig Hans Anton von Beneckendorff und von Hindenburg :ok:

mattpilot 8th Mar 2014 19:09

Oh the huge manatee ....

Arm out the window 8th Mar 2014 21:38

Unanticipated vibration! Struth, I'd say blind Freddie could have anticipated a vibe problem with that setup.

Stanley11 9th Mar 2014 07:59

I'm speechless! In my years of being a heli pilot and engineer, I'm astonished that the designers, engineers, pilots all thought that that could work. Perhaps that was in the era of risk taking and throwing caution into the wind.
I think I saw pilots in each of those cockpits. How could they even coordinate their flight inputs? RIP to the fallen.

Arm out the window 9th Mar 2014 08:31

Yes, I think there was a pilot per machine, with the designated lead guy calling the power settings (remember reading something about this years ago; didn't realise they'd flown it and people had died).

Fat Magpie 9th Mar 2014 09:43

Good grief they built it, I remember seeing the idea as a concept drawing many yrs ago.
RIP the pilot, I wonder exactly how much testing was done before it went for a manned flight?

Blackhorse 9th Mar 2014 11:51

Brantly (any model) Roberson (same but especially R22)

heli1 9th Mar 2014 18:55

The Piasecki Helistat crashed due to structural failure of the low grade pipe work used to connect the H-34 fuselages to the blimp.The idea was to prove the concept before building a definitive version.Moral....don't do things on the cheap ( I still have a piece of the fabric saved from when I met the chief pilot quite a few years ago).
P.S. The Brantly was a lovely helicopter to fly,with a good safety record and a popular trainer in its day.

rjtjrt 9th Mar 2014 22:01

John Dixon posted in
Post 24 of this thread re Piasecki Helistat

Scariest
Some may refer to it as a Zeppelin, but the Piasecki Helistsat looked scary to me from the outset. One day the phone rang in the SA pilots office and the pilot who had hired on to fly it wanted to talk to anyone. He got connected to the pilot in our office who was our strongest in the area of structures/ dynamics ( a former USMC aviator with an Engr MS in that area who came to us from SA Engr Dept. ). The caller was given a whole list of things to look into. Later events seemed to say that some basics were missed. I say that based on the published info which said the landing gear wheels started to shimmy, which then kicked off a mechanical stability ( ground resonance ) situation. With all of the military history of that subject, on that machine, the V-leg gear vs the Straight-legged gear etc, one would have thought that the importance of the landing gear would naturally have been a primary design issue.


Brian Abraham 9th Mar 2014 23:33

Dennis, you may find the following story of interest. Friend was flying an Enstrom doing survey work in outback Oz. Heavy vibration set in so pilot, wanting to get on the ground as rapidly as possible, basically did a power recovery auto. Having put it on the ground the passenger made a comment to the effect "look, someone's been here before us, there's a tail rotor over there". The pilot was somewhat confused as the landing had been nothing out of the ordinary, despite the vibration. Hopping out everything looked normal, save for the obvious fact that the tail rotor had been chopped off by the main rotor. No other damage was evident, however investigation found the forward main transmission mounting bolts had let go (cause of the initial vibration) and at some point during the landing with the pitch pull the gearbox rotated aft and chopped the tail off. With pitch reduced the gearbox fell back into place.

YankeeHotel 11th Mar 2014 10:27

For me, being just a humble fixed wing pilot, this construction looks pretty hmmm let's say interesting. Looking at the amount of fuel this guy takes with him, he is not only brave but very optimistic I think....
Skip to 5:00 for the take off if you're not interested in the extensive ground testing...



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