Ops-Normal.org

They don't come bigger than this!

Yours is definitely bigger than mine. I remember my gob being smacked at that Paris Airshow.

It’s probably a good thing that Slasher is no longer with us

Bearing in mind that the Mi-12 era was around 1970 I wonder how they did tracking of those blades as they are so far off the ground. In those days we were still using tracking flags even on our Bell 212 and it was only just the beginning of having electronic tracking kit such as the Chadwick available. For the uninitiated, tracking by flags involved one person, preferably two people, holding a pole with a canvas strip held between two horizontal projections. Each rotor blade tip was marked with a different coloured wax crayon. The pole was gradually raised to the vertical just outside the rotor disc and then the pole was twisted until the rotors just struck the canvas strip. Adjustments were then made until all the crayon marks overlapped one another. Health and Safety would have a field day nowadays I suspect! One one occasion when I was watching a 206 being tracked by a single person the tracking pole disappeared into the distance when it was launched by the rotor blades! I've even seen a Bell 47 being tracked away from a maintenance base by using a broom handle and a piece of cardboard nailed to it!

Here's a video of a Mi-17 being tracked with a pole - and they don't even have a flag, they've just wrapped the pole in some material!

For those who have wondered about the stresses of a rotor blade in flight this is a video of a Bo105 in aerobatic flight. It has a rigid rotor system - it has no flapping or lead-lag hinges - and you can see how the angle of attack of each blade alters with each revolution as the blade become the advancing and then the retreating blade as the helicopter moves forward. The bits of kit moving up and down near the root are blade mounted pendulum absorbers which reduce the higher harmonic vibratory loads at the rotor hub and in the fuselage. I only flew early versions of the 105 which did not have those pendulum absorbers so have often wonderd how effective they were.

This video of a Mi-8 in flight show the movement of a more tradional rotor blade in flight..

I'm puzzled why the Ruskies thought they needed talking freight in the Attic on a support heli. I would have thought a few maps and a chinagraph pencil for the pilots would have sufficed.

I see (at the end of the Mi17 video) that one guy has a pouch marked FOD - does he scatter it around for others to collect?

The tarred brush was an early form of tracking. It would be pivoted up until a blade or blades touched it. On shutdown a blade flying high could be identified by it being clean with no marks. The trick was to get the same degree of muck on each blade.

At the Paris Air Show where the MI-12 appeared the Russian crew were being quizzed about its progress. They were asked about the certification and they said that that was complete apart from autorotative landings.

"You've got four donkies and you have to dead stick it!!!!"

"Yes, our government has stupid rules as well."

A potted history of the technical spec. on the Mil V-12 helicopter can be found here... Mil V-12 the aircraft was effectively replaced by the Mil V-26




Quite an elegant bird methinks...