Notar And My Curiosity

[mountainflier]

Hey there everyone... I was thinking (always a challenge I know) about NOTAR. I was a good little V-Mag member and searched to see if this topic has been covered - from what I can tell it hasn't.

 

So here is my curious question: Are there any nuances to flying an MD that has NOTAR? Is the tail just as responsive as a T/R system? I understand the mechanics and the physics behind it all. I am just curious about the pilotage component. Any differences?

 

I may be going up in an MD600 (just for a ride - not a checkride) in a few weeks and don't want to sound like a total idiot among my buddies (oops - I hope they aren't reading this)

 

Thanks!

[T tail]

Not as responsive as a nomal two bladed T/R..quite spongy feels like a bit like a 4-bladed T/R if you've flown one of those. Can handle wind coming in from different angles pretty good

 

 

Have fun TT

[Helilog56]

I only have about 90 hrs in one, but here is my take on them. The Notar system used more power to drive the feneston style fan than the design engineers calculated, the C20R+ does the job at the lower altitudes and temps, but performance really drops off quickly when D.A.'s go up.....the short of it is, it's under-powered.

 

Other than that it is a nice aircraft to fly, the yaw authority is managed quit nicely by the aircraft itself. A touch heavier on the tail, but not a real worry with no blades to strike anything back there.

 

Interesting note, it is a seperate endorsement on your Canadian pilot's licence.

 

They never really caught on here in Canada, I believe Helimax in Quebec operates 2 or 3 of them, unless someone knows of any others??

[mountainflier]

Thanks TT and Helilog56!!

 

Your feedback helps quite a bit.

 

If anyone else can tell their experience or stories, I would be most appreciative!

[Bif]

Maybe this is a silly question (quite likely actually), but I was reading about NOTAR's as well recently for curiosity's sake. I'm getting hung up on the wording/physics involved. How does one "pump" low pressure air out of the tail? Doesn't the act of pumping automatically pressurize said air?

 

Someone set me straight please

[Bif]

Taking my info from wikipedia, in case you were wondering

 

"A variable pitch fan is enclosed in the aft fuselage section immediately forward of the tail boom and driven by the main rotor transmission. This fan forces low pressure air through two slots on the right side of the tailboom, causing the downwash from the main rotor to hug the tailboom, producing lift, and thus a measure of directional control. This is augmented by a direct jet thruster and vertical stabilisers."

 

 

Or is the "jet thruster" doing the majority of your yaw control?

[porter]

Maybe this is a silly question (quite likely actually), but I was reading about NOTAR's as well recently for curiosity's sake. I'm getting hung up on the wording/physics involved. How does one "pump" low pressure air out of the tail? Doesn't the act of pumping automatically pressurize said air?

 

Someone set me straight please

 

The term pressure is relative. It is relatively ‘low’ compared to the air coming from the main rotor. Thus the term low pressure air, because it is meeting “higher” pressure air on the slots exit.

[twinstar_ca]

They never really caught on here in Canada, I believe Helimax in Quebec operates 2 or 3 of them, unless someone knows of any others??

 

HAWCS started with an MD520N which was replaced by an EC120... other than heli-max, can't say i know of any others. there was a fellow who had an MD600 for his construction business, i believe, but i don't know if it's still around..

[skullcap]

From what I understand the thruster on end is only for additional control such as sidewards flight, crosswinds or pedal turns. The slot on side of boom which has low pressure air pumped out of it thus causing the boom to become wing(coandra effect) is what counteracts torque.

[Guest Angry Egg Driver]

The MD600 actually has a Rolls-Royce Allison Model 250-C47M,rated at 603 kw (808 shp), derated for reliability and safety to: Takeoff 447 kw (600 shp) Max Continuous Power 395 kw (530 shp).The 520N has the C20R+.

Rupertsland ran a few 600's and Interior helicopters is just in the process of bringing one into Canada for moving drills.