NOTAR helicopters

tracker-man

hey lads,
posted this over on my own forum thought some of you might also be interested!:) Aviation And Aircraft

"NOTAR is an acronym for NO TAil Rotor, developed by McDonnell Douglas Helicopter Systems which eliminates the use of the tail rotor on a helicopter, yielding quieter and safer operation"

I was absolutely amazed to see this, fantastic engineering!

Delta Kilo

What is the science behind them and why is there a requirement for not having a tail rotor?

EDIT: Just seen a diagram on how they work. Pretty cool actually and relatively simple. Here is the diagram:

View Profile

You'd think most military choppers would utilise this design.

Quite simple and clever.

ch252

I guess it's a pretty new concept and the way of the future sure! Thanks for sharing tracker..:)

andy_g

seen this design about a year ago hasnt been much development on it good find tracker

Flyboy!!!

View Profile wrote: »

You'd think most military choppers would utilise this design.

Blackhawks have the tail rotor angled slightly to add an extra bit of lift. As for others, I just don't know...

Way I understand it, the Notar works much the same way the directional control works on a hovering Harrier...?

Stimpyone

It's been around for ages.

http://www.aerospaceweb.org/question/helicopters/q0034.shtml

By far the most recent yaw control strategy developed for helicopters is the NO TAil Rotor (NOTAR) design. NOTAR was first developed by McDonnell Douglas during the 1980s and applied to a modified OH-6 Cayuse. The concept proved so successful that the company began marketing dedicated NOTAR spinoffs of the successful MD 500 family including the MD 520N. The NOTAR system operates by forcing moving air out of slots located on the tail boom. The interaction of this air flow with the downwash of the main rotor is such that it creates a force that opposes the torque of the main rotor. While there are some complex aerodynamics involved, the general idea is to replace a spinning tail rotor with a jet of compressed air squirting out of one side of the tail boom. Varying the strength of the jet gives the pilot yaw control over the helicopter. The NOTAR system is currently available on a number of commercial helicopters including the MD 520N, MD 530N, and MD 600N, and has even made some Hollywood appearances (such as Speed, featuring the lovely Sandra Bullock and the "talented" Keanu Reeves). Though the NOTAR arrangement still requires a long tail boom, the need for a spinning tail rotor is eliminated. This reduces the danger to ground crew, and also allows the pilot to maneuver into positions that he or she normally would not even consider. For example, NOTAR allows a pilot to stick the tail boom into a tree. Try that with a standard tail rotor, and it will be time for an unscheduled landing.

Nforce

Yep, they've been out for ages. I remember seeing a NOTAR MD500 at an Air Spectacular in Baldonnell back in the mid 90's.