UAE bins BAE

[Modern Elmo]

About the Merlin’s alleged lower noise and suitability for Search And Rescue missions: Here’s a comparison of disk loadings for SAR rotorcraft candidates:

http://www.aerospace-technology.com/...s92/specs.html

S-92

max. Gross Weight ( internal load ) – 11,862 kg
Rotor radius – 8.6 m



CH-47D-47E

http://www.army-technology.com/projects/chinook/specs.html


max. Gross Weight - 24,494 kg
rotor radius - 9.15 m ( each rotor )

http://en.wikipedia.org/wiki/Merlin_helicopter

Merlin HM1

Max. takeoff weight (?) – 15,600 kg
Rotor radius – 9.3 m

http://en.wikipedia.org/wiki/V-22_Osprey#Specifications_.28MV-22B.29

MV-22B

Max. takeoff weight – 27,400 kg
Rotor radius – 5.8 m ( each rotor )

Let’s compare disk loadings:

S-92 – 51.1
Chinook - 46.4
Magical Mystery Merlin – 57.4
V-22 – 129.7

I suppose Merlin was designed with a smaller diameter rotor to facilitate shipbard operation. However, higher disk loading has its drawbacks:

Quoting from the sometimes reliable Wikipedia:

“Disk loading

Disk Loading is the pressure (weight force divided by disk area) maintained over the swept area of a helicopter's rotor. A heavy helicopter with short rotors will have more disk loading than a light helicopter with long rotors.”

Higher disk loading also implies more noise and higher velocity and pressure downwash in hover, 'cuz highly loaded rotors is probably turning at higher angular velocity to induce/transmit equivalent (air mass*velocity^2)/2 to a smaller diameter virtual column of air, compared to a helo. with lower disk loading – Elmo

P.S. What is Merlin’s disk r.p.m. when three engines are operating? Does anyone know?