Rotorcraft Weight Estimates Utility

[Whimlew]

I've implemented Raymond W. Prouty's rotorcraft weight estimates utility (http://gliesians.com/rotorcraft-weight-estimates-calculator.faces).

It's been some time since he detailed out the components that could/should be weighted. I'm curious as to what is missing based on the design of newer rotorcraft. This is what the utility does now (Can anyone call out what's missing based on the components in newer aircraft?):

=================================
Item Estimate Weight
=================================
Rotor Group
Main Rotor Blades 927.46 lbs.
Main rotor hub and hinge 754.85 lbs.
Tail Group
Horizontal stabilizer 35.85 lbs.
Vertical stabilizer (Fin) 103.26 lbs.
Tail rotor 173.95 lbs.
Propulsion Group
Engine installation 1127.0 lbs.
Propulsion subsystems 128.64 lbs.
Fuel system 73.44 lbs.
Drive system 1867.25 lbs.
Flight Controls Group
Cockpit controls 38.2 lbs.
System controls (boosted) 172.06 lbs.
Standalone Groups
Body (Fuselage) 1858.1 lbs.
Alighting gear 530.33 lbs.
Nacelles 253.22 lbs.
Auxiliary power plant 150.0 lbs.
Instruments 171.95 lbs.
Hydraulics 89.04 lbs.
Electrical 546.58 lbs.
Avionics 150.0 lbs.
Furnishings and Equipment 638.68 lbs.
Air Cond. & anti-ice 160.0 lbs.
Manufacturing variation 80.0 lbs.
=================================
TOTAL EMPTY WEIGHT: 10029.86 lbs.
=================================

[500guy]

The more stringent crash worthiness requirements put in place in the 90's have made fuel systems, seats and some other structural members heavier. there may be some weight savings in avionics. But all in all that is not to far off. going for a 20,000 gross weight sounds like the target build is a S-61 or similar sized aircraft. I've never flown one but I've head 10-12k empty weight depending on variant and configuration. That's with no AC though!

[212man]

13 decimal places of a pound! What kind of scales are you using?

[[email protected]]

Ah but have you checked the atomic weight of the materials;)

[Whimlew]

two decimals now, thanks for pointing it out....

======================================================
Item Estimate Weight
======================================================
Rotor Group
Main Rotor Blades 927.46 lbs.
Main rotor hub and hinge 754.85 lbs.
Tail Group
Horizontal stabilizer 35.85 lbs.
Vertical stabilizer (Fin) 103.26 lbs.
Tail rotor 173.95 lbs.
Propulsion Group
Engine installation 1127.0 lbs.
Propulsion subsystems 128.64 lbs.
Fuel system 73.44 lbs.
Drive system 1867.25 lbs.
Flight Controls Group
Cockpit controls 38.2 lbs.
System controls (boosted) 172.06 lbs.
Standalone Groups
Body (Fuselage) 1858.1 lbs.
Alighting gear 530.33 lbs.
Nacelles 253.22 lbs.
Auxiliary power plant 150.0 lbs.
Instruments 171.95 lbs.
Hydraulics 89.04 lbs.
Electrical 546.58 lbs.
Avionics 150.0 lbs.
Furnishings and Equipment 638.68 lbs.
Air Cond. & anti-ice 160.0 lbs.
Manufacturing variation 80.0 lbs.
======================================================
TOTAL EMPTY WEIGHT: 10029.86 lbs.
======================================================

[Whimlew]

Thank you for your response and your detailed information. :)