Rotorcraft Design for High-Altitude Rescues (Questions Surrounding Mission…
Rotorcraft Design for High-Altitude Rescues
Step 5: Check if specifications are met and repeat step 4 if conditions are not met
Step 4: Make adjustments, incorporate adjustments and re-iterate through calculations
Step 3: Carry out calculations and check with RFP if technical specifications are met.
Step 2: Come up with a possible design of our own
Step 1: Familiarise ourself with mathematics and design steps of a conventional rovercraft
Things to Remember
It's just 100 pages + 20 pages for altairs design task ! Eazy Peazy!
We got a team of 4 hard-working great individuals! We can do this!
Past Winners have extremely innovative and creative ideas that stray from the norm
THIS IS A DESIGN COMPETITION! THINK OUTSIDE THE BOX!
Challenges of Flying in Mountainous Terrain
Severely Reduced Cruising speed at higher altitudes
Due to RBS and VNE
Eg: Bell 206B at gross weight with a Vne of 140 mph at 3,000 feet will be limited to 84 mph at 10,000 feet.
An Autorotation at this altitude would be deadly, due to lack of landing zones
High Density Altitude
Lack of safe landing sites, if any.
As oxygen’s partial pressure is reduced with height, human efficiency drops rapidly.
The rotor blades are less effective in the less dense air, the overall lifting efficiency of the helicopter is further degraded
If we are working in hot and high conditions, this is the worst as the heat increases density altitude. Increasing ambient temperatures makes air even thinner due to lower ambient pressures.
HOGE and HIGE
Gusty winds or unplanned C of G changes with passenger movement while loading or unloading
Updrafts provide additional lift – often exceeding the power loss we suffer with altitude.
Conversely, downdrafts of 1,000-2,000 fpm will exceed best climb rates and the turbulence within can easily cause your bone dome and cockpit ceiling to merge
A further difficulty when flying in mountains is determining the horizon’s location - Causes disorientation and leads pilots to fly low when approaching ridges
Questions Surrounding Mission Profile and Design
Can the rovercraft operate in night-time conditions along with icing?
How do we increase Service ceiling?
Is it affordable/comparable to other crafts of its type?
What else can it be used for?
Is it easy to operate?
Easy to manufacture?
Reliable and feasible?
Easy to maintain?
Does it meet technical requirements?
What are the most pressing issues around rescue at high altitudes?
Can the landing gear move around the aircraft to match landing surface?
Is the design "Creative" and "Innovative"?
How high can we get the rovercraft?
Do we need to land the rovercraft at all?
What about powered flight on the way up and then autorotation on the way down?
Examples of High Range, High Service ceiling rotorcraft
Lockheed - AH-56A_Cheyenne
Examples of Rescue Rotorcraft
Aerospatiale AS 332 Super Puma
SA315B LAMA (Highest Ever Altitude Record)