Rotorcraft Design for High-Altitude Rescues (Questions Surrounding Mission…
Rotorcraft Design for High-Altitude Rescues
Examples of Rescue Rotorcraft
SA315B LAMA (Highest Ever Altitude Record)
Aerospatiale AS 332 Super Puma
Examples of High Range, High Service ceiling rotorcraft
Lockheed - AH-56A_Cheyenne
Questions Surrounding Mission Profile and Design
Do we need to land the rovercraft at all?
How high can we get the rovercraft?
Is the design "Creative" and "Innovative"?
Can the landing gear move around the aircraft to match landing surface?
What are the most pressing issues around rescue at high altitudes?
Does it meet technical requirements?
Easy to maintain?
Reliable and feasible?
Easy to manufacture?
Is it easy to operate?
What else can it be used for?
Is it affordable/comparable to other crafts of its type?
How do we increase Service ceiling?
Can the rovercraft operate in night-time conditions along with icing?
What about powered flight on the way up and then autorotation on the way down?
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
Things to Remember
THIS IS A DESIGN COMPETITION! THINK OUTSIDE THE BOX!
Past Winners have extremely innovative and creative ideas that stray from the norm
We got a team of 4 hard-working great individuals! We can do this!
It's just 100 pages + 20 pages for altairs design task ! Eazy Peazy!
Step 1: Familiarise ourself with mathematics and design steps of a conventional rovercraft
Step 2: Come up with a possible design of our own
Step 3: Carry out calculations and check with RFP if technical specifications are met.
Step 4: Make adjustments, incorporate adjustments and re-iterate through calculations
Step 5: Check if specifications are met and repeat step 4 if conditions are not met