Hummingbyrd VTOL Personnel Dropship

[Jamie Logan]

Hello, everyone!

 

 

Recently, I took a break from my usual space-faring missions to build a new VTOL dropship. The Hummingbyrd VTOL has four Panther engines which are mounted on hinges that allow the aircraft to alternate between VTOL and forward flight postures. The decision to use Panther engines was made because of their ability to make instantaneous thrust changes via the afterburners, which helps tremendously when landing. The engine housings use two sets of small internal docking ports with one of each offset to the other engine to allow for each set of engines to remain coupled despite no actual axle passing through the engine mount. The downward-facing payload bay contains an extendable crew bench, allowing for quick on-loading and off-loading of passengers. The crew capacity is 10: two pilot seats and 8 seats in the payload bay. The vessel is 119 parts.

 

Notice the highlighted docking port in the far engine housing, as well as the corresponding un-highlighted port in the near housing. Both are attached to the opposite engine housing, but remain docked to the non-offset port in the same engine housing. This prevents flight/aerodynamic forces from causing asynchronous engine rotation, leading to unbalanced thrust and instability.

 

 

 

Shown above is the center of thrust, mass, and lift placement while in VTOL mode. While in this posture, all three are collinear in the dorsal-ventral axis. All tanks with fuel in them are laid out with symmetry front-to-back, allowing the C.O.M. to remain stationary regardless of fuel levels. This is critical for VTOL operations, as any significant deviation of the C.O.M. from the net thrust vector will cause a persistent pitch bias.

 

Shown below is the center of thrust, mass, and lift placement while in forward flight mode. While in this posture, the C.O.M. is offset forward of the center of lift due to the redistribution of engine mass, leading to improved stability while in forward flight. The rear engine set is offset above the longitudinal axis to the same extent that the forward engine set is offset below, allowing the net thrust vector to remain in line with the C.O.M.

 

Action Groups:

AG1) Toggle engine orientation

AG2) Toggle afterburners

AG3) Toggle landing gear

AG4) Toggle payload bay doors and piston lock

AG5) Toggle piston extension

 

Gallery:

 

I hope you liked it! This ship is a joy to fly, and I highly recommend you try it out!

Craft file: https://kerbalx.com/Jamie_Logan/Hummingbyrd

 

 

 

Also, Check out my last mission:

 

Edited May 13, 2020 by Jamie Logan