Photo: Copyright ©1995 Chuck Clark. All Rights Reserved
This frame is dominated by the largest hangar of Area 51, the infamous Hangar 18, officially designated Building 430. It can accommodate the largest aircraft in USAF inventory, up to aircraft with over 230ft wingspan. It is approximately eight stories tall, so it can accommodate anything with a low enough vertical tail-plane (the B747 tail is about 6 stories high). The doors are separated into four sliding sections for ease of opening and closing. One door section can be opened for ventilation while at the same time not allowing spy satellites to view inside.

Hangar 18 is probably not "owned" by one company (such as Lockheed or Northrop), but rather used for projects as needed. Most likely it is simply a multi-purpose maintenance hangar. Sometimes Janets can be seen on the ramp just north of it, and we believe that it is used, at least in part, for maintenance on the Janet fleet. Especially given the absence of any large maintenance hangars at the Las Vegas Janet terminal.

Other speculations about its use include:

• A dedicated QRA hangar for quickly hiding aircraft when a spy satellite flies over.
• An Atmospheric controlled environment hangar; however it lacks roof top ventilation and other features.
• A large development Hangar.
• Storage hangar.
• A hangar used to mount drones on a "mother ship" for launch at high altitude.