Can you see me now? Lakebeds 'restriped'

  • Published
  • By Rebecca Amber
  • Staff writer
Edwards Air Force Base is a prime location for flight test, but not just because of the high caliber of test pilots, engineers and maintenance professionals who train and work here. In fact, it's the natural resources like the 64.55 square miles of dry lakebeds that make the area so ideal.

Each year, the 412th Civil Engineering Group makes repairs on the lakebeds in preparation for lakebed "restriping."

The stripes are created using environmentally friendly oil - SSH1. The markings designate the 18 runways on Rogers and Rosamond Dry Lakebeds.

"Without that it's just a big open expanse," said David Sampson, 412th Operation Support Squadron, airfield manager.

The company contracted for the job, EM Oil Transport Inc., started applying the SSH1 to Rogers Dry Lakebed July 7 and is expected to continue through the next several weeks. This year, the project was awarded $250,000 for materials and will cover the cost of restriping all active runways, the fly-by line and the Compass Rose.

The biodegradable oil is a water soluble mixture of 60 percent oil and 40 percent water. It replaced the petroleum tar-based product that was originally used to mark the lines. The new substance does not last as long, but it does minimize the amount of toxins released into the environment.

Each line is eight feet wide and each runway 300 feet, with only one exception; the South Base runway lakebed extension, which is 210 feet. According to Sampson, the lines were originally created that way because the uniformity is a visual cue for a pilot's depth perception.

"It's actually pretty difficult to land on the lakebed because it's so flat and featureless. When you're landing at a normal airport, you kind of unconsciously know how big houses are so you get a mental idea, without even thinking about it, how high you are," said Sampson, recalling his own experience with landing on the lakebed.

Sampson learned how to land on the lakebed from famous National Advisory Committee for Aeronautics (now NASA) pilot Scott Crossfield, who flew rocket planes in the 50s. His advice was to land like a seaplane, setting an angle of attack and a comfortable rate of descent then roll onto the runway.

In addition to visibility, the runway lines create a safe place for the aircraft to land. According to Sampson, the lakebeds are actually pluvial lakes formed during the last ice age and are about 20,000 years old. As weather conditions change, fissures or cracks can form in the surface of the lakebeds.

Repairs are difficult to make and only done on the runways - not the surrounding area. For smaller repairs, a batch mixer is used to mix lakebed material with water, creating a mud-like filling. Larger repairs require a layered approach that mimics nature. A layer of lakebed material is placed in the hole, wetted and then rolled out. The process has to be repeated until the hole is properly filled and had to be done before the re-striping.

"The thing we've learned over the years, we don't break the lakebed surface if we don't have to. What we'll do is bring in lakebed material from other locations along the lake," said Sampson.

The lakebed can naturally repair itself as wind and water moves the silt over the damaged areas, but it takes time.

"If we designate that a certain lakebed runway is in 'green status,' that means that it's good to go. It has no potholes or fissures and the pilot is guaranteed to have a smooth surface to land on," said Sampson.

The runways are all prioritized and the highest priority areas are marked first. This year, they started with the fly-by line, which is used for pitot static system calibrations. The "old fashioned" system is a manual way for an individual in the fly-by tower to verify a pilot's altitude indicator readings. Circles are placed every quarter-mile along the fly-by line as distance references.

Towards the end of the striping for this year, the iconic Compass Rose will receive a new layer of SSH1. The Compass Rose was originally laid out to give pilots orientation to the rest of the lakebed runways. However, it was set up according to magnetic north - not true north. Since magnetic north moves, the compass rose is no longer entirely accurate.

"When it was laid down it was correct, but the magnetic variation has changed so much since then that it's now off by several degrees," said Sampson.

While it will still offer a relatively decent orientation, Sampson sees it as more of landmark today. The 4,000-foot diameter area can also be used as a landing area, but hasn't been used that way in many years.

Michael King, assistant airfield manager, noted that airfield management always treats the lakebed with the utmost respect because it's "a national asset; we need to protect it as much as possible for future generations and events."

In its early days, the lakebed supported almost all initial flights of new aircraft. In the event of a landing gear malfunction or directional problems, a pilot could land safely in the big, flat, clear expanse. Rocket powered aircraft and lifting bodies, which landed without power or conventional wheeled landing gear, had ample space to skid out on landing.

For similar reasons, the Space Shuttle landed on the lakebed in the 1970s and 80s. In the flight test stages, it was launched from the back of a 747 and landed on the lakebed. Until the orbiter was ready for paved runway landings, it continued to land on the lakebed from space.

Today, the lakebed is used primarily for emergency recoveries and U.S. Air Force Test Pilot School training. Although less often, the lakebeds are also used for flight test. Most recently were the Phantom Eye hydrogen-powered aircraft, RQ-4 Global Hawk cross wind testing and F-35 acoustic testing.

"The lakebed is still a great, safe place to recover if experiencing a gear malfunction," said Sampson. "In the last 15 years or so, we've had a B-1, C-5 and F-16 land on the lakebed when they were unable to safely extend all or some of their landing gear."

"History is heavy out there on the lakebed, you can just feel it."