The list of small plane crashes in Alaska in the past month continues to grow.

Monday afternoon, a Cessna 170 crashed and flipped on its nose off a Lake Hood runway. The pilot, Joseph Gugel, walked away uninjured.

While National Transportation Safety Board officials are investigating the cause, they have their plates full with other investigations that are going on around the state.

With a combination of crashes and mid-air collisions piling up, there has been some alarm over what's happening in Alaska’s skies.

It’s concern that the NTSB says all depends on the situation.

“I had a chance to talk to the pilot. He was uninjured, but there was substantial damage to the airplane,” said Clint Johnson, an investigator with the NTSB who talked about Monday’s Lake Hood crash.

“On rollout indicated that he had a problem or a mechanical failure with the left brake—he was unable to maintain directional control.”

Crashes like the one near the village of Nightmute where two Cessnas, one piloted by Scott Veal and the other by Kirsten Sprague hit each other in the air.

“While they were maneuvering around each other, she lost site of the Cessna 208, the next thing she knew is the vertical stabilizer of the Cessna 208 struck her right wing,” said Johnson. “The Cessna 208 basically spun out of control and crashed pretty much right after the impact.”

Veal was killed; Sprague walked away.

“In the 14 years I have been here, this is probably my fourth or fifth midair, so no they are not common, but they are not uncommon either by any stretch of the imagination,” said Johnson.

“You have to understand that each one of these mid-airs are different situations. They have different circumstances.”

With crashes near Nightmute, McGrath, and in Lake Hood all in the past week, the investigations into the causes are still in the preliminary stages.