Turbulence to Blame in Wake of Sport-Jet Crash

Turbulence to Blame in Wake of Sport-Jet Crash

By Jeff Mattoon

“A police helicopter maintenance crew across the runway saw the whole thing. One of the guys, who had spent twenty-some years in aviation, said he thought by the time he got to the accident he’d see carnage everywhere. But when he got to the wreck, he saw two guys sitting on the ground, and one of them was using his cell phone to take pictures.”

The Sport-Jet shown over Colorado Springs in one of its nearly flawless test flights.

The Sport-Jet shown over Colorado Springs in one of its nearly flawless test flights.

It had the potential to kill, but the crash of the Bob Bornhofen designed Excel-Jet Sport-Jet on June 22 resulted in the incredible saving of two lives. Wake turbulence is being blamed for the crash that destroyed the proof-of-concept very light jet.

“The plane couldn’t have done anything differently to counteract wake turbulence, but what it did—which everyone, especially the insurance people, think is remarkable—is save two lives,” Bornhofen continued.

The Sport-Jet had logged some 25 hours of nearly flawless test flying and was receiving complete praise from test pilots when the accident occurred.

According to Bornhofen, test pilot James Stewart and eyewitnesses, at approximately 9:30 a.m., Stewart was cleared for takeoff on Runway 17 at Colorado Springs Municipal Airport (COS).

Stewart rotated somewhere short of 2,000 feet at full power. The Sport-Jet, at 30 to 50 feet off the ground, immediately rolled to the left 90 degrees. Both Stewart and test flight engineer John Welty, in the right seat, applied full right controls, with little effect.

Unable to maintain lift at that roll angle, the Sport-Jet settled back to the runway, and the left wing contacted the ground. The plane continued down the runway with the left wingtip dragging, gradually moving toward the left edge of the concrete.

When the wing hit dirt, the Sport-Jet cart wheeled, crushing and tearing off the nose, and spinning to tear off the tail. Completing one more revolution, it came to rest on its belly, pointed in the general direction of the runway.

With the engine still racing at full power, Welty shut it down and climbed out of his seat.

“Inside the aircraft, I saw lots of blood—my blood,” Stewart recalled. “I knew that, because I could see John clearly and he was fine.”

Welty then dragged Stewart from the aircraft, and they waited for help to arrive.

No surprise—it’s in the design

From the beginning, Bornhofen has asserted his Sport-Jet was designed for maximum safety and insurability, and in dramatic fashion, it appears some of his assertions are correct. At least two people would wholeheartedly agree. Stewart and Welty are in complete agreement when describing their experience with the Sport-Jet crash.

“I live today because the aircraft and its design allowed that to happen. I would absolutely love to fly the Sport-Jet again,” says Stewart.

It will be some time before Stewart or anyone else gets that chance, but Bornhofen insists the project will continue.

Ominous clouds hang over the wreckage of the Sport-Jet. The totally destroyed nose was instrumental in absorbing tremendous crash forces.

Ominous clouds hang over the wreckage of the Sport-Jet. The totally destroyed nose was instrumental in absorbing tremendous crash forces.

“We have investors who are even more impressed with the Sport-Jet now. In fact, we have a launch-order customer committed for an initial purchase of 100 aircraft with option for 200 more,” he said. “They haven’t lost enthusiasm.”

Another amazed party is the insurance company.

“I was extremely impressed with how well the fuselage remained intact under the tremendous forces imposed upon it during this accident,” says AirSure’s Gary Czajkowski.

In part, that amazement is due to the fact that the engine mostly stayed put. No fuel lines were severed, resulting in no spilled fuel. Some would call it luck, but Bob Bornhofen will tell you something he’s been saying all along—it’s part of the design.

“No fuel spill is significant,” he said. “That’s where you have fire and things get out of control quickly. We removed the aft fuselage and dissected all inlets relative to engine mounts. The engine tried to move forward, but the inlets and mounts held as designed. Even though they were compressed, they didn’t allow the engine to move forward.”

In its preliminary report, the NTSB indicates the Sport-Jet “had no mechanical failures.” The plan is now to regroup with investors and begin production of the conforming aircraft sometime in the near future.

In light of the fact that two people walked away from a crash in his aircraft, and in spite of the total loss, Bornhofen is especially thrilled.

“We spent the week (following the crash) reviewing what design changes we might make, and we really can’t come up with anything,” he said. “I’m not sure what we would change because everything responded so well—and we don’t want to change anything for fear we might not get the same results.”

Big questions, interesting answers

The events surrounding the crash of the Sport-Jet create numerous questions and beg equal answers. With all indications pointing to a wake-turbulence crash, the first and obvious question is why.

Colorado Springs Municipal Airport, which has three runways, now utilizes a combined runway for general aviation, military and commercial operations, where they once were separate. GA aircraft enter the runway from the west and commercial traffic from the east.

When Stewart received clearance for takeoff, he had no idea what kind or if any aircraft had recently taken off. He said that due to construction, pilots entering the taxiway on the GA side of the runway can’t see other aircraft from the commercial side entering or departing the runway.

Consequently, pilots must rely completely on air traffic control to notify them of potential wake turbulence. ATC officials claim a warning was given, but Stewart is emphatic that no warning was given. Investigators will listen to tower recordings and draw a conclusion.

Preliminary NTSB investigations reveal that one minute and 28 seconds prior to the Sport-Jet taking the runway, after being cleared for takeoff by ATC, a Dash 8, which outweighs the small jet—according to Stewart, by a factor approaching 10:1—had taken off. The recommended time to wait is three minutes, and that’s for aircraft that have no more than a 3:1 weight ratio. The problem is not with the Dash 8, but with the type of aircraft it is and its capabilities.

“Pilots need to be aware that the Dash 8 is out there,” Stewart warns. “There’s nothing wrong with that airplane; it just has a lot of power, and it has GA characteristics—that is, it takes off and lands in a very short distance. That means it’s leaving wake turbulence in the same place (on the runway) where GA aircraft operate. That’s a problem.”

It’s a problem because prior to this crash, according to Bornhofen, there were some 29 wake-turbulence accidents on file and nearly all were fatal. To understate the issue, it’s a problem if pilots of light aircraft don’t fully comprehend the negative effects of wake turbulence on their aircraft. It’s especially concerning if ATC operators don’t fully grasp the effects and consequences.

At this point, a definitive conclusion by investigators hasn’t been reached, and responsibility for the accident hasn’t been given, but all indications point in one direction: a lack of ATC creating adequate separation on takeoff between a large and powerful aircraft and a light one, especially considering GA-like takeoff characteristics of the Dash 8.

Stewart, who is a trained Air Force single-seat fighter pilot, is very clear in his thoughts regarding this.

All who have seen the cabin section of the wrecked Sport-Jet convey amazement that it wasn’t destroyed. Bob Bornhofen says he’s not surprised; it was part of the design.

All who have seen the cabin section of the wrecked Sport-Jet convey amazement that it wasn’t destroyed. Bob Bornhofen says he’s not surprised; it was part of the design.

“This was the only airport we flew from that we had actually visited the tower,” he said. “They knew the airplane by call sign, by type, by weight, the pilots, everything. On that day, they didn’t treat us like a light aircraft; they treated us like a large jet,” Stewart exclaims. “You expect these types of accidents from non-controlled airports, certainly not controlled ones. Wake-turbulence accidents shouldn’t exist. We have too much knowledge about how airplanes fly, we have too much information about weather data, and all we have to do is empower our tower people with that knowledge.”

According to the FAA’s Wake Turbulence Training Aid: “Tower controllers are responsible for runway separation for aircraft arriving or departing the airport. Tower controllers do not provide visual wake-turbulence separation to arrival aircraft; that is the pilot’s responsibility. Tower controllers do provide wake-turbulence separation for departing aircraft by applying time intervals. Pilots may request a waiver to the wake-turbulence departure separation and the tower controller will then issue a caution wake turbulence advisory and clear the aircraft for takeoff provided no other traffic conflict exists.”

There is no current requirement of the pilot in charge to acknowledge the warning. The guidelines for avoidance of wake turbulence and who is responsible for such avoidance seems to be black and white, and it is for IFR, but upon further examination, there’s room for interpretation when operating VFR.

For example, with respect to departing aircraft, “Air traffic controllers are responsible for applying appropriate wake-turbulence separation criteria for departing aircraft.” That’s fine, but the criteria by which they sometimes judge the necessity for a warning can be vague.

For example, the guidelines suggest the following: Wake-Turbulence Departure Separation Criteria

Separation criteria (listed by aircraft wake turbulence weight categories and runway situation) are as follows:

• Same or (emphasis added) parallel runways separated less than 2,500 feet:

– Small/large/heavy behind heavy – 2 minutes (same direction).

– Small/large/heavy behind heavy – 3 minutes (opposite direction or intersection departure).

• Same runway:

– Small behind large – 3 minutes (opposite direction or intersection departure).

The Sport-Jet piloted by Stewart was on the same runway as a heavier, but not “heavy” aircraft going in the same direction, so the separation should be two minutes, right? Or since the Dash 8 isn’t a heavy, maybe the separation could be less than two minutes?

The same scenario falls under the second bullet point for “Same Runway,” where small is behind large with a suggested separation of three minutes. Hmmm. What’s an ATC to do?

This apparent lack of clarity should warn all pilots: Be the responsible party when determining wake turbulence. Wake turbulence is a mostly invisible and silent killer that gets you at precisely the wrong time in a flight—when the ground is close. Know the airport you’re operating from and know whether there’s a chance for heavier aircraft taking off or landing in front of you. Of course, this is Aviation 101.

In the case of COS ATC, controllers could have recognized the visual obstructions and offered more information to the departing small jet. In turn, the PIC could have recognized the same and requested information on recently departed or arriving aircraft. Many would say that at a controlled airport, it’s not the PIC’s responsibility for asking for this information.

In the case of the Sport-Jet crash, James Stewart has a very clear point of view.

“The purpose of a tower at an airport is to provide safe operations both on the airport and exit and entrance into the airspace, and they clearly failed miserably,” he said.

Bornhofen offers a more pragmatic opinion.

“One thing in particular we hope comes out of this is a review of ATC procedures with respect to VLJs,’ he said. They really handle more like a GA aircraft than a corporate jet and a three-minute hold versus a two-minute hold is what needs to be done.”

Bornhofen also suggests a series of wake-turbulence safety seminars should be developed specifically for VLJs at least. He also suggests that better controller education should be offered as well.

Intact cabin and a banged head

Considering the violence of the crash, it’s amazing Stewart and Welty literally walked away from it. If it weren’t for a motorcycle-sized battery used to power recording equipment for a wireless camera mounted on the exterior of the aircraft, this would have been a bloodless crash.

Neither Stewart nor Welty spent the night in the hospital. In fact, Welty never went to the hospital. The battery, which was unrestrained, became a projectile, hitting Stewart on the back of the head and creating a gash that required stitches.

“It weighed 23 pounds; the only thing that prevented my decapitation was a small amount of force absorbed by the seat headrest. Otherwise, I would’ve had a really bad day,” quips Stewart.

At this point, the final lesson learned, or at least brought to our attention, is the absolute necessity to tie fast any loose items in the cabin.

Speaking of the cabin…in this crash, the Sport-Jet cabin, designed with roll cage features, did its job. According to Bornhofen, there was no cracked glass, and the door worked perfectly—a certain factor in the two men walking away from this potential tragedy.

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