Mid-air collision in Boulder, CO

There has been a mid-air collision in Boulder, CO.

Four people died aboard a Cirrus, which is shown on an accompanying video descending under its Cirrus Airframe Parachute System while trailing thick black smoke. One person aboard the tow plane was killed. As I write this, the article does not say how many people were aboard the tow plane. It’s possible there was only one. The glider pilot was able to self-detach and returned to the airport.

The crash occurred outside of controlled airspace.

How terrible. My prayers go to the families and friends of all involved.

That is a very busy muncipal airport. My kids play soccer right where the collision occured. If this had happened in March or April, there would have been hundreds of kids and their families right below the collision (although the debris drifted away from the fields.)

Amazing that there were three aircraft involved and the one that landed safely was a glider. The airport is about one mile east of the foothills of the Rockies and it is a paradise for gliders riding the thermals.

It’s usually the case that only the pilot is in a towplane: with less weight aboard, tows are quicker and burn less gas. And one common towplane is a Piper Pawnee, which has just a single seat.

I’ve flown gliders out of Boulder, so very possibly behind that towplane (it’s a busy operation and they have several).

I assumed that. Thank you for the confirmation. (And I’d forgotten about the Pawnee. I was imagining a Cessna 185.)

The article said the glider released prior to collision. I question whether the Cirrus hit the tow wire. It doesn’t make sense that a tow wire strike would cause a fire in both planes. sounds more like a solid collision with both planes.

Checking, it appears the the soaring operations at Boulder (there’s a club and a commercial operator) tow with both Pawnees and Super Cubs. The Super Cub could carry a passenger, but probably would do so only rarely (it’s thought of as somewhat underpowered for tows from 5288’ MSL).

I never imagined a Super Cub could tow a glider. You learn something new every day! Do they have bigger engines than stock?

I have a report from a glider pilot saying that a towpilot on the ground saw the collision, which happened when the Cirrus hit the Pawnee (not the tow rope). The report said that the Pawnee was using one of the standard Boulder tow patterns. The Cirrus would probably have been flying substantially faster than the Pawnee and sailplane (which typically climb at an indicated airspeed around 60 knots).

They are speculating that the Cirrus was a transient aircraft whose pilot may not have been well familiar with Boulder operations. But this is not confirmed.

Ya gotta love stories like this one, obviously posted within hours of the crash when details are not known. A clever touch is the stock picture of a glider (obviously not taken at Boulder) with the caption “Gliders pose a danger to larger aircraft.”

For towing, a 180-hp engine is favored (anything less than that is anemic, even at lower altitudes). I don’t know of a Super Cub with more than 180 hp.

The Aviat Husky is a Super Cub derivative with 180hp, and it has a pretty good reputation as a towship.

It’s good to see that a 12-year-old’s submission to the jr. high school paper is getting national exposure.

At least he didn’t say the crash happened because one or more of the pilots hadn’t filed a flight plan.


A good friend of mine died in a head-on collision between gliders on a ridge in the alps five years ago.

Since then, a lot has happened in Europe with collision warning systems.

FLARM has established itself mainly in the gliding community, with over 13,000 devices in operation. It works on the basis of sending GPS position and barometric altitude over short range radio, and detects possible collisions through flight path prediction.
FLARM devices are more precise and much cheaper than TCAS systems, and as portable devices don’t need certification.

I understand the adoption in the US has been slow, because a critical mass of devices is needed before their use makes sense.

This has been adressed with the PowerFLARM, which is designed for use in powered airplanes. It combines FLARM with GPS signals broadcast by the new ADS-B transponders and therefore has a much higher initial user base. It’s available from April this year.

I’m not affiliated with them in any way, but I try to promote the use of such systems, and hope that accidents like this are not as common in the future.

I looked a bit more closely and found some truly goofy stuff in that article:

It’s actually 18,000 ft.

Deep aerodynamic insight here.

One instrument measures airspeed, but that’s quite a bit different from wind.

Very amusing - the towplane never follows a glider.

Boulder has no tower. There are standard radio procedures which very likely were followed. And reports seem to make it clear that the collision didn’t involve the glider.

There’s also:

I keep wanting to ask, ‘Current regulations state that any aircraft that doesn’t run on electrical driven systems WHAT?’ But…

I’m not an accomplished writer, so I guess I just don’t understand the rules of syntax and composition.

Browning went back and changed the article. Unfortunately, I did not find a cached version of the original article on google. In any case, the article is now pointless. In the original version, Browning blames the crash on the presumed lack of transponders. (The Pawnee and the Cirrus no doubt had them.) He went on to make a number of factual errors, apparently making the point that if gliders carried transponders then these things wouldn’t happen. Or something. Now that he’s changed it, he starts out on his original original tack, then abandons it after the first paragraph and merely states the obvious: There was a mid-air collision, it would have been worse if it happened over buildings, and the Cirrus pilot (implied) might not have seen the glider. Uh… yeah. A fair percentage of mid-airs occur when at least one pilot doesn’t see the other. :smack: :rolleyes:

I read the comments last night. There were 17. Every one of them criticised the article and pointed out some of the factual errors. One or two complained that earlier comments had been deleted. This morning, there are two comments. Yep, William Browning wrote an unbelievably poor, amateurish article, got called on it, and then deleted the comments pointing out his many errors in fact and conclusion.

Hey, I just looked up ‘pusillanimous’ in the dictionary, and William Browning’s picture is in the definition.

I spoke to a soaring friend in Boulder, who had some additional info (which is probably fairly accurate, but not necessarily perfect):

The towplane had a transponder on board. (The Cirrus almost certainly did as well.)

The glider was a ride: a commercially rated pilot was carrying two passengers (there is one model of glider that can carry three people). One passenger had a video camera which recorded the collision. The NTSB (National Transportation Safety Board - responsible for investigating accidents) now has that video.

The collision happened around 2000’ AGL and was definitely between the Cirrus and the towplane - not the Cirrus and the towrope. The Cirrus caught fire and burned all the way to the ground, where it was almost entirely consumed by fire. The Pawnee lost one or both wings and went rapidly to the ground.

Despite some reports of five fatalities, the correct total seems to be three: two aboard the Cirrus and the pilot of the Pawnee.

The Cirrus was apparently a transient aircraft, not based at Boulder or a nearby airfield. My friend says that the proximity of Colorado University and the scenic vistas make this a popular area for sightseeing flights, which have been something of an issue in the past. There is plenty of notice about the level of routine activity (including gliders) at Boulder, but pilots not from the area aren’t always aware of this.

Nice of him to let us know.

Reminds me of that old quote: “The louder he spoke of his honor, the faster we counted our spoons.”

Well, he accomplished the feat of putting words on a website – maybe not accurate ones, but he wrote them.

Not to dispute that the article is idiotic, or that it has anything whatsoever to do with this tragic accident, but per FAR 91.215, b, 5, i, mode C transponder is in fact normally required above 10000’ MSL in the lower 48. My understanding is that because the 250 kts speed restriction is no longer in effect above 10000’, a transponder gives those fast moving aircraft (which almost certainly has TCAS onboard) a fighting chance of not hitting you. Visual collision avoidance is simply not practical at that kind of speed.

Sorry - you are correct. I was giving the altitude above which it’s required for a sailplane.

Ok, no problem. That does make sense.