Was rocket moments from striking Continental flight?

2009-06-15: Because of recent events, I've made several corrections and updates to this article.

"Was rocket moments from striking Continental flight?" asks the headline of a July 3, 2008, article in the Houston Chronicle. Reporter Cindy Horswell's article begins by stating:

A Continental airliner might have been only a minute away from colliding with what the pilot described as a model rocket that shot past his cockpit window ...

But, according to the transcript quoted in the article, the pilot never mentions a "model rocket" ... and he does not describe anything as shooting past his cockpit window.

Terror in the Skies?

The article goes on to imply that the airliner may have been "only a minute away from colliding" with a "model rocket." But there's no evidence that the aircraft was "a minute away from colliding" with anything.

In fact, the article says:

The plane had then reached 4,750 feet elevation and was traveling at 277 mph, records show. [...] "Can you tell me what this is on my 12 o'clock (in front of his plane)? It's climbing about 20 miles up. Is that a rocket launch?" he [the pilot] asks.

The pilot just asks if a rocket was launched. He does not appear concerned. And "20 miles up" implies the alleged rocket was some distance from the aircraft. So, the aircraft was not "a minute away from colliding" with the rocket even if there had been a rocket.

And, we can discount out of hand the idea that a model rocket was involved. Model rockets reach a maximum of a couple thousand feet in altitude - much lower than the aircraft's altitude. So, we know for a fact that a model rocket cannot have been involved.

Larger hobbyist rockets, such as "High-Power Rockets" can, however, reach altitudes of 5000 feet and more. Was a larger hobby rocket involved? If so, it would have to have been a very large rocket. One that should have been easy to spot by those on the ground and by other aircraft.

Hobby rockets are launched ballistically. The are guided only by a short rod or rail on the rocket's launch pad and fins on the rocket itself. Once in the air, gravity causes the rocket's path to form a parabolic arc. To aim a hobby rocket at a moving target such as an aircraft, you would have to precisely determine the target's location, speed, and heading. You'd have to set the rocket's launch pad to point in the right direction (with an accuracy of a percentage of a degree). You'd have to set the angle of the launch rod or rail just right (again, to a fraction of a degree). Then you'd have to launch the rocket at just the right time (to a fraction of a second). Finally, the rocket would have to perform exactly as predicited in spite of any changes in the wind speed or direction.

Therefore, it's highly unlikely that a hobby rocket aimed at an airliner would come anywhere close to the aircraft. In fact, the US military tested the concept of using an unguided ballistic missile to shoot at aircraft. After thousands of tests, they found that it was nearly impossible to hit the aircraft.

A rocket which unintentionally comes near an aircraft is even more unlikely. Rocketry hobbyists do not launch their rockets when aircraft are in the area. And, even if a rogue rocketeer did launch when an airplane was near, the chances of the rocket coming close to the aircraft are very small. Not only would the rocket have to reach the same location as the aircraft, it would have to reach it at the same time the aircraft was there.

No rocket was seen from the ground or found after the event was widely publicized. So, considering the low probability that a hobby rocket would get near an airliner and the fact that no rocket has been linked to the event, we have to come to the conclusion that it is more likely that the pilots saw something other than a rocket.

So what did the pilot's really see?

Later in the article, an air traffic controller is quoted as asking another pilot if he saw a rocket launch in the area. The pilot responds "See some contrail up here, but that's about it."

And that's most likely what the pilots of the Continental airliner saw - a contrail (vapor trail) from another aircraft.

So, was a rocket moments from striking a Continental flight?

So we can now answer the question, "was a rocket moments from striking a Continental flight?"

The answer is definitely "No."

Did the pilots actually see a rocket? The answer is "most likely not."

What Me Worry?

The airliner did not change its course and there was no incident report filed with the NTSB. Nor was there a report of a "near miss" filed with the Aviation Safety Reporting System (ASRS). So it's apparent that the crew of Flight 1544 were not very concerned with what they saw.

Here We Go Again!

In June of 2009, new reports of a rocket seen by pilots appeared in the local Houston media. And the Houston Chronicle once again published a series of articles by Cindy Horswell describing the alleged close encounter between an aircraft and a rocket. These are easier to dismiss than the earlier report, because the articles claim that the rocket came within 100' of an aircraft at 11,000' (or 16,000', the numbers change).

If we assume a rocket was involved, we'd have to assume the person firing it was extremely lucky (or unlucky) that it came near the airliner. It would be a one-in-a-million shot if it were by chance.

If it were intentional, we'd have to assume someone spotted the airliner several miles away; quickly determined its altitude, speed, and heading; aligned the rocket's launch pad to the precise fraction of a degree necessary to reach the right location; aligned the tilt of the launch rail to the precise fraction of a degree necessary to reach the right altitude; then fired the rocket at the precise time for it to reach the target. Then we'd have to assume the rocket performed exactly as predicted and wasn't affected by changing winds at different altitudes as it flew to 11,000 feet.

Or we'd have to assume that some rogue rocketeer is launching hundreds or thouands of large, expensive, rockets at airplanes and got lucky this time.

And for all the rocket scenarios we have to assume that the "rogue rocketeer" is able to launch these large rockets in total secrecy without anyone on the ground noticing or talking about it.

None of the scenarios involving rockets seem as likely as the hypothesis that the pilots didn't really see a rocket. It's much more likely, for example, that the pilots saw something like an airliner. Especially when the wings are aligned with the body or in shadow, an airliner could appear to look very much like a white rocket with triangular fins - which is what the reports say the pilots saw.

In the air, there are no landmarks to provide a reference for size or distance and lighting conditions are often unusal and contantly changing. So, it's easy to understand how pilots make mistakes.

The UFO craze, which reached its peak in the 1960s and 1970s, was begun by a pilot. Throughout that period, pilots reported seeing "flying saucers" and often described them in detail (including describing "exhaust vents" and windows).

Eyewitness reports, including reports from pilots, have proven to be very unreliable. For example, hundreds of witnesses claimed to have seen a missile hit TWA Flight 800. Investigation showed that no missile was involved in the accident.

In this case, the media reports from the previous year may have lead these pilots to believe what they saw was a rocket. And media reports will certainly lead to more reports of "rockets." Once a UFO has been reported in an area, many more reports follow.

A search of the NTSB's "Incident Report" database returns no records for either of the events reported by the Houston Chronicle and the other media outlets. Nor are there any reports in the Aviation Safety Reporting System which is used to monitor and track near misses between aircraft. Therefore, it is safe to assume that the Houston Chronicle and others are engaging in reckless speculation rather than honest reporting.

As an aside: There are a couple more things that make it hard to believe a rocket is involved in the latest "incident."

The rocket is described as being white with triangular fins. Alhough a high-power rocket could be painted white, it's not common. White is hard to see in the sky. So, it's not likely that someone launched a large white rocket which accidently came near the airliner. If the intent was to camouflage the rocket, the rogue rocketeer would have probably painted the rocket blue to make it harder to see in the sky or green to make it harder to find on the ground.

The rocket is described as flying horizontally. Hobby rockets follow a ballistic course. Once the motor burns out, they follow a path determined mostly by gravity. This path is a parabola. For the top of the rocket's flight to appear to be horizontal at 11,000 feet, the alleged rocket must have been launched from some distance away - more than a mile - and at a very low angle above the horizon. To reach 11,000 feet when launched at such a low angle would require a rocket much larger and more powerful than the one described in the reports.

In summary, very few high-power rockets are painted white. Only a few high-power rockets have triangular fins. High-power rockets don't fly horizontally. And, we have no evidence a rocket was launched in the area.

Airliners are often painted white. Most have rudders and rear wings that are triangular. They almost always fly horizontally. And, there's no doubt several were in the area.

Even if you disregard that the chances of a high-power rocket coming close to an aircraft are nearly nil, from just the above statements you can conclude that the odds that the pilots observed a high-power rocket are much lower than the odds that they saw an airliner. While, I can't say for sure that they saw an airliner, it's much more likley than that they saw a rocket.

References:

• Rocketry A Threat To Civilian Aviation?
• ContrailScience.com