Two 747′s Almost Crash Over Scotland — And That’s Not The Scariest Part

747
Flickr photo by Ramón Cutanda

On a course headed for what might have been the worst disaster in aviation history, two Boeing 747 aircraft came within 100 feet of each other in a near-miss event over Scotland.

It happened in June of this year but the report is just now being released by by the UK Airprox Board, which examines near misses in UK airspace. The planes were 30 miles north of Glasgow when an air traffic controller noticed they were moving closer together. Ordered to fly in different directions, cockpit crews apparently got the instructions reversed and wound up flying towards each other.

“It was apparent that both crews had taken each others’ instructions, and the board found it hard to determine why this had occurred,” noted the Airprox report, a reported in a SkyNews article.Odds are all four pilots in the two aircraft probably were not paying a lot of attention to ground control, already having received clearance to cross the Atlantic Ocean. Compounding the problem: both planes had been ordered by air traffic control to fly at 34,000 feet.

The really scary part: A crash was only prevented because two pilots on each aircraft saw each other. Taking evasive action avoided collision with one plane climbing and the other diving.

Crazy Stunt With a Jumbo 747 in Bucharest!

UK Passenger Jet Barely Misses UFO

passenger jet They were on their final approach to Scotland’s Glasgow airport when an unidentified object passed within 300 feet of the Airbus A320 passenger jet. “Er yeah we just had something pass underneath us quite close [1255:30] and nothing on TCAS have you got anything on in our area” said the pilot to Glasgow tower, reports the BBC.

The TCAS’ of which the pilot mentions is the A320′s Traffic Collision Avoidance System, which communicates with other aircraft, several times per second, alerting two aircraft that are dangerously close to each other. The system was silent as the A320 was preparing to land, in clear conditions, at an altitude of about 4,000 feet. It was then that the pilot and non-flying pilot saw an object about 300 feet (100 meters) ahead.

Described as “blue and yellow or silver in color with a small frontal area, but ‘bigger than a balloon,’ the object moved quickly and came so close to the A320 that the pilot filed a near-miss report with authorities.Glasgow air traffic control said that while there were no other objects in the area of the A320 at the time, they did have an “unidentified track history” 1.3 nautical miles east of the A320′s position 28 seconds earlier.

Not likely another aircraft, glider, hang-glider, para-motor, para-glider, hot-air balloon or helicopter – all of which would have shown up on radar. The object is still unidentified.

Here is animation of the event, as it unfolded:

[Photo credit - Flickr user by sebsphotos]

Cockpit Chronicles: Nearly a near midair collision

“Traffic, Traffic!” Announced the computer voice from the speaker on the ceiling just above me.

This is something we hear frequently enough, perhaps once every three or four flights when an airplane in close proximity is climbing rapidly with a clearance to level off 1,000 feet below us. The TCAS (Traffic Collision and Avoidance System) is just giving us a warning that, should the airplane not level off, we may have to take action.

We were at FL390 (39,000 feet), an altitude where the traffic warning was far less likely. The captain and I looked down at the TCAS screen to get a quick idea where we should be looking for the other airplane. It was 800 feet lower than us and at our 2 o’clock position. It was easy to spot, with huge puffy contrails billowing out and slightly below it. A 737 for sure. We were both satisfied that it would pass behind us, since it was moving from left to right across the windscreen. A stationary position in the sky would mean it was coming right at us.

But before we could discuss this passing airplane, the computer voice came on once again.

“Climb, Climb now!”
Our procedures dictate that we should honor thy TCAS request, known as a Resolution Advisory or RA, by disconnecting the autopilot and following the rate of climb commands computed by the TCAS system.

Since it was my leg, I immediately disconnected the autopilot, while glancing down at the vertical speed indicator to find out just how many feet per minute of a climb would be needed. It wasn’t much, in fact. Just 200 feet per minute, hardly even noticeable to the passengers. It commanded a level off when we were at 39,100 feet and shortly after allowed us to settle back down to our original altitude.

All this was done in a matter of seconds, with no input or guidance from Air Traffic Control. In fifteen years using TCAS, this was only my second resolution advisory-the other one having occurred while on approach just east of Port-Au-Prince Haiti years ago.

“Center, confirm we were cleared from 380 to 400?” The other aircraft asked.

The controller said yes, which made us think this could have been an error on the part of the controller.

“Can you explain then what just happened?” The 737 pilot queried.

There was no answer from the controller.

We let the controller know that we had also just responded to a resolution advisory. The other pilot asked for a phone number of the Air Traffic Control center that he could call. We copied this number down as well.

There was some discussion between the captain and I whether we needed to report this as a near midair collision (NMAC). I pulled my manuals out, now conveniently located on an EFB equipped iPad (Electronic Flight Bag) and searched for the NTSB criteria for a near midair collision. Nothing came up.

But I did find an interesting recent change to our procedures. The NTSB (National Transportation Safety Board) requires that any flight responding to a TCAS resolution advisory above 18,000 feet must pull the voice recorder circuit breaker after completing the parking checklist. This would allow the NTSB to analyze the tapes from ATC and the aircraft involved in the loss of separation incident.

Just knowing that the NTSB would be listening to our conversation for the next two hours tends to make you aware of every word you’re saying. In fact, I debated with myself about getting into a discussion during our approach briefing about wind and gust additives that we would be applying for the approach.

I recognize that there’s value in allowing the NTSB access to the conversations that led up to an incident. They’ll hopefully study the procedures and policies that could prevent this kind of situation. There’s still a big brother feel to it.

I couldn’t help but feel bad for the controller on duty. While the captain and I were waiting for the employee bus, he phoned the air traffic control center. The controller explained that a clearance was given to the Trans-Siberiana 1701, but that Trans-Siberiana 1790, who had also asked for a climb, had accepted the clearance instead. All airline names have been changed to protect the innocent.

I looked up the FAA definition of a Near Midair Collision:

A near midair collision is defined as an incident associated with the operation of an aircraft in which a possibility of collision occurs as a result of proximity of less than 500 feet to another aircraft, or a report is received from a pilot or a flight crew member stating that a collision hazard existed between two or more aircraft.

It turned out we were just a 100 to 200 feet away from the NMAC definition. So I guess it was “nearly a near midair collision.”

We both filed a report detailing the events. I recently received the response. We did everything by the book and it obviously wasn’t our fault, which meant that the case was closed as far as our involvement.

Someday I hope we’ll have a third layer of safety in addition to the protection offered by ATC and TCAS in the form of a two-lane airway using a half mile offset to the right. Ever since GPS was invented, we have reduced the normally 8-mile wide airways down to just a few feet thanks to the precise nature of the technology. But with that came greater reliance on TCAS to keep us out of trouble. I wrote about an inexpensive offset airway proposal previously and I’d love for the FAA to take another look at it. Adding layers to our safety net is what has made air travel so much more safe than in the early years of flying.

Cockpit Chronicles takes you along on some of Kent’s trips as an international co-pilot on the Boeing 757 and 767 based in Boston. Have any questions for Kent? Check out Plane Answers or follow him on Twitter @veryjr.

FAA admits near-collision of two jets

Early in the morning on November 23, two jets coming in for landing at Denver International Airport had a near-miss, as one plane tried to make a U-turn into the path of the other, causing the jets to come within 200 feet of one another.

According to ABC News, one jet was in a line of planes coming in for landing. The other was on a parallel path, and needed to be guided in to the line. Air traffic controllers gave the second plane incorrect instructions though, requiring it to turn around to right in the path of the other plane. The plane’s collision avoidance system sounded an alarm, and the pilots were able to avoid the other plane.

ABC News quoted a source as saying that the two planes merged on the radar screen and came with “a blink of an eye” of each other. As is always the case with incidents like these, the FAA is investigating.

Plane Answers: Airliners passing closely (with video) and how are tailwinds figured inflight?

Welcome to Gadling’s feature, Plane Answers, where our resident airline pilot, Kent Wien, answers your questions about everything from takeoff to touchdown and beyond. Have a question of your own? Ask away!

Tim asks:

Kent,

Recently we (my wife and I) were going from PVD to TPA and while gazing out the window on a bright sunny day, we were amazed to notice a large amount (8-10) planes passing by us heading north. These planes “seemed” very close to our plane as I could clearly make out all of the markings on each one. Is this normal practice for the airlines?

Hi Tim,

I had a similar experience recently. Since I normally fly internationally, we don’t see quite as much traffic as you can pass on a domestic flight.

While flying from Dallas to Boston the other day, I decided to take some video during cruise of the numerous aircraft that we flew over or under. It makes for some nice scenes. At one point, we even pass under a pair of B-52′s.

You’re right in noticing that this seems to be more common. Since January 20th, 2005, the FAA has allowed aircraft to be flown at altitudes in 1,000 foot increments. Prior to that, flights above 18,000 feet were separated by 2,000 feet.

You might think this wouldn’t be as safe, but in fact, the opposite is true. Since opening up twice the amount of flight levels available to airplanes, the airspace is effectively doubled, giving controllers more room to operate flights around weather and to provide more direct flights.
Callum asks:

First off, thank you so much for taking the time to answer all these questions. I only recently found the list and I enjoyed reading your answers immensely.

My question is how does the in flight system that displays speed, location, heading etc. know what the tailwind speed is?

I imagine it’s easy to calculate your forward velocity through the air with some kind of windmill like device on the front of the aircraft. If this velocity is comprised of forward motion created by engine thrust and wind speed (positive or negative) how do the plane’s systems calculate each component?

(I bet I’m over thinking it and you’ll have a really simple, obvious answer :) )

Thanks!

Hi Callum,

You’re close. Almost all airplanes have a pitot tube that senses the airplane’s airspeed. Airliners also have GPS and/or ‘laser ring’ gyros that spin fast enough to sense any movement of the airplane. When the airspeed and heading is compared to the GPS or gyros, the relative wind speed can be displayed. We can see this on our map display at a glance, which is handy in the last few hundred feet before landing to get a preview of the crosswind we’ll likely have at touchdown.

I managed to take a quick picture of the highest winds I’ve run across at altitude, which was during a smooth ride, despite the fuzzy picture:

Do you have a question about something related to the pointy end of an airplane? Ask Kent and he’ll try to use it for next Monday’s Plane Answers. Check out his other blog, Cockpit Chronicles and travel along with him at work.