AUS_ATC

Three-plane incident too close for comfort
FAA rules mandate air-traffic investigation

By Jane Roberts
February 20, 2007

The Federal Aviation Administration is investigating of series of errors last Tuesday that caused three planes to land too close together in rapid succession here.

In each case, the amount of space between the planes was compromised by slightly more than a tenth of a mile, which is not enough to be seen by the naked eye but is a breach of the separation rules air-traffic controllers are charged with maintaining.

"It's very unusual; very, very unusual to have three incidents at one time," said Kathleen Bergen, FAA spokeswoman. "None of them in and of themselves are serious, but our standards do remain constant involving heavy jets and smaller jets."

The air-traffic control tower reported one incident. When the FAA began investigating, it found three breaches, she said.

The string of events started shortly after noon when FedEx flight 881 approached for a landing on the center runway.

While still in the air, the pilot reported an auto throttle problem to the tower, which required the plane to slow faster than usual.

When that happened, the plane coming in behind it, a regional jet operated by Pinnacle Airlines, broke the 5 miles of separation the FAA mandates between heavy and small jets.

The FedEx pilot aborted the landing and flew around to try again. As it approached the runway for the second time, the separation between it and another FedEx plane at an adjacent runway was compromised.

"The diagonal separation between those planes should have been 1.5 miles. But because flight 881 again reduced its speed, the separation was reduced to 1.38 miles," Bergen said.

As both FedEx planes were preparing to land, another regional jet operated by Pinnacle was approaching for landing.

Its 5-mile separation was reduced to 4.86 miles.

"The normal procedure we do with every error is to decertify the controllers and put them through some form of retraining," Bergen said.

The FAA has strict separation rules in part to keep small planes from flying into the air turbulence created by large planes.

So far this year, the Memphis air-traffic control tower has reported four operational errors.

The year began Oct. 1.

"In all three of the operational errors, we had more than 95 percent of the required separation. But our job is not to have loss of any," said Peter Suflaw, head of the air-traffic control union at the tower.

Last year, the Memphis tower reported 10 errors and was asked by the FAA to come up with a plan for reducing errors.

-- Jane Roberts: 901-529-2512

Jetjok

MEM ATC,

Thanks for the heads up. Memphis is a really busy environment, as you know, at certain times of the day, and you guys do a fantastic job mixing and matching the arrivals and departures, so that we all get our jobs done. Keep up the good work.

Last night, on the way into Oakland, we were cleared for a visual to runway 29. A Southwest jet was then cleared to follow us, for a visual. He ended up about 3 miles in trail and was finally sent around. The thing that I found interesting was that although the controller knew he was well within the 5 mile bubble, he was not told to go around until we were just about to exit the runway. As we were about to exit onto taxiway "Y", the SW jet was sent around. I'm sure he was less than a mile from touchdown. I wonder why the controller had delayed his breakout of the SW guy until he was well below 500 feet. The closer to the ground, the more "interesting" the go around becomes.

Nick

Maybe they delayed the go-around and the SWA airplane was allowed to get closer to you because they called you in sight. When a trailing aircraft is cleared for the visual behind another aircraft they have in sight, doesn't this clear ATC of all wrongdoing? Don't know for sure but I think that is the case?

Shuckers86

I have a question for you MEM_ATC. I am a Bus driver and it seems we always get the clearance " cleared for the approach, 180 to the marker". This is sometimes a difficult to pull off without cheating, especially land ing north with the frequent tailwind. The final flap speed in the Bus is 175. To slow the Bus while descending on the G/S to get the final flaps and be stable by 1000' is some nights impossible. When I ask for 170 some of your brethren act like I'm stealing one of their children. Any thoughts? You guys do an awesome job night after night. Thank you.

AUS_ATC

Jetjok,

Thanks for the kind words. I believe that the vast majority of Controllers throughout the system LOVE thier job. It's nice to help pilots and passengers get to their destination or through our respective sectors along the way. The traffic, weather and equipment vary from day to day. It's all very familiar at times... yet very different, and that is what makes it so interesting for me.

Regarding the SWA story at OAK that you describe... any airline and aircraft may be cleared for a Visual Approach to follow a Heavy Jet. If the aircraft does not have the Heavy in sight, then ATC is responsible for the Wake Turbulence separation. If the aircraft has the Heavy in sight, then ATC may instruct the aircraft to follow the Heavy Jet, and in this case, the pilot is responsible for his separation.

Depending on the facilities involved, ATC may have an automated method to advise the Tower that the aircraft has the Heavy in sight, and has been instructed to follow. This is taken care of via a Letter of Agreement (LOA) or via the local Facility Handbook or similar document. If an LOA does not describe how this is accomplished, then the RADAR Controller will simply inform the Tower Controller via direct landline.

If the Tower Controller knows that an aircraft has been instructed to follow a Heavy Jet, most Tower Controllers will allow the separation to decrease to the point where runway separation still exists. If it appears that the Heavy Jet will not clear the runway, then the other aircraft is sent around. S-Turns are an option if the Tower Controller feels that his will help, and are certainly an option for the Pilot after making the request with the Tower Controller

I've seen some aircraft land high and long in order to avoid the Heavy Jet and associated Wake Turbulence. Not being a pilot, I can't speak to the safety of these types of operations... but it's legal from an ATC perspective.

MEM_ATC

AUS_ATC

Shucker,

Thanks for the reply and the excellent question.

Shooting from the hip here... most of us are acutely aware of the SLOW speed that you AirBUS drivers operate at. We realize that it's no big deal to sequence and space you behind a... SlowTation, but we will often try to squeeze 170 or 180 out of you depending on the situation.

With that said, we also know that YOU are responsible for the safe operation of YOUR aircraft. If we (ATC) issue you with a clearance to maintain 180 knots to the marker, and this is a speed that you are unable to comply with, or simply uncomfortable with -- just read back the Approach Clearance and tell ATC that your best Approach Speed will be XXX knots. The WORST thing to do, is accept the Approach Clearance and associated Speed Assignment and then fly a different speed -- this would be a Pilot Deviation, and I know you don't want that!

If you know in advance that your Approach Speed will be less than 160 - 170 knots for some reason, it might be nice to let the Final Controller know about this BEFORE he/she turns you onto the Localizer. Some Controllers might grunt and groan at this bit of information from you, but will be privately thankful that you shared this info prior to receiving the Approach Clearance.

MEM_ATC

AUS_ATC

There's more to this story that what was reported... Should be an update in the local newspaper tomorrow.

MEM_ATC

CaptainMark

i just flew with the fo on that flight..he said when they broke out the aircraft went into thrust latch which caused the go around...this "slow faster then usual" is bogus...