Four commercial Jetliners have made emergency landings in the US and Australia during the last 24 hours. In addition, a Military Jet crashed in Idaho, killing the pilot and a small plane in Australia crashed with an unexplained engine failure

Two of the emergency landings describe smoke filled cabins. All four describe engine failures. I am also posting a story about a small plane in Australia that crashed today when the engines failed. Anybody have any statistics on these types of problems? (Part of the reason why this may be important is the ongoing aviation gas crisis in Australia that still has over 5000 planes grounded. Could there be bad fuel elswhere?) There is also a TB 2000 link for the earlier story that has followup stories on the Australian planes problems.

1) Jet Makes Emergency Landing in Neb.

LINCOLN, Neb. (AP) -- An American Airlines flight bound for Los Angeles made an emergency landing here Friday after its right engine lost oil pressure and filled the cabin with smoke. The plane landed safely at 7:05 p.m. at Lincoln Municipal Airport. There were no injuries reported among the 125 people aboard the Boeing 757. The flight was en route from Newark, N.J., to Los Angeles, said John Wood, executive director of the Lincoln Airport Authority. Joseph Sfez of Los Angeles said smoke in the damaged plane's cabin made it difficult to breathe. ``It was scary up there, very scary,'' he said. ``But the captain did a good job.'' The airlines sent another plane from Dallas to pick up the stranded passengers.

Link to Story:

http://www.insidechina.com/frames/frames.php3?url=http://www.newsday.com/ap/national.htm

2) What would cause the cockpit of a commercial jet to fill with smoke?

Australia: Jet makes emergency landing as smoke fills cockpit

1-20-2000

A Qantas jet carrying 68 passengers was forced to make an emergency landing at Darwin Airport this morning.

It is believed the plane was about 20 minutes out of Darwin on its way to Gove when one of the engines failed and there was smoke in the cockpit.

The pilot decided to return to Darwin and alerted the airport of his planes condition.

Emergency crews were placed on standby, but airport management say the plane touched down safely, and no one was hurt.

Link to story:

http://www.abc.net.au/news/newslink/nat/newsnat-21jan2000-29.htm

Link to TB 2000 thread on story:

http://hv.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=002N0r

3) LA-bound Alaska Airlines jet returns to Sea-Tac due to engine troubles

SEATAC, Wash. (AP) -- An Alaska Airlines MD-80 jet heading to Los Angeles returned to Seattle-Tacoma International Airport shortly after takeoff Thursday due to engine problems. There were no injuries, though one engine was shut down due to a compressor failure. Flight 222 took off shortly after 7 a.m. A ground crew member saw sparks coming from one of the plane's engines and alerted air traffic controllers, said Alaska Airlines spokesman Jack Evans. The pilot saw that there had been a compressor problem, essentially a backfire, on one of the engines and shut it down. He then told passengers to assume a crash position -- heads down -- and turned the plane around, landing once again at SeaTac. The airport's fire department was called out to meet the plane and escort it back to the gate. Evans said the engine was removed from the airplane and was undergoing tests to find out what happened.

4) Part falls off plane leaving London's Gatwick

LONDON, Jan 20 - An Airtours plane carrying 152 passengers made an emergency landing at London's Stansted airport on Thursday after part of an engine casing fell off during take-off from Gatwick,

Link to story:

http://www.sacbee.com/news/calreport/calrep_story.cgi?N76.HTML

5) Australia: Four have lucky escape from light plane crash

Four people have had a lucky escape from a light plane crash near Verona Sands in Southern Tasmania.

The Cessna 182 chartered by Tasair is believed to have crashed after its engine failed.

A Verona Sands resident was driving home when a distressed and bloodied young woman waved him down.

She told him the plane had crash landed in the D'Entrecasteaux Channel after suffering engine failure.

The three passengers - two young women and one young man - and the pilot floated to shore with the assistance of life jackets and debris.

All have been taken to the Royal Hobart Hospital suffering lacerations, shock, hypothermia and in the pilot's case a broken leg.

Tasair had chartered the Cessna 182 for back-up during the fuel contamination crisis. The plane's owner, Rick Gumley says the crash could not have been caused by contaminated fuel because it has not flown outside of Tasmania.

Link to story: http://www.abc.net.au/news/newslink/nat/newsnat-21jan2000-272.htm

-- Carl Jenkins (Somewherepress@aol.com), January 22, 2000

Answers

Sheez!

-- Hokie (Hokie_@hotmail.com), January 22, 2000.

Carl

Neither of your links to the Oz aircraft stories seem to work, just brings up a wrong address message page. Story pulled? or

-- JM (chained@tothe.wheel), January 22, 2000.

do you remember the UPS plane on new year's eve that had to make an emergency landing? smoke entered the cockpit??? from whence did the smoke come? honestly, i think the light aircraft link seems like it may be more related to the fuel problems but i think there is a very interesting link between the emergency landings. (you do good work carl in looking for posts and you are as consistent as day and night in your tireless efforts)

Jan 1, 2000 - 12:40 AM UPS Plane Makes Emergency Landing The Associated Press

ALLIANCE, Neb. (AP) - A DC-8 United Parcel Service jet was forced to make an emergency landing Friday in western Nebraska after an instrument screen blanked out and smoke entered the cockpit. Moments before the crew detected the smoke, they had joked about the possible perils of the Y2K computer bug.

"I hope we all don't disappear when it rolls over here," Capt. Joe Stidham said he told an air traffic controller before the plane's troubles.

Then smoke appeared, and the plane made an emergency landing at the Alliance Municipal Airport. The three crew members on board were not injured.

The problems were not believed to be Y2K-related, but the crew was unsure of the cause, Stidham said. After the smoke entered the cockpit, the crew put on oxygen masks and radioed the nearest airport.

The plane had left Louisville, Ky., and was due to arrive in Portland, Ore.

-- tt (cuddluppy@aol.com), January 22, 2000.

Here's an issue I've never seen addressed amoung all the press related to how ready the airline industry is (or was) for Y2K: the "maintenance scheduling" systems! I know that every major airline has a computer system that keeps track of the required maintenance of virtually every part on every plane. These programs are extremly date sensitive also they are for the most part very old. Did they ever get fixed? Did they ever get talked about in the press? Could problems with these systems lead to problems like what you describe in your posting?

-- R. Nystrom (chezlog@ix.netcom.com), January 22, 2000.

To Carl Jenkins,

Thanks so much for posting this story.

To R. Nystrom,

Thanks for your post.

A software engineer told me on recently that annual maintenance scheduling triggers a diagnostic self-check. That entails the recording of a date and time. If the date did not roll over then the PLC can seize and this can result in "functional overflow". Here is the exact wording that he provided me concerning "functional overflow": "Functional overflow is the name given to either of two conditions. In one case, the function (procedure or basic 'task' that a program might perform) overflows the memory space allocated to it. This occurs because it retrieves some data (such as a date) from an area in RAM which is larger that it can accomodate within the variable size within the function. In other words, the function has allocated 26 bytes and the date comes back as 28 bytes. This overflow could cause a problem in a number of circumstances such as, if that variable is used in a calculation, if that variable space is passed back from the function, if adjacent variable space is accessed (it would be corrupted in a pass-by-reference function). As with other software, when the data steps outside the range allowed by the programmer, things aft gang aglay (get snafu'ed).

The other basic functional overflow occurs when spaces allocated to a function cause an overflow error within the OS of the device. In this case, the device's operation as a whole is threatened. The limiting factor is how well crafted might be the exception handling within the OS of the device. As a general rule of thumb, you can figure that the smaller the device (chips, systems, et cetera) the less room there is for robust error handling, so ......."

(End of quoted material. This material has been quoted in its entirety.)

Another problem with annual maintenance scheduling is that the exact date that the date function is activated is the same date every year, but that date is by no means the same in everything that has annual maintenance scheduling.

Annual maintenance scheduling is by no means unique to airlines. The list may be endless. It includes for instance chemical cooling wells. I will also use this same posting to start a thread on the topic of annual maintenance scheduling.

-- Paula Gordon (pgordon@erols.com), January 24, 2000.