Looks like we escaped an air disaster in San Diego last Thursday night. An Airwest Embraer traveling from Portland was about to land when they were given a “go around” order by air traffic controllers at San Diego International Airport. A go around order tells the pilot that their landing has been aborted and that they better get the hell back up and circle the airport one or 20 more times until cleared to land. It’s an unusual move and unplanned by definition. Apparently, the Airwest airplane was several hundred feet from landing on the same runway where a Detroit-bound Delta Airbus was preparing to depart.
Whoops. That is a “near miss” in aeronautic parlance. It’s not exactly as if they were a few feet apart (that’s a Hollywood gimmick) but in the context of large multi-ton aircraft moving hundreds of miles per hour, a near miss has a much wider definition than we would consider when using our little human bodies as context.
This could have been a horrible tragedy but the “system” worked and a runway collision was averted.
In fact, there are so many built-in safeguards and redundancies in air transport that there are probably many “good outcomes” to hairy situations that we simply don’t see.
But we do see when the perfect storm happens and the airplane doesn’t make it out intact. The Delta-Airwest encounter reminds me of a previous incident at the same airport over 40 years go. I wrote about that in a previous blog and will repost here
(I’ve reposted several posts from that blog but it was such an obscure site that I doubt anyone will connect the two…although the obscurity of tragic dog video rivals it).
The final words from PSA 182
When all is said and done, after the raging fires have been extinguished, the corpses bagged and taken away, the mangled wreckage hauled off to be inspected at a hangar where experts attempt to reconstruct the accident, and after the burning memories of death plunging from the sky are slowly blurred in the annals of memory, only the sad legacy of the words remain.
The cockpit voice recorder (CVR) is the intact and irreducible memory that lives on for us to witness and relive. The flight data recorder (FDR) also remains, but it doesn’t speak a normal intelligible language we discern with our ears. It records data and physical positions and properties of the plane’s surfaces and airspeed and countless other physical parameters which are translated by special equipment designed to translate the foreign language. These fixed remnants are the conjurer of the horror from 1978 whose vivid tragic memory has dwindled with time. Legacies of that gruesome collision over the skies of San Diego on September 25, 1978.
The CVR is the human element ingrained in unalterable historical record.
From the Cockpit Voice Recorder Database: (This is a transcript of airplane to air traffic control radio communications interlaced with cockpit traffic chatter between crew members that is not broadcast over the radio but which is recorded as part of the CVR conversation in the cockpit).
08.59:30 APP PSA one eighty-two, traffic twelve o’clock, one mile northbound
08.59:35 RDO-1 We’re looking
08.59:30 APP PSA one eighty-two, additional traffic’s, ah, twelve o’clock, three miles just north of the field northwestbound, a Cessna one seventy-two climbing VFR out of one thousand four hundred.
08:59:50 RDO-2 Okay, we’ve got that other twelve.
08.59:57 APP Cessna seven seven one one golf, San Diego departure radar contact, maintain VFR conditions at or below three thousand five hundred, fly heading zero seven zero, vector final approach course.
09.00:16 APP PSA one eighty-two, traffic’s at twelve o’clock, three miles out of one thousand seven hundred.
09.00:21 CAM-2 Got’em.
09.00:22 RDO-1 Traffic in sight.
09.00:23 APP Okay, sir, maintain visual separation, contact Lindbergh tower one three three point three, have a nice day now.
09.00:28 RDO-1 Okay
09.00:34 RDO-1 Lindbergh PSA one eighty-two downwind.
09.00:38 TWR PSA one eighty-two, Lindbergh tower, ah, traffic twelve o’clock one mile a Cessna
09.00:41 CAM-2 Flaps five
09.00:43 CAM-1 Is that the one we’re looking at.
09.00:43 CAM-2 Yeah, but I don’t see him now.
09.00:44 RDO-1 Okay, we had it there a minute ago.
09.00:47 TWR One eighty-two, roger.
09.00:50 RDO-1 I think he’s pass(sed) off to our right.
09.00:51 TWR Yeah.
09.00:52 CAM-1 He was right over here a minute ago.
09.00:53 TWR How far are you going to take your downwind one eighty-two, company traffic is waiting for departure.
09.00:57 RDO-1 Ah probably about three to four miles.
09.00:59 TWR Okay.
09.01:07 TWR PSA one eighty-two, cleared to land.
09.01:08 RDO-1 One eighty-two’s cleared to land.
09.01:11 CAM-2 Are we clear of that Cessna?
09.01:13 CAM-3 Suppose to be.
09.01:14 CAM-1 I guess.
09.01:20 CAM-4 I hope.
09.01:21 CAM-1 Oh yeah, before we turned downwind, I saw him about one o’clock, probably behind us now.
09.01:38 CAM-2 There’s one underneath.
09.01:39 CAM-2 I was looking at that inbound there.
09.01:45 CAM-1 Whoop!
09.01:46 CAM-2 Aghhh!
09.01:47 CAM Sound of impact
09.01:49 CAM-1 Easy baby, easy baby.
09.01:51 CAM [sound of electrical system reactivation tone on cvr, system off less than one second]
09.01:51 CAM-1 What have we got here?
09.01:52 CAM-2 It’s bad.
09.01:53 CAM-2 We’re hit man, we are hit.
09.01:56 RDO-1 Tower, we’re going down, this is PSA.
09.01:57 TWR Okay, we’ll call the equipment for you.
09.01:58 CAM [sound of stall warning]
CAM This is it!
Mom I love you!
[end of recording]
This transcript is from PSA flight 182 as it headed to San Diego’s Lindbergh Field at 9 on a hot morning after departing from Los Angeles a few minutes earlier (where it had flown from its original departure point in Sacramento).
At 9 am the Boeing 727 was descending through Lindbergh airspace in preparation for landing at the crowded San Diego airport just as a single-engine Cessna 172 was ascending out of Lindbergh airspace after its pilot, David Lee Boswell, had just finished up practicing a couple of ILS (instrument landing system) approaches which was only possible locally at the Lindbergh airfield which was equipped with such navigation tools. As Boswell ascended, PSA 182 was beginning its final descent.
The CVR tells the story. All transmissions are time stamped. “RDO” are airplane radio transmissions. “APP” refers to the tower approach transmissions. Busy airports have different radio frequencies for all stages of departure and approach. The denotation of “CAM” refers to the “cockpit area microphone.” These are recorded conversations between crew members. There are no such things as secrets in the cockpit. Everything is recorded. CAM dialogue is not transmitted over the airwaves.
The airplane’s CVR script tells us that there was some confusion and unclear verbiage regarding the PSA crew’s required acknowledgement of visual separation with the smaller aircraft in its vicinity. In fact, at one point it appears a plane transmission leads the air traffic controller to conclude that the PSA crew does in fact have a visual on the Cessna, while the CAM dialogue clearly demonstrates this was not the case. One crew member even joked, “I hope” which was followed by laughter.
The Cessna is instructed to remain at or below 3,500 feet altitude and to fly at a “070” heading. Headings are the meat and potatoes of directional instructions for airplane pilots. You can think of the sky as a large compass made up of 360 points of direction. North is 360 degrees, East, 90, South, 180, and West, 270. Northeast would be 45 degrees. The instructions to the Cessna to continue on a 070 heading meant that it was to fly in a slightly northeastern direction with emphasis on the eastern. The Cessna initially complied, but for unknown reasons, Boswell changed course to a heading of 090 degrees (due east) which brought it into the parallel path with the larger Boeing which was on the “downwind” leg of its approach, meaning that it would eventually turn back into its ultimate final runway descent. As the Boeing descended the Cessna ascended. Various inherent physical limitations prevented the flight crews from seeing the other clearly and muddled communications prevented relaying of visual engagement with the other plane that was sharing this dangerous patch of airspace. The tower appeared to dismiss the PSA’s “I think he’s passed off too our right” when it clearly conveyed ambiguity on the part of the flight crew. As the airplane that was “overtaking” the other, the onus was on the PSA crew to pass clearly, but they didn’t adequately ensure that the tower was aware they did not have visual separation from the Cessna.
At approximately 09:01:47, the climbing Cessna struck the Boeing from below. Both planes suffered fatal damage to their right wings and they plunged into the North Park neighborhood of San Diego, just a few thousand feet separating their final resting places. Two aboard the Cessna, 135 on the PSA jetliner, and 7 people on the ground were killed. Over 20 houses were destroyed or seriously damaged. Bodies were reportedly strewn across yards and lodged in tree branches. An inferno scorched the neighborhood where the 727 struck almost vertically.
Here is some sick-ass footage from the classic 70’s gore-fest, Faces of Death.
And from Documenting Reality. (not sure what’s more stomach-turning: dead passenger guts or 1970’s moustaches – Bartleby TDV)
With 144 fatalities, this was the deadliest airplane crash in the history of American aviation, exceeding the 134 people killed in a New York accident in 1960 involving TWA and United Airlines airliners. The San Diego “record” was short-lived because an American Airlines jet crashed in Chicago the following May, killing 273 people.
One thing that has always given me chills about this disaster are the unknown crew member’s last words of doomed farewell as he announced, over the radio, “Mom I love you.”