When all is said and done, after the raging fires have been extinguished, the dead bodies bundled up, 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, the words still remain. The cockpit voice recorder (CVR) is the intact and irreducible memory that remains for us to witness and relive. The flight data recorder (FDR) also remains, but it doesn’t speak a normal intelligible language we hear with our ears. It records data and physical positionings 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 that has dwindled away in most human memory. 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.
Courtesy of the Cockpit Voice Recorder Database
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 is a transcript of airplane to air traffic control radio communications interlaced with cockpit traffic chatter between crew members that is not broadcast but which is recorded as part of the CVR exchanges.
This CVR 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 short while before (where is 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 Lindbergh which was equipped with such advanced 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, however.
Essentially this 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, yet, simultaneously, the CAM dialogue clearly demonstrates this is not the case. One crew member even jokes, “I hope” which is followed with laughter.
The Cessna is instructed to remain at or below 3500 feet altitude and to fly at a “070” heading. Headings are the meat and potatoes of directional instructions for airplane pilots. Think of the sky as a large surrounding 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 continue on a 070 heading to the Cessna 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 nearly same parallel path as the Boeing which was on the “downwind” leg of its approach, meaning that it would eventually turn back into its ultimate final runway descent. While the Boeing descended, the Cessna ascended. Various inherent physical limitations prevented the flight crews from seeing the other clearly and muddled communications prevented clear communication about lack of visual engagement with the other plane sharing the patch of airspace. The tower seemed 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 from the other, but they didn’t adequately ensure that the tower was aware they did not have an unquestionable good visual separation of 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 all killed. Over 20 houses were destroyed or seriously damaged. Bodies were reportedly strewn acrsoss yards and lodged in tree branches. An inferno scorched the neighborhood where the 727 struck almost vertically.
From Documenting Reality
With 144 fatalities, this was the deadliest airplane crash in the history of aviation in the United States at the time, exceeding the 134 people killed in a New York accident in 1960 involving two TWA and United Airlines airliners. And in fact, the “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.”