Case Study: Pan Am 806

Something was obviously wrong, and on April 27, 1974, a team of eight full-time investigators from the Federal Aviation Administration began an intensive inspection of Pan American’s operations.

For six weeks, with the willing cooperation of Pan Am staff, they turned the airline inside out. They flew on the routes and observed that 43 percent of crews were failing to carry out established cockpit procedures. They watched captains going through proficiency checks in the simulator, and while they were watching, 36.8 percent failed. They noted, ominously, that some of these would have passed by the examiners if the investigators had not been present.

“It is common gossip among the airmen, and in some cases cabin staff,” said the final report, “that Pan Am has captains and first officers that are considered substandard by their peers and have been carried by the company and need the help of strong co-pilots. Further, efforts were made by certain first officers, second officers, and flight engineers to specifically avoid having a flight schedule assignment, if at all possible, with some substandard captains.”

In other words, Pan Am was employing pilots with whom other pilots were scared to fly.

Norris, pp. 14 -15

A Meadows clerk wrote out airwaybill number 026/3397 9525, describing the contents of the consignment as “Filler Catalyst – (non hazardas [sic]),” and had it delivered to the P.A. freight office at Aukland International Airport.”

It was only hours later that employees of Pan Am loaded the restricted material on board Clipper 806, soon bound for Pago Pago. MEK peroxide is not a “filler catalyst,” whatever that is supposed to mean.

Godson, p. 27

There were 117,000 pounds of jet A-1 fuel aboard the aircraft upon departure from Aukland. The planned fuel burn-off for the flight to Pago Pago was 48.500 pounds. [ . . . ] The aircraft was carrying 37,900 pounds of stored fuel to be used on a later leg of the trip.

NTSB-AAR-77-7, Appendix C

The CVR readout and the interview with the first officer established that the runway was in sight when the aircraft was about 8 nmi from the runway threshold. The runway probably remained in sight during most of the approach.

NTSB-AAR-77-7, p. 18

The aircraft descended about 500 ft. below the published minimum glide slope intercept altitude of 2,500 ft. before the glide slope intercept point was reached. [ . . .] The safety board was unable to determine the reason for this deviation from approach procedures.

NTSB-AAR-77-7, p. 18

As the aircraft approached the glide slope, it continued through and above it as the captain started his descent. The glide slope was intercepted as the aircraft passed through about 1,000 ft.

NTSB-AAR-77-7, p. 19

[Analysis] indicated that the aircraft encountered gusty wind conditions with a predominantly increasing headwind and/or an updraft about 50 seconds before impact. [ . . . ] The windshear was evident by a sharp increase in airspeed and a shallowing of the descent path. Consequently, the aircraft went above the glide slope. [ . . . ] The sound spectrogram showed that at this time, the thrust was reduced to apparently correct the high and fast condition.

As the aircraft passed Logotala Hill, it apparently came out of the increasing headwind or updraft condition and the positive performance effect was lost. In fact, a wind which produced a small negative performance effect was probably encountered. The thrust was well below that normally needed for a stabilized approach and about 16 seconds before impact, the aircraft started a rapid descent of about 1,500 fpm.

Thus, the Board concludes that the captain recognized the initial effect of the windshear condition and acted to correct the aircraft’s flight profile by reducing thrust, but he did not recognize the second effect as the windshear condition changed. Consequently, the aircraft, with low thrust, responded to the changing wind by developing a high descent rate. The captain had at least 12 seconds in which he could have taken action to arrest the descent in time to prevent the accident. During that time, the total thrust available exceeded that required to maintain constant airspeed in level flight. That the necessary pitch attitude and thrust changes were not applied can only indicate that the flightcrew was not aware of the high descent rate and the impending crash.

Evidence indicated that when the sink rate increased, the captain may have been looking outside the aircraft and therefore was not flying by reference to the flight instruments. At the time the sink rate increased to about 1,500 fpm, the aircraft was over an area devoid of lights (known as a “blackhole”), a heavy tropical rainstorm was over the airport and moving toward the approach end of the runway, and the first officer had called the runway in sight.

NTSB-AAR-77-7, pp. 19 – 20

At 2340:22.5, the first officer stated, “You’re a little high.” [ . . . ]

From 23:40:29.5 to 23:40:34, the radio altimeter warning tone sounded twice. At 2340:33.5, the first officer interrupted the second warning tone with, “You’re at minimums.”

As 2340:35, the first officer reported, “Field in sight.” Seconds later, the first officer stated, “turn to your right,” followed by “hundred and forty knots.” This was the last communication reported on the CVR.

NTSB-AAR-77-7, p. 3

At 2340:42, the aircraft crashed into trees at an elevation of 113 feet, about 3,862 feet short of the runway threshold.

NTSB-AAR-77-7, p. 3

Captain Leroy Petersen had been off flying status for four months for medical reasons and cleared for flight after “voluntary simulator training” after which it was said, “by the end of the period, Captain Peterson was doing very good work.” The NTSB report leaves his capabilities at that, neglecting to mention:

He passed these tests, but the flight section was carried out in daylight under visual meteorological conditions.

Norris, p. 20

December 20, 1951: Thinking and judgment of a professional and intelligent airmen were marginal.

July 2, 1957: ILS work with the ZR [navigation instrument] very poor.

August 29, 1963: Repeated four-engine ILS approach too fast [ . . .] over-control on ailerons caused vertical bar excursions.

June 1, 1965: Failed FAA oral exam for 707 type rating.

June 21, 1965: Failed FAA flight portion of the exam required for issuance of a Boeing 707-20 rating. Unsatisfactory landing technique.

June 25, 1965: Failed re-check for FAA 707-20 rating.

June 26, 1965: Three-engine ILS missed approach was very weak.

October 16, 1965: Heading control not precise. Over-control of elevator and throttles on ILS, introducing yaw and roll.

December 21, 1972: Repeated three-engine ILS for glide-slope tracking.

June 28, 1973: We had to repeat three-engine ILS, due to being out of limits at decision height.

Norris, pp. 21 – 24

Captain Petersen was a man who had trouble with instrument landings, and he had suffered this deficiency throughout his career.

Norris, p. 24

June 6, 1966: Student a little slow. Knows procedures but hesitates to make corrections.

August 21, 1966: Student unable to execute ILS due to slow scan resulting in poor airspeed control. Did not stay on either glideslope or localizer within prescribed minimums.

August 23, 1966: Quite a bit behind the aircraft throughout.

August 15, 1967: Lack of thinking is still causing difficulty.

November 12, 1968: Slow following approach procedure.

Norris, pp. 25 - 26

September 22, 1964: Slow reaction to corrections on power. Airspeed and heading control slow.

October 20, 1964: Instrument scanning a little slow.

April 27, 1965: Slow scanning and erratic altitude control.

November 30, 1965: Altitude control was ragged, and there was little or no use of vertical speed.

December 18, 1966: He is unable to see objective of minima.

December 23, 1966: Due to the unsatisfactory rating he received on many items, it is recommended that the type rating training be discontinued.

May 8, 1967: This pilot is slow and indecisive about almost everything he does.

Norris, pp. 28 – 30

The aircraft continued through the jungle vegetation, struck a 3-foot-high lava rock wall, and stopped about 3,096 feet from the runway threshold. The aircraft was destroyed by impact and the subsequent fire.

NTSB-AAR-77-7, p. 3

Passengers who survived the accident said that the impact forces were slightly more severe than a normal landing. No damage to the cabin interior was reported. Large fires were seen outside the right side of the aircraft. One person opened an overwing exit on the right side of the aircraft; flames came in through the exit, and he closed it. Other survivors opened the left overwing exits, and all the survivors except the first officer escaped through these exits.

NTSB-AAR-77-7, p. 11

Postaccident investigation revealed that the forward and the rear entry doors were not opened or used for escape. The forward door was opened about 2 to 3 inches, but the aft door was closed.

NTSB-AAR-77-7, p. 11

The injuries sustained by the fatally injured passengers as well as the surviving passengers were direct results of the post crash fire.

NTSB-AAR-77-7, p. 27

The aircraft was carrying restricted cargo. The cargo, listed as article No. 727 by the International Air Transport Association (IATA) Restricted Articles Regulation, was methyl ketone peroxide (MEK peroxide). IATA regulations specify the maximum quantity that may be packed in any one outside container is ½ kilogram (1 pound) or ½ litre (1 pint). . . . The weight of the MEK peroxide in the cartoon was 4 kilograms.

NTSB-AAR-77-7, p. 15

Though its passenger load was well below capacity, the Boeing 707-321B sat heavy on the tarmac at Aukland on that late summer evening. Of its gross weight, 40 percent consisted of 52.3 tons of A1 jet fuel. [ . . . ] There was nothing unusual about this for a Pan American aircraft at this moment in history. It was all part of the company’s economy drive. During the oil crisis, fuel was in short supply and more expensive at some airfields than at other. It was Pan American policy to pick up excess fuel at the cheaper locations, so that less would be needed when the aircraft landed at more expensive points.

Norris, pp. 18 – 19

Then why were NONE of the doors used?

Taking into account the limited details available and speculating on what must have happened inside Clipper 806’s cabin, there seems to be only one possible conclusion.

Remembering that it takes a properly trained person only a few seconds to move a Boeing 707 door from a “closed and locked” to a “fully open” position, there was plenty of time for those on board to deploy, at the very least, SOME of the four doors had they acted quickly enough.

Of the four, the only one remaining after the fire was on the front left-hand side. The investigators found it dangling, partly opened, on its hinges. Firemen and others all confirmed that the door was unlocked, but it was not FULLY opened. The rescuers discovered more than twenty bodies neatly stacked one on top of the other in the immediate vicinity of this egress.

Since NONE of the crew’s corpses was found near the doors, what more than likely happened was that as the Clipper slid through the jungle undergrowth, panic-stricken passengers left their seats and headed for the main exits, both at the front and the rear of the plane. [ . . .] The cabin staff did not take part in this premature escape attempt. Moreover, two stewardesses’ bodies were found well away from the rear main door. Why they did not lead or at least help with as escape, nobody knows.

[ . . . ]

The facts are that the passengers were at the exits before the more than likely completely inactive crew. There was a general panic when difficulty was experienced in getting them opened.

[ . . . ]

If you know what you are doing, unclosing the exits of a Boeing 707 is really not that problematical. They are “plug-type” in operation. All that has to be done, once the locking handle has been turned, is to PULL THE DOOR INSIDE – the exact opposite of what the printed emergency instructions say is to be done.

Godson, pp. 211 - 213.

“Do you have an opinion as to whether or not the flight crew of Flight 806 acted in a manner consistent with Pan American’s operating procedures?”

“No,” Bassett replied firmly. “They did not.”

Did he consider the approach to Pago Pago at night a black hole?

It was not a black hole to Captain Bassett, and he proceeded to blow the theory apart. It simply did not matter whether there were lights on the ground along the approach path or not, he said, because right down to the decision height of 280 feet the captain would be flying on his instruments, not looking outside. When he raised his eyes, he would have the runway lights in front of him. So much for the black hole.

[ . . . ] He went on to itemize the errors:

• The rate of descent had exceeded 1,000 feet per minute. There should have been a warning call at 900 feet per minute and there was not.

• There should have been a callout at 100 feet above decision height. There was not. Nor was there a call at 500 feet above the ground.

• The speed of the aircraft, which should have been stabilized at 150 knots from a point some seven miles out, had gone up to 180 and perhaps 190 knots inbound from Logotala Hill.

• The flaps should have been put down at the intersection of the glide slope, and it had not been done.

Norris, pp. 251 - 252

The National Transportation Safety Board determines that the probable cause of the accident was the flightcrew's late recognition and failure to correct in a timely manner an excessive descent rate which developed as a result of the aircraft's penetration through destabilizing wind changes. The winds consisted of horizontal and vertical components produced by a heavy rainstorm and influenced by uneven terrain close to the aircraft's approach path. The captain's recognition was hampered by restricted visibility, the illusory effects of a "blackhole" approach, inadequate monitoring of flight instruments, and the failure of the crew to callout descent rate during the last 15 seconds of flight.

NTSB-AAR-77-7, p. 15