Pan Am Flight 845

Infobox Airliner accident|name=Pan Am Flight 845
Date=July 30 1971
Type=Ground equipment strike
Site=San Francisco, California
Fatalities=0
Injuries=29 (10 serious)
Aircraft Type=Boeing 747-121
Operator=Pan Am
Tail Number=N747PA
Passengers=199
Crew=19
Survivors = 218 (all)

Pan Am Flight 845 was a passenger service between Los Angeles International Airport and Tokyo, with an intermediate stop at San Francisco. On July 30 1971 the Boeing 747 flying this route (registration: N747PA, name: "Clipper America")cite book
last = Thompson
first = Nigel (editor)
authorlink =
coauthors = Ricky-Dene Halliday (co-editor)
title = Airliner Production List 1984/85
publisher = Aviation Data Centre
date = 1984
location = London
pages = p. 231
url =
doi =
id =
isbn = 0946141096] struck the Approach Light Structure (ALS) navigational aids at the end of San Francisco International Airport's runway 01R on takeoff for Tokyo.

Cause of the accident

The accident was a direct result of a failure in operational procedures. The takeoff had been calculated for runway 28L, but after pushback the crew were informed that this runway was closed and were directed to runway 01R, a considerably shorter length with different wind conditions.

Although this runway was safe for use by Flight 845, having convert|9500|ft|m of usable length, the flight crew neglected to alter the preset "bugs" indicating "Vr", "V1" and other speeds. Consequently these critical speeds were called late and the aircraft's takeoff roll was abnormally prolonged. In fact the first officer called "Vr" at convert|160|kn|km/h instead of the convert|164|kn|km/h indicated because the end of the runway was "coming up at a very rapid speed."

Damage

The aircraft's aft fuselage, landing gear and some control surfaces and structures were damaged by the impact. Three lengths of angle iron up to 17 ft long penetrated the cabin, injuring two passengers. The right main landing gear was forced up and into the fuselage, and the left main landing gear was ripped loose and remained dangling beneath the aircraft. Other systems damaged in the impact included Nos 1, 3 and 4 hydraulic systems, several wing and empennage control surfaces and their mechanisms, electrical systems including the antiskid control, and three of the evacuation slides.

The flight proceeded out over the Pacific Ocean for 1 hour and 42 minutes to dump fuel in order to reduce weight for an emergency landing. During this time damage to the aircraft was assessed and the injured treated by doctors on the passenger list. After dumping fuel, the aircraft returned to the airport. Emergency services were deployed and the plane returned and landed on runway 28R, using only the landing gear on one side of the aircraft. As the gear partially collapsed, the aircraft skidded into the dirt area next to the runway and came to a stop, but there was no fire.

Subsequent to the accident, the aircraft was repaired and returned to service. N747PA, which was the second 747 built, was leased to Air Zaire as N747QC from 1973 until March 1975, when returned to Pan Am, where it was renamed "Clipper Sea Lark", and then "Clipper Juan T. Trippe" in honor of the airline's founder. It remained with Pan Am until the airline ceased operations in 1991, and was transferred to Aeroposta of Argentina, then briefly to Kabo Air of Nigeria, back to Aeroposta, and was finally scrapped in 1999 in San Bernardino, California. [cite web
last =
first =
authorlink =
coauthors =
title = Aeroposta N747PA (ex N747QC)
work =
publisher = Airfleets
date =
url = http://www.airfleets.net/ficheapp/plane-b747-19639.htm
format =
doi =
accessdate = ]

Injuries

There were no fatalities among the 218 passengers and crew aboard, but two passengers were seriously injured during the impact, and during the subsequent emergency evacuation twenty-seven more sustained injuries, eight of them serious.

Rods of angle iron from the ALS structure penetrated the passenger compartment, injuring passengers in seats 47G (near amputation of left leg below the knee) and 48G (severe laceration and crushing of left upper arm).

After landing, the aircraft veered off the runway on its damaged landing gear and came to a halt. Evacuation commenced from the front due to a failure to broadcast the evacuation order over the cabin address system, the order being given by one of the flight crew exiting the cockpit and noticing that evacuation had not commenced. Three evacuation slides near the front of the aircraft were unusable and some passengers moved aft to use other slides. Soon afterwards the aircraft tilted back to rest on its tail, leaving the forward evacuation slides in a near vertical position. Eight passengers using these slides sustained serious back injuries and were hospitalised. Other passengers suffered minor injuries such as abrasions and sprains.

Investigation

An investigation determined the cause of the accident to be erroneous information from the flight dispatcher to the crew regarding weight and runway length. The takeoff had been computed for a different runway to that eventually used.

References

External links

* [http://www.airdisaster.com/reports/ntsb/AAR72-17.pdf NTSB accident report (PDF)]
* [http://www.panamair.org/accidents/accidents.htm Entry in a list of Pan Am accidents 1932-1988]