Accident McDonnell Douglas DC-8-63CF N4909C, Friday 27 November 1970
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Date:Friday 27 November 1970
Time:17:05
Type:Silhouette image of generic DC86 model; specific model in this crash may look slightly different    
McDonnell Douglas DC-8-63CF
Owner/operator:Capitol Airways
Registration: N4909C
MSN: 46060/472
Year of manufacture:1969
Total airframe hrs:4944 hours
Engine model:Pratt & Whitney JT3D-
Fatalities:Fatalities: 47 / Occupants: 229
Other fatalities:0
Aircraft damage: Destroyed, written off
Category:Accident
Location:Anchorage International Airport, AK (ANC) -   United States of America
Phase: Take off
Nature:Passenger - Non-Scheduled/charter/Air Taxi
Departure airport:Anchorage International Airport, AK (ANC/PANC)
Destination airport:Tokyo-Yokota AFB (OKO/RJTY)
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
Narrative:
The DC-8 operated on a flight for the Military Airlift Command (MAC) from Tacoma-McChord AFB to Cam Ranh Bay in Vietnam via Anchorage, Alaska and Yokota, Japan.
The flight departed from McChord Air Force Base with 219 passengers and a crew of 10 aboard. It landed on runway 6L at Anchorage International Airport at 15:32 hours local time. During the landing rollout the captain used reverse thrust and medium heavy braking to bring the aircraft to a stop on the icy runway. Braking action was fair to poor and only light braking was
used while taxiing to the ramp. After the aircraft was parked and chocked at the terminal ramp the parking brakes were released.
The airplane was refueled with 117,227 pounds of JET-1-A fuel for a computed takeoff gross weight of 349,012 pounds. The allowable takeoff gross weight was 350,000 pounds. Because freezing drizzle was falling, the aircraft was deiced just prior to its departure from the ramp.
The flight departed the ramp at approximately 16:54 and, upon request, received clearance to runway 6R.
The takeoff checklist was completed except for the transponder and ignition override items, while the aircraft was being taxied to the runway. The flight was cleared to taxi into position to hold on runway 6R at 17:00:25, and was cleared for takeoff at 17:02:40.
The captain stated that after the flight had been cleared into position he taxied slowly onto the runway and stopped the aircraft with the nose pointed slightly to the right of the centerline. He also stated he did not set the parking brakes while on the runway awaiting takeoff clearance and, further, that the parking brakes had not been reset at any time subsequent to brake release at the terminal ramp.
The first officer had been previously assigned to make this takeoff and while the aircraft was in position on the runway, the captain briefed the flightcrew that he (the captain) would handle the brakes, set the engine power, and make the necessary airspeed calls attendant with the takeoff. The remaining checklist items were completed by the crew at approximately 17:03.
The captain stated that he advanced the power to 80 percent (N2 compressor rpm), released the brakes and said, "lets go to" the first officer. He then advanced the throttles to the takeoff power of 1.87 EPR.
No movement or sliding of the aircraft was noticed by the crew prior to the brake release.
At around 145 knots the acceleration flattened out. Takeoff was continued since there was enough runway length remaining. When VR was called (153 knots) the aircraft was 1800-1500 feet from the end of the runway. The aircraft was rotated but did not leave the ground. After leaving the runway, the captain decided to abort the takeoff.
It continued along the ground and struck a low wooden barrier, the instrument landing system (ILS) structure, and a 12-foot deep drainage ditch before coming to a stop approximately 3400 feet beyond the end of the runway. The aircraft was destroyed in the intense ground fire which developed subsequent to the crash. Forty-six passengers and one flight attendant received fatal injuries as a result of the post-crash fire.

PROBABLE CAUSE: "The failure of the aircraft to attain the necessary airspeed to effect lift-off during the attempted takeoff. The lack of acceleration, undetected by the crew until after the aircraft reached V1 speed, was the result of a high frictional drag which was caused by a failure of all main landing gear wheels to rotate. Although it was determined that a braking pressure sufficient to lock all of the wheels was imparted to the brake system, the source of this pressure could not be determined. Possible sources of the unwanted braking pressure were either a hydraulic/brake system malfunction or an inadvertently engaged parking brake."

Accident investigation:
cover
  
Investigating agency: NTSB
Report number: DCA71AZ012
Status: Investigation completed
Duration: 1 year and 6 months
Download report: Final report

Sources:


Statistics

  • 9th worst accident in 1970
  • 7th worst accident of this aircraft type
  • 2nd worst accident of this aircraft type at the time

Location

Images:


photo (c) NTSB; Anchorage International Airport, AK (ANC/PANC); November 1970; (publicdomain)

Revision history:

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