Accident Boeing 707-227 N7071, Monday 19 October 1959

Date:	Monday 19 October 1959
Time:	16:20
Type:	Boeing 707-227
Owner/operator:	Boeing
Registration:	N7071
MSN:	17691/45
Year of manufacture:	1959
Total airframe hrs:	173 hours
Engine model:	Pratt & Whitney JT4A-3
Fatalities:	Fatalities: 4 / Occupants: 8
Other fatalities:	0
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	16 km NE of Arlington, WA - United States of America
Phase:	Manoeuvring (airshow, firefighting, ag.ops.)
Nature:	Training
Departure airport:	Seattle-Boeing Field International Airport, WA (BFI/KBFI)
Destination airport:	Seattle-Boeing Field International Airport, WA (BFI/KBFI)
Investigating agency:	CAB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
The Boeing 707 N7071 was operating on a customer guarantee and acceptance training flight prior to delivery of the plane to Braniff. The plane was being flown by a Braniff captain and a Boeing testpilot as instructor. Other Braniff and Boeing personnel were on board as crew members and observers. A series of Dutch Rolls were performed; one of the rolls was executed beyond the maximum bank restrictions. Control was lost, but the aircraft recovered. During the recovery however, the no. 1, 2 and 4 engines were torn off. An intense fire burned away portions of the jet control near the no. 2 engine attachment area. An emergency descent was carried out and the plane crash-landed along river.

PROBABLE CAUSE: "The structural failure induced during an improper recovery attempt from a Dutch Roll which exceeded the angle-of-bank limits prescribed by the company."

Accident investigation: