Sabenapilot From Belgium, joined Feb 2000, 2734 posts, RR: 46
Reply 1, posted (9 years 2 months 3 days 19 hours ago) and read 7384 times:
The 707 -which was a very modern plane back then- suffered what is known as a trim runaway, an unwanted continuous operation of the elevator trim, causing a slow but steady and ever increasing pitch variation of the plane (in this case: nose up).
The trim runaway started somewhere during the initial approach and the crew fought increasingly hard against it during their ILS approach, but in the end could no longer hold it and had to make a go-around on final. The plane initiated a turn and climbed steeply to around 1,500 feet before stalling and crashing to the ground, killing all 71 persons on board as well as 1 person on the ground.
A stewardess on board of that flight happened to be a niece of my grandmother, BTW.
For some time after the accident, Sabena -and I think many other airlines too- had a set of strong steel cables fitted to the overhead panel of the cockpit so that in case of a trim runaway, the trim wheel could be physically blocked by the flight engineer to prevent catastrophes like SN548 from happening again. Don't know if it would have worked though....
The subsequent investigation fully cleared the crew from any wrong-doing and concluded a structural error to be at the basis of this tragic loss. It made several recommendations to Boeing to improve the design and thus safety of the flight controls on their 707.
Until today, it is not known what exactly triggered to electro-motor to run continuously, but since then, trim mechanisms have been altered so that pilots can always either physically overpower the trim force or alternatively that the system disconnects if it feels any force opposing its operation.
This crash was the worst accident in Belgian aviation history and also the last fatal accident for Sabena. There is a small memorial in front of the catholic chapel of the old terminal in BRU where you can see the names of those killed today, 45 years ago.
CV990 From , joined Dec 1969, posts, RR:
Reply 2, posted (9 years 2 months 3 days 17 hours ago) and read 7364 times:
The Boeing 707 was such an incredible airplane and many of us flew them. I had the chance to fly 3 times in a 707, and I found always a great plane, safe, reliable and strong. In my point of view this accident of course was sad in one point, also I think we must give a great honor to all crew inside that 707 at that particular moment, I'm sure they tried to the limits of the human nature the best to land safely the airplane....unfortunetely they lost that battle, but their effort was not in vain, that accident gave the possibility to Boeing to correct and shape even better the 707. I read in the past some reports about this accident but today when I read Sabenapilot words I fully understood the accident.
Regards and it should be a time for us to pay honor to all of those that died that day!
First crash/loss of a B707 with PAX on a scheduled flight. All others were training flights :
1 - AUG 15th 1959 : AA N7514A Training flight
2 - OCT 19th 1959 : Boeing N7071 was operating a customer guarantee and acceptance training flight
3 - DEC 24th 1960 : BOAC G-APFN overran runway at Heathrow (not a "crash")
4 - JAN 28th 1961 : AA N7502A Training flight
5 - FEB 15th 1961 : SN OO-SJB Brussels