Crash of a Douglas DC-8-63 in Toronto: 109 killed

Date & Time: Jul 5, 1970 at 0809 LT
Type of aircraft:
Operator:
Registration:
CF-TIW
Survivors:
No
Schedule:
Montreal - Toronto - Los Angeles
MSN:
46114/526
YOM:
1970
Flight number:
AC621
Location:
Country:
Crew on board:
9
Crew fatalities:
Pax on board:
100
Pax fatalities:
Other fatalities:
Total fatalities:
109
Captain / Total flying hours:
20990
Captain / Total hours on type:
2899.00
Copilot / Total flying hours:
9323
Copilot / Total hours on type:
5626
Aircraft flight hours:
453
Circumstances:
Flight number 621 of Air Canada DC-8-63 CF-TIW with 100 passengers, six cabin air crew and three flight crew aboard on July 5, 1970 from departure at Montreal International Airport until its final crash at Toronto International Airport lasted slightly more than 52 minutes. This aircraft took off at Montreal at 07 hours and 17 minutes EDT, initially touched down on runway 32 at Toronto International Airport at 08 hours 06 minutes and 36 seconds EDT and finally crashed at 08 hours 09 minutes 34 seconds EDT. The flight from Montreal to Toronto was routine. The flight during this interval was also routine. The "In-Range Check" was made when the aircraft was about 10 miles from Toronto International Airport on a southerly heading. The "Before-Landing Check" was made when the aircraft was about 8 miles from this Airport, and just commencing its turn onto final approach. On this Before-Landing cockpit check, which includes the lowering of the undercarriage, the item "spoilers armed" was intentionally omitted. During this period there occurred a conversation between the Captain and the First Officer as to whether the ground spoilers would be armed 'on the flare' or 'on the ground' and an agreement between them as to this was reached. The agreement was that the First Officer would arm them 'on the flare', that is, immediately before the aircraft touched down on the runway. Power was reduced then on the aircraft for the purpose of the flare and the Captain gave the order to the First Officer by saying 'OK'; and immediately thereafter the ground spoilers were deployed. The spoilers were deployed when the aircraft was about 60 feet above the runway. As a result, the aircraft sank rapidly. Practically immediately thereafter the Captain, with an exclamation, applied full throttle to all four engines and pulled back the control panel causing the nose of the aircraft to rotate upwards. During this sequence the First Officer apologized to the Captain for what he had done. Notwithstanding the action taken by the Captain, he did not succeed in preventing the aircraft from touching down on the runway. Instead, the aircraft struck the runway very heavily. It remained on the runway only about half a second and then rose back into the air at which time the ground spoilers commenced to retract and then did retract. When the aircraft struck the runway, number 4 engine and pylon separated from the aircraft and fell on the runway along with a piece of the lower wing plating (which allowed fuel to escape and subsequently ignite). Damage was also done at this time to the attachments relating to number 3 engine, but that engine after touchdown continued to function. After this touchdown, the aircraft climbed to an altitude of 3,100 feet above the ground. During this climb, there were conversations between the First Officer and the aircraft airport control tower from which it is patent, that the air crew considered that they would be able to cause their aircraft to circle for another landing attempt on runway 32. In fact, the air crew did not know, until only about 40 seconds prior to the final crash, that the happening of such final crash was irreversible. During this climb, fire and smoke were seen trailing behind the aircraft intermittently. About 2 and one half minutes after the initial touch down of this aircraft on the runway, the first explosion occurred in the right wing outboard of number 4 engine location causing parts of the outer wing structure to fall free to the ground. Six seconds later, a second explosion occurred in the vicinity of number 3 engine and the engine with its pylon ripped free of the wing and fell to the ground in flames, trailing heavy black smoke. Six and one half seconds later, a third explosion occurred which caused the loss of a large section of the right wing, including the wing tip. The aircraft then went into a violent manoeuvre, and with the right wing still ablaze, lost height rapidly and at the same time more wing plating tore free following which the aircraft struck the ground at a high velocity, about 220 knots in the attitude with the left wing high and the nose low. At final crash, all persons aboard this aircraft were killed.
Probable cause:
Within the meaning of the word "circumstances" ("of any accident") in section 5A of the Aeronautics Act, Revised Statutes of Canada 1952, chapter 2 as amended, there were several contributing circumstances to this accident. Without attempting to weight each or to list them in order of priority, they are set out hereunder:
- The failure of the Captain to follow the procedures laid down in the 'Before-Landing Check' in the Air Canada operating manual, in respect to arming the ground spoilers in this aircraft on this day,
- The action taken by the First Officer, contrary to the order of the Captain on this day, in pulling the ground spoiler actuating lever aft manually to the "Extend", position when the aircraft was about 60 feet above runway 32 at Toronto International Airport,
- The failure of the manufacturer of this aircraft to provide a gate or equivalent means to guard against such inappropriate manual operation of the ground spoiler lever in flight,
- The acceptance and approval by the Ministry of Transport, of the design of the ground spoiler system in this aircraft,
- The acceptance and use by Air Canada of this aircraft with this defective design feature in its ground spoiler system,
- The failure of the manufacturer and Air Canada in their respective manuals unequivocally to inform that the ground spoilers of this aircraft could be deployed when it was in flight by doing what the First Officer did in this case; and, also, to warn of the hazard of extending the ground spoilers when the aircraft is in flight and especially when it is close to the ground,
- The failure of Air Canada to cause its Ground Training School personnel to instruct student pilots that the ground spoilers of this aircraft could be deployed in the way the First Officer did in this case or to warn that the ground spoilers could be deployed when this type of aircraft is in flight and especially when it is close to the ground,
- The failure of the Ministry of Transport to detect the deficiencies and misinformation in the manufacturer's aircraft flight manual as to the operation of the ground spoiler systems on this type of aircraft; and the failure to require the manufacturer in such manual to warn of the danger of inappropriate deployment of the ground spoilers on this type of aircraft when in flight and especially when it is close to the ground,
- The failure of the Ministry of Transport:
1) to have noted the differences in the manuals of Air Canada and other Canadian aircraft operators in relation to the hazards of operating this ground spoiler in this aircraft,
2) to have alerted Air Canada of this, and
3) to have taken appropriate remedial action so that Air Canada's manual in respect thereto was not deficient in respect thereto,
- Under the subject overload conditions, the failure of the manufacturer to design attachments of the engine pod to wing structure to provide for safe sequential separation, or failing which to otherwise ensure the integrity of the fuel and the electrical systems.
Final Report:

Crash of a Vickers 757 Viscount in Toronto

Date & Time: Jun 13, 1964
Type of aircraft:
Operator:
Registration:
CF-THT
Survivors:
Yes
Schedule:
Montreal – Toronto
MSN:
302
YOM:
1958
Flight number:
AC3277
Country:
Crew on board:
3
Crew fatalities:
Pax on board:
41
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
10060
Captain / Total hours on type:
117.00
Copilot / Total flying hours:
2657
Copilot / Total hours on type:
46
Circumstances:
On final approach to Toronto-Lester Bowles Pearson Airport, while at an altitude of 700 feet 3,200 meters from the runway 28 threshold, the engine number lost power. The captain decided to shot down the engine but mistakenly stopped the engine number one. Unable to restart the engine number one, the crew increased power on both right engines number three and four but due to an asymmetric thrust, the airplane banked left then stalled and crashed short of runway threshold. All 44 occupants were evacuated safely while the aircraft was damaged beyond repair.
Probable cause:
The reason of the loss of power on the engine number two was caused by the presence of a foreign object the origine could not be determined. However, the reaction of the crew was incorrect due to lack of coordination.
Final Report:

Crash of a Douglas DC-8-54F in Sainte-Thérèse-de-Blainville: 118 killed

Date & Time: Nov 29, 1963 at 1833 LT
Type of aircraft:
Operator:
Registration:
CF-TJN
Flight Phase:
Survivors:
No
Schedule:
Montreal - Toronto
MSN:
45654
YOM:
1963
Flight number:
TCA831
Country:
Crew on board:
7
Crew fatalities:
Pax on board:
111
Pax fatalities:
Other fatalities:
Total fatalities:
118
Captain / Total flying hours:
17206
Captain / Total hours on type:
561.00
Copilot / Total flying hours:
8302
Copilot / Total hours on type:
390
Aircraft flight hours:
2174
Circumstances:
The Douglas DC-8 aircraft was on a regular scheduled flight Montreal-Dorval Airport (YUL) to Toronto (YYZ), Canada, scheduled to leave Montreal at 18:10. There were some delays in the boarding of the passengers and Flight 831 started its takeoff roll on runway 06R at approximately 18:28. Weather was reported as overcast, light rain and fog, visibility 4 miles, surface wind NE at 12 mph. The flight was instructed to report passing 3000 feet and 7000 feet on the climb-out from the airport. The aircraft took off normally, reported in at 3,000 feet and acknowledged a clearance for a left turn to St. Eustache. This was the last radio contact with the flight. The aircraft then deviated from its normal flight path about 55 degrees to the right and began a quick descent. At 18:33, 16.9 miles from the airport, the DC-8 struck the ground at a speed of 470-485 knots descending at an angle of about 55 degrees (+/- 7deg). The airplane plunged into the ground and totally disintegrated upon impact. There were no survivors among the 118 occupants.
Probable cause:
It is concluded that the actual cause of the accident cannot be determined with certainty. It is concluded that the most probable chain of events which occasioned the crash can be identified as follows. For one of the reasons which are set forth below, the pilot applied the near maximum available Aircraft Nose Down Trim to the horizontal stabilizer. The aircraft then commenced a diving descent building up speed at such a rate that any attempted recovery was ineffective because the stabilizer hydraulic motor had stalled, thus making it impossible within the altitude available to trim the aircraft out of the extreme AND position.
(a) The first reason which might have indicated to the pilot the necessity for applying, nose down trim could have been icing of the Pitot system as discussed in the Analysis of Evidence. While the experience and competency of the crew would likely have led them to recognize the fault in time to take corrective action, the possibility that this condition caused the application of AND trim cannot be dismissed.
(b) The second reason could have been a failure of a vertical gyro. The evidence indicated that it was possible to have a failure of a vertical gyro without an associated warning flag. If such a failure occurred and the aircraft was being flown with reference to the associated artificial horizon instrument it is likely that the pilot would be misled by the erroneous indication and could have applied nosedown trim. Aircraft CF-TJN was equipped with a standby artificial horizon located on the Captain's instrument panel and this cross reference together with the experience and competency of the crew would likely have led them to recognize the fault in time to take corrective action. Again, the possibility that this condition caused the application of AND trim cannot be dismissed.
(c) The third reason could have been an unprogrammed and unnoticed extension of the Pitch Trim Compensator. This would have had the effect of moving the control column back, the elevators up and the aircraft to a nose up condition. The pilot would likely have counteracted the pitch up force of the elevators by trimming the horizontal stabilizer to or near to the limit of the Aircraft Nose Down setting. The evidence shows that the simultaneous application of up elevator from the PTC and the application of as little as 0.5 degrees of Aircraft Nose Down trim on the horizontal stabilizer has an adverse effect on aircraft stability and can create a difficult control problem. The problems of instability and control are more serious as further AND trim is applied. In aircraft CF-TJN 2.0 degrees of AND trim was available and it appears that the pilot applied at least 1.6 degrees of the available trim. It is unlikely that the flight crew were aware of the serious stability and-control problems that we now know can result from the combination of extended PTC and AND trim, even if they had been aware that the PTC had extended. The aircraft would then be in a condition where a slight displacement from its trim point would lead to divergent oscillations. In other words, a minor change. of attitude, easily caused by the existing turbulence, would build up into large displacements. The inadequate control available to the pilot and the lack of an external horizon reference would likely result in the aircraft eventually assuming a dive attitude.
It is concluded that an unprogrammed extension of the Pitch Trim Compensator is the most probable cause for the pilot having applied Aircraft Nose Down Trim, which initiated the chain of events that culminated in the crash.
Final Report:

Crash of a Vickers 757 Viscount in Toronto

Date & Time: Oct 3, 1959
Type of aircraft:
Operator:
Registration:
CF-TGY
Survivors:
Yes
MSN:
143
YOM:
1956
Country:
Crew on board:
4
Crew fatalities:
Pax on board:
34
Pax fatalities:
Other fatalities:
Total fatalities:
0
Aircraft flight hours:
9404
Aircraft flight cycles:
7800
Circumstances:
On approach to Toronto-Malton Airport, the crew encountered poor weather conditions with thunderstorm activity and heavy rain falls. The aircraft descended below the glide until it struck the ground. On impact, then undercarriage and the engines were sheared and the airplane slid for several yards before coming to rest 3,400 feet short of runway threshold. All 38 occupants were evacuated, ten of them were injured. The aircraft was destroyed.
Probable cause:
The accident was the consequence of a misjudged approach on part of the flying crew but weather conditions were considered as poor with presence of windshear.

Crash of a Lockheed 18-08A LodeStar in Toronto

Date & Time: Nov 4, 1943
Type of aircraft:
Operator:
Registration:
CF-TCX
Flight Phase:
Survivors:
Yes
MSN:
18-2063
YOM:
1941
Country:
Crew on board:
0
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
0
Circumstances:
Shortly after take off from Toronto-Malton Airport, while in initial climb, the aircraft stalled and crashed in a field. While all occupants evacuated safely, the aircraft was written off.
Probable cause:
Dual engine failure shortly after rotation.