This Really Terrified Me! | The Crazy Story of Pacific Western flight 314

0:04 [Music] what you're about to see is a combination of several factors that by themselves would be very tricky for Pilots to deal with but combined forms the stuff of nightmares stay tuned back in the 1970s Pacific Western Airlines or pwa ran an extensive short Hall Network connecting cities across the vast interior of Western and Northern Canada although the airline was owned by the provincial government of Alberta it also served many cities in neighboring British Columbia including the city of Cranbrook located in the Rocky Mountains near the US Border in the afternoon of the 11th of February 1978 a pwa flight crew therefore Was

0:51 preparing to fly a regularly scheduled service from Calgary Alberta over to Cranbrook the aircraft they were about to operate it was a boing 7372 200 one of the earliest versions of the 737 family and one that is actually still used by several Regional Airlines in Canada to serve remote Arctic destinations it's uniquely fit to do so because of its sturdy frame reliable engines and its ability to fit gravel kits making it possible to fly to dirt runways but Cranbrook wasn't at all that type of destination it wasn't a large city but it did have a proper Runway measuring 6,000 ft equipped with an instrument Landing system full approach lighting and most of the anemi is that

1:37 one would expect from a modern commercial airport but the one thing that it didn't have was an actual control tower and we'll get to the significance of that in just a moment now the pilots of this flight would have been extremely familiar with flights to unted airports because pwa serve those types of airfields virtually every day and normally without any type of issues the pilotin command on this flight was 30 years old and had almost 5,200 hours of Total flying time of which more than half had been operated on the 737 so he was quite familiar with the type his first officer on this day was 25 years old and quite new with about 1,300 hours of Total time including only 81 on the 737 which he had just started flying for

2:26 pwa as they sat down for their quick pre-flight briefing they would have noted that the aircraft was in good working order with nothing in the technical log that would affect their flight but the weather at their destination wasn't ideal there had been heavy snowfall in Cranbrook during the morning with almost a meter of snow on the ground and some continuing light snowfall at the time which restricted visibility down to 3/4 of a mile or about 1200 M but since Cranbrook had an instrument Landing system these conditions weren't really a big problem and this kind of weather was also common in the Rocky Mountains during the winter so there was no question that they would go ahead with the flight while the pilots completed the pre-flight setup

3:11 three cabin crew members helped board the flight's 44 passengers for a total of 49 people on board keeping the turnaround relatively quick pwa flight 314 soon started taxiing out to the runway in Calgary where after receiving their take-off clearance the two pilots powered up the 7372 2002 cigar bar-shaped JTA Delta engines and then started accelerating down the runway becoming Airborne at 12:32 local time and it was at that moment over in the Calgary control tower that the first link in a disastrous chain of events began to take shape you see it was standard practice for controllers to provide an estimated time of arrival or ETA to the controllers at each aircraft's destination in order to give

3:57 them heads up when the aircraft would likely come in and according to the Canadian ATC manual at the time this ETA was defined as the estimated time of arrival over the approach 8 to be used and there was no real information about how that ETA should be calculated in the case of Cranbrook aircraft arriving from Calgary normally performed an ILS approach to R6 from the north so controllers would estimate the time of arrival over the initial approach fixed for that approach which was a non-directional radio beacon in the nearby town of shuk Masuk pilots and controllers normally call this the shum Beacon although it was officially known by its two-letter designation Sierra x-ray now because the manual didn't

4:45 provide any clear instructions for formulating an ETA each controller had a slightly different technique for taking into account factors like weather and the procedures that they expected the aircraft to use and the result of that was that etas were often considerably different from what the actual arrival time would be as a matter of fact pwa flights from Calgary to Cranbrook almost always took about 25 minutes with very little variance only a couple of minutes in either direction pwa Personnel well they were well aware of this and ground staff in Calgary actually passed an ETA for flight 314 to their counterpart in Cranbrook that was extremely accurate to within one minute

5:30 but that ETA was only used for passenger handling purposes and it wasn't normally communicated to anyone outside of the company itself so without specific knowledge of pwa's operations the ETA calculated by Calgary Air Traffic Control Made incorrect assumptions about how flight 314 would fly its approach into Cranbrook and that meant that while the internal pwa prediction was that flight 314 would arrive at 1255 Calgary ATC predicted that it would arrive 10 minutes later at 1305 and this was the figure that they transmitted over to Cranbrook now you may recall that Cranbrook was an uncontrolled airport without a real Tower so who was

6:15 receiving this message then well actually what Cranbrook had instead of a control tower was something called an a radio station this concept exists in most countries and each country calls it something different but basically this position serves to provide advisory information about conditions at the airport without the authority to give real instructions to aircraft like an air traffic controller can and since Communication in general is so important I am super happy to present today's sponsor s an eim app that will keep you connected wherever you go s is created by the tech Geniuses over at the Nord group who are a fantastic group of supporters for our content and with s you will never need another physical SIM

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7:47 great 15% discount on your first purchase that's s.com pilot with the Code Pilot thank you s now let's continue with those a radio operators I mentioned before at Cranbrook the air radio operator was responsible for keeping flight Crews updated with the latest weather informing them of any other factors that might affect their approach or landing and also controlling the movement of ground vehicles on the runway at the time that flight 314 took off the Cranbrook Air Radio operator was monitoring the progress of a snow plow that was clearing snow away from the runway in between the scheduled arrivals when snow was falling continuously like it was on this day the air radio operators's manual recommended that snowplows should be called back only

8:34 about 5 minutes before an aircraft expected arrival time this would minimize the amount of snow that could accumulate between the departure of the snowplow and the arrival of the aircraft and therefore provide the best possible Landing conditions for the aircraft but at this point it's important to stop and note that the air radio operator's manual wasn't based on any official regulations at the time and in fact the position of an air radio operator was basically not even mentioned in Canada's Aviation rules at all one of the side effects of this lack of formalization was that the practices for controlling ground Vehicles were incompatible with air traffic controllers entirely separate practices for formulating etas so unaware of this fact the

9:21 Cranbrook a radio operator believed that pwa flight 314 would arrive at 1305 as he had been advised so unless the flight crew informed him otherwise he would order the snowplow Off The Runway at 1300 now the air radio operator had been working at that position for 5 years so he had probably observed long ago that Calgary's etas were not always trustworthy but again keep in mind that unless the pilots themselves provided a different time Calgary's ETA was all that he really had to work with this was a problem because Calgary's etas were never intended to be used for separating aircraft and ground vehicles and the controllers who formulated them probably had no idea they were being used for

10:06 that purpose all this just goes to show how a lot of standard practices back in 1978 hadn't been formalized and regulated to the extent that they are today and these gaps were about to have serious consequences for pwa flight 314 now speaking of safety gaps before we go any further I want to also talk about the design and operation ation of the 7372 200 trust reverses because those are also going to play a big role in this story trust reverses help slow the airplane down after a landing or a rejected takeoff by basically redirecting the direction of the trust into a slightly forward angle and while they are very loud and noticeable to passengers they're actually just a

10:52 braking assistance mechanism most of the real deceleration still comes from the regular wheel brakes but trust reverses can make a major difference when the runway is slippery or wet and they also help reduce the brake energy that goes into the brake discs which lowers the overall brake temperatures and therefore facilitates quicker turnaround so almost every transport category jet now has them the boing 77200 has what's known as bucket style reverses which reverse the trust Direction by folding down over the back of the engine to physically deflect the exhaust for forward as it leaves the engine for the pilots to deploy the trust reverses the trust levers must first be in the idle position to avoid generating any forward trust and the

11:39 pilot can then move the reversal levers which are attached to the trust levers in order to command the hydraulic reversal activators to open the bucket doors and then moving the reversal levels beyond the first detent will cause the engine to spool up which will then increase the amount of reverse trust as long as the buckets are correct correctly in position once the plane has slowed down moving the reversal levels back to their resting position then reduces power again and finally commands the hydraulic directional control valve to sto the bucket doors now because reverse Trust on the 77200 was only intended for use on the ground and could be catastrophic if activated in the air this system featured several different lockout

12:24 mechanisms to prevent unintended use in the air of the reverses one lockout mechanism prevented the pilot from moving the reversal levels unless the trust levels were in the idle position and it also prevented the pilot from increasing reverse trust until the reverser doors had fully deployed at the same time another lockout mechanism prevented the pilot from applying forward trust using the regular trust levels when the reversal doors were open or at least that was the idea you see the design of this lockout system had some serious flaws the issue was that the lockout was governed by a rotating cam instead of a solenoid or some other type of electrical connection with a solenoid you can have

13:11 a binary choice where if the doors are closed the trust levels can be moved and if the doors are not closed they can't but a purely mechanical cam allows for an infinite range of in between positions where the doors are neither open nor closed and forward trust is neither fully blocked nor fully allowed in fact as the bucket doors approached the sto position they would start turning the cam to release the lockout allowing forward trust to be applied proportionally to the amount that the cam had rotated this meant that it was technically possible to start applying forward trust when the doors were almost closed rather than fully closed but this wouldn't actually have been a major issue if not for the influence of yet

13:56 another safety system you see in order to prevent the reversa doors from leaving the closed position when the plane was in the air an airr interlock would activate to cut hydraulic power to the door actuating system and this would happen as soon as the weight on Wheel switches on the main landing gear sense that the aircraft was Airborne this meant that even if the pilot tried to deploy the reverses in flight they wouldn't be able to do so but it also meant that if the plane lifted off the ground while the reverses were still open for some reason there would be no hydraulic power left to close them at some point during the 1970s this discrepancy was pointed out to Boeing so in 1977 boing added a caution to the

14:42 flight crew operations manual warning that attempting to go around after deploying the reverses could cause one or more of the reverses to get stuck open now going around after deploying the reverses has been prohibited basically everywhere ever since trust reverse became a thing not only because of problems like this but also because of the high risk of overrunning the runway while trying to regain take of speed you see even with a well functioning design it always takes a while for the reverse system to go from deployed back to idle sto and locked and then for the engines to spool back up again to give enough thrust and that poses a very real and serious threat that Pilots have a hard time accounting for anyway this still happen s

15:29 occasionally even today but as it turns out pwa Pilots were widely aware that some of their colleagues had successfully done these type of Maneuvers on multiple different occasions now for me personally it was drilled into me very thoroughly that once I've started moving the reversal levers there's absolutely no possibility of a go around anymore but that kind of strict training isn't universally applied or equally effective in all cases and it certainly wasn't as strict back in 1978 now on the 7372 200 if one reverser did get stuck open in Flight the airplane would still be controllable in theory and there was also a way to get it closed again on the rear overhead

16:14 panel behind and above the pilots there were two thrust reverser override switches each protected by a guard and a witness wire and those switches would restore hydraulic power to the reverses in flight so that the pilot could store it this meant that if a reverser came open in Flight there would be a warning light on the dash and the emergency procedure associated with that light called for using those trust reverser override switches now I know that this is a lot of technical information but try to hang on to it for a little while because we we'll be needing it pretty soon again anyway returning to the story by this point flight 314 was climbing away from Calgary and approaching its cruising altitude of flight level 200 or 20 ,000 ft but the flight was so short

17:02 that at 12:42 Just 4 minutes into the cruise the first officer sent in a request to the Calgary controller to start The Descent the controller came back and cleared flight 314 to approach Cranbrook but he also told them to descend and gave them the local altimeter setting 2 minutes later as the flight was descending through 18,000 ft the first officer signed off with the Calgary controller and instead contacted Cranbrook a radio to report that they were clear for the approach and to request the latest weather the air radio operator reported that the wind was out of 1 15° at 6 knots and that there was no traffic known in the area this was then read back by the first officer but the air radio operator then added um and

17:48 314 the sweeper on the runway has been for some time trying to keep Snow back for you I'll let you know what it's like as soon as I get a progress from him and the visibility well not much change in the weather maybe visibility about 3/4 of a mile in snow and in response to that the first officer simply said 314 checks now I want to stop here and add some context to what was going on at that very moment because it turns out that the captain who was Pilot Flying wasn't listening to the Cranbrook Air Radio instead His Radio was tuned to a company frequency and he was busy chatting with another pwa p about the stock market and some other casual things now back in 1978 the sterile

18:35 cockpit rule didn't exist yet that's the rule that prohibits pilots from having off-topic conversations below 10,000 ft and during other critical phases of flight and it is also worth mentioning that even if the sterile cockpit rule had existed this flight was still a little bit more than 10,000 ft above the field elevation so it technically wouldn't have applied here but what now happened serves as a great example of why it's a good idea to keep the cockpit sterile at least during The Descent in basically all cases you see this was a very short flight without much on root time for chitchat and the fact that the captain felt comfortable having an idle conversation during The Descent but it basically tells me that he was likely very familiar with this route and maybe

19:21 more than a little bit complacent about it anyway the consequences of that was that he didn't hear the Cranbrook Air Radio operator talking about a snowplow on the runway and this fact caused quite a bit of controversy after the accident because the flight Crews destruction at this critical moment wasn't listed in the final report as a contributing factor in the accident and that was even though several members of the investigation team later told an independent review that in their opinion this Factor was actually important and I couldn't agree more the final report and the independent review of Canada's investigation agency both characterized the Pilot's decision to engage in off-topic conversations as unprofessional and poorly disciplined

20:09 and in fact one of the investigators told the review board that they would have cited this as a contributing factor if it hadn't been for the pressure that they received from the airline pwa but with the benefit of almost 50 years of hindsight I would say that the real causes of this distraction would be more appropriately described as the absence of a sterile cockpit philosophy and probably an overly casual culture at pwa at the time that's rather than some kind of personal failings with these particular Pilots anyway returning to the moment of the radio call we also need to address the question of why the first officer didn't speak up about the snowplow once the captain came back on the frequency unfortunately the cockpit

20:55 voice recording from this flight was lost so we don't know exactly what was said in the cockpit but it's pretty self-evident that the first officer either didn't hear about the snowplow or if he did he failed to highlighted to the captain the reason for this isn't really discussed in the report but from my point of view it could be because the wording used by the air radio operator actually had two possible interpretations one of those was that a snow sweeper was currently plowing the runway and that it would be called back inside once the driver reported that he was done and that was obviously what the air radio operator actually meant but another interpretation was that the snowplow had previously been out on the runway at some undetermined time and

21:42 that the air radio operator was going to ask the dri how much he had done in a cockpit environment with multiple distractions it's possible that the first officer heard something like the second interpretation and didn't process that the snow sweeper was at that moment still on the Runway which actually would kind of make sense since they had already received approach clearance and he obviously had no way of knowing that the standard practice of cran Brook was to call off the snow sweeper 5 minutes before their expected arrival and that the only ETA that the radio operator had so far was 10 minutes wrong so now since Cranbrook airport didn't have radar the only assurance that the snowplow would exit the runway

22:27 before flight 314 landed was the assumption that the pilots would report their position during the approach and indeed it was customary for Pilots approach in Cranbrook to inform the radio operator when they crossed the shum Beacon and entered Final Approach guidance for Pilots at the time recommended making a report on Final Approach to uncontrolled airports but this guidance lacked regulatory Force so while Pilots almost universally agreed that proper airmanship demanded a report it was not technically required legally speaking anyway all that we know is that the crew of flight 314 didn't make such a report when they started their approach maybe because they were distracted with something else who knows so in fact the first office's

23:14 acknowledgement of the information about the snowplow was the last transmission made from flight 314 prior to their arrival so what now actually happened was that the air radio operator expected flight 314 to report over the shoe Beacon and probably also to request an update on the visibility and status of the snowplow and when he didn't hear those calls he assumed that this meant that the flight wasn't on Final Approach yet if the pilots had made the routine report that everyone else normally made the air radio operator would have realized that flight 314 was only about 5 minutes away from the airport and he would then have told the snowplow to vacate the runway but that tragically didn't happen happen as flight 314 approached

24:01 Cranbrook airport following the guidance from the instrument Landing system they had no way of seeing the snow plow through the falling snow with only 3/4 of a mile of visibility the approach lights and the runway lights would have become visible well before the actual Runway surface did and to make matters even worse the snow plow was facing away from the airplane with a plume of snow flying off its brush which only further obscured it against the white background this also meant that the snowplow driver couldn't see the airplane coming since it was approaching from behind him and the a radio operator wasn't a controller and didn't have a control tower so he was unable to see either the snowplow or the airplane this all meant that by this

24:47 point flight 314 was on course for a disaster but one last twist still remained in store at time 12:55 pwa flight 314 touched down on 16 about 800 ft down the runway and the captain immediately applied reverse trust to begin slowing the airplane down but almost at the exact same moment that he started moving the reverse levers he suddenly saw the snowplow on the runway in front of them which if that would have happened to me would have probably scared the living daylight out of me now it would have been immediately obvious that they would hit the snowplow if it didn't take action straight away so acting lightly on almost pure Instinct the captain now called for a go around

25:32 stole the reverses and then started pushing the trust LS forward to go around or toga trust it is possible that as he started pushing the trust levs the equally startled first officer might have also tried to do the same thing and medical examinations later suggested that the captain may have fractured his tumb when the first officer pinned his hand against the trust levers but if that did happen it wasn't the biggest problem that the captain now faced because in the rush of aborting the landing so quickly he had missed that the left trust traversa doors hadn't fully closed when he started pushing the trust levs forward which again he was able to do since the lockout cam had already partially released at the same time he started

26:18 rotating to raise the nose causing the main landing gear to lift off the Runway which deenergized the weight on Wheel switches this now cut off hydraulic power to the revers the doors while they were still at least 4 to 5 cm short of being fully closed so as the plane now accelerated back into the air the force of the air flow into that 5 cm Gap started to push the bucket doors back open again and the hydraulic actuators couldn't resist this Force because they had been deenergized as a result within seconds the left trust ravs now fully deployed in flight and as that happened a safety system noticed this deployment and snapped the left trust lever back into

27:04 idle in order to prevent the development of full reverse trust but the open bucket doors and the asymmetric loss of trust now left the plane with a severe imbalance of thrust and drag still climbing into the air but losing speed the 737 cleared the top of the snow plow by about 50 ft prompting the driver to exclaim where the hell did he come from back on board the plane it must have been absolute chaos in the cockpit as the flight crew now tried to handle the sudden loss of trust during a go around while dealing with massive stress from the surprise of seeing the snowplow confusion from the deployment of the reverser and possible pain from the captain's fractured tumb both Pilots now

27:49 applied right rodder and right Aeron to compensate for the plane's strong desire to YW and roll to the left but they were now flying at the very limits of what was theoretically possible and that was because amid the confusion they hadn't remembered to retract the flaps and landing gear which now increased their drag even further so on top of the loss of trust and drag from the buckets they were now losing air speed fast and since the authority of the flight controls is proportional to the air speed they would soon be unable to stop the left ya if this continued unfortunately in such an extreme situation with so much stress and so little time to react it would have taken almost superhuman instincts to avoid the loss of control and it was

28:37 at this point at the worst possible moment that one of the pilots momentarily stopped applying right rodder now investigators later noted that the guard over the left trust reverser override switch was found open and that the witness wire was broken while the right switch was untouched so they speculated that one of the pilots might have seen the trust ravs a warning light and attempted to follow the emergency procedure that I described earlier and in the process of trying to reach up and flip that override switch the first officer might have accidentally lifted his foot off the Brader pedal or even touched the left but remembering this obscure switch within a matter of seconds in such a high stress environment is pretty hard

29:22 to imagine for me as a pilot also while the guard had been opened the switch was never actually moved so it is unclear if anyone actually got that far due to the loss of the cockpit voice recorder we will never know if the pilot somehow remembered the override switch but in any case they didn't manage to store the reverser before ultimately completely losing control of the plane the momentarily loss of the right rder input caused the plane to yaw and then roll sharply to the left at which point recovery became impossible due to low speed over the air radio frequency one of the pilots was now heard shouting we're going to crash the first officer evidently soon stomped on the right rod pedal again and someone also started retracting the

30:08 flaps towards 15° but at that point it was already too late the plane banged over 90° to the left and slammed into the ground beyond the end of R six less than 20 seconds after the start of the go round on impact the front of the plane broke apart and the center Wing set C was consumed by an explosion as the fuel tanks ignited almost everyone on board was killed during the crash and the following fire but the tail section came to rest mostly intact and a flight attendant and a passenger were able to escape through one of the rear exit doors three other passengers also escaped from the tail section through a break in the fuselage and one passenger was thrown out from the plane during the crash and survived after landing in the

30:55 deep snow still strapped in his seat responding fire trucks couldn't reach the scene due to the deep snow so firefighters and Witnesses weighed out to the wreckage on foot where they managed to find the Survivor inside of the forward cabin but that passenger unfortunately passed away in a hospital a few days later in total only six people survived this accident while 43 others lost their lives although the investigation into this crash was hampered by the severe fire damage to both the flight recorders investigators were able to determine that the contributing factors included an incorrect ETA from Calgary ATC the Pilot's failure to report crossing the skam beacon the deployment of the left

31:41 Trust revers In Flight inadequate regulations governing Communications at uncontrolled airport and the inability of the Boeing 737 to safely perform a go-around after reversal deployments on touchdown today the procedures used by pilots controllers and advisory Services as uncontrolled airports are much more formalized in order to prevent the kind of miscommunication that led up to this strategy the investigators also noted that for an airline like pwa which was operating large Jets into small uncontrolled airports during bad weather the ability to go around after revers deployment was desirable but no aircraft at the time was required to have this capability so as a direct result of this accident Canada became one of the only

32:28 countries to require manufacturers to demonstrate in Certification testing that their aircraft could safely go around after a revers deployment and this type of a gound has since become known around the world as the cran Brook maneuver in honor of pwa flight 314 today more robust lockout systems help ensure that reverses stay sto when the plane is still in the air and better training has helped make Pilots less likely to attempt the Cranbrook maneuver in the first place and that's especially important because even modern day trust reversing systems are not always 100% perfect as the pilots of this TAP Air Portugal flight found out the hard way now thank you so much for watching and if you want to see

33:13 my next video before anyone else then please go to patreon.com Mentor pilot and sign up my name is Peter hornfeld you are watching Mentor pilot and I hope you will have an absolutely fantastic day bye-bye