Oil pressure warning indicators preceded the Feb. 9 crash of a Bombardier Challenger 604, which killed both pilots in a dual engine failure according to a preliminary report from the NTSB.
Information retrieved from the flight data recorder revealed the crew received three Master Warnings within a span of seven seconds. The first warning, indicating a left engine oil pressure issue, occurred at 15:09:33, followed immediately by a similar warning for the right engine at 15:09:34, and finally, a general engine warning at 15:09:40. “The system alerted pilots with illumination of a ‘Master Warning’ light on the glareshield, a corresponding red message on the crew alerting system page and a triple chime voice advisory (‘Engine oil’),” noted the report. The oil pressure warnings would be among other indications of engine failure.
Approximately twenty seconds later, at 15:10:05, the aircraft was at an altitude of about 1,000 feet and a speed of 122 knots when the crew announced they had lost both engines and were making an emergency landing. Seconds later, with the aircraft’s altitude at 875 feet and a speed of 115 knots, the pilots transmitted they would not make the runway. At 15:10:47, ADS-B track data ended with the aircraft positioned directly above Interstate 75 near Naples, Florida.
Dashcam video showed the aircraft in a shallow left turn before leveling its wings and touching down aligned with traffic. The left main landing gear touched down first, and then the right main landing gear. Subsequently, the aircraft veered into the grass shoulder before impacting a concrete sound barrier where it became engulfed in fire.
Both pilots were highly experienced—accumulating a combined more than 35,000 hours of total flight time with nearly 3,000 hours in the make and model.
The NTSB said the information is preliminary and subject to further investigation.
They almost pulled it off. To bad they had all of that fuel on board. Really quick thinking on the pilot’s part. About as good an effort as can be expected given the circumstances.
This is taking me back in time to my days at Lockheed. When a three engine L-1011 suffered failures of all three motors due to a loss of oil quantity and pressure. Airplane landed on one of the three motors while that motor was failing. They could not even taxi the airplane.
Could this be similar to the Challenger failure? We shall see.
https://en.wikipedia.org/wiki/Eastern_Air_Lines_Flight_855
This is taking me back in time to my days at Lockheed. When a three engine L-1011 suffered failures of all three motors due to a loss of oil quantity and pressure. Airplane landed on one of the three motors while that motor was failing. They could not even taxi the airplane.
Could this be similar to the Challenger failure? We shall see.
Was that an Eastern Airlines flight – possibly into Miami? I recall reading about a situation where the mechanic hadn’t changed the oil properly and the oil started leaking out of each engine in flight. If they hadn’t shut the first engine down immediately (saving a bit of engine life for a rstart when the other 2 eventually buned up) – and then didn’t get it started the first attempt – they likely wouldn’t have made it to the runway. Remarkabe story.
I think this is it – worth a read if you haven’t heard it before:
https://en.wikipedia.org/wiki/Eastern_Air_Lines_Flight_855
Google Eastern flight 855
If they had just a little more altitude when the engines failed they might have made it. Very sad. What are the chances of both engines failing minutes before touchdown?
How does one have a dual engine oil pressure failure? Is there a single point of failure mode?
Only if you leave the same o-ring out of both engines.
Weird for sure. It’s got me wondering if there is some odd, improbable failure mode involving the oil replenishment system, possibly the manual selector valve the directs oil from the replenishment oil tank to the oil storage tank at either engine. That seems to be the only (obvious) overlap point between the two engines’ oiling systems.
As the first post pointed out , given the circumstances the pilots did the best they could. Kudos to the FA who got the passengers off the plane.
As a former CRJ pilot, Id like to point out at an oil pressure warning may be the result of an engine failure and not the cause of it. The two engines are very independent, so how do both fail at the same time? Bird strikes? Compressor stalls? Fuel contamination? Or perhaps it truly was an oil issue.
My guess is fuel starvation.
Did you notice the massive fire? Really?
British Airways 38 had plenty of fuel when they crashed short.
There’s a difference between fuel “starvation” and fuel “exhaustion”. Starvation means the engines are deprived of fuel even if there’s adequate fuel on board. Exhaustion means you ran out of usable fuel.
Exhaustion is unlikely, since the engines on most multi-engine aircraft will not simultaneously quit when the tanks run dry. Not sure about the Challenger, but the engines on most multi-engine airplanes burn out of separate fuel tanks. That’s part of the safety/redundancy design. Unless the pilots were intentionally cross-feeding from one tank to feed both engines, exhaustion is very unlikely.
As for the fire, some Citations have a couple hundred pounds of unusable fuel. That will make for quite a fire. I can only imagine that the Challenger, being a pretty long range jet with large tanks, has a fair amount of unusable fuel. A descending nose-low attitude wouldn’t help matters if the tanks are running low. I’m not saying that they ran it out of fuel. It seems a bit unlikely given the light passenger payload and the size of the tanks (just shy of 20K lbs). I have to believe that they would load enough fuel to give themselves plenty of margin since W&B doesn’t seem to be an issue? Tragic, for sure. Prayers to the families of the crew.
Fuel starvation means the engine is starved of fuel, which can happen with full tanks if something goes wrong with the fuel delivery system. Empty tanks would be fuel exhaustion.
Is this a guessing game? Is there a pize?
Small note for AvWeb. In the title of this AvWeb article, the author says “NTSB cites Oil Pressure…” Cites is a bit misleading in the title. To me the reader it has the implication of causation. Perhaps saying “NTSB notes Oil Pressure…” is more appropriate.
Bill, I’ve written to AvWeb about similar inaccurate headlines. The definition also says “cite” means to mention. I only cite that to avoid mentioning it. 🙂
While “mention” is an oft-used (and incorrect) synonym, “cite” connotes “authoritative”. None of the “citations” in any of my papers and reports were mere “mentions”. In today’s increasingly fact-free public communication, one can “mention” any obvious falsehood, and a disturbingly large certain percentage of the population will believe it as truth.
I’m with Bill T, that usage is misleading, especially in a head. These are the things that the green eyeshade-wearing ink-stained wretches of my era knew in their creaking bones. Too bad most of us are dead.
Yeah, I get it. Cite might have been the wrong word. Notes was probably better. I’ll change it.
The crash is a mystery for sure. It could be a complex mystery. Likewise it could be a simple mystery such as the fuel boost pumps not being armed. No less tragic in either case. I pray for the families of the lost crew. I know their pain.
I am totally unfamiliar with this fuel delivery and storage system. But it certainly sounds like both engines flamed out. (Fuel starvation) Which caused the low oil pressure master warning.
The oil pressure warnings happen any time the engine is shut down, but it doesn’t happen immediately. I hear folks talking about fuel starvation, FOD, etc, but the problem may have been more subtle, developing for some time prior to the first recognition of trouble, and when events are spread out in time, it’s a lot harder for the crew to recognize and recover from a complex scenario. This feels like it could be an important teachable moment for our industry.
Does the warning system inhibit and prioritize warnings.?
I think they may have been on fuel crossfeed.
My experience is on the CRJ, but fuel cross feed is a rarely used function, normally used only if an engine is shutdown.
Pull up British Airways Flight 38. Ice in the fuel caused it to gel and partially blocked the fuel filters. They had enough flow for idle but when they pushed up the thrust levers on final neither engine responded
It may also be a possibility that idle-cutoff was accidentally entered when selecting flight idle. It has been done several times. Tired, distracted pilots or even mis-rigging could cause it to happen. When you don’t need any thrust the first indication of engine shutdown is usually the oil pressure warning. If they were accidentally shutdown together the warnings would be very close together. A restart by simply moving the throttles out of cutoff would not be possible. 1000 feet of altitude would leave no time for a restart.
From AIN online article on the same subject: “Both engine throttle levers were found near the IDLE stop position”
Looks like we may have a smoking gun
James Fallows has suggested that one of the pilots may have inadvertently unlocked the safety stops that prevent the engine throttles from continuing into the OFF position. That explanation would account for both engines simultaneously shutting down, as well as for the oil pressure warnings for both engines prior to them shutting down. Embroiled in the distraction of both engines shutting down, the pilots might not have noticed both throttles were in the shutdown position.
All this rampant speculation…. O-rings? Fuel starvation?? Birds???
What do we really know?
The preliminary report states both engines showed no damage. (No birds)
The aircraft burned (it had fuel)
Both engines shut down at the exact same time (fuel cutoff)
Oil pressure warnings sounded (these will occur weight off wheels if the engine is shut down)
Pilots made no radio calls prior to stating they’d lost both engines, indicating there most likely wasn’t an issue up to that point.
There is a video out there that someone made, showing how when the right seat pilot is flying a CRJ (or 604), that a if the left seat pilot reaches over to select flaps, their forearm goes right behind the red fuel cutoff levers. If the throttles are pulled to idle by the right seat pilot while the left seat pilot’s hand is on the flap selector, the video shows the red cutoff levers hitting the pilot’s arm, this raising upwards and shutting off the engines. Comments elsewhere state that SkyWest had this happen once, at altitude, and were able to restart the engines. Since these engines are not FADEC controlled, they won’t relight on their own. In this case there was insufficient time or altitude to attempt a restart (most likely).
The CVR transcripts, when released, will be the telling tale, but I’d bet money that the above is exactly what happened.
First, I would like to commend Amelia Walsh on the many fine articles she has offered us on this platform. As a young writer, she will gain experience with time and through our constructive criticism. With the rational media rapidly disappearing, let’s put on our “adult in the room” hats and support her.
While I worked as a mechanic at Bradley Field on the first “Canadair Challenger’ (great-grandfather of the Bombardier 604), I by no means am an expert on the “systems”. But it is my impression that NTSB is doing their usual “thing” by collecting evidence that confirms the pilot report of “…lost both engines!”. I believe that NTSB does not suspect that a compound oil pressure “failure” is anything more than confirmation that bioth engines were indeed not running.
Given the demonstrated reliability of GE’s CF-34’s, it is not likely to be any other cause than fuel starvation (certainly NOT fuel exhaustion, given the post-crash fire). If this predicted cause is a reasonable assumption, then the question becomes what could terminate fuel flow simultaneously on both engines? My selection would be icing at a valve, a fuel filter, or at a fuel/oil heat exchanger inlet.
I usually am critical of others who try to predict aircraft accident causes before the investigators issue their evidentiary findings, so just label me as a hypocrite and I probably will be forced to agree.
I’m thinking that someone put normal engine oil but not the required synthetic oil. Coking of the oil, bearing failure and seizing of the main engine compressor/turbine shaft bearings
.
To both engines, at the exact same time?
Well, as the previous folks said, the pilots will get an engine oil pressure warning as the engines quit, so two independent to the individual engines, then a master make sense –
At 1,000 ft and 115 kts, they had a couple of options, then when they were just over 800, there was still time to find a place other than a highway, but I don’t know the terrain and of course there are always infrastructure elements –
Never thought I’d say it’s easier to land on a carrier –
Does the 604 have a flight data recorder? If so, would it document movement of the fuel cut-off levers mentioned by HousesbiggerHousessmaller?
If the 604 is not equipped with a flight data recorder, why not? Given the value of the aircraft, a FDR would seem a very reasonable provision.
John Caulkins suggests ‘icing at a valve, a fuel filter, or at a fuel/oil heat exchanger inlet’ as the likely cause of the 604’s simultaneous dual engine shut downs. I find it difficult to imagine that the independent fuel tanks, fuel delivery lines, fuel filters, and fuel/oil heat exchangers on each independent engine would cause an instantaneous simultaneous shut down of both engines. Perhaps the 604’s engines share more critical fuel system components then I am aware of.
Modern turbojet engines will run for a substantial period of time with no oil or oil pressure. The engine will probably be badly damaged but it will still run.
The near simultaneous oil pressure warnings are an indication that both engines were inadvertently shut down.
The report states that the touchdown was aligned with southbound traffic. The video suggests that that is incorrect. The left main gear initial contact was in the center lane of three lanes. The aircraft crossed the right lane, the safety lane and traveled into the grass at a substantial angle to the Interstate. This was further affected by contact with a road sign with a steel pole. The contact with the concrete barrier spun the airplane around approximately 120 degrees.
Had the airplane landed “aligned with southbound traffic” the outcome would likely have been survivable for the pilots.
As I posted previously an examination of the satellite view of the area indicated that the Interstate was the ONLY viable choice.
From the second paragraph “information from the flight data recorder—“
The British Airways accident was a very long flight at unusually low (extreme) temperatures. No relevance to the Challenger accident
Also just a trace of water on one side and none on the other for the Challenger.
Let’s see. Did anyone check the FBO truck for two oil fill caps?
Did the inbound pilots ask the FBO to check engine oil after the last flight? And then if it was a different crew, no one told the new crew about the oil check so they didn’t think of checking the caps? Or maybe the captain asked, s/he forgot to tell the f/o who did the walk around, or just forgot?
There is no common point of failure for TWO engine oil pressure indications except quantity. Actual loss of oil. Only way you’d lose it is if the caps were removed and not replaced.
No jet pilot that I know of would ever ask the FBO to check the oil on a Challenger as if it was a C-150. Simply does NOT happen. They may have their own maintenance tech that does that, but you don’t leave an order at the desk to “Oh and check the oil”.
The premise that both oil pressure lights/warnings would occur simultaneously after a two hour plus flight with the oil caps removed is beyond absurd. The warnings occurred because the engines had been shut off.
Of course, the FDR would show the shutdown. And not as a dual engine failure but the steps to shut them down would show up as such in an FDR
The oil pressure warning is displayed when the engines are shutting down.
The open question is why are the engines shutting down. Pilot(s) error or fuel contamination are possibilities.