Originally Posted by Clandestino
First issue with QH90 was very primitive (but legal at the time) FDR, which did not record attitude or power. In AirRabbit's alternative view on the accident, holes left by primitive recording equipment are filled by conjecture
Of course anyone here is free to offer their opinions ... but what I have offered is not “conjecture” any more than it is questioning the conclusions reached based on the information gathered ... as differentiated from the material eventually included in the official Accident Report. So, let’s look at facts and questions ... and let the reader come up with his/her own “conjecture.”
Fact: According to the Accident Report, the Trump De-Icing Vehicle did not incorporate the “mix-monitor” which allows the operator to ascertain that the desired mixture is indeed being delivered at the nozzle.
The Trump De-Icing Vehicle used to deice/anti-ice the accident airplane had recent “repairs” completed that resulted in the nozzle dispensing fluid at 18 percent glycol mixture from the deicing wand at a minimal flow rate, but when the operator increased the flow rate, all of the additional volume flow came from the heated water tank, and none from the glycol tank – effectively lowering the solution percentage by an unknown but substantial proportion, potentially reaching a solution of “zero glycol” being dispensed.
Question: Why is it that this information was not included in the Accident Report?
Answer: Up to you.
Question: Could the deicing/anti-icing solution provided by this “repaired” deicing vehicle, in combination with the ambient temperature of 24F, applied to a “cold-soaked” airplane, have had any effect on whether or not ice could accumulate on the aircraft? Could this solution, in combination with any potential snow fall, have had any effect on whether or not ice could accumulate on the aircraft?
Answer: Up to you.
Originally Posted by lomapaseo
It's easy for some to suggest that wing contamination might have played a part (after all the evidence melts immediately after a crash).
However the validated contributions are covered in the NTSB report hence the recommendations regarding engine power set "check'.
The Forum thread we are burried within is an equally important opportunity thread to discuss wing ice as a prime consideration on its own without mixing it up in a controversial message about Air Florida in the Potomac
Fact: Of course a snow-covered or an ice-covered wing would not be recovered from the Potomac. That is precisely why it is important to understand just how the deicing and anti-icing of the airplane took place – at least as important as knowing what snow actually fell between that process and the takeoff. All 3 aircraft (the accident aircraft, the aircraft preceding and the aircraft following) were in the same line for takeoff on the same runway. All 3 aircraft were exposed to the same weather conditions (including snow fall) for the same length of time.
Question: Why would only one of those aircraft (the one in the middle) have had a problem?
Answer: Up to you.
The first of the 3 causes of the accident, cited by the Accident Report:
“...the flightcrew’s failure to use engine anti -ice during ground operation and takeoff...”
Fact: The CVR transcript shows that during the “after start” checklist (which was conducted as a challenge/response exercise) at the F/O’s challenge (reading the checklist) item “Anti-ice” (referring to the engine anti-icing switches) the response, provided by the Captain, is indicated as “OFF,” and is shown within parentheses. The legend for the CVR shows that any transcript content contained within parentheses indicates “questionable text.”
Question: In that there are only two positions for those switches, either “ON” or “OFF,” when the response, as recorded on the cockpit voice recording tape, is not clear, why was “OFF” chosen to be placed within those parentheses instead of the only other alternative, “ON”? This is the only indication that engine anti-ice was not used. If the actual recording is not clear, and there are only 2 choices – why was “OFF” determined to be the response that should be included within those parentheses, instead of “ON”?
Answer: Up to you.
(Information: Just in case anyone may be interested ... when the wreckage of the airplane was retrieved, the position of the switches on the overhead panel and the position of each of the 3 associated valves in each of the engines were inconclusive – which is not uncommon for the amount of impact destruction experienced.)
The second of the 3 causes of the accident, cited by the Accident Report:
“...their decision to take off with snow/ice on the airfoil surfaces of the aircraft...”
Fact: for that day, the recorded information regarding snow fall was as follows...
Moderate snow began at 1240 and ended at 1320.
Heavy snow began at 1320 and ended at 1525.
Moderate snow began at 1525 and ended at 1540.
Light snow began at 1540 and ended at 1553.
Moderate snow began at 1553 and ended at 1616.
Again, the airplane preceding and the airplane following the accident B-737 were subjected to the same processes and weather prior to takeoff.
Question: If it was the snow fall that accumulated on the B-737 between the gate and their takeoff that caused the accident – what prevented the other two airplanes from suffering the same fate?
Answer: Up to you.
The third of the 3 causes of the accident, cited by the Accident Report:
“...the captain’s failure to reject the takeoff during the early stage when his attention was called to anomalous engine instrument readings.”
Fact: The first time the F/O expressed anything that sounded like he was questioning something was at 1600:02 when he said, “That don’t seem right does it?” This was followed at 1600:05 by “Ah, that’s not right” and then an inaudible comment, followed by the Captain saying “Yes it is, there’s eighty” at 1600:09. Then at 1600:10 the F/O said “Naw, I don’t think that’s right, followed at 1600:19 with “Ah, maybe it is.” Two seconds later, at 1600:21, the Captain says “Hundred and twenty.” Then the F/O says “I don’t know.”
Observation: The committee that listened to the actual CVR recording apparently concluded that the F/O was expressing a concern over an “engine anomaly,” and of course, that is certainly a possibility. For almost 20 seconds it would appear that both the Captain and the F/O were attempting to recognize something in the cockpit that was causing the F/O to make the comments he made – apparently without being able to identify what that was.
Question: What would have been anomalous to the F/O and not to the Captain? Would this be the only thing that would have caused the F/O to make the comments he made?
Answer: Up to you.
Fact: A landing airplane was on final when the accident B-737 was cleared into position and cleared for takeoff. Approximately 20 seconds elapsed from the time the tower advised that there was a landing airplane on final at 2 and ˝ miles behind the departing B-737 (at 1559:28) to the time the CVR recorded the sound of the engines spooling up toward the desired takeoff setting (at 1559:48). Another 14 seconds had passed when the F/O first indicated that there was something that he thought didn’t “seem right” (at 1600:02). Another 7 seconds had passed when the Captain noted that the B-737 had reached 80 knots (at 1600:09).
Question: How far behind the B-737 was the landing aircraft at these points?
Answer: Up to you.
Fact: At 1600:11 the landing aircraft called, “Fourteen fifty-one, cleared to land over the lights” (which extended 2400 from the runway’s threshold). We do not know the specific point over those approach lights the landing B-727 actually was at the time of that radio call.
Question: At this point, how far behind the B-737 was the landing aircraft?
Answer: Up to you.
Question: Would you have aborted the takeoff?
Answer: Up to you.
Fact: The accident report states “there were other incidents similar to this one reported, in which the crew was able to overcome the contamination, but they needed the proper thrust level of 2.04 EPR.” On the same day as the Air Florida accident, another B-737 attempted a takeoff out of Oslo, Norway, where the taxi and takeoff were conducted during a snowstorm. During the takeoff, as the crew began to rotate, the airplane pitched-up and due to the asymmetry of the deformity of the wings, began a roll. Neither the pitch nor the roll was controllable by the crew. Even though the throttles were “slammed” to the firewall immediately and the fact that the pilot used full opposite aileron and full opposite rudder, the pitch and roll of the aircraft was not controllable. Apparently, due to the radical bank angle reached (approaching 90 degrees), the nose dropped back down toward the horizon, and with the throttles fully forward, the airplane began to accelerate. As the acceleration continued, apparently lift was produced over the outboard portions of the wing, including the ailerons, and the crew was able to roll back to level flight. The crew recovered the airplane; but that recovery was below 100 feet above the ground.
Question: Why were the only incidents of B-737 pitch-up and/or roll-off described in the Accident Report those that were recoverable?
Answer: Up to you.
Originally Posted by lomapaseo
Have a question about adhering ... then ask the regulator
Care to interpret it yourself then accept the violation
If it is still on your aircraft when you push back then it is adhering.
There is still room in an SOP once you depart with a clean wing. But you need to start someplace with a known degree of safety
My first inclination is to say “from your lips to the hearts and minds of aviators everywhere.” However, I am mindful of the fact that most of those aviators are heavily influenced by all sorts of external factors – their boss, their job, their salary, etc. Most of these external factors have a tendency to influence the way individuals interpret specific issues to result in the most advantageous and to the least negative impact possible. To that end, I’m taken back to the simple fact that the FAA has maintained that the only time they feel it necessary to specifically define a word that they use in their regulatory documents is when the definition they desire to use is either not included in the dictionary or the dictionary definition is not the meaning the FAA wished to convey. Terms that are used in the regulations are either defined in the regulations (some place) or they rely on the traditional understanding (i.e., dictionary definition) of the term. Since the term “adhering” is not found in the regulations – in those parts or sections were there are requirements laid out for taking off or landing in inclement weather conditions or in their primary rule dealing with definitions, the only definition that can be applied to this term is the definition found in the dictionary. According to Merriam-Webster, the term “adhere” means (in the context used in these rule sections) “...to hold fast, or to stick through gluing, suction, grasping, or fusing.”
As long as the rule uses that term, I think we all have to recognize that there is likely to be a substantial number of people who will find that definition to be a way to continue operations when that continuation may not be the most conservative decision.