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View Full Version : UA23 into Dublin 2013 - Pitot Icing etc etc


Gary Brown
10th May 2016, 19:15
This United23 Newark-Dublin descent (FL250-235) incident has been somewhat "under the radar" and was only - pretty briefly - discussed here at the time as a "turbulence and minor injuries" incident. But it's clear that it was much more than that.

The Irish AAIU has just issued its final report (http://www.aaiu.ie/node/921) which makes for more serious reading. And which report - quite explicitly, in an appendix - draws certain parallels with other recent Unreliable Airspeed Incidents following on pitot icing events (think AF447...). Basically it a tale of a minor weather event (perhaps avoidable...) that soon led to unreliable data in the cockpit, non-standard ("startled") crew responses, poor cockpit communication, and mistaken diagnoses and choices, with consequent damage to the aircraft plus injuries to cabin crew and passengers (fortunately minor). The flight crew - in the various immediate de-briefs and later interviews - seemed largely unaware of (and rather unclear about) what had actually happened during the incident. And - one must add - their training, the available documentation and - maybe - even the data and warnings presented to them don't seem optimal either.

As ever, worth a careful read. But for the grace of........

SeenItAll
10th May 2016, 21:10
And yet they landed the plane in nonemergency status with only minor injuries and damage -- in the face of an incident type indication that has given rise to a half a dozen or more absolutely wrong reactions with fatal results (i.e., pulling back on the stick or only increasing thrust). When things happen, there will always be a "startle effect." Be glad that here the co-pilot's instincts and training were to execute a throttle-up and stick down -- although with the benefit of a longer analysis (i.e., 2.5 years by the AAIU) these actions proved not to have been needed. From reading the report one gets the idea that these investigators would have praised the pilots of SR111 for calmly going through all of their checklists and dumping fuel while the cabin was filling with smoke.

Amstrong
10th May 2016, 23:18
Pitch & power. I don't see any reason to pitch down to -16 when you know you were just doing 300KTS at 0 pitch (collision avoidance excepted) Simple physics and a serious lack of SA imho. What I found interesting was the fact the captain PM was totally unaware even after the incident that the "drops" were caused in fact by his copilot PF inputs on the control column. So far for the old. A vs B. columns/side sticks ad nausam repeated arguments...

beardy
11th May 2016, 06:06
I think that the passengers and crew were very lucky that the use of incorrect procedures didn't make the situation any worse than it became.

I am glad that the copilot knew how to deal with a stall, but sad that neither he nor his captain didn't recognise that this wasn't a stall.

Whilst reference is made in the report to Window of Circadian Low, and dismissed as not being a factor, no reference is made to duty hours, nor commuting, nor cumulative fatigue, apart from a statement from the Operator that the crew were fully rested. They would say that wouldn't they.

PEI_3721
11th May 2016, 11:32
The discussion at http://www.pprune.org/tech-log/536706-brand-new-boeing-unreliable-airspeed-procedure-3.html might relate to this incident.

Has anyone a link to the "Boeing Flight Operational Technical Bulletin on the subject of unreliable airspeed issued dated 4 June 2013" as referenced in the report at para 2.6 (page 43 - 44).

For info see Flight Operational Technical Bulletin Ice Crystals. (http://www.dispatcher.org/images/Library/All_Model_Tech_Bulletin_20110516_Ice_Crystal_Icing.pdf)

4runner
15th May 2016, 16:27
Pitch & power. I don't see any reason to pitch down to -16 when you know you were just doing 300KTS at 0 pitch (collision avoidance excepted) Simple physics and a serious lack of SA imho. What I found interesting was the fact the captain PM was totally unaware even after the incident that the "drops" were caused in fact by his copilot PF inputs on the control column. So far for the old. A vs B. columns/side sticks ad nausam repeated arguments...

Dear Armstrong,

Thanks for your armchair evaluation.


Love,

Line Pilots

deefer dog
15th May 2016, 21:32
Didn't like the "tone" of the report. Seemed to me the investigators wanted it to be known that they had "suspicions" about non pulling of the CVR CB, and "recollections" of the crew.

UK AAIB take a lot of beating when it comes to conducting, writing and getting out what could be learnt from a report. 6 out of 10 for the Irish.

DaveReidUK
15th May 2016, 21:52
Seemed to me the investigators wanted it to be known that they had "suspicions" about non pulling of the CVR CB, and "recollections" of the crew.

The AAIU's statement that "the Investigation notes and accepts the Co-Pilot's statement that he thought the circuit breaker for the CVR had been pulled" doesn't seem to support that hypothesis.

Capn Bloggs
16th May 2016, 02:06
What I found interesting was the fact the captain PM was totally unaware even after the incident that the "drops" were caused in fact by his copilot PF inputs on the control column. So far for the old. A vs B. columns/side sticks ad nausam repeated arguments...
If you're already doing 300KIAS, it wouldn't take much forward-stick to induce the result. Whether you'd spot that at night is debateable. Full back stick, continuously, would be a different matter... ;)

Agree with your comment on the need for the pitchdown, though.

Lonewolf_50
17th May 2016, 13:03
Whilst reference is made in the report to Window of Circadian Low, and dismissed as not being a factor, no reference is made to duty hours, nor commuting, nor cumulative fatigue, apart from a statement from the Operator that the crew were fully rested. They would say that wouldn't they. This can be filed under "once again, lesson probably not learned."

Sober Lark
17th May 2016, 15:42
https://www.youtube.com/watch?v=58K4FhkVG7U

topgas
18th May 2016, 11:19
The Commander informed the Investigation that he had approximately 32,000 hours, but that he did not keep a logbook. Therefore his exact flight experience could not be determined.

Is that slightly unusual? (non pilot asking)

Algol
18th May 2016, 12:56
Many years ago I had a pitot heater failure during descent (on a turboprop). It was a sunny day with barely a cloud in the sky. Except, We had to pass through a thin and wispy layer over our destination. It was barely 50' thick and I could see the ground through it.
The instant we entered it my airspeed needle wound around hard right, twitched, then dropped back to stall speed and shot back up again. The second we exited the layer it returned to normal.
Now, even though I knew exactly what was happening, and even though I was (for all intents) VMC, the sheer disorientating shock of that rocketing airspeed was unbelievable. It took every fibre of my will to not react instinctively to what it was doing.
On a dark and stormy night it would have been much harder.
I'm not sure how you train for that kind of shock.

RAT 5
18th May 2016, 16:41
It was then determined that the Commander’s airspeed instruments were reading correctly, and the Commander took control of the aircraft. The aircraft was returned to normal flight and the Commander handed back control to the Co-Pilot.

I have not read the full pdf: report, only the intro page. The PF F/O declared his instruments seemed to be unreliable. Therefore I find this statement rather disturbing; or had they made some switching? Opinions?

4runner
18th May 2016, 22:01
Is that slightly unusual? (non pilot asking)

No. He's a Captain at a major US airline. All his records since his military discharge are on file with his airline and training with airline and the FAA. He's probably approaching 65 years old and makes $300,000 a year and doesn't give a shit enough to keep a logbook anymore. All his recency of experience are also on file and it's not required by the FAR's to log your total time. Now watch the 250 hour P2F austronauts begin their evaluation....

stilton
19th May 2016, 01:36
Seems to be a cultural thing, I know very few US major airline pilots that keep a master logbook strangely enough.


They will keep a 'mini log' for tax purposes but not a real log book.


It's a bit of an effort but i've always kept both up to date.

4runner
19th May 2016, 02:00
Then we get furloughed and scramble to fill the logbooks in while looking for overseas work...guilty...

Judd
22nd May 2016, 10:45
The AAIU's statement that "the Investigation notes and accepts the Co-Pilot's statement that he thought the circuit breaker for the CVR had been pulled" doesn't seem to support that hypothesis.


Of course the co-pilot would say that, wouldn't he? Mandy Rice-Davies all over again. It should take less than three seconds for a captain to take over immediate control. After all even junior flying instructors do that every day if the student cocks up a landing.


But from the report, it seems the captain sat on his hands and failed to do so until other gyrations ceased. Why the inordinate delay which further exacerbated the situation? Presumably if the F/O was PF the captain had given him "the leg" and was totally relaxed in the belief the F/O could handle anything unusual. It is called complacency. There are some captains who display marked reluctance to take control quickly from their F/O. Lack of moral courage maybe and the desire not to be regarded as a 'wimp.'


Clearly a monumental over-reaction by the F/O to bunt the aircraft twice despite every indication all it was a erroneous airspeed reading. Leaving the automatics engaged during this event again demonstrated the danger of automation dependency. The ability to instantly switch off the automatics (Click-Click) and go seamlessly into manual flight where necessary to fix a problem, is a skill rarely practiced during simulator training. Yet it is a vital airmanship skill that all airline pilots should possess. Without being given regular the opportunity to practice that skill, competency soon atrophies.