QF Q400 Crew Forget Landing Gear
 

Landing gear not retracted after take-off demonstrates how diverted attention or focus may result in errors of omission...

https://www.atsb.gov.au/media/news-i...ted-attention/

BN2 endorsed?

Any ideas on why the altitude limitation?

Intriguing. Seems like a question for the likes of john tullamarine.

Maybe the differences in the aerodynamic/stability/loss of an engine consequences of the drag of/turbulence in the wake of the undercarriage at altitude?

Intriguing.

Was it a passenger who told the hostie to tell the pilot?

Didn't notice the extra drag reducing ROC? Didn't notice the handle in the Down position and three green lights looking at them?

not an expert on aerodynamics but I'd imagine it has to do with increased drag and entering increased stall speed with altitude.

As for why they didn't notice roc or green lights. Expectancy bias for both. They were light on this flight but heavy in previous flights. The expectancy bias is something Qlink has been honing honing in on in c and t. It's not an isolated case though. Seen lots of read and not actually checking in checklists throughout my time.

At least they avoided the knee jerk reaction when they noticed it and checked speed before raising. Instant reaction across many of these incidents is to go for the lever first. A similar example occurred inside my employer however flap related, and when they noticed at a significant height, pulled the lever immediately without checking they sat well over max retraction speed. Training Department was not happy.

NASA did a study by riding jump seat and observing events on sixty flights, eight hundred ninety-nine deviations were observed (194 in checklist use, 391 in monitoring, and 314 in primary procedures). Included A320, 737, 757, 767, 777 and EMB 175/195.

Checklists and Monitoring in the Cockpit: Why Crucial Defenses Sometimes Fail

https://human-factors.arc.nasa.gov/p...010-216396.pdf

So it's confirmed (again): Humans make mistakes.

But our laughably described political 'leaders' want the punters to believe that: "There's no margin for error in aviation."

That's why the powerless are beasted and over-regulated by CASA. CASA can get away with it, practically, and it makes the punters feel safe. If only they knew the reality.

I think you will find its more to do with compressibility. Flap and gear will have limiting mach numbers. Not sure on the specifics of the q400 but I think you will find that its Vlo will crossover to its max mach number for the gear at 15,000. The mach number is probably not stated though, hence the altitude restriction.

Why can a gear down ferry be done up to a max of FL200 then?

FFS give it a rest These observations continue under the heading of LOSA. The first LOSA conducted at Qantas was on the 747-400. The results caused a collective gasp of surprise.

I note the report dismisses the possible effect of a COVID related influence. During COVID LOSA was suspended so it will never be known what effect COVID might have had on operations.

What would the passenger limitations, baggage limitations, fuel limitations, CofG limitations and other conditions of that ferry be, noclue?

Of course…

But the context of my response that mentioned you was not the mistake, but rather the altitude limitation on the undercarriage remaining extended on this aircraft type. I’d hoped you’d be able to shed some light on why that limitation exists.

Maybe Bombardier calculated the likely altitude that passengers and FA would notice that the gear should not be down, so make sure it's retracted by then. Looks like they were spot on and crew were alerted right as they passed that altitude. What was the altitude of the other one that reached cruise altitude and exceeded max gear speed?

I could only hazard a guess as I have no knowledge of the aircraft's certification.

My guesses might include door/structure airloads at the max gear speed, for the limiting height, perhaps Mach related compressibility problems, perhaps something as simple as the OEM's determining that there was no design/operational need for the gear to be qualified for higher levels in a manner similar to the usual F200 flap limit on jets.

Sometimes one needs to dig deeply into the design standards to tease out some of these sorts of conflicting requirements.

LB-How would not having pax or bags loaded affect a “compressibility” speed/Mach limit on the gear.

The report stated there was “no effect on serviceability of the aircraft” with having the gear extended above the FL150 limit? So what’s the limit for?

How would not having pax or bags loaded affect a “compressibility” speed/Mach limit on the gear.

I think the question was more a case of "tell us all the details of the supplement, rather than just the height limit" ?

The report stated there was “no effect on serviceability of the aircraft” with having the gear extended above the FL150 limit?

I think you may have misinterpreted the statement. More a case, I suggest, of the minor exceedance not causing any associated damage .... as one would expect to be the case. There are very few occasions in certification where the aircraft is left near a cliff in the event of minor limit exceedances.

So what’s the limit for?

As suggested before, one would really need to be familiar with the certification reports, which usually are held quite proprietary by the OEM. Alternatively, one can engage in an extensive ferreting exercise in the design standards to see what possibilities might present.

Like most limits, there can be lot of excess margin built in. But you have to set it somewhere.
Would not have taken a Q400 long to get to FL159!