Posts by SkippyBing

Re: harmonising the guns

Meanwhile the Fairey Fulmar had a full 60 seconds worth. Didn't do a huge amount for the performance to be honest, what with it still only having a Merlin, plus a second crew member, folding wings etc...

Also a lot of P-51s that got a Griffon in place of the Merlin.

Re: Arghh!

'So in order to test this out, they glued split peas to the aircraft to simulate the dome head rivets'

I believe they then removed split peas until they found the optimum amount of dome headed rivets to use to minimise production time while maximising speed.

Re: darn it...

'Last time I looked Greenland wasn't west of West Sussex'

Look closer, it's not east of it.

Re: harmonising the guns

Yes you have to be a very good shot to get hits at anything over a few hundred yets, especially with the original fixed site. I think Screwball Beurling mastered the art of deflection shooting and was so good some of his kills didn't appear on the gun camera footage. Much easier to just get closer.

The later gyro gunsite improved the situation a lot as it took the guesswork out to an extent.

Re: Arghh!

And when you own your own Spitfire you can paint it in an authentic finish.

Incidentally at least one Spitfire and one Seafire were stripped to a bare metal finish during the war. Not sure about the Spitfire but the Seafire was with the 21st Aircraft Carrier Squadron, I think on HMS Hunter, and can be seen in photos of the ship entering Singapore.

Re: harmonising the guns

Some Hurricanes had 6 machine guns in each wing. Which sounds impressive but was less destructive than a couple of 20mm cannons (cannon rounds are explosive).

I think the standard for the RAF was to harmonise at 400 yards, although oddly I have it on reasonable authority the RN had a policy of harmonising at infinity.

'Most surviving Spits from the early years have had them replaced by the later Griffons' have you got a reference for that because I can't think of a single example where that's happened. It's certainly not a straight change of nose as you'd also need bigger underwing radiators, thicker wing skins, etc etc. The closest is where Griffon engined examples have had a Griffon from a Shackleton replace the original unit.

Re: So...

Four is out, five is in. With four you could get a hung vote which isn't helpful.

Re: So...

AF447 was iced pitot tubes so unrelated to the AoA sensor which was working fine throughout, even if the pilots were ignoring it. AoA is nice to have but airline pilots don't fly to it, it is useful/vital for fixed wing carrier landings but that's not really a 737 use case.

Re: They won't fly again

In a purely logical sense you may be correct about the relative risks. However airlines try to sell tickets to human beings who tend not to be purely logical and have different safety thresholds depending on whether or not they're in charge of the vehicle.

And those airlines are the people Boeing are trying to sell 737s to.

Re: Ryanair

Amusingly I don't they'll be able to change the 4 digit ICAO code which is B38M for Boeing 737-800 Max.

Re: AFAIK

I down voted, I'm not bothering with the correct explanation of the system because I and others have already posted it here multiple time.

Re: Will the 737 MAX ever be safe?

The throttles remained at the take-off setting throughout so they didn't open them up, they were always open. Secondary effect of controls, throttling back lowers the nose, the last thing they wanted to do with an aircraft whose primary controls are already fighting them to do that.

Re: Will the 737 MAX ever be safe?

'Changing the throttle will push the nose up or down, so the MCAS is there to stop them from pushing the nose up too far and causing a stall'

Not the actual problem, the larger engine cowlings actually generate lift at high angles of attack pushing the nose higher up as detailed by a previous response. The engines could be turned off and it would still be a problem. Although not the biggest one you'd have at that point...

Re: Will the 737 MAX ever be safe?

The problem is no one will insist on the 737NG because it's less fuel efficient than an A320. Radical idea, Boeing develop a new single aisle design rather than doing a pimp my ride on a 50 year old design...

Re: Why is there a choice?

Generally depending on the classification of the problem the authorities grant some leeway in applying the AD. E.g. within next 28 days which gives the airlines some flex to incorporate it into the next scheduled down time. In this case they probably believe that the interim measure is safe enough that it doesn't require the AD to be applied immediately.

Re: Spurious, Curious

'because if you are making an approach into a carrier landing in borderline or even moderate level the very *last* thing you need is a bloody variable cross wind.'

Which is why they always turn the carrier so there isn't a cross wind.

'It'll be even more damn fun in a VTOL because as I understand it, and I might be wrong, the F35 doesn't have the same control finesse as the Harrier.'

Presumably because you're making things up? Having had a brief from Commander Air on Queen Elizabeth the F-35 can manoeuvre at low speeds in ways that would have led to the Harrier crashing, which as he's flown the latter and seen the former during trials on QE I'll take as a more reliable source.

Re: Literally..

She's not fully operational for another couple of years though, and to be fair this happened on HMS Invincible when I was on her in 2003, so a few decades after she entered service. That was in the Captain's sea cabin though which made it the only time I've heard an emergency broadcast for a flood 10 decks above the waterline...

Re: AV-8B

It's fine in the flying department, compared to any other 4th/5th generation jet it has the highest flying hours per accident of any type.

MCAS doesn't correct for pitch changes with thrust, it corrects for a reduction in stick force near the stall which could lead to an irrecoverable stall. The money saving came in not telling pilots about it in order to make the conversion training as minimal as possible.

The Max is stable until it approaches the stall when the engine nacelles start to generate lift, reducing the stick force required to raise the nose.

For certification there's a requirement that it requires a given stick force to raise/lower the nose enough to change the speed by a set amount. The Max fails this without MCAS, designing it out would end up with a very different aircraft and require complete recertification. To minimise the training in the differences to keep a common type rating with earlier models, and make the costs attractive for airlines, they didn't mention MCAS in the conversion course.

Re: Almost.

Not quite true, many aircraft have pitch changes with a change in thrust. This is due to the centre of thrust being above or below the centre of drag/gravity. This doesn't make them unstable, continuing to change pitch once the change in thrust had happened would make them unstable.

The issue with the Max is that at high angles of attack the control force needed to increase pitch decreases due to lift from the engine nacelles. Which means if you hold the same back pressure the aircraft will continue to pitch up rather than stabilising at a new attitude/speed combination. This makes it unstable, and also required MCAS to meet certification requirements.

The Max actually has fairly benign flight characteristics until you get near the stall.

There's a saying, if you think flight safety is expensive, try having an accident.

Re: back in MY day...

An interesting point considering at no point were the pilots having any problem with navigation. The problem was with ATC not being told where the aircraft was.

The E6B was certainly still part of the CPL syllabus when I did it back in 2012 so I doubt your last sentence holds.

'attempting to set them into a position they were already in would feel immediately wrong even without looking'

There's a mental process called cognitive dissonance where you carry out an automatic action without realising it's the wrong one. It's possible all they were thinking was toggle that switch, and did, without registering which way up it was. I've read an account by a helicopter pilot who dropped an under-slung load rather than turn on the landing light, which must have been a bit of a surprise to all involved! In that case there were two switches on opposite sides of the control.

Technically Boeing is now Chicago based. I'm sure locating the HQ halfway across a continent from where the work is done is unrelated to their current tribulations...