Aircraft General Discussion

It would be more likely to be the rotor that would damage a glider. Quite often, under the lenticular wave cloud there is a rotor cloud much closer to the ground. What happens is that the rushes over the mountain range, down on the leeward side and then up again into the first wave, forming the lenticular cloud up high. Underneath a horizontal rotor can form, with wind close to the ground actually going in the opposite direction to the wind at altitude. Sometimes wisps of cloud can be seen in the rotor, and they can be seen to be rotating quite rapidly.

I grew up in Masterton, in the Wairarapa, which is a valley in the lee of the Tararua ranges. The ranges lie across the prevailing northwest wind, so often provide good wave conditions. Masterton is quite fortuitously in quite a good position as it can be experiencing a gentle wind from the east when the rest of the valley is experiencing a strong norwester.

The wave conditions can prevail for the length of the ranges in the North Island from East Cape to Cook Strait, and across the strait for the full length of the South Island. So some very long glider flights have been made. Often more than one wave cloud can be seen, eg a second wave forms downwind of the first. The Tararua ranges are only around 5000 feet high, but the wave cloud can be at around 20,000 feet or so.

John

I'd agreed. The down of a wave is as smooth as the up, except that the glider is imitating a house brick. On the other hand rotor can be as rough as it comes. On the ground it can be dead calm under the rotor, whereas at a few hundred feet it is all hell let loose. At Aboyne, in a southerly, I've seen the windsock point to all four cardinal points, followed by straight up.

I had to look up the Sheffield incident - February 1962. It was part of severe westerly gales across a large part of the UK, over a couple of days. However, at least one report mentions a resonant lee wave effect. I think it is most likely that the damage was caused by rotor that reached down to the ground, rather than the wave per se.

Sometimes the only way to get into wave from a hill or winch launch is to climb in the rotor first; exciting stuff. Here's a picture of what happens when you get in the down of the wave and don't twig what is going on. You end up in an unsuitable field, but the only one I could reach:

This is a picture of a roll cloud:

It was taken in North Wales, looking north towards the coast. The gliding site is the triangular field lower centre. The rotor worked rather well and could be soared almost like a ridge. The wave was odd that day too. The picture was taken after a climb to 20000 feet over Snowdon, having jumped foward two 'bars'. There were no lenticular clouds, just hazy blue sky. Unusually for high wave the climb rates were weak. I didn't see anything much above 150ft/min. The approach into the gliding club was exciting; the glider fell out of the sky at 200 feet and I ended up looking at the ground through my feet.

Andrew

I think this qualifies for inclusion in this thread:

**LINK**

http://www.darpa.mil/news-events/2017-02-06

Demonstration of SideArm

MichaelG.

Ooops ... double post

Edited By Michael Gilligan on 12/02/2017 18:03:03

I do like the implication that only the US Navy has the technology and skill to launch and recover aircraft from a floating platform, y'know like an aircraft carrier.

That said, something that caught my attention was that unless the moving object just happens to be traveling along a path that might coincide with some stationary structure, all this technology 'aint worth spit, as they apparently say out west. It's like the fielder standing six feet to one side of where the ball's traveling; the thing is heading straight for the boundary.

Ian

Never mind cuckoos I've just watched the first Spitfire of the year doing aerobatics over the bungalow. Quite a work out; apart from the normal loops and rolls there were high speed dives, and more unusually a stall and one turn of a spin.

On another matter I note that the AAIB final report on the Hawker Hunter crash at Shoreham in 2015 was published last week. I haven't read all of it yet, as it's over 400 pages.

Andrew

.

The demonstration involved catching a Lockeed Martin Fury ... which would be 'returning home' rather than just happening to be traveling along a path that might coincide with some stationary structure.

MichaelG.

Microsoft Flight Simulator ver 5 for MS-DOS - Pilot's Handbook (284pp)

Does anyone want this period piece (complete with plan of Orly runway)?

Free to collect or sent for postage (504 gms net)

Edited By ega on 19/03/2017 16:08:26

I often fly to Sydney from Albury.

Nice to know that the SAAB's work ok when a bit falls off. **LINK**

* Danny M *

Saw the Saab on TV news, bit of a bother, reminds me of an incident in the early 1960s, one of our pilots radioed in to New Plymouth that his engine was "missing". The tower suggested he try switching the mags, the pilot didn't think this would work, as the engine was missing in that it had fallen out of the aircraft. The aircraft a Cessna 185 was landed with little damage on some clear land.

Ian S C

Not very comforting:-
"Some things just can’t be seen,” Mr Smith said. “Ninety-nine-point-nine per cent of the time something like this doesn't happen.”

That means that 1 in 1,000 flights have a serious incident. I think Mr Smith doesn't understand statistics!
BobH

Civil airworthiness requirements are 1*10^-9 catastrophic failures per fleet flying hour. MIL is 10^-6.

So, 1*10^9 hours is the fleet safe life, divide by fleet numbers, divide by hours flown per year, gives you a rough guess at the maximum fleet life in years from that perspective. There are many many many other considerations though, dual redundant load paths, redundant systems, preventative maintenance (particularly D-check) fail safe and rip-stop construction all play a major role.

Martin Bakers Meteor WL419 was just out for a fly round Chalgrove airfield, haven't seen it for a while. Flew over my house but grabbed camera too late, wind blowing our way so good whiff of kerosene after he landed.

Mike

Luv the smell of Avtur. Good to hear that there is still a Meteor airworthy.

Ian S C

Martin Baker (now Lockheed Martin) still have two Meteors serviceable for ejector seat testing. The testing program seems a lot quieter in the last few years so most flights are probably just to keep them in good working order.

Mike

Two different firms (unless they have merged very recently). The Martin in Lockheed Martin was the old US aircraft company that made the Canberra bomber under licence, the B57 powered by J65s (A.S. Sapphire also built under licence).

JA

Just had a look at Martin Bakers web site, still a british company making ejectors seats.

Martin P

These 2 Starter Cartridge Cases had spent much of their life on a Mantelpiece in my parents home. As a child, I was always fascinated with the shine and colour, so had the job of cleaning them and other Brasses

.

My father told me he had saved them from the days of his career with Hawkers at Dunsfold. He told me they were used on one of the 2 Avon engined F1 Hunters which were going through further development into 1953-

As there is no value, or other purpose to them, I decided to make use of them and incorporate both as Fuel Tanks for a 1954 Villiers powered Water Pump project. Also have 2 x 30mm Cannon Cartridges from the Aden Cannon Pack trial firings. which I'll try and incorporate.

Bit more cleaning to do inside first. Just have to find a use in the Workshop for the pair of Hinges believed to be from a Gloster Meteor Elevator....any takers for varification if I stick an image up on here?.

He was obviously not allowed to obtain a memento of his development work on the P1127/ Kestrel, but I was introduced to Bill Bedford (when I was 10) who gave me his Autograph......a start to my eventual career of obtaining Autographs from Thousands of Pilots.........on Weight and Balance Loadsheets !

Regards

Posted by Richard S2 on 25/03/2017 17:21:45:my eventual career of obtaining Autographs from Thousands of Pilots.........on Weight and Balance Loadsheets !

One of my steplads used to do those for DHL mail flights out of Nottingham.

He must have been OK at it because he was never on the sharp end of a pilot's wrath when they aren't right!

Neil