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Re: The impossible turn

Posted: Fri Aug 07, 2015 11:49 am
by Colonel
[quote]light the brakes on fire in a single engine plane[/quote]

Easier than you think.  5606 is merely
mineral oil, which all four-bars know has
a flashpoint of only 400F.

See 83282 and Skydrol.

Re: The impossible turn

Posted: Fri Aug 07, 2015 12:05 pm
by David MacRay
Interesting. If I am using the brakes in the 172s, I suspect I made some form of a mistake.

Re: The impossible turn

Posted: Fri Aug 07, 2015 1:06 pm
by Colonel
Not if you are doing a runup or turning
out of wind.

It's ok to use the brakes on a little airplane
if you are going less than 10 mph.  They
are for taxi use only.

Re: The impossible turn

Posted: Fri Aug 07, 2015 5:19 pm
by David MacRay
I indeed meant post landing, though you are right about possible wind pushing me along on taxi back.[quote]taxi use only..[/quote]

Oh, I should probably try to hide this like a bad dog but..
I did commit a braking crime on a Calgary flying club plane at least once.
The dreded "powered brake drag taxi."
If I end up with a tail wind taxiing I need to remember to pull the throttle before jumping on the brakes.

I am not proud but suspect I got a little anxious to get to the run up bay in under $200 possibly.
It seemed so far away since they lengthened the runway. I almost got the rolled up newspaper for it.

I certainly agree with your "correct use" of brakes to keep the little crafts still while NOT causing a backfire checking the mags. That should not cause much heat at the calipers.

Re: The impossible turn

Posted: Sat Aug 08, 2015 5:29 am
by Eric Janson
[quote author=Colonel link=topic=588.msg2326#msg2326 date=1438943264]

Do you fly approaches in your jets on the back
side of the power curve?  If you are willing to do
so in the L39 (not necessary in L29) you can get
it stopped in 3000 feet at sea level density altitude
or thereabouts.[/quote]

We have a flight envelope protection system.

Lowest selectable speed is 1.23Vs

For my aircraft Minimum landing distance (from 50 feet and 145 knots) with maximum manual braking at 550,000lbs is 4750'. If you need it there is a lot of braking available. We don't operate into anything less than about 8000'.

[quote]Must be a coincidence.  Remember, skill,
knowledge and experience don't count for
anything in aviation any more.  Only SOP's
do.[/quote]

Seems to me you can combine all of the above.

Unfortunately you are correct - I'm also seeing a "dumbing down" in Aviation.

Re: The impossible turn

Posted: Sat Aug 08, 2015 6:48 am
by Colonel
[quote]I'm also seeing a "dumbing down" in Aviation[/quote]

It was not always like that.

[img][/img]

[img][/img]

Re: The impossible turn

Posted: Sun Aug 09, 2015 3:31 pm
by praveen4143
Landing with a tail wind is not the monster that it is set out to be. I consistently test my pre-solo guys to land with up to 7-8 knots tailwinds in a simulated engine failure from the crosswind leg, and no one has broken anything yet. Just remember that the airplane will float that much longer! I believe Cessna POH says 10% extra for every 2 Knots of tailwinds. So when you try it out for the first time, try at a longer runway just so you don't scare yourself!

Also, flying in the hills of interior BC, there are so many times where the winds change for almost every 100-200 feet of altitude on approach. Quite often, you have to decide to either have a headwind on approach and tailwind on the ground or vice versa.

Incidentally, I once had to land a Cessna 172 with a 25 knot tailwind because my passenger was feeling really sick and each time I banked the airplane it only got worse for him and I decided to go straight in and land instead of joining downwind and turn twice to make the approach. Used up about 2500 feet of runway to land without needing any brakes and spent a cool 1500-2000 feet of that just floating down in the flare, but nothing broke! So that is not impossible.

Now with regard to the impossible turn, like Chuck and others mentioned, totally depends on how quickly the pilot recognises and decides to turn around and skill of said pilot, also how the airplane flies... The pilot in the video appears to be doing it intentionally and hence had a very quick response and it helped quite a bit!

Re: The impossible turn

Posted: Sun Aug 09, 2015 5:55 pm
by Colonel
Cessna 172 POH says 500 feet required to land.

So, when you are landing on 5000 foot runway,
you have a 10x factor.  That's an awful lot.

Landing a 172 at night at Pearson.  ATC hollering
at me to keep the speed up, I think I was 150
mph over the numbers.  Got it easily stopped,
the runway was so incredibly long.

With a longer runway (eg 8000 feet) I am
perfectly happy doing a 180 mph side-by-side
formation landing in the Pitts.  That speed
seems to work well, mixing it up with the
Boeings.

Re: The impossible turn

Posted: Sun Aug 09, 2015 9:13 pm
by HiFlyChick
[quote author=Eric Janson link=topic=588.msg2324#msg2324 date=1438942754]
...Here's what happens when Brake Energy Limits are exceeded. There are photos online of the damage.

[url=[/url]

An ILS with a 25knot tailwind will give result in 2 exceedences - maximum tailwind limitation and rate of descent above 1000'/min (unstabilised approach). These kinds of things will get you fired.

We fly to very strict limits in the "4-Bar" World.
[/quote]

Man, that was quite the video!  Several times it looked like everything had cooled off and died down and then an explosion would occur and things suddenly got bad real fast...

I had no idea that tires would blow like that when they were not obviously on fire - I thought there'd be lots of flames first and then an explosion.

You make some good points, Eric, even for light twins (which won't have so much momentum putting such strain on the brakes).  Landing with any tailwind adds to the wear and tear on the brakes and tires, which in turn adds to the cost.  There are times when a bit of tailwind makes sense (i.e. to avoid circling, especially in low vis and/or with high terrain), but otherwise you have to weigh that extra wear and tear cost against potential gain, which is sometimes only a few minutes saved.

Re: The impossible turn

Posted: Mon Aug 10, 2015 12:08 am
by Chuck Ellsworth
Hey Colonel.

That picture of the 747 landing at the airport in Rand South Africa brings back memories.

I had a guy who talked a real good talk about how good he was, however he could not put the PBY on that runway, the first time he tried he would have landed with both mains on the grass.

The second try he would have got the left main on but my side would have been on the grass.

His excuse was the runway was not wide enough for an airplane as big as a PBY.

Anyhow I refused to waste any more time with him and told him to find another pilot to do his type rating.

He was there to buy the airplane and told the owner he was one of the best pilots in California.....I told the owner I would hate to see the worst pilot in California.

Anyhow it was simple....buy the airplane and find another pilot to give him the type rating.

Turned out the guy did not have the money.....so no great loss.