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SR20 runway overruns OK-BOL at LKFR, and OK-AER at LZMA

Today in the morning there were two images posted under facebook group “Doletis” for Czech pilots that cought my attention.

The original FB post commented that this happened at LKFR two or three days ago (770m grass) with 4POB and full fuel. I commented that 770m grass is too short for a heavily loaded SR20 and some other people commented in the similar manner. The post mysteriously disappeared during the day including all comments and my FB activity history also shows no mention of my comments. There is also no mention about the accident on Aviation Safety Network or anywhere else. Mysterious…

LKHK, Czech Republic

there is no METAR for LKFR but nearby LKMT was METAR LKMT 151000Z 03010KT 9999 FEW047 21/10 Q1013 NOSIG. The downhill runway at LKFR is 26.
So without too much speculating I think the pilot decided to take-off down hill with tailwind instead of uphill with head wind. Not the first one to make this mistake.

LKKU, LKTB

It is not a mistake generally, of course. It depends on the wind and the slope.

But an SR20 will usually be overweight with 4 POB and full fuel. And even if it isn‘t, but merely close to MTOW, in certain conditions, it will be performing too bad to get off on grass strips.

As to why coverage, even on ASN disappeared, that‘s a mystery indeed. Someone very important, maybe?

Mainz (EDFZ), Germany

well, there are cases where take-off down the hill with tail wind make sense but my experience is if you are in doubt, it´s always better to go up hill.
Land KFR is not the kind of single direction runway with that significant gradient. and one more advantage – going uphill you have way more time to decide to abandon if necessary.
edit –

Last Edited by Michal at 19 Jun 18:54
LKKU, LKTB

boscomantico wrote:

As to why coverage, even on ASN disappeared, that‘s a mystery indeed. Someone very important, maybe?

It’s still on FR24 anyway — including the attempted departure on the 15th.

ESKC (Uppsala/Sundbro), Sweden

my experience is if you are in doubt, it´s always better to go up hill.

Interesting. My experience is the opposite. So I guess it depends on type, as well as wind and slope – and obstacles, of course.

At home we have only 2.5% slope overall and even with quite a long runway (more than 1,400 ft) I’ve only ever taken off uphill in a helicopter (or the FW equivalent, a CH701).

A clue is that there aren’t many light GA airplanes which climb better than about 6% at MTOW.

Glenswinton, SW Scotland, United Kingdom

hold your breath, I am in process of calculating exact numbers from AFM – even we all know this is more than indicative ;-)

ok. done now. If the guy was on a very light weight (2600 lbs, unlikely), he had a theoretical chance to make it. Thin but not impossible – provided the grass was only wet, not swamp as indicated by NOTAM. If he was at MTOW no chance for sure. And to my big surprise the uphill headwind take-off is much worse. Even I believe 22% at sea level for each 1% of upslope is overestimated. But this is what AFMS says so we need to respect.

Last Edited by Michal at 19 Jun 20:30
LKKU, LKTB

Jacko wrote:

A clue is that there aren’t many light GA airplanes which climb better than about 6% at MTOW.

Is it really so? Even spamcans like the C172 and PA28 make about 9% at MTOM, MSL, ISA and Vy. More of course at Vx, but that gradient isn’t given in the POH.

Last Edited by Airborne_Again at 19 Jun 19:33
ESKC (Uppsala/Sundbro), Sweden

An SR22 does way more than 1300fpm at 130kts all the way to 10kft no? that is about 10% “flying climb gradient” and probably it can fly near steeper terrain gradient with extra help of ground effect, so let’s call it 20% or 30%?

The first problem is accelerating to VS0 when the wheels are on the ground and the distance it takes, that has lot do with wheels friction-to-normal ratio, the slope gradient ratio and thrust-to-weight ratio at slow speeds than wings lift-to-drag at high speeds and also there is “acceleration” and “speed”, for instance, one can’t accelerate on the roll when “ground climb gradient” exceeds thrust-to-weight ratio (even with zero friction) but he may still fly unaccelerated at constant speed on a similar “flying climb gradient” even with higher drag-to-lift ratios…

The second problem is accelerating from VS0 to VY and the third problem is flying a climb gradient at constant VY these will involve T/W – L/D vs gradient

Last Edited by Ibra at 19 Jun 20:29
Paris/Essex, United Kingdom

Just to clarify things. This SR20, not SR22. Huge difference in performance between the two.

LKHK, Czech Republic
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