MRU Hits Fence

[Lurch]

Occurrence April 1st, but the Fire Department gets called on the 2nd, CADORs comes out 19 days later?

CADORS Number: 2016C0999 Occurrence Category(ies):
• Collision with obstacle(s) during take-off or landing whilst airborne.
• Other


Occurrence Information Occurrence Type: Accident Occurrence Date: 2016-04-01
Occurrence Time: 2340 Z Day Or Night: day-time
Fatalities: 0 Injuries: 0
Canadian Aerodrome ID: CFN7 Aerodrome Name: SUNDRE AB (CFN7)
Occurrence Location: SUNDRE AB (CFN7)
Province: Alberta TC Region: Prairie and Northern Region
Country: Canada World Area: North America
Reported By:
• NAV CANADA
• Transportation Safety Board of Canada
AOR Number: 199070-V1
TSB Class Of Investigation: Class 5 TSB Occurrence No: A16W0037

Occurrence Event Information


Aircraft Information Registration Mark: GEKA Foreign Registration:
Flight #: Flight Rule: VFR
Aircraft Category: Aeroplane Country of Registration: Canada
Make: CESSNA Model: 172R
Year Built: 2011 Amateur Built: No
Engine Make: AVCO LYCOMING Engine Model: IO-360-L2A
Engine Type: Reciprocating Gear Type: Land
Phase of Flight: Takeoff Damage: Substantial
Owner: Mount Royal University
Operator: Mount Royal University (2921)
Operator Type: Commercial CARs Subpart: 406

Aircraft Event Information •Collision with object
•Forced landing



Occurrence Summary Date Entered: 2016-04-19
Narrative:
A Chief pilot at Mount Royal University called to advise that a student, performing circuits from Springbank, AB (CYBW), had crashed a Mount Royal University Cessna 172R (C-GEKA) at Sundre, AB (CFN7) while approximately 200 ft west of Runway 09. The emergency locator transmitter (ELT) was not activated and there were no injuries.

O.P.I.: Further Action Required: No


Occurrence Summary Date Entered: 2016-04-26
Narrative:
UPDATE: TSB#A16W0037: C-GEKA, a Mount Royal University Cessna 172R, was on a dual training flight at Sundre, AB (CFN7), conducting a soft field departure from the grass beside Runway 24. During the takeoff, the left landing gear caught the top rail of the fence at the end of the runway. The aircraft executed a forced landing into a field off the end of the runway and the left landing gear collapsed. The aircraft sustained significant damage, but there were no injuries.

O.P.I.: Further Action Required: No

http://www.mountainviewgazette.ca/artic ... y-20160419

A small aircraft forced to land in a field west of Sundre on April 1 was the result of the plane hitting a fence at the end of a runway, officials have determined.

On April 1 the single-engine Cessna 172 with two persons on board came down in the field immediately west of the Sundre airport after attempting a takeoff.

The plane is owned by Mount Royal University (MRU) and had two people on board, an instructor and a student. Neither party was injured in the crash.

Sundre RCMP Sgt. Jim Lank said a followup investigation, including consultations with Transport Canada, has determined the cause.

“Inquiries with MRU revealed that a flight instructor and a student had been conducting ‘forced approaches’ when they struck a fence,” said Lank. “It was decided that the contact caused damage and an emergency landing was attempted.

“Due to the soft surface ground in the field further damage was caused to the landing gear and belly of the aircraft.”

Gerrit Vermeer, Transportation Safety Board of Canada spokesperson, confirmed the aircraft was attempting a takeoff when it hit a fence at the end of the runway.

“This was a fairly simple incident,” Vermeer. “What was reported to us was that the aircraft departed from the grass runway 24 at Sundre and didn’t appear to perform as expected, and got to the end of the runway and one of the landing gear caught the top rail of a fence.

“Apparently the impact slowed the aircraft sufficiently that the pilot selected to perform an off-airport landing in a field off the end of the runway.”

When Sundre firefighters arrived at the scene after receiving a 911 call on the following day, they found fuel leaking from the aircraft, says Sundre fire Chief Marty Butts.

The plane was later dismantled and removed from the field.

The Flight Instructor is probably happy his interview with Jazz was before the accident.

[leftoftrack]

Wow with friends like you............

[Mercator]

Shit happens !! That's why we train !!!! Good job by the instructor and student, they will have stories to tell for a while, and I am sure a cold beer went down real quick later on that day.

[North Shore]

Shit happens !! That's why we train !!!! Good job by the instructor and student, they will have stories to tell for a while, and I am sure a cold beer went down real quick later on that day.

Good Job?! Hardly. I'd call it a fcuk up - by the instructor. Their job, as PIC, is to keep their students and aeroplane safe while the students learn. Allowing the student to cut a takeoff so fine that they hit a fence is poor judgement, IMHO.

[trey kule]

Mercator..

Really...a good job?

[Mercator]

Ok so what do you say to that.

There where no injuries on what could have been tragic, I think that is commendable to begin with.

On a soft field take off, lift off occurs at lowest possible speed (Ref FTM ). Where do you call a reject???
Think about it !! How safe would it be to put it back on the grass strip and bring it to a stop!! Cmon give the instructor a break.
If you guys are aware of how he/she caused the "fcuk" up then go ahead start hammering away your passion for bashing on the forums.

I am sure the instructor must have saved many days before this unfortunate one.

[CpnCrunch]

It looks like the fence is about 3ft high. Do they train students to stay in ground effect a few feet off the ground until reaching Vy after a soft-field takeoff?

[BBQ Chips]

I would hardly call hitting a fence and then putting it down in the rhubarb a good job, unless they had a catastrophic failure at the end of the runway (maybe they did). We have all fucked up, most of us have gotten lucky. I'll reserve my opinion until the results of the investigation come out.

[trey kule]

Soft field and short field are two different techniques"

But, as someone said, let us wait until the facts come out. Hard to think of a training situation where you could hit a fence..

[pdw]

This could be the last we'll hear of this accident.

Soft field and short field are two different techniques"

But, as someone said, let us wait until the facts come out. Hard to think of a training situation where you could hit a fence..

A steady change in progress in between the ATIS intervals so at 4:40 local this becomes a gentle downwind softfield takeoff at Sundre. Very easily a windsock misread to some extent too, if takeoff is elsewhere than familiar, ie: not seeing accurate angle/strength from rwy24 grass while mentoring the "techniques". [WX history April 1/23:40Z, the Sundre component shifted 180degrees over about an hour].

[CpnCrunch]

Soft field and short field are two different techniques"

2400ft isn't short field. However it's short enough you definitely don't want to hang around in ground effect.

But, as someone said, let us wait until the facts come out.

They won't come out. It's a class 5 investigation. This is the best you'll get.

Hard to think of a training situation where you could hit a fence..

It's not really that hard. Most schools teach you to stay in ground effect after a soft-field takeoff. If you do that you'll almost certainly hit the fence, as you won't be in ground effect if you're above the height of the fence.

I'm sure there's a few people reading this who trained at MRU, so they can presumably tell us how MRU trains their soft-field takeoffs at Sundre.

[trey kule]

Well, if the facts will never come out, there is nothing to learn here, so unless people want to "throw thoughts out there", it is pretty much the end of the discussion.

I have no idea what field length at that particular day's density altitude, and aircraft weight would constitute a short field. You are amazing that you can just pull those numbers up.
In any event My comment about soft and short field differences was a bit more generic.

As to this hold it in ground effect.. I think there is a bit more to the technique than that. Unless you plan to never climb. And ground effect , I believe, extends higher than 3 feet AGL on a 172. I dont know for sure. I would expect that you only need to hold a small aircraft in ground effect until you reach the best angle or rate of climb speed. In this case it would seem best angle would have been appropriate until the fence was cleared.

Maybe it would be a good time for the MRU SMS to look at how these techniques are being taught. Would not hurt regardless of the reason..

[CpnCrunch]

Yes, you're right...I forgot Sundre isn't at sea level.

DA = 4845ft
PA = 3589ft

Takeoff ground run (on pavement) @ 2450lb = 1370ft
Takeoff dist over 50ft (on pavement) = 2500ft
Ground roll on grass = 1370 * 1.15 = 1600ft
Runway length: 2500ft

Also, the runway has a 0.5% upslope. The POH doesn't say how that affects takeoff, but it will likely increase ground roll by another 10%, i.e. about 1800ft.

So yes, it would be considered a short field.

As for ground effect, once you're 7ft off the ground you only have 20% ground effect. 14ft off the ground you have 10%. Less than 20% is neglible for all intents and purposes, so if you're in ground effect you're probably going to hit the fence (unless, perhaps, you can judge your height to within 2-3 feet and be sure you're not going to get any downdrafts).

[trey kule]

So yes, it would be considered a short field.

According to who? And why.? You calculations indicate about 1.33 times needed runway, and no special technique. Or were you using charts indicating a short field technique? I am not familiar with a 172 POH, so I am not sure if they show such charts.
If not , and this is normal takeoff technique, this is certainly not a short field. And even if it is, more than enough room to climb above a 3 foot fence..


Regardless of that, why would ayone, as an instructor, not choose conditions where there is a large margin of safety? It may surprise some instructors that students must actually learn and practice a technique before being expected to perform it as they should.

As to your ground effect response. It seems you have made an indefensable statement originally, and now are attempting to tenuously hang on to it. Ground affect heights will vary by aircraft type,. Are we to assume that the figures you are tossing out then , refer to a specific type that has specific mods or none?

Ground effect with flaps set for short field, or flapless?

Perhaps share with us where you came up with those percentages. I am sceptical, but always willing to learn if someone is not just pulling numbers they think sound right out of thin air.

[CpnCrunch]

According to who? And why.? You calculations indicate about 1.33 times needed runway, and no special technique.

There is no definition of short field, but 1.33 times needed runway would generally be considered short field. I just did a "short field" checkout with runway 1.5 times required ground roll.

Or were you using charts indicating a short field technique?

Yes. The 172 POH only gives values for short-field takeoff technique.

If not , and this is normal takeoff technique, this is certainly not a short field. And even if it is, more than enough room to climb above a 3 foot fence..

Yes, it should be......if you use the correct technique and the grass is short and dry.

Regardless of that, why would ayone, as an instructor, not choose conditions where there is a large margin of safety?

Yes, agreed. Some FTUs ban short+soft operations.

As to your ground effect response. It seems you have made an indefensable statement originally, and now are attempting to tenuously hang on to it. Ground affect heights will vary by aircraft type,. Are we to assume that the figures you are tossing out then , refer to a specific type that has specific mods or none?

The numbers I gave were specific to the 172. See the graph here:

http://www.boldmethod.com/learn-to-fly/ ... nd-effect/

(Wheels 7 feet off ground = wings 0.4 spanlengths above ground, which only gives you 20% ground effect).

[Mercator]

Yes, you're right...I forgot Sundre isn't at sea level.

DA = 4845ft
PA = 3589ft

Takeoff ground run (on pavement) @ 2450lb = 1370ft
Takeoff dist over 50ft (on pavement) = 2500ft
Ground roll on grass = 1370 * 1.15 = 1600ft
Runway length: 2500ft

Also, the runway has a 0.5% upslope. The POH doesn't say how that affects takeoff, but it will likely increase ground roll by another 10%, i.e. about 1800ft.

So yes, it would be considered a short field.

As for ground effect, once you're 7ft off the ground you only have 20% ground effect. 14ft off the ground you have 10%. Less than 20% is neglible for all intents and purposes, so if you're in ground effect you're probably going to hit the fence (unless, perhaps, you can judge your height to within 2-3 feet and be sure you're not going to get any downdrafts).

Yes, well explained.

I would agree that short runway and high DA contributed to the incident.

Also also....schools need to start teaching rejected take offs on grass strips if they are sending students there on training flights.
Rejecting a take off on grass is such a bad idea.

[pdw]

... Runway length: 2500ft

Also, the runway has a 0.5% upslope. The POH doesn't say how that affects takeoff, but it will likely increase ground roll by another 10%, i.e. about 1800ft.

172S POH: Increase Takeoff Distance 10% for every 2 knots tailwind.
5-6kts NE:
1800ft + (1800 x 25-30%) = 2200-2340ft.

[Nark]

Yes, well explained.

I would agree that short runway and high DA contributed to the incident.

Also also....schools need to start teaching rejected take offs on grass strips if they are sending students there on training flights.
Rejecting a take off on grass is such a bad idea.

What?
Please explain to me why rejecting on grass is a bad idea?

Perhaps I can put that gem of advice in my every filling toolbox of expirience.

Or did you mis-speak and mean to say, have an abort point prior to commencing your takeoff roll, on a grass strip...

[Mercator]

Please explain to me why rejecting on grass is a bad idea?

Perhaps I can put that gem of advice in my every filling toolbox of expirience.

Or did you mis-speak and mean to say, have an abort point prior to commencing your takeoff roll, on a grass strip...

In terms of using brakes, it can mess things up.

[PilotDAR]

It is possible while executing a short field technique takeoff, to get the plane stuck in ground effect - acceleration poor, climb out of ground effect unlikely within the space available. You're stuck at the level of the fence. The more AoA you apply to try to get out (up), the more drag you create, and less likely you are to climb away. Though counter intuitive, you have to lower the nose a little to keep the plane in ground effect, and assure that you accelerate by easing the nose down slightly but progressively as you speed up, and then climb to clear the obstacle.

When I am in a tight runway with a big obstacle, I aim the plane at the mid height of the obstacle, and assure acceleration. When I have the speed to climb away, I will climb up over the obstacle. Attempting to climb away more slowly than Vx is going to result in disappointment.

Like "ground rush", "obstacle rush" can lead an unwary pilot to try to force the plane over an obstacle, and that's about the worst way to climb away. A review of the performance data should tell the pilot whether the conditions and dimensions are enough for a safe takeoff at that time from that place. If the data says it will work, a well executed short field technique will get you safely out.

I suggest that students be trained to always perform either and a short field or soft field technique. If ever there is a reason to not do one of those two techniques during training, then just do a "normal" takeoff, but otherwise, practice the critical techniques at every opportunity possible. If a student practices many soft and many short field landings, they will experience the imperfect ones (which would likely be self induced anyway) and learn to recognize better when things are going wrong. That greater experience in recognizing it's going bad, will help with aborts - which , yes, can be performed on grass too!

Taking a 172 off a decent grass runway is simple stuff - it should be a basic skill. It is that basic skill in handling the aircraft, and recognizing performance or lack there of, which will prepare the student for the more demanding takeoffs. Those more demanding takeoffs could come during experience building, when float or ski flying. In most cases the dimensions of the "runway" are not documented, the obstacles are not stated, the surface is much more varied in terms of its effect on takeoff performance, and you gotta figure the winds out for yourself. Or, you might be flying a different type, for which detailed performance information is not available, and you have to figure it out for yourself on the fly...

I am unsympathetic to an instructor who chooses to land a 172 in a grass runway, and then cannot get it back out safely.