172 wire strike Duncan BC

[CpnCrunch]

Final report now out:

http://www.bst-tsb.gc.ca/eng/rapports-r ... 7p0007.asp

They weren't doing a touch+go after all: they tried to take off again after realising they couldn't stop in time. Report seems to indicate that airspeed was too high and they floated, then bounced a few times while trying to force it on to the runway.

[rookiepilot]

Ouch. Sad outcome at an unforgiving airport for training looks to me (never been there).

My shortest runway I can think of is 1800....with friendly stuff on either end. Gotta be on speed....

[CpnCrunch]

The report makes some incorrect implications about the decision to perform the landing, saying "leaving 174 feet of runway", and saying they didn't calculate the landing distance. I think in this case it was the writer of the report who didn't bother doing the proper calculations. There are no obstacles on the approach, and you can touch down rights at the threshold if you're on a normal 5+ degree glideslope. The CFS says there are trees, but as the report points out those trees are 350 from the threshold, so they don't constitute a "50 foot obstacle". Typically you would use the ground roll distance here rather than the 50-foot landing distance, planning to touch down shortly after the threshold, and it's pretty obvious that there is a large margin even touching down 1/3 of the way down the runway with a 2kt tailwind. (That runway is also 0.5% uphill which somewhat cancels out the tailwind). I'm certain the instructors have looked at the performance charts and knew it was safe under those conditions.

You do just need to apply firm braking in a 172S if you land 1/3 down the runway. The problem seems to be that they were still too fast when they touched down, and it all went badly wrong after that.

I'm wondering if putting the flaps to 20 degrees contributed to the inability to gain airspeed. Although the POH says to use 20 degrees of flap in a balked landing, it's talking about retracting from 30 degrees, and it says to retract to 10 degrees once 60kts is reached.

[SuperchargedRS]

So Kristen was hurt badly in this accident, and if you feel like helping out with her recovery, head on over here.

https://www.gofundme.com/kristen-ursel

Man...



Donated, hope she has a good recovery

[rookiepilot]

The report makes some incorrect implications about the decision to perform the landing, saying "leaving 174 feet of runway", and saying they didn't calculate the landing distance. I think in this case it was the writer of the report who didn't bother doing the proper calculations. There are no obstacles on the approach, and you can touch down rights at the threshold if you're on a normal 5+ degree glideslope. The CFS says there are trees, but as the report points out those trees are 350 from the threshold, so they don't constitute a "50 foot obstacle". Typically you would use the ground roll distance here rather than the 50-foot landing distance, planning to touch down shortly after the threshold, and it's pretty obvious that there is a large margin even touching down 1/3 of the way down the runway with a 2kt tailwind. (That runway is also 0.5% uphill which somewhat cancels out the tailwind). I'm certain the instructors have looked at the performance charts and knew it was safe under those conditions.

You do just need to apply firm braking in a 172S if you land 1/3 down the runway. The problem seems to be that they were still too fast when they touched down, and it all went badly wrong after that.

I'm wondering if putting the flaps to 20 degrees contributed to the inability to gain airspeed. Although the POH says to use 20 degrees of flap in a balked landing, it's talking about retracting from 30 degrees, and it says to retract to 10 degrees once 60kts is reached.

1/3 down is 1000 feet left or less, on a damp runway. That is not a ton of margin with zero wind. First bounce should have been an immediate GA, sorry to say.

I have lots of time in the S and they love to float, and don't slow down well even at idle on a steep approach.

It's a 60 Kias approach airplane, and light can be done at 55. Probably less.

I wonder if circuit height winds were a 10-15 knot tailwind. (No PDW comments)

That would be a problem on that runway in that plane getting slowed unless approach was much shallower.

[CpnCrunch]

First bounce should have been an immediate GA, sorry to say.

I have lots of time in the S and they love to float, and don't slow down well even at idle on a steep approach.

It's a 60 Kias approach airplane, and light can be done at 55. Probably less.

Yes, the main problem was the speed, and then the decisions made after that. If you're much above 60kt in that plane, you're not going to be able to get it down on a short runway.

From the sound of it, I don't think the mildly moist runway would have affected braking very much if any.

[pelmet]

Took a very long time for the Cadors report to come out, Not sure why.....

"C-GZXB, a Cessna 172S aircraft operated by Victoria Flying Club, departed from Victoria Intl, BC (CYYJ) with an instructor and student pilot on board, to conduct a day visual flight rules training flight. About 1 ½ hours into the flight, an approach was made to Runway 31 at Duncan, BC (CAM3) to conduct a short-field landing. At about 1311 Pacific Standard Time, the aircraft touched down approximately one third of the runway beyond the threshold and a balked landing was attempted. The aircraft struck trees and then a power line off the north end of Runway 31 and came to rest upside down under the power lines, about 500 feet from the departure end of the runway. The instructor sustained serious injuries, while the student received minor injuries. The aircraft was substantially damaged, and the emergency locator transmitter activated. There was no fire."

Flaps could cause a problem if they were not retracted, or if retracted quickly at a low speed. Both unkowns. As well, the report states they touched down 1/3 down the runway, but it doesn't say how much runway was left when they initiated the go-around.

From the final report.....

"The aircraft touched down about one-third of the way down the runway, at which point the instructor took over control of the aircraft from the student pilot, retracted the flaps, and pulled the control column to the full nose-up position. However, the aircraft bounced and became airborne several times before the tires remained in contact with the runway, and it was therefore not possible to apply full braking until the aircraft's weight was fully transferred to the landing gear."


Lessons to be learned.....A172S only has 30 degrees flaps unlike some of the older models. That missing ten degrees does make a difference between the two. That being said, the type had operated in here plenty of times before but.....best not to land with a tailwind on a fairly critically short runway as each knot has a significant effect when the runway is tight and each knot of tailwind has significantly more detrimental effect as compared to the benefit of an equivalent amount of headwind. A damp runway doesn't help when max braking becomes a requirement which makes it even more important to plan in advance that....If there is a significant float, that is when the decision should be made to go-around if not earlier when high and fast. Once down an significantly down the runway after having applied lots of braking, it depending on what is at the end of the runway, it probably becomes preferable to have an overrun. Of course, there are ravines at the end of each runway which just means that going around in the event of any significant float is absolutely essential.