Flight Review question? What would you Pick?

What is the highest elevation airport you would have attempted this takeoff in under those condition

  • Sea Level @ 0F

    Votes: 1 6.3%

  • Sea Level

    Votes: 2 12.5%

  • 3000 Feet

    Votes: 4 25.0%

  • 4000 Feet

    Votes: 3 18.8%

  • 5000 Feet

    Votes: 2 12.5%

  • 6000 Feet

    Votes: 2 12.5%

  • 2000 Feet

    Votes: 2 12.5%
  • Total voters
    16
brcase

brcase

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Display name:
Brian
I think there is a lot more going on with accident than many pilots realize.
in Part for example: (your sample Flight Review question)
If you were going to take off from a similar airport , with that airplane, and a full load,
What is the highest altitude you would attempt this take off from based on attached performance chart? (i.e. What elevation would the airport need to be at?)
Would you have picked the same number before seeing this video?
See the performance chart attached:
from the NTSB report
Runway length was 5000ft
Temperature (about 80 degF)

for ref:
Empty Weight =~1320
Gross Weight = 2400
Useful Load = ~880lbs

Pilot stated airplane was within 86lbs of Gross Weight.
I read that to mean it was 86lbs over gross, but for the sake of this exercise lets say he was at gross Weight.
We will also say no wind, (you can see the windsock appears to show them taking off into probably at least a 5kt wind at about the 1:00 minute mark. Pilot stated 10G20 at about 30deg from down the runway. NTSB says with tailwind, not sure where they got that.)

Someone else can post the formulas to calculate how much 86lbs more would increase the TO distance and Decrease Climb Rate/Angle.

upload_2022-4-26_16-58-2.png
 
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In my opinion, that chart is nowhere near enough information to answer the question. Actually it's not even relevant to the question. It would be helpful in determining if there's enough runway AFTER you determine if there's enough performance to make the climbout. I'd want to see a climb performance chart. If the plane doesn't have one, it would be important to have some experience with it at max gross and similar altitudes before exploring the corners of the envelope. In the video the problem wasn't lack of runway, looks like there was miles of that. It was lack of power to climb out of ground effect.
 
Jim K said:
In the video the problem wasn't lack of runway, looks like there was miles of that. It was lack of power to climb out of ground effect.
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I've seen that video several times and if something was lacking it was a brain for the pilot:

 
Jim K said:
In my opinion, that chart is nowhere near enough information to answer the question.
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But you got to realize that is the information the pilot had available. What would you have done different and by how much?
 
Daleandee said:
I've seen that video several times and if something was lacking it was a brain for the pilot:
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Everyone thinks that before the accident it is when they start really looking at how he got to that decision, you might find that pilot might have been you?

The Poll is basically asking how much more margin would you give yourself?
Would that Margin have been the same before you watch the video?

No one as answered the Poll yet. Is there really no one that would take off on a Sea Level Runway at 0F (1863 feet required and an 766 ft/min climb rate?)

Brian
 
brcase said:
But you got to realize that is the information the pilot had available. What would you have done different and by how much?
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Again, if that's the only information in the POH, I can't answer the question as I have no experience in that aircraft. I wouldn't put myself into a situation to have to make that decision in a completely unknown aircraft.

I can tell you that I would've aborted the takeoff a LONG time before I reached the trees. Even if the POH said it would work, it was clear there was something wrong.
 
someone mentioned Climb Rate/Angle.

By my best Guess
Jim K said:
Again, if that's the only information in the POH, I can't answer the question as I have no experience in that aircraft. I wouldn't put myself into a situation to have to make that decision in a completely unknown aircraft.

I can tell you that I would've aborted the takeoff a LONG time before I reached the trees. Even if the POH said it would work, it was clear there was something wrong.
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Fair point, in that familiarity with the airplane could make a big difference.
To make the answers more consistent I probably should have stipulated that it assumed you were familiar enough with the airplane to know you can normally achieve book numbers.


And the Poll isn't really about what a happened, because I stated this is only part of the equation, I left out pilot Technique, Aircraft Condition, or changing Weather conditions for example,
It is more about what kind of personal minimums do you really have and quantifying them. Also any discussion about other factors and considerations is good.

You bring up another good point. But another Flight Review kind of question, if you want to look at Abort points? (Another Poll Question?) At what time stamp would you have aborted.
I was trying formulate another good question on it, but was having difficulty in that I agree I don't think most of us would have taken off on a 5000ft runway when the book says it required 4800 ft.
Or would we? Assuming we know we can usually make the book numbers.
4800feet is over a 50ft obstacle
we think the winds are 20G30 Pretty mostly a headwind
It is probably at least another Mile before we get to an actual 50 foot obstacle. It took him almost over 90 seconds to get to the 1st real obstacles and my best guess he had climbed about 250ft at most before impact
It is a huge valley with a reputation of being an easy strip to get in and out of.

I can see a rather high percentage of pilots standing on the end of the runway saying this isn't that bad, lets go. Then the question is how many of them would have aborted if it looked like the video. I will see if I can find another video example from a nearby airstrip, of the guys that didn't abort.
 
DesertNomad said:
If it is 0F outside, I am not in an airplane, but sitting by the fire with a hot cup of tea.
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Good answer I will be sitting there with you, But the point wasn't really about the temperature it was more would you take off on a 5000ft runway when the book says you can clear a 50ft obstacle in 1863ft. How about if it says 2500ft? 3000ft? etc.
 
Looks like he cleared the RW at about 1:30. It was about another minute before he was out of options. I will admit that learning more of the facts in this case gives me a bit more sympathy for the pilot. According to the chart it should've been doable. I wouldn't want to cut it that close, but I could see the thought process. The plane was off before the 5000', and he probably thought it was working out.

I'm a flatlander, but I do have a western trip planned this summer, so this is certainly on my radar. The only time I've ever really had to consider it was a 2000' grass strip in the Archer I used to fly. IIRC with the DA and weight I conservatively needed 1500', but I also had another mile of flat field before there were any obstacles, so there wasn't much real peril involved. I like to say I want 1.5x, but obviously I didn't have it that day and went anyway....

To answer @brcase 's question, my gut feeling is 5000', but that's just based more on picking numbers I feel comfortable with rather than any real personal minimum.
 
brcase said:
We will also say no wind
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Probably removing one of the bigger environmental impacts on performance…wind isn’t just horizontal. I’ve stayed on the ground when my climb performance would be fine in still air but the wind gave too much potential for vertical motion.
brcase said:
To make the answers more consistent I probably should have stipulated that it assumed you were familiar enough with the airplane to know you can normally achieve book numbers.
Click to expand...
I’d bet the average pilot taking a flight review doesn’t have a clue how his performance compares with book…I’ve seen far too many pilots who would never take off with less than a 50% margin over book, not realizing they actually use more than that.

what is the ground roll percentage of the 50-ft number? What’s the correction for the unpaved surface?
brcase said:
At what time stamp would you have aborted.
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Not enough information. I’d apply the 50/70 rule, among other things, and I see no indications for either of those in the video. Did he make static rpm? What was his mag check like?
brcase said:
I was trying formulate another good question on it, but was having difficulty in that I agree I don't think most of us would have taken off on a 5000ft runway when the book says it required 4800 ft.
Or would we? Assuming we know we can usually make the book numbers.
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Ive taken off with less margin than that in feet, but it was a higher percentage (10% or so of takeoff distance). But it was based on my performance, not just “book”. And we’re really talking apples and oranges on the video, with runway available vs 50-ft distance.
brcase said:
It took him almost over 90 seconds to get to the 1st real obstacles and my best guess he had climbed about 250ft at most before impact
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So for whatever reason, the book numbers are worthless, as there’s nothing that goes down below 200 fpm.
 
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What time of day did he depart? I would have planned for wheels up at first daylight.

My 145 HP C-170 at gross does not get the climb rate stated in the manual, probably 20-30% less. And I’m talking my experience during takeoffs at less than 1000’ DA. Cruise climbing 5-7k’ PA isn’t awe inspiring.
 
EdFred said:
I would have done the takeoff as depicted in the video, but would have circled over the treeless area and getting all the altitude I needed before going over the trees to get out of the bowl. And if I couldn't get altitude, I'm landing, and someone (or two) is getting out.
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This here.

The POH you posted show that this would meet my minimums-ish for aircraft and airport. No obstacles and I reach 50 feet by the end of the runway. What the pilot didn’t do and what I brief is that if there are any issues on take off with no runway remaining, I immediately aim for box climb over the airport (unless it’s an emergency where I need to put it down). That’s already assuming I get speed before my abort point (50/70 rule). Further, anytime I’m in a high or heavy situation, I aim to sit in ground effect as long as I can. This is totally free performance via lower induced drag… so why not use it!

Other items that bother me, high DA means leave at least 10-20% margin from max gross. Finally, early departure (cooler air, lower DA) is your friend.

@Jim K For your trip, it’s all about DA. So flight plan to minimize DA. High DA also means different engine management as well as higher ground speed tor T/O and Landings. Happy to chat with you about some strategies, or come join me at BJC in June. I’m attending the CPA mountain flying course again - such great knowledge about mountain flying!
 
EdFred said:
I would have done the takeoff as depicted in the video, but would have circled over the treeless area and getting all the altitude I needed before going over the trees to get out of the bowl. And if I couldn't get altitude, I'm landing, and someone (or two) is getting out.
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And leaning the mixture for best power.
 
brcase said:
Everyone thinks that before the accident it is when they start really looking at how he got to that decision, you might find that pilot might have been you?
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I've made some stupid decisions and I've had moments when I needed a brain. I have no idea of what information he had available and some have noted his improper leaning technique.

If I had made the decision to attempt that take off I certainly hope that I wouldn't fly for 5000' feet in ground effect and the have the plane touch back down and still not close the throttle and regroup. The airplane was absolutely screaming at him the entire time ... and he wasn't listening.
 
asicer said:
And leaning the mixture for best power.
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Can't tell for sure, but early in the video it looks like the mixture knob is all the way in. That certainly would've reduced power output enough to make it not climb.

From the ntsb final:
"When questioned by the IIC what the leaning procedures were for the
engine, the pilot stated that the Franklin engine could not be leaned for takeoff."

I take back what I said about feeling sympathy for him.
 
MauleSkinner said:
...
I’d bet the average pilot taking a flight review doesn’t have a clue how his performance compares with book…I’ve seen far too many pilots who would never take off with less than a 50% margin over book, not realizing they actually use more than that.
...
Click to expand...

This. I know what my minimums are for the planes I fly, that I can safely clear obstacles with, and they're significantly higher than the numbers in the 40-50 year old POH. Maybe the book numbers are optimistic, maybe my skills are lousy, maybe I'm a baby and want 20' of clearance over that 50' obstacle. But whatever the cause, it's not hard to work out some real numbers with some safety margin.

I can't tell anything from that chart, because I don't know how that plane flies at close to max gross. Some planes fly great at max gross, some, depending on temperature, not so much.
 
MauleSkinner said:
Probably removing one of the bigger environmental impacts on performance…wind isn’t just horizontal. I’ve stayed on the ground when my climb performance would be fine in still air but the wind gave too much potential for vertical motion.
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agreed, I was getting towed in the next Valley over they day this video was released. About a month after the accident. Normal climb is about 400ft/min. But with strong winds aloft in that area we were hitting large areas of mountain wave (not rotor) where we were showing 200ft/min down.
 
MauleSkinner said:
I’d bet the average pilot taking a flight review doesn’t have a clue how his performance compares with book…
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Agreed, but they should at least have a clue after doing a flight review with me. We usually figure out the required take-off distance, then go see how close we can match it.

The variation of this question I often do on flight reviews is say we figured out the 50ft obstacle clearance distance is 1500 feet. With how close to the end of the runway are you comfortable taxiing to and then taking off, given the current conditions?
The poll is a variation of the question, with the conditions provided.

Brian
CFIIIG/ASEL
 
As silly as it sounds the one big thing is to consider is running the numbers for a 5kt tailwind. Looks like the terrain was climbing.
A longer ground roll might be worth it for descending terrain.

Or maybe a shallow 180 turn to descending terrain after takeoff. Climb in a hold (of sorts).
 
I know I’d add 25% for grass since the chart provided doesn’t say how much to add. Gusty winds are also a factor. Based on math-in-my-head I’d try it at 2000’ MSL but not 4000.
 
Experience with a particular aircraft in similar conditions trumps the book. The book may not adequately reflect engine condition, humidity effects, runway conditions, and pilot proficiency. Or the actual (not calculated) weight of the aircraft. In high denalt conditions I would want wide margins before attempting a takeoff, and/or experience with similar conditions or loading. The lack of willingness to fly during the takeoff roll in this case should have been a blinding clue.

I've been in this situation once due to squirrely mountain-diverted winds on a 3000 foot runway, and I aborted at 1500 feet down the runway when the aircraft didn't offer to climb properly out of ground effect. That probably saved me from going into the trees. (Another plane took off immediately before me without incident, which was confusing for sure.) 10 minutes later, the wind shifted significantly and I was able to takeoff successfully without complications. And that was 200 lb under gross without significant denalt considerations. You gotta pay attention to what your airplane is trying to tell you.
 
Perhaps the real question should be, would you take off with a 9,000 foot density altitude in an airplane with performance similar to an older 172 at maximum gross weight?

I would consider it in some cases but there's not much to work with at that point. The airplane likely wouldn't climb much higher than where it is at, once it's off the ground. I'd breathe a lot easier if the DA was lower or the airplane was a bit lighter.
 
EdFred said:
I would have done the takeoff as depicted in the video, but would have circled over the treeless area and getting all the altitude I needed before going over the trees to get out of the bowl. And if I couldn't get altitude, I'm landing, and someone (or two) is getting out.
Click to expand...
I was looking on google earth after watching this video and thinking the same thing. There is much space to the right and left of the runway at the same altitude. I'm thinking he might have been afraid to turn(and lose lift) or maybe he hadn't even considered a circling exit. Fixation?
 
There is no way I would have kept going after the bounce at the end of the runway. That was a loooooong way from the start point.
 
Do we know what the pressure altitude would have been on that day? Maybe his starting point was off the chart?

If you look at the worst climb performance on the chart 100 deg. F at 6000 ft. shows climb rate of 343, it didn't seem like he was getting that.
 
Okay. I looked this up. The accident occurred in 2012. The density altitude was 9200, which is 3200' beyond the performance charts. The pilot was asked by the investigator about the use of the mixture control, and the pilot said the aircraft could not be leaned for takeoff (really?). He took off with a fully loaded airplane at a density altitude of 9200, probably overly rich, and when he could barely climb, he kept going, pushing his luck until he had no options.
 
exncsurfer said:
Do we know what the pressure altitude would have been on that day? Maybe his starting point was off the chart?

If you look at the worst climb performance on the chart 100 deg. F at 6000 ft. shows climb rate of 343, it didn't seem like he was getting that.
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The airplane looked like it was overloaded too.
 
This accident had nothing to do with the length of his ground roll; he was off the ground in plenty of time. And the trees he hit didn't even seem particularly close given how long it took to reach them. My completely speculative speculation is on too hot, too heavy, and failing to maintain Vx until clear of all obstacles. Could be the video, but he seemed slow to me.
 
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