Experienced Pilots: Do you always calculate takeoff distance?

Discussion in 'Pilot Training' started by Chrisgoesflying, Jan 11, 2021.

  1. EdFred

    EdFred Taxi to Parking

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    I have the same thing only with the back seat. Except I haven't noticed a speed gain or loss with the backseat in or out. :D
     
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  2. Daleandee

    Daleandee Pattern Altitude

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    I do have a scale in my hangar. I don't use it all the time but if I'm suspicious I'm gonna put them on the scale and weigh any items taken along. My plane is "cozy" so I have to be careful with the weight I put in it. The CG is well behaved and isn't hardly a concern but when flying "fluffy" folks I have to know what they weigh. Looks can be deceiving.
     
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  3. neilki

    neilki Pre-takeoff checklist

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    My response was to the OP; and I stand by it.
    If you've been flying for 12 years, and posting here too; there there are likely less experienced people who look up at you, and will follow your example.

    It's great that you've decided to interpret a FAR to justify your response; you are PIC of your own operation; however, this is a Forum for Pilot Training. While GA's accident rate is trending slightly down, many of the accidents still prevalent are ones of judgement. 'Thinking it's gonna be OK' is not a good one. I understand you know your plane. That wasn't my point.
    In addition; "I've been doing this the same way for 12 years and nothing bad ever happened" is pretty much the definition of a Hazardous Attitude"

    Many readers here jump between rental planes; or multiple types. They'd be well served by taking a few moments to consider take off performance. It also leads to consideration of all manner of problems later in the takeoff roll & climb.

    I can only imagine a Flight Review or check ride will go more smoothly if your first answer is 'Yes; every time..."
     
  4. EdFred

    EdFred Taxi to Parking

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    No. I've been flying longer than that. I've been flying THAT plane for 12 years. The question was do I always calculate takeoff distance and I explained why. Your hazardous attitude jab couldn't be more off. But I suppose I should have expected it since you take partial quotes and twist them to say something that wasn't said. First the regs, and what I said.

    And you would imagine wrong. I walked into my IR check ride a million years ago, and said "I didn't do any planning or calcs for the XC?" "Why?" "Weather is crap, we aren't going" Then walked the DPE how I would have done it, but still didn't do the actual calculations. Gave him worst case numbers, showed that we were 50% over required fuel, etc...

    No reason to use a micrometer when cutting with a chainsaw.

    Just like I wouldn't do/nor expect someone to do calculations when their worst case scenario (max gross/high DA, etc) takeoff number is less than 30% of the runway they are using. I'll help them UNDERSTAND the calculations rather than just doing brainless math.

    All that said, I *have* done the math when I was going to go into a field max gross on a blazing hot/humid day, and it was like 1200' of grass. I made other arrangements. But I don't ALWAYS do it.
     
    Last edited: Jan 27, 2021
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  5. neilki

    neilki Pre-takeoff checklist

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    There's nothing 'twisted'. I posted reference to the regs. I'll highlight for you- (current as of January 25th 2021)
    §91.103 Preflight action.
    Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight. This information must include—

    (a) For a flight under IFR or a flight not in the vicinity of an airport, weather reports and forecasts, fuel requirements, alternatives available if the planned flight cannot be completed, and any known traffic delays of which the pilot in command has been advised by ATC;

    (b) For any flight, runway lengths at airports of intended use, and the following takeoff and landing distance information:

    (1) For civil aircraft for which an approved Airplane or Rotorcraft Flight Manual containing takeoff and landing distance data is required, the takeoff and landing distance data contained therein; and

    (2) For civil aircraft other than those specified in paragraph (b)(1) of this section, other reliable information appropriate to the aircraft, relating to aircraft performance under expected values of airport elevation and runway slope, aircraft gross weight, and wind and temperature.

    Best of luck fighting the FAA on that one. The section you referred to "become familiar" is a catchall, but b) 1 & 2 are pretty clear.

    While I can understand if your last check ride was 'a million years ago' you might not be familiar with how they're conducted now; I can assure you; things will be much easier (and cheaper) if you are understand this is absolutely fair game for a Flight Review or IPC.
     
  6. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    And they clearly don’t require calculating takeoff and landing distances for each flight.
     
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  7. YKA

    YKA Pre-takeoff checklist

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    ^^^^^ Couldn't agree more with this.

    Who on earth is going to get ready to fly their plane they fly frequently, and know they use about 8% of the runway to get off the ground usually. But say oh no, the the temperature is 4F above standard, and I am 30 lbs heavier than usual because of that extra bag i put on the back seat, then do a full weight and balance? Nobody is going to except for that 1 in 10,000 guy who worries constantly about everything. Everyone else says to themselves, well instead of using 8% of the runway today, i might need 8.1% of it. Common sense is not very damn common anymore.

    Those same people who worry about everything for no reason, probably feel uncomfortable when their fuel gets down to 2/3 full, or the destination airstrip is 10 degrees off reported head winds, or is shorter than 9,000' long, or only 200' wide, despite being in a Cessna 182. I actually met one of those guys. He asked me to come with him, and pilot his 182, because the destination airport was only 2800' long, and we would be down to half fuel when we got there. He sat right seat, and didn't give me so much as 1 comment about the actual flying, despite it being his plane. His home field made him nervous because the runway was only 5700'. He would fill the tanks even if they were at 3/4 full still, just to take his son up for a 45 minute sight seeing flight.
     
    Last edited: Jan 27, 2021
  8. EdFred

    EdFred Taxi to Parking

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    If not twisting, then reading comprehension issues? First you left of the pertinent part of the regs to support your position in your previous post. Then you post this (quoted) gem and bolding only certain parts while not emphasizing that "become familiar" is also in this regulation. Where does 1) and 2) say perform calculations every flight? 1) and 2) are under the umbrella of "become familiar," not separate.

    I never said my last check ride. Where did I say my last check ride? I've had 4 or 5 check rides since then.

    Try again. Maule covered it more succinctly above. See if you can misquote him too.
     
    Last edited: Jan 27, 2021
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  9. neilki

    neilki Pre-takeoff checklist

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    @YKA -Love your Goldie picture. Got one at my feet!
    I said earlier that not everyone here does fly the same plane all the time. This is a Pilot Training' forum, not a SuperCub board.
    Pilots in training generally move from one type to another; and often advance through multiple ratings. A bunch of old hands saying 'its not necessary because I fly a certain type or familiar place all the time' isn't the intended audience.
    I Instruct on occasion; I do it because I feel I have some value to add. A day in a Cirrus or 172 does not put any money in the bank!
    You can disagree with my interpretation of the regs all you like; but I'm certified to teach them. I would still advise against picking a fight with the FAA over 91.103. I've seen it; and it wasn't pretty
    All I wanted to achieve by my initial answer was to highlight the requirement to prepare for flight. People get hurt because they don't anticipate what can go wrong. It's horrible to see how many people have fallen victim to entirely preventable, obvious in hindsight mistakes.
     
  10. EdFred

    EdFred Taxi to Parking

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    So you make your students do a takeoff calculation every single time on a 10k runway in a Skychicken? I don't. We go over all the W&B and landing calcs several times during the instruction process, have them know the worst case scenario plus a safety factor. That way when "we just got socked in because the forecast got botched" over that 2000' grass strip, they aren't digging out the AFM/POH, looking for performance section, trying to fly the plane, doing a calculation, trying to fly the plane, trying to read some size 4 font graph, trying to fly the plane, dropping the POH, trying to fly the plane, looking for the page again, trying to fly the plane... This way they can go, "worst case scenario plus fudge factor for this plane to get out of there is 1400' at full gross, we can do 2000 since we are 200 under gross" and 91.103 is covered. Become familiar.
     
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  11. neilki

    neilki Pre-takeoff checklist

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    I didn't say it had to be done in the plane. This is preflight planning.. its clear neither of us is advocating being heads down unless the brakes are set.
    I didn't misquote you. I referred to the 'check ride you did' a million years ago' you'd said nothing about the '4 or 5 checkrides' you've done since.
    Sorry if I touched a nerve; I didn't mean to antagonize you; but I certainly don't think I misquoted you.
     
    Last edited: Jan 27, 2021
  12. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    What were the circumstances of the fight?
     
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  13. RussR

    RussR Pattern Altitude

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    I always have to question any absolutes. And “every time” just seems very unbelievable. Let me give you just one example, from my experience.

    I was participating as a pilot/CFI for a local “Air Camp” where on the last day of the week all the students got to go on a plane flight. I flew 10 kids one at a time that day, back to back, out of a 5000+ ft runway in a 172.

    The same situation happens all the time with Young Eagles.

    You’re saying that you would (and I should), between each flight, recalculate takeoff and landing distance based on the next passengers weight, the slightly different temperature, wind, barometric pressure, and fuel used on the last flight? That seems like way overkill to me and I honestly can’t imagine anyone actually doing that.

    If you would actually do that, well, more power to you. But I can’t imagine anybody actually being violated for not doing this, unless of course the weight/balance/takeoff/landing distances were actually pertinent to a mishap. If you have a specific example of someone being violated for not doing these calculations when it didn’t play a role in a mishap (and where the performance was later calculated as sufficient) please tell us, I’d be very interested.
     
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  14. YKA

    YKA Pre-takeoff checklist

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    Golden retrievers rock! He is 15 weeks old today, and my little buddy that goes almost every where with me.

    As for the flight up that day in another guys 182, and back the following day, I didn't then, nor do I even know have a lot of 182 time. I was still pretty low TT, around 700 hours was all. But I had been to that airport once before and it is a paved 2800' trees at one end, and just some obstacles maybe 12 feet tall at the other end. It is in a narrow valley so turns in the pattern are sharper than usual for someone who turns slow, but normal for me. I didn't even calculate a thing that day. I called and got the weather along our route, vfr valley buzzing, not straight line, lots of tall mountains, and narrow valleys, or narrow to him, nothing to me. I knew that we would use around half fuel, or close enough to half fuel to just say half. I estimated 60 lbs of bags i tossed in the baggage area, looked at him and said your about 240 ish i would guess, he said 245, added my 169 for summer dress. Said lets go. I wasn't calculating a damn thing precisely, and no fuel at our destination, so that really made him panick, I couldn't have cared less. We blasted off, flew 4 different valleys vfr at mostly 8500 feet, about 20 nm out i started radio calls to traffic with my intention. Not hearing a peep, and flying approximate 45 degrees across mid field to what I thought would be my down wind, sure enough the wind sock confirmed my guess of wind direction, i turn about 400 feet away from the mountain to the east and called down wind, and did a short basically 180 turn to the left calling it base and final, dropped the flaps and put it on the numbers, and being that parking is at the far end, didn't touch the brakes till i was maybe 60 feet from the only taxi way that is at most 20 feet long, that goes to a parking ramp big enough for maybe 4 planes our size. I parked it in the ramp, shut it off, and we by hand spun it around and pushed it back. I grabbed a few big rocks people left there to chock the wheels, filled out the logs, and said to the 182 owner, its just that easy. No cabs here, so now the 45 minute walk to main street. Next day leaving i dipped the tanks, had just under half, and after a preflight look and run up, back tracked the 2800 feet, which means clearing probably 60 foot trees about 500 feet past the end of the runway. He actually wanted to take off the other way because no tall trees that way. I said no damn way, that means about a 5 knot tail wind, and uphill. We are going into the wind and downhill, trees are nothing at all. We landed about 25 minutes after take off, at a bigger airport for fuel. Filled the tanks, and blasted off again. Couldn't be an easier flight, and no fancy math needed. We were well under gross despite the bags, and him being obese, and despite a few trees, we had a ridiculous amount of runway to spare. Beating myself up sitting there calculating the crap out of it all was pointless, and no i wasn't some high time 182 guy. My previous 20 hours in a 182 was plenty enough to show me how they performed. And to top it off, those were cool fall days, maybe 12 to 15 Centigrade.
     
  15. Ryan F.

    Ryan F. Cleared for Takeoff

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    I didn't read the entire thread so forgive me if I missed some pertinent comments, but I have a suggestion.

    From a "Systematic Approach to Safety" standpoint, it's important for the pilot in command to look at takeoff performance on every flight and ensure the aircraft as loaded, the runway length and condition, and atmospheric conditions are all compatible. However, there are a few ways to accomplish this. They don't all require the pilot of a Cessna 172 to crunch the numbers down to the decimal point when departing from sea level on a dry, 9,000 ft. long runway.

    In my case I took a cue from the Citation 510 (the "Mustang") AFM which provides "Takeoff Performance Simplified Criteria."

    510-simplfied.png

    The idea here is that V1, Vr, V2, and Vse will all "work" provided the weight of the aircraft, the altitude of the airport, and length of runway fit into "the box," along with some configuration requirements, consideration of obstacle in the flight path, etc. etc. 9+ times out of 10, I can get a Citation Mustang to easily fit into this criteria. It's a nice tool.

    I decided to do something like that with my Twin Comanche. I spent some time parsing performance data and came up with this table, which is on the bottom of my QRC:

    qrc-perf-table-twinco.png

    You probably get the idea here pretty quickly, but since I do fly from shorter runways, particularly here in the NE, I ran three common weights (3600 lbs = max gross, 3400, and 3200) along with temps and a headwind correction for each.

    Those numbers are all for S.L. so after doing some crunching, I was able to determine that all of the runway lengths at 2000 ft. PA would be increased by less than 500 feet. So the first note in grey bar, bottom left, states "add 500 ft. to rwy" if the airport PA is 2000 ft. For 4000 ft, I need to add 1000 ft. These are conservative numbers. The actual increases are always less, sometimes substantially so. The idea is that as soon as I get "close" it's time to crack open the AFM and do the actual calculation.

    The very last, bottom right field is my "catch-all" which I glance at any time I'm flying out of a runway 4500 feet or longer, which is often enough. I can prove with my performance charts that if the runway length is 4500 ft. or great, and the airport PA is 4000 ft. or less, I'll have the accelerate stop performance needed to safely depart. That's sort of an equivalent of the Citation 510 data.

    No reason anyone couldn't do the same for their personal aircraft. Of course this is for a twin, so I'm looking at accelerate stop, and that wouldn't be the case for single engine airplanes.
     
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  16. Shawn

    Shawn En-Route

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    My procedure is a bit different yet as scientific a calculation...my "Weeeeeeeeeeeee" happens at rotation...if "OH S#!T" occurs before that, I abort.
     
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  17. eman1200

    eman1200 Touchdown! Greaser! PoA Supporter

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    I like it!
     
  18. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    Obviously it falls under “good idea”, etc., but what’s your take on whether accelerate-stop distance is “legally required” for the (light) twin?

    and, of course, the follow-up question would be accelerate-go.
     
    Last edited: Jan 28, 2021
  19. Ryan F.

    Ryan F. Cleared for Takeoff

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    My "take" (which is just my opinion) is as follows.

    If lack of pre-flight action, to include performance calculations relating to takeoff or landing, can be pointed towards as a contributor to an unsafe outcome, incident or accident, that pilot stands a good chance of being found in violation of 14 CFR 91.103 and possibly other regulations or FAA guidance.
     
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  20. RussR

    RussR Pattern Altitude

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    The Piper Seminole, as one example, does not even publish an accelerate-go distance chart (and, in my opinion, it would be foolish to even attempt such a maneuver).
     
  21. Ryan F.

    Ryan F. Cleared for Takeoff

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    Very few manufacturers (nearly none) of light piston twins under 6,000 lbs. MGTW and 61 knots Vso elect to publish that data. The only example I'm personally aware of are certain models of the Beechcraft Baron which max out in the mid to high 5,000 lb range. There may some other high powered light twins out there with accelerate-go numbers but I haven't stumbled across them.

    For that matter, some don't even publish accelerate-stop data... (Diamond DA-42)
     
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  22. AlphaMike

    AlphaMike Pre-takeoff checklist

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    I really don’t know if I qualify as an “experienced pilot” but I usually walk out onto the field with my scarf waving in the wind. Lick my finger and hold it up. I take a deep breath and taste the humidity. Deep exhale and say. Yes! I believe today will be a good day! I shall defy gravity today! Then I pull my 182 out of the hanger, start her up and listen to the AWAS. If everything seem ok, I go fly around.
     
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  23. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    I've flown turbine airplanes where I wouldn't attempt an accelerate-go as published.
     
  24. RussR

    RussR Pattern Altitude

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    Agreed. The Beech Duchess is one exception, which does publish both distances.
     
  25. YKA

    YKA Pre-takeoff checklist

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    Don't be a moron and crash, and the government will not even come ask to see the piece of paper where you worked out all the calculations.
     
  26. Kritchlow

    Kritchlow Final Approach

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    As I’m sure you both know, most 121 operators use reduced takeoff power, and essentially calculate power to use the entire length for balanced field (of course they also factor required gradients).

    My point being, we never actually know the exact takeoff distances. We do know that the field is balanced.
     
  27. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    Balanced field is the goal of corporate jets as well...some are better at it than others.

    I’d bet that the CJ simplified criteria that Ryan posted isn’t balanced based on the V-speeds used, but especially without being field length critical, it doesn’t really matter.