And modern carbon racing bicycles are extremely light. The headstock, hubs and drivetrain components are the weightiest of those.
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Indeed, there’s over 100 years of mechanical engineering and material science in modern bikes, you’re not going to improve on that easily unless you need significantly different tradeoffs.
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Using a bicycle also solves the landing gear problem and will help considerably with acceleration on the takeoff run.
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She can be my FO, anytime!
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Wow! She’s a mensch with wings!
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Wow, great job!
Apparently a 787 had a runway overrun on departure from Munich yesterday.
That looks like it almost ended in a catastrophy, curious about what the investigation report will say.
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That looks so slow for a 787, I wonder if they smashed some wrong data into the FMC.
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GIGO. The weight and balance software works off the data it’s given. If you tell the flight planning software that the plane weighs 300k pounds instead of 600k pounds, it believes you and comes up with a power setting based on your numbers. That’s all true. But whether it really has anything to do with this, I of course am clueless.
EDIT: Jinx @TheAlmightySnark!
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We all are! Just looks hella sluggish even for a fully laden 787. Something definitely was wrong with the power, either the requested delivery or the selected setting.
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Don’t they have safe abort criteria like V1 by that time or portion of runway?
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Yes, but it’s based on correct performance calculations, which again is based on the weight entered in the FMC. If that’s wrong, the V1 speed is wrong.
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Clearly I did not give that a lot of thought 
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No. We, at my various airlines, used to use “balanced field length” when computing V1 and power settings. This “balanced” the two computations of accelerating to V1 and stopping with accelerating, losing a motor and clearing the 50’ obstacle. Now the math is unbalanced and, for us anyway, it brings us a bit closer to the end of the runway at rotation. But at no point do we have any way of knowing where that rotation will be. There is no sanity check that says “if we don’t hit Vr by this point on the runway, we abort.” And this is a good thing. Because if pilots felt armed with that knowledge, the rates of unnecessary aborts would increase. And unnecessary aborts are what kills people and bends metal. Had the Vietnamese had such a sanity check, they would have aborted and they would likely have had a worse outcome. So I am here to defend the system. It’s just math. Be careful and crosscheck each other and the operation is safe.
In the interest of safety though I am obligated to add that this happens far too often. Exactly what happened to Vietnam airlines has happened at my airline and, I would submit, every major airline. When the procedures for computing takeoff performance and/or weight and balance change, these events happen. I’ve seen it.
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Well, if I may nitpick a little for context; you do abort before V1 in case of an engine failure/fire and other severe faults. But no, V1 is not correlated to a runway distance that is presented to the pilots. So V1 has no meaning in this case, unless they decided to go with an engine out, before V1. Doesn’t seem to be the case, though.
As you say, this has happened before. Crosschecking is extremely important, as well as including a sanity check. Basically asking yourself if these numbers makes sense.
But what if they were given the wrong numbers by load control..?
@Troll I was only addressing this specific part of Sobek’s question because it is a good one. Fighter pilots get to airlines (in the US anyway) and this fact blows their freaking minds. Because they DO compare speed and runway position on takeoffs with heavy loads. But fighters are different. They tend to takeoff in full mil power or burner; while airliners rarely do. So the runway position check is also a check that the engine(s) are producing advertised power. Airliner engines on the other hand dependably produce the same power for a given EPR or N1 for the life of the engine. Those same former fighter pilots quickly figure out that doing a speed vs position check in the airline world is simply not practical, and almost certainly far less safe than trusting the data.
Well…almost all do. When I got my seaplane rating last year I discussed this with the owner of the operation. (He taught having a point on the shore of the lake that you’ll abort at if not yet airborne). He flies at FedEx and, formerly, F-16s. He has advocated for some sort of runway distance check at his airline without success. He didn’t sell me either. But I get the idea.
We (you and I) have a very good idea what the final weight will be before we even get to the plane. On my yoke I always clip the following:
ZFW
TOW
LW
plus,
planned Gate Fuel
min fuel for takeoff
and REMF at landing
When we get our final weights during taxi I compare my expectation with the final TOW when the FO announces and points at the FMC (our procedure). My expectation NEVER and I do mean has never differed from the final figure by more than 2000 pounds (less than 1%). That’s the sanity check.
But the risk is not gone even after doing that. Because you can still program the data for 9R (say, 11000’ long) and takeoff—or attempt to—on 9L (say, 8200’ long). And of course wind, runway condition and temperature also must be accurate. The potential for human error is immense.
If we wanted to be safe-ER, we would always make these calculations at the gate and NEVER on taxi. That’s how it used to be done. But we made mistakes then too. I only know that this is a problem. A frighteningly common one.
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Is there a practical way (in the sense of, one that you can quickly activate in an emergency situation like this) to override the calculated takeoff power settings on these modern FADEC engines?
Yes. You just push the power levers to the stops.
I will also add that another BIG threat is that we often will push back with no idea what runway we will use. In Chicago for instance, you leave the ramp often with 3 potential runways with wildly different lengths. Only when you check in with ground do you know which one you’ll use.
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