Gentlemen,
I have a serious problem with some of the above posts:
a) the sequence of events is not proven
b) the brakes may have failed due to the accident, instead of believing that the accident happened because of the brakes
c) being a CFII myself, I know that if I simulate a power failure with a student, it is always MY hand lying on the throttle / power lever and not the student’s until the safe outcome of the maneuver is guaranteed; also I know that I’m the responsible person for any maneuver I let somebody else fly. I’m pretty sure that any other serious CFI would think the same.
Tim, I completely agree with you. I was attempting to be a little sarcastic with my post. In other words, I believe that it would be very unlikely that both brakes spontaneously failed, without being related to the accident. I’d think that there was a cause and effect relationship.
In other words, I believe that it would be very unlikely that both brakes spontaneously failed, without being related to the accident.
Since all directional control comes from brakes how could you have only 1 brake fail without causing an accident, especially if you were drifting off the runway in the direction of the working brake?
I think Andy B’s point is that there are two hypotheses:
A. Plane made a hard landing, and one or both brakes (doesn’t really matter, either scenario would cause problems), which presumably had been trouble-free until then (otherwise two CFIs would have noticed while taxiing before take off), chose that exact moment, by wild coincidence, to fail. Therefore shoddy workmanship “caused” the accident.
B. Plane made a hard landing, and the landing ITSELF damaged one or both brakes, making it impossible to control and stop the plane. Therefore, whatever caused the hard landing – apparently, the simulated engine-out – “caused” the accident and damage.
Andy is suggesting that Hypothesis B is a lot more likely than A. I would agree. Are you suggesting something different?
Here’s a little info about the design of the break system. All break callipers have some sort of blead valve, to blead out the air in the lines. The Cirrus’s happens to be on the bottom of the break calliper(I think this is a common design). So, if you have a very hard landing of the sort that this cirrus did then the valve and possibly more will be ground off by the runway as the main gear strut flex’s to absorb the impact, allowing the brake fluid to flow right out on to the ground.
In my opion Cirrus has a good design. GA A/C aren’t designed to be able to take an impact of that sort and not get damaged. If this kind of hard landing had occured in any other plane then both people in the plane would have had serious injuries.
B. Plane made a hard landing, and the landing ITSELF damaged one or both brakes, making it impossible to control and stop the plane.
Most of my landings are hard and I have yet to damage anything on a 172. I would hate to think that every time I land I risk a major accident in a Cirrus.
This is a pretty long thread about failed brakes. Maybe I missed something, but I didn’t see anything other than an anonymous post about failed brakes. I’ll bet the final NTSB report will state that the brake system appeared to function normally. If there is credible evidence of brake failure, I apologize. Otherwise, we shouldn’t continue to speculate about the brakes based on an anonymous post.
Absolute baloney (B.S.) Brake caliper bleeders are always on the top side of the caliper. If they were not, the aircraft would have to be turned upside down to bleed the brakes.
You do remember that we’re talking about a VERY hard landing, after a simulated engine-out gone bad, right? The 200+ planes flying have collectively made tens of thousands of landings, some share of which must have been garden-variety “hard” landings. No one is talking about routine brake damage on normal bad landings. I’ve proven this myself!
So if you want to become fearful after the episode, here’s what to fear: every time you cut the power 250 feet up on takeoff, you may risk an accident.
Excuse me, I think you mean “brakes”. “Bleed” valves have to be turned to be opened. Grinding them off doesn’t open them.
Even Jeff has more mechanical knowledge than you aparently do. If you had ever “bled” a brake line, then you would know that grinding one off doesn’t open it.
Hey Anonymous, why don’t you use your name when posting? How cowardly! You seem to have such detailed information about this event, but you have no credibility since you don’t use your name. You statements are worthless without credibility. I find it hard to believe that you would “blame” Cirrus for this aircraft accident when it seems as though two “boneheaded” instructors who were “hot-dogging” destroyed a customers aircraft. When do people take responsibility for their own actions! or postings for that matter! Just my opinion from the information presented.