Worth sitting through, especially on the effect of weight, bank angle on true Vmca. The presenter might have discussed Vsse (safe single engine which sensible ATOs stick to in Vmca demonstration exercise), and Vmca/Vs crossover – he recommends 5,000’ AGL for Vmca demo, while arguably the consensus is 2,000 feet AGL using Vsse. A normally aspirated twin loses thrust with altitude, and therefore at some point Vmca becomes lower than Vs (which for sub sonic puddle jumper twins is a constant CAS with altitude), resulting in a loss of control, not through Vmca, but because the aircraft has stalled with asymmetric thrust.
Thanks for posting, Robert. Good refresher.. Indeed very important to automate into your reflexes to not only push the right pedal but to also to ‘bank into that foot’. And to keep your heading until reaching a safe speed.
I try to stay seriously above Vmca during and after take-off for two reasons.
1) to have a wide margin to cater for my inevitable delay in response to an engine failure (as suggested), and
2) a bit of nose down provides a lot better visibility to avoid traffic and birds.
I have been taught not to rely on “dead leg dead engine” logic. It has to be confirmed by other means e.g. looking out the window, or instruments.
Keeping plenty of speed on may help control but it comes at the expense of climb rate.
Thought provoking stuff – certainly the ‘failings’, or prejudices if you prefer, mentioned by the presenter have all been passed on to me at some time by various instructors / examiners as received wisdom ever since I passed my B Rating back in 1980.
The comments, upon the two referenced accidents, also beg the question of how many instructors, on behalf of aircraft owners or the flight schools employing them, will actively promote maintaining the aircraft on the runway until the suggested (revised) speed is attained. In my experience, there is a high level of encouragement to get the aircraft off the ground as soon as practicable, avoiding excessive wear and tear on the aircraft’s undercarriage.
The alternative, one presumes, is to remain in ground effect until the required speed is attained, resulting in the use of a greater runway distance – if it is indeed available – thus taking off on a 700 – 800 metre runway may well present some challenges in a full laden MEP circa 2000kgs.
The comment upon climbing to (say) 1000’ in level flight before making any attempt at a turn is also, in my experience anyway, rarely actively promoted during MEP EFATO training. Personally, I almost always climb away to 1000’ on runway heading in an MEP although I have witnessed, many times, pilots lift the gear and make a rapid turn almost as soon as the wheels have left the tarmac.
How much traction the presenter’s idea will achieve, in instructor / examiner circles, remains to be seen.
Thanks for posting the video, I shall certainly look more critically at VMCA figures in future.
Excellent video and I learned a lot from it. Thought provoking insights.
Long time ago I used to fly a C421 from a 750m runway. During training the instructor made sure that we never rotate below blue line.
