Originally Posted by
rnzoli
In VMC, yes, in IMC, a little more tricky. We need a 20:1 engine out glide ratio to maintain a 3 degree glide path. Most small singles have only 10-to-1 ratio, so it will be double of the regular decent ange, at 6 degrees.
With that, ILS G/S intercept will be very difficult. A localizer approach may be more fitting to this situation, with all step-downs doubled (but in AGL!) and communicated to ATC.
So with that in mind, I personally think it is safer to pull the chute in IMC, rather than re-designing the approach plate for a 6-degree descent, under the pressure of an ongoing emergency.
You are definitely correct that IMC would be more difficult. But I would suggest trying it to a certain point…..the point that is close to or at the minimum chute pulling altitude. If things are going obviously well….continue. If things are not going well….pull the chute.
I agree with your info about glide ratio and glide slope. One might want to fly well above the glide slope on approach or choose the ILS with the tailwind.
This accident pilot gave up much of his extra energy while still having power, by descending and ending up low when nearing an airport with a long runway. That left him with much less options.
Then the chute was pulled and someone on the ground was seriously injured.
Perhaps he wanted to reduce power to potentially extend engine operation for a few extra minutes but having a parachute changes the dynamics of your options.
One never knows potential alternative outcomes, but there were good odds that he could have made the airport which was reporting clear skies and had a long runway. If he had maintained a higher altitude, he might have been able to glide down to an easy landing on the runway once power was lost.
Be cautious about giving up your energy.