Parachutes for Planes

Philip Greenspun's Homepage : Philip Greenspun's Homepage Discussion Forums : Ask Philip : One Thread
Notify me of new responses
Being a relatively new pilot, what are your thoughts on Parachutes for Planes?

-- John Milazzo, June 29, 2003

Answers

The idea is sort of good and I wrote about it a little bit in my aviation section (see the comparison between Cirrus, which has a parachute, and the Diamond Star, which I bought and which does not have a 'chute).

Sadly, however, it seems that the vast majority of accidents are not the sort that an airframe parachute would have prevented. I think mid-air collisions of the sort described in the article that you reference account for only about 2 percent of accidents. The extra weight of the 'chute (about 10% of the capacity of the airplane, assuming full fuel), however, will make the airplane more likely to stall and spin, which is in fact a very common way to have a fatal accident.

If you're going to fly to very remote areas or over water or in any other situation where an emergency landing would be tough it would be nice to have a 'chute but maybe even nicer to have a twin-engine airplane with modern computer controls so that it didn't become lethal in the event of a single engine failure. Diamond is actually making a plane like this, the DA42, which should start shipping in about one year.

There is also the question of how forgiving an airplane is of pilot error. Cessna 172s are incredibly forgiving and consequently have about the best safety record of any plane. Sadly the price that they pay for being able to continue to fly while going very slowly is a slow cruise speed (dragging big wings). The Cirrus cruises fast but falls out of the sky and kills all of its occupants at speeds where a Cessna 172 is still flying. My Diamond Star is a compromise between the two (can fly almost as slow as the Cessna and cruises halfway between Cessna and Cirrus). The quote in the article that "Over time, the company will prove that it has the safest single-engine plane in the sky" strikes me as fanciful. It will never have a reliable engine like the single-engine turboprops (little jets turning a big propeller) such as the Pilatus PC-12. It will never handle safely at slow speeds like a Cessna 172. All of the situational awareness benefits claimed for Cirrus's avionics can be achieved by adding a few modern devices to a Cessna from the 1950s (or by buying a new Cessna).

To summarize, the parachute addresses the paranoia that humans naturally feel about flying but it won't help in the vast majority of situations that actually cause accidents (flying into clouds by mistake and then proceeding into terrain, getting the airplane too slow and spinning out of the sky, etc.).

-- Philip Greenspun, July 1, 2003


Parachutes for planes would and could work if the will and investment was forthcoming by the airlines.A controlled break up of a fuselage with impact cabin foam and then the parachutes, would almost certainly guarentee most passengers would survive from even the most catastrophic mechanical failures.Most of the aircrashes of recent years all had sufficient time to react if these sort of safety measures were in place.Of course it wouldnt come cheap and thats why we dont currently benefit from this level of reassurance at the moment.

-- peter miller, November 14, 2006

Parachutes for airliners is a pointless idea because travel by scheduled airline flight has a near perfect safety record. There is virtually nothing to be gained by outfitting airliners with parachutes.

-- David Sanford, March 9, 2007

This thread is rather stale, but it's worth pointing out that this is referencing adding parachutes to small (4-6 seat) general aviation airplanes, not airliners.

-- Joshua Levinson, April 8, 2009

I know this thread has to do with small Cesna type planes, but it had me thinking about solutions for large commercial aircraft. What could be a solution? Then I remembered when I used to be in the Marines and I had to load my HMMWV into the back of that aircraft. There's a track system inside that aircraft that allows for quick deployment of large articles( palletized equipment and so forth. Well, What if commercial aircraft were constructed in this manner, with the track system. Seat modules could be attatched to the track, each seat module equipped with a parachute robust enough to carry the weight of four passengers. Of course these aircraft would include a passage through the rear pressurization bulkhead, but hey, isn't that why there are people employed as engineers? So when this aircraft becomes unstable, explosive removal of the rear bulkhead occurs and as the bulkhead travels away from the aircraft, a tether unlocks the catch that holds all the seats in place and the seats begin to deploy out of the rear. As each seat module leaves the aircraft, static lines release the chute for each module thereby making it possible for most of the occupants to eascape disaster. This could work although the weight addition would require people to travel with less luggage, so what? What's more important, more luggage or life? Cost is invloved as well, but what price do we put on life? Now I know from what I read about flight 447, that disbersment of people into such a fast airstream as when occurred in this accident caused people to suffer fractures and probably fatal expansion of the body or suffocation or frost freezing, so perhaps this system wouldn't deploy until it reached a safer elevation and slower airspeed. Whatever the case, if the plane split open, some seats would release from the aircraft and some chutes would open. many people would still die but perhaps some would live. My guess is that Aircraft companies probably don't want survivors from the crash for fear of astronomical lawsuits against the aircraft companies.

-- Roman Steven Yneges, June 18, 2009