Basic Configuration for a "Safe" airplane

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

challenger_II

Well-Known Member
Joined
Jul 15, 2009
Messages
497
Location
Fisher County, Tx. USA
Gatorade bottles negate your major factor...

Not so. By increasing fuel supply to be longer duration than bladder capacity, fueling errors can easily be avoided. The required fuel quantity to do so decreases linearly with age (of the pilot, not the airplane). The latter is nature's way of contributing to flight safety.
 

Marc Zeitlin

Exalted Grand Poobah
Joined
Dec 11, 2015
Messages
1,000
Location
Tehachapi, CA
Runway should still be much easier. The reason is that you can much more easily build sensors and automated control into the runways and taxiways. This is too expensive to do on roads, but a minor bump in price for an airport...
Sure - at large, B, C, or D airports, it's a drop in the bucket, and could relatively easily be done. But that's a small percentage of all airports and then restricts the "autonomous" aircraft only to airports with substantial infrastructure to support them. If the idea is to carry cargo between small towns in Alaska in crappy weather, so as not to endanger pilots, well, THOSE airports, and the other 90% of airports in the lower 48, will not have that infrastructure.

And we haven't even started to address the ATC issue :).

Way OT at this point...
 

Voidhawk9

Well-Known Member
HBA Supporter
Joined
Mar 26, 2012
Messages
630
Location
Timaru, NZ
Why not have motorcycle-style reserve for fuel? If you run out, switch to reserve, which ought to be setup to be enough to fly to a reasonably nearby airport and land safely. You get to run out of fuel, have your moment of panic, then switch over, land safely, and be much more careful next time.

Of course, some folks will just run it on the reserve setting all the time, but the solution for them isn't in the airplane design.
 

ToddK

Well-Known Member
HBA Supporter
Joined
Jan 13, 2016
Messages
512
Location
Shweaty Texas
Why not have motorcycle-style reserve for fuel? If you run out, switch to reserve, which ought to be setup to be enough to fly to a reasonably nearby airport and land safely. You get to run out of fuel, have your moment of panic, then switch over, land safely, and be much more careful next time.

Of course, some folks will just run it on the reserve setting all the time, but the solution for them isn't in the airplane design.
I read or saw something about a guy who had a small tank that held a few extra gallons, when the engine stutters you switch over and have 30 min to land.

I see the logic of it, but have to balance it against the added complexity and weight. My experience is that simpler is often better. Hard to beat an easy to read sight gauge.
 

D Hillberg

Well-Known Member
Joined
Nov 23, 2010
Messages
1,401
Location
very low low low earth orbit
FILL ALL EMPTY SPACES WITH CEMENT

COVER WITH DUCT TAPE AND BUBBLE WRAP

100 FOOT SAFTEY AREA SUROUNDED WITH A MOTE AND RAZOR WIRE FENCE

IN THE MIDDLE OF NOWHERE

:pilot: That'll fix it
 

speedracer

Well-Known Member
Joined
Feb 4, 2020
Messages
164
I'm a fuel sissy. I usually land with at least 5-6 gal in each tank mainly because my fuel gages are older than dirt and I don't trust them.
I did some remaining fuel testing with my Long EZ. I ran one tank down till no fuel showed on the sight gage on that side and checked the time. It took about 30 minutes at cruise RPM till the engine sputtered. I switched tanks, landed, put gas in that tank, went up and repeated with the other tank - same thing, about 30 minutes. I don't have the sump blisters, but a 1.5 gallon sump under the passenger thigh rest. Also, the sump has a partition at 1/3rd the way across the sump. The 2/3rd side has a flop tube for inverted flight, but no inverted oil system so inverted flight is brief. When I was doing my leak testing during the build I figured out there was a small leak in that partition. I decided to not fix that. Now when the plane sits overnight the tanks level themselves. I know that some builders didn't bother with that partition, but when their engine sputters.....
 

PiperCruisin

Well-Known Member
Joined
Jan 17, 2017
Messages
227
Location
Idaho
Why not have motorcycle-style reserve for fuel? If you run out, switch to reserve, which ought to be setup to be enough to fly to a reasonably nearby airport and land safely. You get to run out of fuel, have your moment of panic, then switch over, land safely, and be much more careful next time.
I have two wing tanks where I could do just that. Only did it once and it was on purpose because I wanted to run it dry to pull the tank and send it off for work before annual. The dip stick showed nothing. Climbed to 3k AGL above the airport, switched to the low tank and circled for 40 nervous minutes before it stuttered and I did the world's fastest tank switch.
 

challenger_II

Well-Known Member
Joined
Jul 15, 2009
Messages
497
Location
Fisher County, Tx. USA
Tony Bingelis depicted just such in one of his building books: two fuel ports in the tank, one with a 2-3" standpipe, the other built flush to the bottom.

Why not have motorcycle-style reserve for fuel? If you run out, switch to reserve, which ought to be setup to be enough to fly to a reasonably nearby airport and land safely. You get to run out of fuel, have your moment of panic, then switch over, land safely, and be much more careful next time.

Of course, some folks will just run it on the reserve setting all the time, but the solution for them isn't in the airplane design.
 

wsimpso1

Super Moderator
Staff member
Log Member
Joined
Oct 18, 2003
Messages
8,231
Location
Saline Michigan
SVSUSteve has posted many times on the topic of making the airplane safer when crashed. It might be worth looking up his posts on the topic. He is firm believer that the airplane can be designed to be far more protective of the occupants in a crash.
 

Victor Bravo

Well-Known Member
HBA Supporter
Joined
Jul 30, 2014
Messages
9,579
Location
KWHP, Los Angeles CA, USA
Back to the original thread topic, I personally believe the basic configuration for a "safe airplane" is something that is designed to have predictable and benign flight characteristics, and and gives the pilot adequate warning that a significant problem is developing.

It is fairly well demonstrated that all this can be achieved using a conventional "Cub" (or Ercoupe) configuration, or a Rutan style canard, or a Fauvel wing, or a Horten wing, a three-surface config. etc. etc.

No matter what you do to idiot-proof it, no matter how much software or hardware you build in to serve as some kind of fail safe, the airplane has to be designed around some minimum level of pilot skill and operator judgment. Same as a car, a bicycle, or a skateboard. Without that as part of the equation you will be chasing yourself around in circles with no end.

For the people who want (or need) something that does not require them to possess some basic level of skill and judgment, all these new whiz-bang Uber-Air and Bezos-Copter and Venture-Vulture Tilty-Wingy-Thingy self-flying air taxis become relevant.

And just when I thought that I was the smartest guy in the room to have come up with that brilliant concept (of those who can't operate the machine having to hitch a ride with someone else driving)... I looked over and saw Granny, Special-Needs Bob, and Drunken Freddie walking to get on the bus instead of walking over to drive a car.
 

Pops

Well-Known Member
HBA Supporter
Log Member
Joined
Jan 1, 2013
Messages
9,641
Location
USA.
On my first flying job, my boss told me to fly on one fuel tank and check the time it took for the engine to quit. Then you know how long you can fly on the other tank before the engine quits for good. I told him, no thanks.
 

Chilton

Well-Known Member
Joined
Jun 28, 2014
Messages
180
Location
Jersey, channel islands
No matter what you do to idiot-proof it, no matter how much software or hardware you build in to serve as some kind of fail safe, the airplane has to be designed around some minimum level of pilot skill and operator judgment. Same as a car, a bicycle, or a skateboard. Without that as part of the equation you will be chasing yourself around in circles with no end.

.
Basically trying to make an aircraft idiot proof is an arms race with nature making better idiots, and nature ALWAYS wins.

BETTER training is part of the answer, but much of it is down to attitude which is very hard to train.
 

Topaz

Super Moderator
Staff member
Log Member
Joined
Jul 29, 2005
Messages
14,751
Location
Orange County, California
Much of it comes down to an unhealthy attitude about "safety." There's no such thing, only relative amounts of it, that you have to weigh against the rewards the amount of risk gain you. Technology does not provide a blanket improvement in safety. For every improvement in "safety," there is a cost somewhere else.

People trying to chase "perfect" safety are chasing a phantom.
 

PiperCruisin

Well-Known Member
Joined
Jan 17, 2017
Messages
227
Location
Idaho
The safest aero wise is a canard/tandem wing style that refuses to departure stall, or spin in on approach .
They have a pretty good strategy, but John Denver might not totally agree. Yes, he had a fuel issue. Yes, he also died of "blunt force trauma". I think anytime we're more than 20 feet in the air, there is some significant risk, but I'll take some of that risk to fly.

Canards also typically have higher stall speeds so increased energy at impact = lower survivability.
 
Top