normb@tekred.UUCP (Norm Babcock ) (02/15/85)
After being baffled, confused, and abused by CFIs, books, other
pilots, and my bartender, I'm appealing to the final court of
net.aviation.
The perfect approach is: 1. High with full flaps, no power
2. Low with full flaps, lotsa power
3. Partial flaps, some power
4. No flaps, power on/off
Obviously we need to set some conditions, let's say steel runway,
wind maximum of ten knots, no more than 15 degrees off the r'way
heading, single engine, 125/150 HP maximum, little or no mechanical
turbulence, sunny day, stock market up, and war hasn't been
declared.
I've been chewed out for not using full flaps in a 150, exceeding
55 kts, and for not being at idle, all during gusty conditions.
This by a CFI. I've gotten looks of horror for using 60 kts and
20 degrees of flap on a calm day. ("You'll kill yourself someday
flying like that."
Other comments include: "Full flaps and ANY power is like driving
with the brakes on.", "You gotta have a few extra knots in case
you get a wind shear." "Never use flaps if the crosswind component
is more than ten knots.", "Hot landings abuse the tires and brakes,
land as slow as you can.", "Flaps are your most effective airbrakes,
always use them, and when you have to land in a cowpatch, you'll
be ready."
normb@tekred.UUCP (Norm Babcock ) (02/15/85)
Re Flap Flap posted yesterday, the computer burped and sent it before I had a chance to edit it. The idea was to find out how you guys handle approaches, use flaps, and when. Norm tektronix!tekred!normb "Final approach sounds so final", she said.
marcum@rhino.UUCP (Alan M. Marcum) (02/15/85)
Lots of philosophies abound on this matter. Some of these
philosophies are a bit outdated, but should still be understood.
Back in the olden days, engines failed frequently. Knowing that,
the accepted pattern was high, power off, with a slip down to the
field. This was done so that if the engine quit, you could
ALWAYS make your field.
Today, engines rarely fail (but they still do, occasionally...).
Most approaches flown are such that if an engine failure occurs
after about ten seconds past the numbers (remember that spot where
your instructor ALWAYS pulled the power during primary training? the
spot where you would JUST make the field if you did it right?) until
maybe 1/2 mile final, you'll be short of the field. Many singles
are flying in the IFR environment, shooting approaches, mixing it
up with the big guys. Just TRY to request an old-days pattern
at, for example, DCA or SFO!
From my training (and current practice), follow the manufacturers
recommendations. Every plane I've flown should touch down near
power-off stall. Why? The less kinetic energy you have at
landing, the greater the chances for a safe one, the less energy
there is to dissipate in a critical situation. Remember good-ol
1/2*m*v**2 from high school physics? That v**2 is a doozy!
Flaps both slow you down, and cause the wing to generate more
lift at lower speeds. Yes, we practice no-flaps landings, mostly
in case of flap extension failure or emergency high-wind
landings. I'll land with full flaps, and, ideally, with the
stall warner beginning to bleep. IF there's a big crosswind
(8-10kt component), or conditions are gusty, I'll come in with
partial flap, carrying a bit of extra airspeed (1/2 the gust
component over normal approach).
A good approach is a stabilized approach. Track the VASI,
gradual deceleration, reduce power over the fence, roundout,
flare.
Flying a mid-60s Debonair (old 4-place Bonanza) taught me a great
deal about the last phase of the approach. The plane has a
vernier throttle -- very similar to most mixture controls. If
you flew the approach right, you gradually screwed out the
throttle during the final few seconds of the approach. Over the
fence at the right airspeed, screw out the throttle, and she just
landed by her lonesome.
--
Alan M. Marcum Fortune Systems, Redwood City, California
...!{ihnp4, ucbvax!amd, hpda, sri-unix, harpo}!fortune!rhino!marcumdoug@terak.UUCP (Doug Pardee) (02/18/85)
Boy, is this gonna bring out a wide variety of answers!!
While everyone discusses the routine aspects, I'll comment on some
seldom-mentioned points. First, using full flaps in some planes
results in a hopelessly narrow zone between touching down with the
nose too low, and either stalling or just "running out of elevator".
Very-low-wing planes like the Mooney and the Comanche are most prone
to this. To achieve a flared attitude in a Mooney with full flaps,
you are forcing all of the air being displaced by the underside of
the wing to try to go through the couple-inch-wide slit between the
trailing edge of the flaps and the ground.
For my second point, a true story about a CFI friend. He was giving
lessons in a 150, and the manoeuver in question was a forced landing.
After the student had the emergency field "made", my friend put in
the throttle and flipped the flap switch to "up". All of the preceding
is totally routine. But... the flap fuse blew, leaving 40 degrees of
flaps. Now a 150 with full flaps doesn't want to climb anyway, but
this was with an outside temp of 105F. He did find the spare fuse
in time, but a solo pilot wouldn't have.
But wait, there's more... Some high-wing planes are laid out such
that with the flaps down the doors won't open. Think about the
ramifications of a survivable forced landing where the battery
didn't make it. Not that flaps are your only problem -- the frame
could have gotten bent, preventing the door from opening.
As for me, I never use flaps. But that's because I don't have any :-)
--
Doug Pardee -- Terak Corp. -- !{hao,ihnp4,decvax}!noao!terak!dougbrent@phoenix.UUCP (Brent P. Callahan) (02/21/85)
Ideally, light aircraft should have speed brakes a` la space
shuttle. Then you could approach high and energy rich and
fly the glide slope using the speed brake as if it were a
throttle.
Do sailplane pilots use their speed brakes this way ?
--
Made in New Zealand --> Brent Callaghan
AT&T Information Systems, Lincroft, NJ
{ihnp4|ahuta|pegasus}!phoenix!brent
(201) 576-3475rl@ucsfcgl.UUCP (Robert Langridge%CGL) (02/22/85)
In article <1034@phoenix.UUCP> brent@phoenix.UUCP (Brent P. Callahan) writes: >Ideally, light aircraft should have speed brakes a` la space >shuttle. Then you could approach high and energy rich and >fly the glide slope using the speed brake as if it were a >throttle. > >Do sailplane pilots use their speed brakes this way ? Yes. Though precision on how "...high and energy rich..." is advisable. --|-- *~~~~~~~~\bob/~~~~~~~~* ^ ^ Bob Langridge (UUCP: [...]!ucbvax!ucsfcgl!rl) Computer Graphics Laboratory (ARPA: rl@ucbvax 926 Medical Sciences or University of California langridge@sumex-aim) San Francisco CA 94143 (Phone: +1 415 666 2630)
boris@mit-athena.UUCP (Boris N Goldowsky) (02/22/85)
Sailplane pilots do make high and fast approaches and use the spoilers to both slow the aircraft down and keep on the glideslope. You can't go around, so you DON'T come in low. Boris Goldowsky !decvax!mit-athena!boris, boris@mit-athena.arpa [Is it obvious that I'm a beginner?]
ems@amdahl.UUCP (ems) (02/26/85)
> Ideally, light aircraft should have speed brakes a` la space > shuttle. Then you could approach high and energy rich and > fly the glide slope using the speed brake as if it were a > throttle. > > Do sailplane pilots use their speed brakes this way ? > While not an expert, (I have taken one lesson), we did it that way. You only get one chance. You can more easily burn off speed and altitude with speed brakes than you can gain them if you encounter unexpected headwind .... E. Michael Smith ...!{hplabs,ihnp4,amd,nsc}!amdahl!ems Comedo ergo sum The opinions expressed by me are not representative of those of any other person - natural, unnatural, or fictional - and only marginally reflect my opinions as strained by the language.
dennis@terak.UUCP (Dennis Kodimer) (02/28/85)
> > Do sailplane pilots use their speed brakes this way ? > Indeed they do. I was taught (and used to apply before I got married and couldn't afford it) two methods to settle a sailplane in reuseable shape. First is power style holding airspeed with attitude and prefering slip to spoilers or flaps. (Ever heard of a slip sticking on final?). Second is Kamakaze style... Turn final at 300+ AGL and point the nose 30 feet ahead of your intended berth and hold it there. As you slide out of the sky like a roller coaster (sailplanes are notorious for low low drag) use airbrakes (spoilers) to keep around 60 knots IAS. And lastly, be sure you're not too fascinated by the sight of the airstrip expanding before you with one spot still, to forget to flare. This has the advantage of the pilot knowing his glide slope will reach the runway. What it really does is translate the problem from glide slope management into energy dispersal. It can be heart stopping, though, to enter final too high and then find that spoilers on some craft (especially those ubiquitous Switzer 2-33s) make more noise than decelleration. This leads to method 2a (unknown to most power folks and outlawed at most profitable sailports) called `circling on final'. I'll bet a few landings in a sailplane for some folk would eschew their low-and-plenty-of-power approaches. You rarely get to go around. -- Quite sincerely, ...still waiting for the electrician, Dennis Kodimer or someone like him. uucp: ...{decvax,hao,ihnp4,seismo}!noao!terak!dennis phone: 602 998 4800 us mail: Terak Corporation, 14151 N 76th street, Scottsdale, AZ 85260
lmiller@ucla-cs.UUCP (02/28/85)
Sailplane pilots most certainly do use the spoilers/speed brakes as suggested. For a number of reasons, you fly your approach at a speed equal to or somewhat greater than best L/D (around 60 in a 2-32, for example), which is substantially higher than 1.3Vso (around 30-35). You use the spoilers/speed brakes to accurately control the glide slope, and to correct for the usual wind shear near the ground (diminishing head wind). L. Miller
jc@sdcsvax.UUCP (John Cornelius) (03/01/85)
Sounds to me as though everyone has said everything already. The major reasons given for doing high performance landings on steel runways of infinite length on calm days are 1) It's just for practice to keep my skills sharp 2) What if I have to really come into a strip of length 1400' with 50' trees on either end? I should know how! 3) I can save up to .2 hours on the Hobbs meter in this rental 182 which translates into $10.00 if I can only make the first turnout. 4) It's fun. From time to time I will advance any of these reasons but the one that's most embarrasing is when there's another pilot in the plane and you're going to show him how you can make the first turnout. This will be the only time in your life that you will blow a tire on the runway. Naturally there are a dozen or so King Aire's in the approach system at the time so they will all have to make missed approaches until you get your C-172 off the active runway. John Cornelius Western Scientific