Pilots,
And here, I looked outside this morning thinking it would be a nice day to go putter around in the sky... until I checked out the METAR in the area...
KONT 131500Z 05029G53KT 1 3/4SM HZ BLDU CLR 17/M11 A3018 RMK AO2 PK WND 06053/1458 VIS 3/4V4 (5 NM E)
Since most of our aircraft stall somewhere between 29 and 53 kts, it is possible to land, stop, and then have a gust pick you right back up into the air! Unless you have found a way to bring a half-ton anchor with you, this is no-fly wind!
ADDS has these 1,000 words to say about the turbulence risk as well:
Ouch. As they say, "it's better to be on the ground wishing you were in the air, than to be in the air wishing you were on the ground"
So what do you do if you are flying into an area which hosts such a maelstrom? Obviously, the time to reflect on your preflight briefing is for when you're on the ground -- it's bacon-saving time.
The following are my opinions. I believe this is more an art than a science, so here goes -- feel free to add to, disagree with, or raspberry the whole thing. Your CFI will have more specific advice based on your flying strengths and weaknesses.
Like all bone-headed pilot tricks, it is easiest to return to better conditions. Ask SoCal approach where there are reasonable winds. Here in SoCal, you might find conditions downright serene at Fullerton or John Wayne. The saddleback and chino hills do a good job of throwing those weird winds upward -- of course you get to fly through that mess, and it won't be pretty, but this morning Fullerton is showing 14kts steady, and Hawthorne is calm. Safe havens, both with cafe's so you can wash your nerves down with an Iced Tea. (Neither serve alcohol, sorry pilots :) )
If you wanna give it a shot, you're in for an exciting landing. You can also pick a longer and wider runway for the attempt. Chino and Riverside both have bigger strips than we offer, and if you're really in the soup, you can't miss San Bernardino's runway.
However, I believe turbulence is 75% psychological. If you can think about the inherent dangers, you might realize that the wind won't hurt you if you prepare for it, and act rationally. Let's break down the risk factors a bit:
The dangers of turbulence come in a few different flavors. Generally, they are:
1. Structural Failure
For our stout and slow Cessnas, this is seldom a problem. As you know, the speed of air over our wings generates lift -- in 17J, for instance, this lift in straight and level flight is about 2,450 pounds -- or ~1.25 tons. With a 3.8G design limit, wings level would take 9,310 pounds of force to even begin damaging the wings, and the FAA requires a 50% margin over that, or a whopping 13,965 pounds of force (7 tons). In level flight, you will need something on the order of a 200kt gust to exceed design specs, and probably more like 300kt to begin structural damage. Hopefully you would notice this on your airspeed indicator and pull up (gently) to keep airspeed down. However, I have never heard of even 100kt winds in the southland, so this is a fantasy. I think my house would blow over before an airplane would get damaged in 100kt winds..
Outside of a thunderstorm, and as long as you diligently stay away from Vne speeds, this is a non-issue.Remember also that updrafts have a way of catching your airplane on one wing only, creating a roll effect. You'll want to be lively on the controls to keep the airplane upright. If you are spending time fighting the airplane, remember to hold basic
Attitude, which is to say, the plane upright. Worry about altitude and heading later, in fact, unless you're near terrain, I'd only hold heading to within 30 degrees, and altitude to within 1,000' if I was in severe turbulence. Tell SoCal what's going on after you get things under control. Remember, Aviate, Navigate, Communicate. Fly the plane first!
For those of you flying autopilot-equipped aircraft (1ES, 17J, 85Y), remember that in severe turbulence, the Autopilot will disengage as a safety measure. Otto is a fair-weather friend only!
2. Injury in the cockpit.
After you've navigated your 300kt winds like a fighter ace, wouldn't you feel silly to bang your head on the headliner, forcing your poor passengers to land the plane hollywood-style?
It is common safety practice to tighten your seatbelt and shoulder harness, if equipped, anytime you encounter turbulence. Don't strangle yourself, but you will want these straps to be very firm, pressing you into the seat slightly. This will keep you "in command". Ask your passengers to do the same. Inertial-reel seatbelts (1ES, 17J) will tighten automatically in response to a gust force.
3. Altitude loss near the ground.
Here's a doozy. Since the up and downdrafts in turbulence interact with the aerodynamics of your aircraft, you will find it more difficult to hold an altitude. That's fine for buzzing around at 5,500 feet -- but when you're trying to land an aircraft, this is trouble. You're being pitched up and down at 500fpm on final approach. So what now?
Well, it is necessary when encountering a downdraft close to the ground -- to climb. Simple enough. This is immediately done with a pitch up, but if you're over the fence at 1.2 Vs0 airspeed, you don't have much to trade for that altitude. So come in a little faster.
The rule of thumb I have always heard, especially in gusty conditions, is to add 1/2 of the gust spread to your approach speed. At Ontario this morning, the winds are 29kts gusting to 53kt. A whopping 24kt spread. That's going to be a wild ride -- add about 12 kts to your approach speed. This will give you both the ability to counter downdrafts, as well as make rudder and ailerons more effective to keep you down centerline and ready to touch tarmac in style.
What you do not want to do is scream down final approach at cruise speed, and then float the full length of the runway, ending up in the weeds. That's bad form, and totally unnecessary. You will find even 12 knots will be enough to tame the gusting beast. You just want the ability to make small, instantaneous corrections.
So that's not all so bad -- let's discuss the practical aspects of landing Runway 7 at Corona.
Due to the trees on approach to runway 7, landing in santa ana conditions over 25kts is very turbulent. It requires an iron will, an active throttle, and knowledge that trees are soft. Our training tells us that this is no different than any other landing -- just bumpier -- sometimes a LOT bumpier.
Many pilots will land without flaps, or with reduced flaps. Probably not a bad idea, as you gain additional airspeed, firming the controls and giving you instant altitude if you need it -- just remember that your landing roll will increase.
Runway 7 does not have a VASI. Since downdrafts are possible, do not "drag your butt" in on final. Maintain good separation with the trees until the landing is assured.
Remember, as long as you have fuel, you have options. If you cannot stick the landing, go around! -- head to CNO or RAL. If those don't work, head west, the wind doesn't make it that far over. We would rather have you safe and driving back, than to have you trying to land a plane in conditions that are too difficult.
At the end of the day -- be safe, decide the best course of action, and execute it. If it doesn't work, have plans B and C in your back pocket. And if you're in doubt about flying at all, call up one of our CFIs, see what their thoughts are. If you can hear the wind in the telephone, chances are good, you'd do better to pick up a book and comfy slippers today.
For more depictions:
NOAA Turbulence:
http://adds.aviationweather.noaa.gov/turbulence/NOAA PIREPS:
PIREPsBy the way, here are the last 2 hours' worth of PIREPs -- I don't think anyone is having fun flying today:
POC UUA /OV CCB /TM 1530 /FL100 /TP LNC4 /TB MOD-SEV 100-040 /RM DURD
PRB UA /OV AVE/TM 1537/FL322/TP B737/WV 001061KT/TB MOD CHOP/RM F.400 MOD CHOP ALSO AWC-WEBSWA
BFL UA /OV EHF/TM 1541/FL300/TP B737/TA M40/TB 360067/IC NEG/RM SNA-SEA DURGC MDT TURB SFC-150 AWC-WEBASA
SNA UA /OV SNA /TM 1546 /FLUNKN /TP B752 /TB MOD BLO 160 /RM DURC
SNA UA /OV KSNA/TM 1550/FL001/TP B734/WV 030035KT/RM ON FINAL RWY01L WIND 030/35G45, +/-10KTS AWC-WEBASASAN UA /OV KSAN/TM 1555/FLUNKN/TP B739/RM DURGC PEBLE3 LGT CHOP SFC-300. AWC-WEBASA
BUR UA /OV KBUR/TM 1605/FL350/TP B738/TB MDT/RM OCNL-CONT MDT TURB FROM FRIANT THRU DESCENT TO 2000AGL AWC-WEBASA
BFL UA /OV EHF/TM 1615/FL300/TP B739/WV 34856KT/TB NEG/RM AWC-WEBASA
SMO UUA /OV SMO210001 /TM 1619 /FL003 /TP H25B /RM LLWS + - 10KTS
OXR UA /OV VTU305025 /TM 1630 /FL055 /TP C210 /TB LGT CHOP
WHP UUA /OV BUR360005 /TM 1630 /FL080 /TP C56X /TB SEVSNA UUA /OV SNA /TM 1645 /FLUNKN /TP C750 /TB MOD BLO 010 /RM LLWS + - 15 KTS FINAL RWY 1L
ONT UA /OV KONT/TM 1653/FL070/TP B737/TB CONT MOD 070/RM CONT MOD TURB FL030-070 ON DEPT AWC-WEBSWA
SDB UA /OV GMN/TM 1659/FL280/TP B737/WV 009053KT/TB MOD CHOP/RM FL260
TRM UUA /OV TRM /TM 1659 /FL025 /TP BE36 /WX BLSN E CAN NOT SEE SALTON SEA /TB SEV /RM CAME OUT OF SEATS, HAD TO LND UDDONT UA /OV KONT/TM 1700/FLUNKN/TP B734/TB CONT LGT UNKN/RM DURGD OCNL MODT. NEG LLWS. APPCH END RWY 8 WINDS PRETTY MUCH CALM BUT DEPT END WINDS INCRS TO 50KTS AWC-WEBASASDB UA /OV GMN /TM 1701 /FL135 /TP AA5 /TB NEG
SNA UUA /OV SNA /TM 1719 /FL002 /TP E135 /RM LLWS -20 RWY 1LMHV UA /OV MHV /TM 1720 /FL105 /TP M20P /TB NEG /RM LGT CHOP BLW 095 1000 FPM UDDFTS
ONT UA /OV PDZ360005 /TM 1721 /FL050 /TP CRJ7 /TB MOD /RM MOD TUB BTN 5000-6000
Yikes.
Blue Skies -- calmer winds.
- Mike
.JPG)
