Is it better to be lucky than good? False choice. Cover the board and aim for both lucky and good, although this philosophical mobius strip leads to the inevitable conclusion that skill has a lot to do with making luck. I’m blathering on about this because just six months ago I wrote a blog explaining how 2021 was a bad year for me personally with regard to fatal accidents. Four friends or acquaintances died in crashes.
This year is not going much better. In the past month, two friends have emailed reporting the death in crashes of people they knew. Both were previously certificated pilots coming back into flying, possibly because Basic Med made that possible. I’m not casting aspersions on that program, just noting that expansion of the pilot pool has always had a price in blood and that may still be so.
Circling back to luck is the video we’re running this week of an accident that occurred at California’s Cable Airport in January 2022. The lucky part accrues from the fact that any pilot who finds himself in a 90-degree bank at 30 feet with no roll control survives at the whims of gravity and flat dirt that’s not too hard. (The video was posted by Aviation Safety Network.)
The particulars of the accident are that the pilot of a Cessna 120 approached Cable’s Runway 24. On short final, he encountered rotor wash from a Huey helicopter operated by the local sheriff’s department that caused an uncontrolled roll to the right at low altitude. The airplane struck in that attitude—nose first—and pirouetted into a slide that just missed the end of a hangar block. The pilot sustained minor injuries, but the airplane was seriously trashed.
I read a lot of accident reports and about one in 50 turn out to be, well, really interesting. This one was one of those, by dint of the pilot having attached his own detailed analysis and statement of what happened that lends far more detail than the NTSB’s minimal analysis. In toto, with the pilot’s report, it’s possible to learn something from this; without it, not so much.
If the pilot’s statement was accurate, there were two helicopters operating at the airport, neither of which observed recommended procedures for the airport. One of the helos crossed in front of the Cessna without announcing its intentions, according to the pilot’s report. He was in the midst of applying go-around power when he encountered the rotor wash and lost control.
The pilot provided his own historical analysis by noting there aren’t many such accidents in the database. Is it because pilots know to give helicopters a wide berth or because medium to heavy helicopters don’t mix that much with light aircraft? I’d guess more the latter than the former. A Huey—think Bell 204/205—grosses around 9500 pounds so in a slow taxi hover, it’s pushing a lot of air and making a lot of local turbulence.
But a big heavy lift helo like a CH-53 (46,000 pounds) or a CH-47 Chinook (50,000 pounds) raises a hell of a ruckus. These aren’t commonly seen at civil airfields, but they’re far from unheard of, either. I once saw a pair of CH-53s do low passes at First Flight Airport in North Carolina. They show up unannounced at other airports, too. My former Connecticut homebase, Waterbury-Oxford, got regular visits from Blackhawks (13,000 pounds) flying from the nearby Sikorsky factory.
I guess I knew to give them plenty of separation, but if I knew you’re supposed to be at least three rotor diameters away—according to AC 90-23G—I’ve forgotten it. Also, in a slow hover taxi, a helicopter disturbs the air a little above it, too. And even on the ground, three rotor diameters may not be enough. Here’s another rotor wash encounter that didn’t result in an accident, but nonetheless caused alarm.
So to be honest, I’m not sure I wouldn’t have blundered into the same situation the pilot at Cable did. The helo was crossing his path, so it wasn’t like the wake should be persistent. But now, we all know not to do that.
One aspect of this story that doesn’t appear in the NTSB records is the chaos helicopters sometimes cause on the ground that don’t result in accidents or reportable incidents. Not to generalize too broadly here, but helicopter pilots are sometimes oblivious to the minor issues they cause on the ground when hover taxiing. I witnessed one here at Venice when a Jet Ranger taxied by a line of transient aircraft—not all of which were tied down—and blew a couple out of position, although no damage was done. The mother of all downwash terror is the V-22 Osprey. In this 2010 incident, 10 people were injured thanks to a crew oblivious to what was under the downwash. This one was even more spectacular and completely destroyed a hospital’s emergency helipad.
In my flying career I have often left an airplane secured only with chocks while taking a lav or lunch break. It would have taken, what, an extra minute or two to tie it down? I don’t expect a V-22 to show up, but then again, neither did that hospital. Like it or not, we’re on our own out there and we can’t count on fixed or rotor wing pilots to always do the right thing.
Yes, rotorwash can be a problem. In Hawaii in the late ’70’s my Infantry unit was in the field and a young soldier was standing atop an M561 Gama Goat holding up the sling to hook up to a hovering CH-47. When the aircraft was at the correct position the soldier was blown OFF the Goat. He shook himself off, got back on the vehicle, and completed the hookup. Later. after I got out, I eventually received my A&P and always remembered that incident when I worked at PHI in Louisiana.
Having once been “rock and rolled” on a hold short while a Chinook landed in front of me….
NOT a “bash the controllers” point – but an observation. Controllers need to think “outside the rotor disk” too.
Cleared to land on an 8,000ft runway in a thrifty, nifty, 150 – I simply didn’t want to be anywhere near the taxiing Blackhawk on the close parallel taxiway as I flared. I announced: “landing long after passing the taxiing helicopter”. I then powered up to hold about 250ft as I passed the helicopter and then continued to land once well past. It was over so quickly that the tower controller’s acknowledgement of “Oh – good idea – cleared to land long” wasn’t out his mouth before I was flaring for the real landing. With an 8,000ft runway it was possible. If it had been a shorter runway – a go-around would have been in order.
These autonomous flying taxis must be approaching the 4 tonne mark of the Huey — big batteries four motors and rotors, and four passengers who put 80 kg on the form when 100 kg will be accurate. (Not joking, ask anyone who has to weigh people these days…)
Maybe municipal parks departments will site the landing pads where the downdraught will do the most good in clearing leaves in the autumn.
These autonomous flying taxis must be approaching the 4 tonne mark of the Huey — big batteries four motors and rotors, and four passengers who put 80 kg on the form when 100 kg will be accurate. (Not joking, ask anyone who has to weigh people these days…)
Note to self: Three rotor diameters PER ROTOR is not unreasonable… just sayin’…
Lucky or good? A quick review of the relevant research and analysis shows that luck has an unacceptably high failure rate.
This is the wrong conclusion to draw from the data. Where luck prevails, nothing happens and everyone goes home to eat dinner. This happens far more often than accidents do. Any rate involves both a numerator and a denominator; the denominator in this case for a “luck failure rate” is massive and mostly unmeasurable.
I don’t like mixing rotary and fixed wing at all. At peril of accusations of discrimination, the more correct term being discretion, rotary and fixed operations should be separated at airports with the real estate to accompany this. It just makes sense.
Second that on separation of rotary wing and fixed wing! Also, helicopters practicing autorotations to a runway occupy the runway for too long, in my experience. (I’ve seen gliders do the same thing…)
A few months back, I walked by a CH-53 that was on the ground, rotors turning, idling. The downwash from that big bird was very strong. I’m not calibrated for winds that strong, but I try to avoid helicopters on the ground, too.
So here’s a question, and hopefully not an invitation to trolls. At some point, electric vehicles will be appearing at airports. Eyeball engineering says that less disk area (summing up all the disk areas of the rotors) could (weasel word) mean higher downwash velocities, and more hazard.
Has the FAA considered this? Has anybody?
I decided to visit The Promenade in Brooklyn a few years ago. A nice sunny day for a walk by the East River looking out to view the lower east side of Manhattan. Tour helicopters are everywhere, taking off from the East side helicopter pier when they all disappeared. Looking towards the Hudson river by Battery Park, V-22 Ospreys came into view and one by one landed on the empty pier. Each one with green paint, no markings. On the street side of the pier, black suvs with lights on, possibly a visit from potus to a private function or U.N. meeting? At least two Ospreys landed, maybe three but I counted five in all. Lifting off, the departed south towards the Hudson heading south. Had binoculars to view it all. No one blown away from rotor wash, dresses flying up, etc. Couldn’t find any local news covering this surprise event, possibly deliberate to provide as much secrecy of the potus visiting any public area. All this took place in probably less than an hour or so. Having not flown in many years, I forgot TFRs were probably put up for that late morning/early afternoon VIP visit to NYC.
I learned to fly out of Elmendorf AFB in the early 70s, and many of our “sorties” in the 150s were to Fort Richardson’s then towered single airstrip. In fact, that’s where I solo’d. I remember early on my instructor warning me to beware of two things, Beavers on skis and helicopters of any size.
I don’t know where the 3x the rotor diameter thingy came from, but in my view, that’s not enough. In recent years, I’ve been pummeled by the helicopter down wash of a relatively smallish Bell that was hovering a goodly distance from the taxiway, far more than 3x the rotor diameter, as I taxied by. I’ve watched a civilian Huey toss large portable plastic barriers around as he hover-taxied—because one of those barriers nearly hit my tied down airplane, its pilot and I had a relatively pointed discussion after he set down. He had hovered directly over a line of parked aircraft (including mine), all of which were fortunately tied down, without any recognition of the potential for damage he had caused.
A situation similar to the one at Cable involving an ANG Blackhawk and a Cirrus at KFNL a few years ago had the same results—and again a trashed airplane without serious injuries to the pilot. My observation is that helicopter downwash is less predictable than wingtip vortices—and those aren’t nearly as predictable as the FAA would like us to think.
So my personal practice has evolved into avoiding being anywhere near any size helicopter. I’m happy to get out of the pattern, or if I’m taxiing, to hold in place, to avoid being blown around. It’s not worth pushing it.
I flew helicopters for the US Army for over 20 years. It never ceases to amaze me to see helicopters, especially single engine, hovering around at twenty or thirty feet above the ground. When I first learned how to fly, it was in the OH-13 E & G models, admittedly there were some engine reliability problems, but we were taught to hover 2 to 5 feet above the ground. There were reasons for this, 1) develop and maintain precision hovering skills, 2) when the engine craps out, not if, a successful hovering autorotation is far easier from three feet +/- than twenty, and 3) the rotor wash is much less at the lower altitudes (safety for others in the near vicinity). Had that Huey hovered across the runway at three feet, the Cessna 210 “may” have been able to successfully complete his go around. Just another point of view.
I recall watching a POTUS, Nixon I think it was, arriving by VH-3 at the ABC studios in Hollywood, which were embedded in a residential area. The smooth and deliberate low angle approach created a fairly impressive trail of flying dirt, dislodged landscaping and a considerable amount of roofing material from several homes. I spoke with one of the advance crew after the excitement died down and his comment was “yeah, well, it’s part of the cost of doing business.”
Key point, separation should probably a minute or two, just as you would want from a transport aircraft. Unless perhaps the video is sped up, I counted 15 seconds from the helicopter crossing the runway to the arrival of the Cessna over the runway.
Helo was originally on the south side of the runway and appeared to be landing there. Then he decided to land somewhere else and crossed the runway in front of the 140 on short final to land on the north side.
Correction it’s 21 seconds per the counter.
Yes the 140 was powered up for go around when he hit the wake. The Helicopter crossed the runway in front of him unannounced when the 140 was on short final. Read the pilot report. It is well done.
I have my plane in a hangar at an airport near Houston, Texas. I am in the middle row of five rows of hangars separated by about 75 or so feet. A couple years back, a guy had his Robinson helicopter in a hangar across from mine and down two units. When he would take off, he would pull the ‘copter out, close his door and start up, taking off from between the rows. On returning, he would descend to about 10 feet at the end of the row, then slowly move down to his hangar and land. Trapped between the hangars, the amount of down wash created from the small Robinson still blew all sorts of dirt and debris into my hangar and blew things around inside my hangar. I can’t imagine what a larger ‘copter like a Huey or Blackhawk would have done in the same situation. Fortunately he moved out and went away within a couple months. Not sure if it was his idea or the airport’s.
Always sad to see a broken plane… and they never seem to fly straight when ‘fixed’…
They fly plenty straight if the rebuilder has a straight jig and the required skills.
Same happened to me (though, without the crash) back in 1997 at KGFK. I was fortunate enough to have enough airspeed to fly past the rotor wash, but I ran out of both aileron and rudder, and was still rolling to the right. No mention by local controller that there was a hovering helicopter ahead and to the right while I was taking off. That one went in the “luck” category. Years before, I was almost blown off the taxiway by a Saab 2000 conducting a full static run. Again, no mention by ground controller. I’m hyper-aware of my surroundings now.
Some time ago at KPDK a S76 helicopter was crossing over mid field to land… with a Cessna taking off below it… the Cessna was swatted out of the sky.
Always pay attention to helicopters if you are in a small plane. It is as bad as flying behind a 747.
The problem is that helicopter behavior is often erratic and unpredictable, not to mention unannounced on frequency, as in this case. If the helo blasts across an active runway when you are on short final, you cant go left, cant go right, and with 85hp you cannot get above them if they are at 30 feet instead of 5 feet like they should be. I was lucky to get under one, but probably only escaped by a second or two on short final. There should be a database for reported near misses – it would dwarf the number of accidents.