The Great Ongoing Aviation Thread (general and other)

Crossing under runways isn’t real common but it’s not real rare either. Crossing under taxiways is a bit more common. Off the top of my head:

Las Vegas has one road going under two runways. As does LAX as you say. FLL has one road going under one runway. As does STL. I’m not recalling another LA area airport like that. Which are you thinking of?

JFK has two separate roads underpassing taxiways. ORD has one. TPA has one. MCO has two. DFW has two or four or five depending on how you keep score.

There are also innumerable places where internal airport service roads duck under taxiways. ORD probably has 15 underpasses like that. The only vehicles on those roads are fuel trucks, catering trucks, employee busses, igloo trains, etc.

ETA: LGB is the other LA area airport. It has a road tunneling under one runway.

Of course at almost every airport where a road goes under a runway it also goes under associated taxiways. The ones with taxiways I mentioned above are ones where the road goes under taxiways only, not runways.

Not that there’s a huge distinction from the engineering POV. They’re both pretty substantial constructions with substantial load-bearing requirements.

Sorry for the triple post. At least this one is 12 hours after the other two.

Here’s the last remnants of a novel situation at Lindberg Field (KSAN) in San Diego, CA. There’s a part-time use taxiway crossing a major boulevard. It was built for seaplanes.

https://www.google.com/maps/@32.7276828,-117.1798346,3a,60y,90t/data=!3m6!1e1!3m4!1sCQIXT7saWLHBCbv-MxWbiQ!2e0!7i13312!8i6656

That link has you sitting on a public road looking at a retracting gate. Behind the gate is a regular daily use taxiway at Lindberg Field. If you rotate 180 degrees you’re looking at a Coast Guard aircraft parking ramp and hangar facility that leads to a seaplane ramp into San Diego Bay. Rotating 90 degrees in either direction you see the main road (Harbor Dr.) that leads to both the airport terminal and the Point Lomo peninsula.

In the “satellite” view the arrangement of the airport and of the Coast Guard facility and seaplane launching ramp is obvious. Nowadays those hangars hold helicopters and you can see the helo parking and landing area markings painted on the concrete in front of the two hangars. You can also see the seaplane ramp at the southeast corner of that parking area.

Back in the '60s when I was a kid there were also hangars and buildings on the north side of the road. That was before they extended the runway all the way to the east. The runway used to physically end about where the 27 is painted on it now. That triangular area south and east of the 27 was full of USCG and USN seaplane facilities.

Where the taxiway to the water crossed the then much smaller road there were railroad style crossing gates and lights to block the vehicle traffic while the amphibians waddled back and forth between the water and the hangars on the airport side. Some days the crossing gates got a lot of use. I always liked the X-shaped signs that looked like this http://sinisterwriter.com/wp-content/uploads/2016/02/rrxing.jpg but said “Aircraft Crossing”

All that stuff died out by the mid 1970s and was torn down by the mid 80s. I don’t know if they ever open the taxiway gates nowadays, but they do still have all the airport-style pavement striping appropriate to doing so. Naturally they’d have to use police to stop the vehicle traffic on Harbor Dr.

Next time I get through SAN I’ll ask about the gates. It’ll be months from now.

Sydney has a major road that goes right under the middle of the airport.

Interesting link. On the water side of the road the gates have posts in the ground blocking the route. Those would have to lift out for the gates to be functional.

Removable bollards.

Agree those are probably removable bollards. At max zoom you can see a small fillet at the base of each. Typically permanent bollards don’t have that. You can also see the cyclone fence there is really a long-span swing gate, not a permanent unmoveable fence.

You can also see in both the streetview and the overhead view that there’s a similar cyclone fence across the top of the seaplane ramp. In streetvew it also looks like a long-span pivoting gate rather than a permanent fence.

I have no idea if they’re ever used any more, but somebody chose to keep that option available.

Here’s another novel arrangement: I mentioned in my first post that FLL has a runway going over a road. That same runway also goes over some well-used railroad tracks. What’s doubly weird is how they did it.

Florida is dead flat and you can’t dig a road (or railroad) underground near the coast without it promptly filling with water.

The runway (Runway 10R here (pdf) http://flightaware.com/resources/airport/FLL/APD/AIRPORT+DIAGRAM/pdf) used to end west of the structure labeled “Bridge” at lower right. The road and railroad already existed at ground level just beyond the end of the runway.

When they wanted to extend the runway to attract more long-haul flights to the airport the solution was to build a 55 foot high bridge for the runway and taxiways to go over the existing road & railroad. Then they built an artificial hill for the runway to run gently upwards onto the bridge. The elevation at the west end is 10 feet and it’s 65 feet at the east end. At the far west end the slope is gentle; then about halfway along the runway there’s a real definite bulge upwards as you climb the hill onto the bridge.

This really is a runway on an overpass, not a road in an underpass.
I also forgot to mention ATL (pdf http://flightaware.com/resources/airport/ATL/APD/AIRPORT+DIAGRAM/pdf) near bottom center where a runway and associated taxiways were built over a freeway. In this case the road was originally built at the natural ground level around the airport. Then they wanted to extend the airport out over the road. IIRC they had to first dig a trench and put the freeway down in it, then carve the rolling terrain flat for the runway. An awful lot of dirt got moved.

Like the note on the chart says, you’ve got to be careful not to mistake the freeway underpass structure for a connecting ramp between the runway and the taxiway. Turning off there would trigger quite an impressive accident.

I thought ONT did, too, but it’s been a few years since those were my stomping grounds, so I may be misremembering.

Addison in N Dallas also has an street under the runway. Not a regular airline airport but …

That makes three then. The other one I am thinking of is Van Nuys (VNY) in the San Fernando Valley. Sherman Way, one of the major thoroughfares across the valley, goes right under it.

Aerial photo. Sherman Way is the major road crossing under the airport in the lower half of this photo.

Not that I recall although I haven’t flown through there in several years. Google maps seems to say “no” also.

I didn’t know that about VNY. Cool. Thanks. I used to occasionally fly into Burbank and we go right over VNY on the way in. But a little busy just then for sightseeing.

I’ve been there on foot. We sometimes use a hotel nearby for layovers. Some great Mexican eateries around there too.

I forgot about the road under the airport. Have you been to Cavanaugh’s museum https://www.cavflight.org/ there? If you’re ever in Greater Dallas it’s worth a stop.

I hope you don’t mind indulging me a little and allowing me to change the subject and relate my latest flying experience (non-work).

Pre-flight nerves

I was asked recently to do some flying in a Tiger Moth. The excuse was that the owner, who I work with, had lost his medical and needed a safety pilot to fly with him. A win/win situation (ignoring the medical problems for the moment), I get to slip the surly bonds of earth in a more traditional manner and he gets to fly legally. It seems he is keen for me to fly it without him as well, so I might just get to introduce my children to real flying. Something I’ve been meaning to do for a number of years but haven’t got around to.

I last flew a Tiger Moth in 2001. I’d flown about 250 hours in them up till then (actually I’ve just checked, it’s 275.5 hours, electronic logbooks are awesome!) This seemed like a lot at the time, and in a way it was, it made up about a quarter of my flying experience in 2001, but now it’s just a brief episode in my log book.

I wasn’t sure if it was actually going to happen, my colleague’s illness may easily have prevented him from finding the time or even having the desire to go flying with me, but plans were made, a date was set, and I rocked up at a small, slightly dishevelled, private airstrip bordered by trees, a river, and industrial buildings. A runway and a couple of taxiways had been maintained by a lawnmower in amongst sparse weeds. A large troop of kangaroos* roam the perimeter fence and later I’m warned to keep an eye on them, be ready to abort a landing or take-off if they decide to bound across the runway at the wrong time.

My friend isn’t here yet but I take a look around and find an open hangar with a couple of people pottering around with rotted wooden wing frames (“gotta hang these up on the wall to make room for a bench we’re building”). Also in the hangar is a Tiger Moth, a Chipmunk, and a Jabiru. In adjacent hangars I find a Stearman and another Tiger Moth. Elsewhere there is apparently a Yak of some description but I didn’t get to see it. Already I am struck by this little collection of aircraft. Back in the “before time”, when I flew because it was fun, I would have known about all the old aeroplanes in the neighbourhood. I would be on first name terms with the owners and there’d be a reasonable chance I would’ve flown some of the machines at least once. Not anymore.

I don’t mind admitting that I’m a bit nervous at this point. I know I’ve flown these things before and didn’t find it difficult. I’m sure I can do it again. But it’s been 16 years. The airstrip is not the wide open space I’ve been used to in the past and am used to now. I remember that the Tiger Moth needs left rudder instead of right to counter the engine torque and spiralling slipstream, but how much does it need? Is it a lot or not? I can’t remember that. Tail draggers have a bit of a reputation for being difficult. I don’t remember them being difficult, but maybe that was just because I was young, had good reactions, and flew a lot. I found myself being psyched out by the very taildragger myths that I had spent time in the past telling people were not really true (“I’d much rather be in a Pitts Special in a strong crosswind than a C172,” I’ve said, “it may be twitchy but it’ll do exactly what you tell it to do, just make sure you tell it to do the right things :).”)

To compound my doubts, this Tiger Moth is different to the ones I’d flown before in one major respect, it has brakes. I’d never seen one with brakes before. I knew they existed, different countries built Tiger Moths and each had different ideas how they should be, the Canadians even built the things with a canopy. Some have leading edge slats, some have anti-spin strakes, some have the oil tank strapped to the fuselage while others are bolted on, and some have brakes. This shouldn’t be a problem, the vast majority of aeroplanes have brakes, but I knew a guy who put a Tiger Moth on to its nose by using the brakes a bit too enthusiastically, so it was another niggling doubt. It also has a “gosport tube”, of all things, for communicating between pilots. A gosport tube is a glorified garden hose that goes from a mouth piece, that looks a little like a device designed for women to pee in, to some ear cups, and is supposed to transmit speech well enough to be heard above the cacophony of the engine, propellor, and wind.

This might be a good time to give a brief description of these aeroplanes. A Tiger Moth is generally a very simple machine. The ones I’d flown were very “pure”. A tail skid rather than a wheel, no mixture control, no generator, no battery, no starter motor, no carb heat control (though they do have an automatic carb heat that comes on at low throttle settings), and no brakes. That said, many of them do have leading edge slats which are a lift generating device most commonly associated with high performance swept wing jets. On Tiger Moths, when unlocked, they deploy automatically at low speed and give a few extra knots of margin above the stall. One concession to modern flying that my previous steeds had was a radio/intercom powered by a standalone rechargable battery, not a fucking gosport tube!

So the scene is set. The airstrip didn’t inspire confidence, I hadn’t flown a Tiger for years, and this one was different to what I’d flown in the past.

Chocks away!

After I’d spent a bit of time looking over the machine and noting its peculiarities, my colleague arrived. Without much further fuss, we removed the Tiger from the hangar, and I was briefed on the plan for the flight. We were to fly to another private strip about 25 NM away and do a bit of air work on the way including stalling and steep turns. It was basically a checkout for me. There was a handheld radio with a headset connected in the rear cockpit but you couldn’t use that and the gosport tube so the radio was ditched in favour of being able to communicate between ourselves. We would have to be careful to avoid a couple of busy airstrips en-route, but I’d done some homework and knew where they were.

He asked if I was happy to sit in the back, this is the seat you fly it from, the front is for passengers and instructors; I was happy to sit where ever he wanted me to and told him such.

With the help of the chaps I’d found in the hangar we got the old girl started** and taxied out, getting a feel for the brakes with a few turns as we went. The front set of controls weren’t connected to the brakes so they were all mine. (“Don’t use them for landing, they are only for assisting the turns while taxiing”, I am told.) At the end of the runway we swing the tail around to face towards the trees and buildings at the opposite end. It is perhaps a blessing that I can’t see the trees and buildings because, being an old fashioned taildragger with a long nose and twice the number of wings currently in fashion, the forward view is almost entirely obstructed by fuselage, wings, and my friend in the front cockpit. I open the left door so I can lean out and peer down the side of the nose in the hope of getting an idea of where we are going.

Holding the brakes we run the engine up for a mag check at 1500 rpm. Any higher and the brakes won’t hold it. That done, I open the throttle, probably a little more cautiously than I’d’ve done in the past, and finding the swing to be negligible, continue to open it all the way.

We are off! The tail comes up quickly and with a couple of dabs on the rudder to keep straight we bounce gently over some undulations in the strip and I find myself airborne at around 50 knots or less. In my working life, in a regional jet, I sometimes taxi at 30 knots. 50 knots is not even fast enough for the rudder to become effective. At 50 knots the airspeed indicator hasn’t really become “alive”. 50 knots doesn’t even have a marking on the airspeed indicator, it goes 0, 60, 70, 80, 90, 100 etc. In my working life, 50 knots and not moving at all, is considered to be roughly equivalent.

We climb out at 60 knots, or at least I try to, I’m a fish out of water at this stage and it’s a little turbulent which makes my efforts at holding a speed worse than they otherwise would be. As we climb I try a few turns, concentrating on coordinating the rudder with the aileron. The Tiger Moth has so much adverse yaw (yaw in the opposite direction to the roll) that the ailerons only go up. If you push the stick right, the right aileron goes up which dumps lift from the right wing, and the left aileron stays roughly level***. This makes the roll quite sluggish, or at least that’s how I remembered it, but this didn’t seem anywhere near as bad as I thought it would be. In fact, I was pleasantly surprised to find the controls were quite well harmonised. The amount of rudder required to balance the aileron inputs seemed right and the control forces were nice and light.

At 2500’ we levelled off and headed towards our destination. In the cruise the speed hovered somewhere between 60 - 80 knots. It was a warm day and thermal as well as mechanical turbulence meant we were constantly moving from general updrafts to downdrafts and if height was to be maintained, speed had to vary. The problem with a machine with such a slow cruise speed is that 20 knots of headwind takes 25-30% of your groundspeed away resulting in a significantly increased flight time. 20 knots of wind is near enough to 0 for planning purposes in the jet; this was like punching in to a 100 knot headwind.

In the cruise, the view out the front was marginal. The horizon just cuts across the top of the nose while the top wing obscures much of the area above it and the lower wing obscures the area below. There’s not much to be seen forwards, even in level flight.

Once I’d got a feel for the aeroplane and started to get comfortable, I found my thoughts turning to our lack of a radio. It made me more anxious than I was expecting. I’d only ever flown with no radio once before, some 18 years ago, when ferrying a Tiger Moth from a maintenance facility to our base airfield. That time a lot of it was through controlled airspace and the flight had been organised with ATC over the phone. Even though I couldn’t talk or hear, I knew they knew I was there and were keeping traffic clear of my route. This time no one knew about us, and we truly had to rely on “see and avoid” which I think is a fundamentally flawed concept. Perhaps I’d been spoilt all this time. It’s a big sky, I’m sure we will be fine, just keep scanning.

AEROPLANE! A fucking aeroplane just flew right past our left wing at our level going in our direction! Once I got my heart of the floor and jammed it back into my chest I remembered the hangar chaps had said they’d follow us out in their Jabiru. They’d caught up with us and were sedately overtaking. They waggled their wings and I waved back. I tapped my mate in the front on the shoulder and pointed it out. “If this was WW1, we’d be dead right now” I said to him.

Which brings me to the gosport tube. Well I’ll be! It sounds like a ridiculous system that can’t possibly work very well at all, but it turns out it is actually very effective. All the advice and, sometimes, commands coming from the front were clear and easily audible over the engine and slipstream noise. It’s a bit disconcerting that you can’t hear yourself talk, but presumably he could hear me as well as I could hear him.

I’d tried to set a course of about 120º initially but found that I couldn’t get the compass to work. It was the same type fitted to previous Tiger Moths I’d flown but I realised I had literally never bothered to look at it before or learn how to use it. It had some kind of locking device which, when unlocked, allowed the compass to be freely rotated, and when locked seemed to not move at all, regardless of whether you were turning or not. I gave up playing with it after a while and just looked outside. The weather was good and I knew the area pretty well from ground level so found my way with out much trouble.

Once near our destination we did a bit of air work. A stall and some steep turns. I’d been a little tentative up to this point, but I was asked for a steep turn to the left and I obliged by bumping up the the throttle and rolling into about 45º of bank. At these slow speeds, the turn is completed quite quickly and any sloppy pitch control has little effect on our altitude, so I found that in little time we had turned through 360º and I felt a little bump as we flew through our wake. “Maybe I can do this after all,” I thought.

Happy landings

It seems my companion was a little bored at this point. He took the controls and gently aerobatted his way down to the circuit height. I was given control again for the landing. The first circuit was a slight disaster. Stripped of all my airline crutches and having no real reference for where and how high I should be, I ended up high and fast and had to do an orbit on finals to get close to a normal approach profile. From there the final approach went ok, I toyed with a bit of sideslip to see how that felt and carrying a trickle of power over the fence, I checked the sticked forward as the main wheels touched down while chopping the last of the power. No bouncing and I managed to keep it straight. Remembering the warnings about the brakes, I kept my heels firmly planted on the floor.

Well, that was a relief. I’m not sure I can say “it all came back to me”, it very much felt like a new aeroplane type. Perhaps it’s most accurate to say that my muscles seemed to remember what to do while my mind was thinking that it all felt different and new.

Well that will do for now. The strip we landed at was home to more Tiger Moths and we enjoyed coffee and a chat with the locals. We flew back later in the afternoon and my first go at landing at the Tiger’s home strip proved to be too much for me, but that is another story.

TLDR: I flew an old biplane and loved it!

  • I want to call them a “bounce of kangaroos”, but apparently “mob” or “troop” is the appropriate collective noun.

** Open the throttle. “Tickle” the carb (push a button on the carburettor that primes it with fuel). Pull the prop through four compressions forwards. Close the throttle. Pull the prop through eight compressions backwards. Set the throttle. Left mag ON, right mag OFF. Standing behind the prop, pull it through a compression and with some luck it will start.

*** More correctly, the Tiger Moth would have a lot of adverse yaw if it didn’t have this aileron design feature.

Wonderful place but I get grumpy when I am around war birds for long (CAF) etc. because I never nor will ever be rich enough to play. Now, too old also. Grump.

But I can brag that I hand propped an AT-6 for my friend several times.

Great post. Hurry with part #2

Really brings back memories for me of the 60’s & 70’s and the things I go to do.

Great story Richard. And engagingly told. Yes, yes; please do part 2 in eh near future.

I know Tiger Moths only from museums although I have some time in a Stearman of the same general vintage. It’s neat to hear some of the detailed idiosyncrasies.

I’ve only flown light planes a few times during this stint with the airlines. Agree that without the usual “crutches” as you say the job of piloting the small planes presents a lot of unfamiliar challenges and you feel silly each time you fall short in one.

But I’m always all smiles when I get done doing it. It sounds like you had a great time too.

You’re not alone in that.

I like looking but could never afford to touch either. I often wonder how so many good old boys got that much spending money. It sure never happened to me.

Some things make me happier to not think about. That’s one of them.

I was lucky enough to have walked four times, and driven twice, across the runway at Gibraltar. The fence around the runway in the vicinity of the road crossing is surprisingly short; IIRC, it’s a regular 3ft chain-link fence, like you’d find in someone’s backyard. It’s also fairly close to the runway, which probably explains the height (or lack thereof).

Gibraltar is a really cool place to visit if you ever have the chance. Take your passport, whether you walk or drive, as it’s a no-kidding international border crossing between Spain and the UK.

I564 passes nearly directly under “the numbers” of Rwy 10 at KNGU (Chambers Field, Naval Station Norfolk, VA). Several years ago, a C-5 was semi-(in)famously stopped on the runway, almost directly over the highway, for several hours due to a taxi error by the crew. Ooops. image link

Learjet 35 crashes on approach to Teterboro. 2 crew fatalities.

I work for a company that has warehouse space in that industrial park; maybe ¼ - ⅓ mile away. I’ve ridden down the road where it crashed.

Ouch. Nothing on NTSB.gov about it yet. The news vid shows a sunny non-windy day and the post-accident fire appears to have plenty of kerosene in it. Makes me wonder what went wrong that close to the runway.

In other jet crash news …

A couple years ago a Hawker Hunter crashed during an airshow in the UK. The UK AAIB recently released their final accident report.

If interested see Hawker Hunter crashes into main road at air show - Miscellaneous and Personal Stuff I Must Share - Straight Dope Message Board for the original thread from then and my recent revival of it with this news and relevant links.

http://www.skynews.com.au/news/national/nsw/2017/05/17/search-continues-for-missing-nsw-plane.html

This man was supposed to be sitting next to me tonight and tomorrow night. This is his second night out there, if still alive, so not looking good :(.