Lidle's final maneuver is focus in crash investigation

[BrianNC]

NEW YORK -- Aviation experts said Friday that inexperience, the tight airspace over the city, mechanical failure, hazy weather or a gust of wind through New York's concrete canyons could explain why Cory Lidle's plane failed to execute a U-turn and slammed into the side of a high-rise.

According to radar data, the single-engine plane appeared to be making a difficult but commonly performed left turn over a 710-yard-wide section of the river between Manhattan and Queens when it crashed Wednesday, killing the New York Yankees pitcher and his flight instructor.

The Federal Aviation Administration said it would review safety concerns about the corridor, and Friday it banned small, fixed-wing planes from flying over the river unless the pilot is in contact with air traffic control.

Much is still unknown about the crash. Investigators said they have not determined who was at the controls.

So far, the National Transportation Safety Board has said it doesn't know whether the plane had a mechanical problem. The propeller was still turning when the plane hit the building. That suggests the engine was still running. There was no indication that the pilot had issued a distress call.

Some aviation experts said that it could come down to a lack of experience by the pilots.

Lidle was new to both flying and to his plane, a Cirrus SR20. His instructor, Tyler Stanger, was a veteran pilot and teacher, but the 26-year-old Californian had limited experience flying near Manhattan.

That might have made for a less-than-perfect mix in the narrow aviation corridor just east of the city's skyscrapers, on a less-than-perfect day of low clouds and limited visibility.

Paul Czysz, professor emeritus of aeronautical engineering at St. Louis University, said the accident was probably the result of inexperience.

"He probably never should have been there in the first place," Czysz said, referring to either Lidle or his instructor. "That corridor is very heavily traveled."

The Cirrus, made of a light composite weighing only 3,000 pounds, could have easily been blown off its track during the turn by a gust of wind, Czysz said.

"The problem is that it's so light," he said. "The wind between those buildings can go 80 to 90 mph, and it could grab hold of that airplane and take control from the pilot."

Bill Waldock, aviation safety professor at Embry-Riddle Aeronautical University in Arizona, said it is a plausible theory that the airplane was blown around by the wind.
"You get some real strange winds going through those canyons of buildings," Waldock said. "It's a weird area to try to maneuver airplanes in any way."

But John Fiscus, a flight instructor who specializes in teaching pilots who to operate Cirrus aircraft, said he did not believe the turn was anything the plane or a good pilot couldn't handle routinely.

"I wouldn't call it a hard maneuver to pull off. It's just turning around," he said. "I've done that before, and it is not what I would term tight."

Fiscus noted that Lidle's plane appeared to be following common practice, operating at a normal height and at a safely medium speed when it entered the turn. Many pilots, he noted, perform the maneuver daily without mishap.

"This is the first time this has ever occurred where an aircraft has accidentally hit a building," he said.

Brian Alexander, a pilot and New York lawyer who has been involved in several cases involving Cirrus crashes, said investigators should examine closely whether mechanical problems might have caused the pilot to lose control or made the craft unstable.

Meanwhile, investigators picked through the last of the wreckage from the crash -- bits of wire and larger parts of the plane laid out Friday on a Manhattan street.
The neighborhood was also gradually returning to normal. Police said they hoped to reopen the closed-off area by the end of the day Friday.

At the end of a street, near a small park that overlooks the East River, investigators from the National Transportation Safety Board bent over the evidence, apparently trying to match up pieces to reconstruct the aircraft.

Copyright 2006 by The Associated Press

[Airdale]

Originally Posted by BrianNC

The propeller was still turning when the plane hit the building. That suggests the engine was still running.

Windmilling possibly? Last I checked, propeller driven airplanes will windmill unless the pilot feathers it. Thus suggesting the engine was still running is not nearly accurate enough. They need to examine the internal engine parts to determine the cause for the engine to stop running. Most likely because it wasn't strong enough to carve through a building.

[BrianNC]

Here is a good post by SteveC in another thread regarding that turn:

I've been following some conversations on another site that also has some pilots experienced with the area, and most (not all) say that the East River is too tight for safe 180 degree turns at low level (below building height). Not saying that it couldn't, or isn't done, just that the margins are tight.

Some of the data that I saw (unverified) gives the width of the river in that area at around 2000 feet. Consider that the diameter of a 180 degree turn, 30 degree bank, at 80 knots is very close to 2000 feet. Add in the fact that the SR20 stall speed, clean, level flight, at 30 degree bank, is 70 KIAS.

If you increase the bank angle to 45 degrees, but also increase airspeed to stay above a stall, you will find a turn diameter of 1800 feet at 100 knots. Way too close to 2000 feet, and you still have to assume that they started their turn somewhere over water, not right at the east shore of the river. Then add a 13+ knot wind from the east pushing them even further into the buildings and things don't look too good for a successful completion.

Considering that he was a low time private pilot, and the CFI was from out of state and probably unfamiliar with the area, it is all too easy to see the links of the accident chain forming. I could even see them starting up the East River by mistake (low vis) rather than the Hudson. Hard to say...

[kellwolf]

Originally Posted by Airdale

Windmilling possibly? Last I checked, propeller driven airplanes will windmill unless the pilot feathers it.

Keep in mind that the Cirrus has a constant speed prop. No pretty blue lever to play with, but it still has a constant speed prop. Odds are you can't feather it since it's a single engine. If you're feathering it, you're going down either way. You'll just have less drag to the site of the crash.

Couple of things they can look at to determine if the prop was still spinning (which isn't that big a deal but sounds good on TV). Score marks on the props, torsional damage, and bent prop tips can all show that the prop was turning at impact. Some of the data can even be translated into a rough estimation of RPM at the time of impact.

[SpiraMirabilis]

The SR22 has a constant speed prop, which is the one with the blue lever to play with. I've never flown in a SR20 so I don't know if it does, but it probably has a fixed pitch prop like most cessnas which will windmill.

[themctm]

Too bad it wasnt Jeter

[Bandit_Driver]

Originally Posted by SpiraMirabilis

The SR22 has a constant speed prop, which is the one with the blue lever to play with. I've never flown in a SR20 so I don't know if it does, but it probably has a fixed pitch prop like most cessnas which will windmill.

I was always told that if an engine making power when the prop strikes an object the prop tips will bend forward. If it isn't making power then they will bend back. I am not sure if it is true but thought I would throw it out there and see if anyone else has heard the same.



SIMPLE™ Single Movement Power Lever http://www.cirrusdesign.com/aircraft/engine/In an effort to make flying an aircraft more effortless, precise and enjoyable, CIRRUS engineered a proprietary design that incorporates the propeller governor lever with the throttle lever. This lever, conveniently located on the center console is referred to as SIMPLE™. As the governor controls the RPM, the engine oil pressure changes the propeller pitch. Because propeller speed is adjusted automatically, you can minimize your workload and maximize your flying enjoyment.

[roundout]

Originally Posted by SpiraMirabilis

The SR22 has a constant speed prop, which is the one with the blue lever to play with. I've never flown in a SR20 so I don't know if it does, but it probably has a fixed pitch prop like most cessnas which will windmill.

the SR20 and SR22 both have constant speed props but neither has a blue lever to control the prop RPM. it's done automatically (mechanically, not digitally) on both.

[SpiraMirabilis]

Really? Thats braindamaged. I've never flown any of the Cirrus planes, but having the plane automatically decide what RPM it wants to turn at is not a good idea if you've already got a constant speed prop. Its not very hard to learn how to use 2 knobs instead of 1.

[BrianNC]

Originally Posted by SpiraMirabilis

Really? Thats braindamaged. I've never flown any of the Cirrus planes, but having the plane automatically decide what RPM it wants to turn at is not a good idea if you've already got a constant speed prop. Its not very hard to learn how to use 2 knobs instead of 1.

Well, you better get used to if FADEC becomes the norm as many think it will. It is considered an improvement by many.

[SpiraMirabilis]

Glass cockpits and GPS systems are an improvement as well but I would still prefer steam gauges and VOR navigation on most GA aircraft -- if they're a/c used for instruction anyway.

[kellwolf]

Originally Posted by SpiraMirabilis

Glass cockpits and GPS systems are an improvement as well but I would still prefer steam gauges and VOR navigation on most GA aircraft -- if they're a/c used for instruction anyway.

Give me a GPS with a moving map display, TIS and XM Weather uplink when I'm in hard IMC anyday. I like SA.

[Seggy]

I'll take two VORs, DME, and a crappy weather radar to fly in IMC anyday.

Oh wait I do.



Some GA aircraft have WAAAAAAAAAAAAAAAAAAYYYYYYYYYYYYYYYYY to much stuff out there for pilots starting out.

[triplec76]

I would say if the pilot knows how to use the equipment properly, it's never too much.

[Flysher]

Originally Posted by Seggy

Some GA aircraft have WAAAAAAAAAAAAAAAAAAYYYYYYYYYYYYYYYYY to much stuff out there for pilots starting out.

Thats the best thing I've read in a long time. Couldn't agree more.

[BrianNC]

Why? If he is going to be flying a plane with nothing but VORs, etc., fine. But to say someone ought to train on equipment that is becoming obsolete just for the heck of it, well, I don't see the point.

[Doug Taylor]

Technology isn't a substitute for good old fashioned situational awareness and experience.

[SpiraMirabilis]

Originally Posted by BrianNC

Why? If he is going to be flying a plane with nothing but VORs, etc., fine. But to say someone ought to train on equipment that is becoming obsolete just for the heck of it, well, I don't see the point.

VORs will always be around because of how reliable and simple they are. But primarily because you need to develop certain skills rather than rely on the fanciness of the plane to fly itself for you. There are pleanty of doctors and lawyers who are "pilots" but couldn't fly any other plane than the one they own. I have heard this: "Cirrus 12345, traffic at 3 o'clock, 5 miles, a 172." - "Uh, I don't see him on my garmin." (TCAS I/TCAD or whatever is used in his plane.) He's started to rely on his plane to keep himself clear of traffic, I was aghast.
Also, training on glass cockpits originally tends to ruin your scan going back to steam gauges which is where you're going to do essentially all of your multi-engine training.

Its not like its training on obsolete equipment -- theres not many people who train people for ADFs anymore. Thats pretty much only good for listening to Rush Limbaugh.

[BrianNC]

Originally Posted by Doug Taylor

Technology isn't a substitute for good old fashioned situational awareness and experience.

Agreed, but unless you are talking about all pilots flying with ded reckoning, everything we use is "technology", including VORs. It is just a matter of how advanced it is. Just about everything gets replaced by something else eventually.

[Doug Taylor]

What I'm really saying is that nothing can match the power of a clean windscreen, a yoke and a pilot who knows where the hell he is.

[Sprint100]

Originally Posted by BrianNC

Agreed, but unless you are talking about all pilots flying with ded reckoning, everything we use is "technology", including VORs. It is just a matter of how advanced it is. Just about everything gets replaced by something else eventually.

In this case, SA (I'm in a tight corridor) and experience (I can't do this maneuver here) would have helped extremely, so much to the extreme that it could have possibly prevented the accident

[falconvalley]

Originally Posted by Bandit_Driver

I was always told that if an engine making power when the prop strikes an object the prop tips will bend forward. If it isn't making power then they will bend back. I am not sure if it is true but thought I would throw it out there and see if anyone else has heard the same.

In a very simplied way, yes. It's actually airspeed/impact angle versus prop speed. The faster the airplane is going when it hits, the more likely the prop blades will be bent back, however, even if the engine is developing power. A better clue to finding out if the engine was spinning the prop is to look at overall scratching on the blades and compare that to the engine's impact angle.

[MFT1Air]

Originally Posted by SpiraMirabilis

Glass cockpits and GPS systems are an improvement as well but I would still prefer steam gauges and VOR navigation on most GA aircraft -- if they're a/c used for instruction anyway.

I'm liking Doug's comment:

Originally Posted by Doug Taylor

Technology isn't a substitute for good old fashioned situational awareness and experience.

[kellwolf]

Originally Posted by SpiraMirabilis

VORs will always be around because of how reliable and simple they are.

People used to say the same about NDBs back in the day. Mark my words, once the system becomes reliable, those VORs will be replaced by the intensely more accurate GPS (or whatever other system might be out at the time). I seriously doubt they will always be around.

Its not like its training on obsolete equipment -- theres not many people who train people for ADFs anymore. Thats pretty much only good for listening to Rush Limbaugh.

See above. NBDs and ADFs used to be as widespread as VORs. Then VORs replaced them, more or less. Like it or not, every piece of tech will eventually become replaced and obsolete.

We can argue ad nasuem (and have) over whether it's good to train in an a/c with bells and whistles or not. Here's my take: if you know how to use it and it enhances SA, then why not use it? Doug says nothing is a substitue for SA, and I agree. But just b/c you CAN get there with dual VORs and a DME doesn't mean you SHOULD dump the in-flight wx, the moving map displays and the other tools at your disposal if they're available. If it starts hurting more than helping, THEN start dumping them until you can handle the workload. Until then, I see it as increasing SA, not hindering it. I'd rather be tracking a magenta line (or white) line on a moving map that show me all the airports around me, some of the traffic and an overly of that level 4 off to my right than just tracking a VOR HOPING I don't hit anything that's gonna make me roll sideways.

[tonyw]

Originally Posted by BrianNC

Well, you better get used to if FADEC becomes the norm as many think it will. It is considered an improvement by many.

Yeah, I like the idea of one lever to use versus three. Push forward for more power, pull back for less. No more fussing with the mixture and the prop.