Tag Archives: Aviation Safety

Small airplane and tour helicopter collide over Hudson River, NYC

A the helicopter Eurocopter AS350 (N401LH), operated by Liberty Tours, which conduct tours of NYC and the harbor, carrying a pilot and 5 Italian passengers and a Piper PA-32R Lance (N71MC), collided and crashed into the Hudson River on Aug. 8, 2009 killing 9 people. According to the witnesses and reports, the Piper, that had just left Teterboro Airport with a pilot and two passengers, and was bound for Ocean City, N.J., appeared to overtake the Liberty tours helicopter and hit it. The aircraft were flying Southbound along the VFR corridor, a special route below 1100 feet MSL (Mean Sea Level) which runs below the tops of several buildings and skyscrapers to the West of Manhattan.

I took the following picture from the Empire State Building in March 2008. It shows two sightseeing helicopters flying over the Hudson River to the West of Manhattan.
Hudson Corridor

Even if mid-air collisions are not so frequent (since it is not easy to get into another plane in the air neither intentionally nor casually), the Hudson Corridor can be considered somehow dangerous: it is really busy and congested, traffic is hard to scan because pilots tend to wander to the view of the NYC skyline and other aircraft camouflage themselves with the “noisy” background. Aircraft within the “exclusion zone,” the airspace which extends up to 1.100 feet, are not required to communicate with the ATC (Air Traffic Control) ; pilots must talk to ATC when they are entering that zone and when they are flying out of it, but once they’re operating in that area, they’re flying under visual flight rules and must keep listening watch on the CTAF (Common Traffic Advisory Frequency) to self-announce their position. There’s a sort of convention for pilots to broadcast position, altitude and next reporting point at several locations along the Hudson River corridor: abeam the Statue of Liberty, Holland Tunnel, Empire State, etc.

A screenshot from a Fox News exclusive video of the mid-air
mid air FN

The following text is an excerpt of an article published by New Jersey Real-Time News at www.nj.com website. It is quite interesting, since it provides some information about previous similar accidents, involving sightseeing tours helicopters in NYC:

Liberty Helicopters, which is based in New York City, operates out of two helipads, one at W. 30th St. on the Hudson and the other downtown, at Pier 6 on the East River. The helicopters can carry eight people, including 7 passengers, who pay $150 for a 6-8 minute tour and $230 for 16-20 minutes, The tours typically take in the Statue of Liberty, and Ellis and Governors Islands.

Liberty tours describes itself as “the largest helicopter sightseeing and charter service in the Northeast.”

The company’s helicopters have been involved in several incidents in its 23-year history. Eight people escaped serious injury in July 2007 when a Liberty tours helicopter experienced engine trouble and made an emergency pontoon landing in the Hudson just north of the Lincoln Tunnel.
AP Photo/Fox News ChannelThis image courtesy of Fox News reportedly shows the collision between a tour helicopter and a small plane over the Hudson River in New York today. Fox News reports that they obtained the image from tourist traveling on a tour boat.

Liberty helicopters was investigated by the National Transportation and Safety Board 11 years ago after the rotor of one of its helicopters made contact with a building at the heliport at W. 30th Street as it was landing. Four people suffered minor injuries in the Dec. 31, 1996 incident. The NTSB report cited pilot error and a strong tailwind.

Residents along the westside of Manhattan have long complained about the fumes and noise from the various sightseeing tours that operate out of the three heliports in Manhattan and Jersey City. A lawsuit against the owners of the W. 30th street heliport settled a lawsuit last year when it agreed to cap tourist flights between June 2008 and May 2009 at 25,000.

In October 2006, Yankee pitcher Cory Lidle was killed with his flying instructor after taking off from Teterboro for a Manhattan sightseeing trip. After flying south down the Hudson, and around the Statue of Liberty, Lidle’s single-engine plane failed to negotiate a turn over the East River and crashed into an apartment building at 72nd St. Under exiting regulations they flew the whole route without advance permission, required only to stay over the river and below 1,100 feet. Days later, however, the FAA changed the rules for fixed-wing aircraft, requiring they ask permission before flying along the East River.


Gov. Jon Corzine and Hoboken acting mayor Dawn Zimmer held a brief press conference a few hours after Bloomberg, expressing their condolences to the families of all the victims. Corzine also cautioned that,”we wouldn’t want this kind of circumstance repeated. We need to be mindful there are many more people living along the waterfront,” these days. He also hearkened back to the U.S. Airways flight that safely landed in the Hudson in January, sparing all lives on board.

An interesting and detailed description of the Hudson River VFR corridor can be found here:

Alitalia MD-11 hard landing at Kai Tak

In the previous post about Kai Tak (“Kai Tak thrilling approach”) I explained how particular and somehow dangerous an approach to RWY 13 in Hong Kong Kai Tak International Airport could be. Today, I was notified about a cockpit video showing an approach to the former HK airport with a flare in crosswind conditions that bring the aircraft in a dangerous attitude before touch down (the pilot screams “Piano” at 03:45, more or leass with the Italian meaning for “gently”) at 10 feet that causes a bank angle warning message (3:47). Interestingly, the video does not show the famous IGS approach plus visual approach to RWY 13 but an easier approach to RWY31……

The mysterious end of Air France flight 447 (AF447)

As everybody knows, on Jun 1, 2009, an Airbus 330 of the Air France, flying as AF447 from Rio de Janeiro (SBGL) to Paris (LFPG) was reported missing while overflying the equatorial Atlantic Ocean. Although the pilot did not radio any kind of alert message, since the news was reported by the mass media, the first speculations suggested that the plane may have flown into a thunderstorm and break up as a consequence of the severe turbulence it may have encountered or because it was hit by a lightning. Even if in-flight break up is not unprecedented, as I’ve explained many times in this blog (make a quick search using the word “turbulence” in the search box located on the upper right hand coloumn of the site), if not impossible, a catastrophic impact of turbulence on a civilian plane is at least extremely rare. Explosions caused by a lightning strike (search for “lightning”) are rare as well. So which was the root cause of the loss of the Air France 447 that cost the lives of 228 people on board? It is extremely hard to say for many reasons. Unlike the previous crashes I’ve analysed on this site, the AF447 is much more mysterious. There are just a few details available, there are no witnesses, there are no radar logs, there are no communications by the pilots reporting an emergency or a failure. And, most important, it will be very hard to find the FDR (Flight Data Recorder), as the few aircraft’s remains surfaced on the Atlantic Ocean, 650 chilometers from the Brasil’s coastline, in an area where the sea is some 9.000 feet deep. For sure, what can be said is that the pilots, most probably, did not have time to radio a “Mayday”. This can be caused by a quick event (an explosion, an airframe collapse, a sudden illness) or by a concurrent radio failure. In my opinion, the radio failure is unlikely, as the A330 has plenty of communication equipments (VHF and HF radios, INMARSAT, ACARS, etc.) and also because this would imply that there were two failures more or less at the same time: a catastrophic failure and a radio or electric failure (of both the 3 generators and the Ram Air Turbine?). A sudden loss of pressurization could have been a cause, if the pilots did not react quickly and did not wear the masks before loss of consciousness occurred. But, if this is what happened on AF447 the aircraft would have not exploded, but fly under autopilot until it had fuel in its tanks.
What could have caused a catastrophic collapse (bomb explosion aside) could have been something similar to what other two Airbus 330 of Qantas experienced in the last months. As I wrote on this site on Oct. 7, 2008:
On Oct. 7, an A330-330 “VH-QPA”, flying from Singapore to Perth as Qantas 72 with 303 passengers and 10 crew members on board, made an emergency landing in Learmonth Western Australia after it suffered a sudden change in altitude that caused 33 (still unconfirmed figure) injuries”. Then, on Oct. 20, 2008, I explained: “Even if it is too early to have a full explaination of the causes of the Qantas flight QF72 plunge that caused many injuries (see also: “Qantas flight forced to land: is turbulence dangerous?”) the preliminary review of the data recorded by the Digital Flight Data Recorder (DFDR) made by the ATSB indicated that the event developed in three steps:
the aircraft was levelled at FL370 when initiated an uncommanded climb of about 200 ft, before returning back (autonomously to 37.000 feet). About 1 minute later, the aircraft pitched nose-down, to a maximum pitch angle of about 8.4 degrees, and plunged about 650 feet in about 20 seconds, before returning again to FL370. Finally, about 70 seconds after returning to the cruising level, it pitched again nose-down, to a maximum angle of about 3.5 degrees, and descended about 400 feet in about 16 seconds, before returning once again to FL370. Such a “behaviour” seems to rule out the hypothesis of a CAT (Clear Air Turbulence) and the ATSB is in fact focusing on the faulty data in Air Data Intertial Reference Unit (ADIRU) 1 that “deceived” the aircraft’s flight control system. The ADIRU is an aircraft’s vital system. It feeds other on board key systems (autopilot, engine control system, flight control system, etc) with information about speed, altitude, position and attitude of the plane. On board the Qantas 72 flight, the ADIRU generated false warnings (stall, over-speed, etc) that the flight control’s computer faced with incorrect aircraft movements. The reason for the faulty data is still unclear. Someone pointed to the possible corruption caused by an electronic interference from an onboard portable device (laptop, PDA, tablet pc, etc.). Following the event, the ATSB initial report, Airbus issued recommendations to A330 and A340 operators that are equipped with the same ADIRU, including guidance and checklists for crew response in case of a similar inertial reference system failure
Another similar event, involving the Airbus 330 ADIRU, occurred a few weeks later when, on Dec. 27, 2008 a Qantas Airbus A330-300 cruising at FL360 (36,000 ft) enroute from Perth to Singapore, at about 1729 Local Time, experienced an autopilot disconnection followed by an ECAM (Electronic Centralized Aircraft Monitor) message (NAV IR 1 Fault) indicating a problem with ADIRU Number 1. The crew actioned the Airbus Operations Engineering Bulletin (OEB) procedure by selecting the IR 1 push-button to OFF and the ADR 1 push-button to OFF. Both OFF lights illuminated. The crew elected to return to Perth and an uneventful overweight landing was conducted. At the time that the autopilot disconnected, the aircraft was approximately 260 nautical miles (NM) North-West of Perth airport and approximately 350 NM South of Learmonth airport.

Even if someone speculated the area around Perth was a sort of “Perth Triangle” interested by strong radio signals (by some sort of secret naval station), the above two Qantas safety events show that there were some problems with the ADIRU of the Airbus 330 in the recent past. What if the AF447 experienced an uncommanded flight controls input at high speed, high altitude (in severe turbulence/thunderstorm conditions) like Qantas 72?

Rome International Air Show (Ostia Air Show): 31.05.09

I’ve already discussed the Eurofighter low passage in a dedicated post. Here are the pictures I took from both the small dock located to the left of the display area and from the top of the Plinius lido building, slightly right of the previous spot. I was initially cleared to take pictures from one of the organisation’s boats but there was slight sea and I had to stay “feet dry”.
Full collection of pictures taken on May 30 and 31 is available at the following address:

Rome International Air Show (Ostia Air Show): 30.05.09 (rehearsals)

The following pictures represent a selection of all the images taken during the rehearsals of the Rome International Air Show.
Full collection of pictures taken on May 30 and 31 is available at the following address: