Monthly Archives: October 2008

Podcast 1: Airshows above the surface of the water

I’ve recently started a contribution with FLIR, the Flight Line Internet Radio. I provide comments and articles dealing with the world of aviation that are aired by the first Internet-based radio station dedicated to aviation enthusiasts. FLIR is a radio station broadcasting 24/7/365 (streaming available at the address www.flightlineinternetradio.com that has a global reach, with various topical segments that can entertain almost anyone that enjoys flight. What makes FLiR different is the concept of attracting listeners because of their hobby or passion instead of their geographical location or age. The radio station follows a general format of a traditional local radio station, mixing topical segments with music and normal radio commercials. My segments are played 4 times a day. After being aired by FLIR, my spots will be available as mp3 files as Podcasts (you can subscribe the feed http://cencio4.wordpress.com/feed/ with Podcast clients such as iTunes, Juice, or CastPodder and automatically download the content as it becomes available). Even without subscribing the feed, I will write a post each time a Podcast is availble, providing the direct link to the mp3 file. The Flight Line Radio is not only on the Internet. Flight Line Radio receiver program offers personal radio receivers to entertain guests and patrons of events. Flight Line Radio has developed the technology to transmit multiple channels of private audio content to large groups of people in a very large venue area, several square miles in fact. No other company equals the coverage area that Flight Line Radio can offer: in this sense, FLR has invested years in developing an obtaining the appropriate technology and licenses to operate this type of radio network. The receivers are proprietary so the audience can be controlled, and they have the power to cover virtually any sized venue. FLR is on-site at major aviation events like Oshkosh and Sun ‘N Fun, offering personnel radio receivers to listen to the announcers and comms.

“Mammaiut” is the historical motto of the Soccorso Aereo (SAR, Search And Rescue) of the Aeronautica Militare Italiana (Italian Air Force, ItAF). It is shouted by the personnel of the 15° Stormo during official ceremonies in place of the “Ghere Ghe Ghez” shouted by the other units of the ItAF. It was also shouted to honour the lost ones during the funerals of the crew members of the HH-3F “Pelikan” that crashed in France on Oct. 23 during a flight from Dijon to Florennes where the helicopter had to attend the TLP course. “Mammaiut” means “Mum, help me”, an SOS request that sounds perfectly suitable with the current Italian SAR situation. After loosing an helicopter and 8 experienced crew members, the ItAF has decided to ground all its fleet of 30 remaining HH-3Fs until the root cause of the crash is found. The aircraft, performing the daily SAR Service on an H24 basis from Pratica di Mare, Rimini, Brindisi and Trapani airbases, will be “partially” replaced the AB.212AMI-SAR serving with the Squadriglie of Istrana, Linate and Decimomannu. Dealing with the reasons of the tragic accident, I believe that the aircraft crashed into the ground at very high speed and (almost) disintegrated. Most probably, the aircraft suffered a catastrophic collapse and smashed into the ground without giving the crew enough time to react. I believe that they had no warning sign inside the cockpit and for this reason they did not radio any message to the other aircraft that was leading the formation. The pilots had no time to react, nor they did try to slow down the speed to solve the problem nor to land. Everything happened very fast and the aircraft fell at high speed in less than a second. I think only a structural damage, a collapse of the rotor or a fracture of a blade could have such a devastating effect.

In my opinion, Facebook is funny and useful. I use it often to keep me in touch with all of my relatives and friends, to share pictures and news even if they live or work on the other side of the World. The social network has also plenty of groups, were you can discuss, share pictures and information with people that is not strictly a “friend” (someone that is directly connected to you). One of the groups I recently subscribed is the official Virgin Atlantic airline one. A couple of days before I joined the group, something strange happened on that page. A small group of airline’ staff posted some comments about the company’ safety standard and wrote also some malicious comments about passengers. Unfortunately I could not read what those employees wrote, since the staff admins deleted all the “bad comments” and started a disciplinary action. According to the information I obtained, the removed posts regarded the 13 B747-400 that the airline operates from London Gatwick and London Heathrow airports. Some of the crew members referred to the Jumbo as old, dirty “deathtraps” (even if they are quite new, since they entered service in 2001!) and criticised the Virgin Atlantic’s will to comply with the safety regulations and recommendations. Other comments regarded the type of passenger on the typical route flown from Gatwick. In particular, some of the employees referred to the passengers flying from London to Orlando as “chavs” (from Wiki: a slang term in the UK for a person whose lifestyle, branded casual clothing, speech and/or behaviour are perceived to be common, proletarian and vulgar) even if it must be said that flying to leisure destinations, it is quite normal to find Economy classes seats crowded with school childs and young people. Crew members operating on those routes should be used to “manage” such kinds of passengers.
A VS spokesman explained to the BBC that all the malicious comments were removed because “Virgin Atlantic does not tolerate any criticism of its passengers or industry-leading safety standards and is taking this matter very seriously. Safety is the airline’s top priority..”. I’m pretty sure such comments could be useful, but most probably they should be done elsewhere: I don’t think an airline public fans club is the right place to write such things (especially when they are wrong). Just think to a “nervous flyers” who reads an aircraft being called deathtrap by a qualified crew member. The impact could be devastating for both the passenger and airline.

In the last years I watched the proliferation of pictures showing aircraft flying at high altitudes followed by the characteristic white trails (I discussed this thing in Italian in this post: Scie di condensazione o scie chimiche?).

In most cases, these images have the aim to highlight aircraft that, according to someone, can be associated to weather modification or military experimentation. Usually, those people use the term “chemtrails”, that is the short form for chemical trails, a definition which comes from contrails, short for condensation trails.

Let me say that I’m sure that some kind of testing has been conducted with similar aims and that someone is probably studying the possibility to change the climate somewhere. However, I’m also sure that the majority of the images that have been circulating on the Internet show a normal phenomenon, that has nothing to do with a conspiracy or with the attempts possibly done by some nation to modify the weather using airplanes.

The contrails appear for the quick condensation of the water vapour that is contained in the exhaust of the engines and in the surrounding air (due to a quick decrease in pressure and temperature) and crystallization of it around the solid aerosol particles ejected by the aircraft’s engines. As temperatures where the change of state happens are extremely low (from -40° Celsius), contrails should appear from altitudes around 8.500 meters (in ISA, International Stardard Atmosphere, that has a ground temperature of 15° C and a vertical temperature gradient of -6,5° C/1,000 meters).

Actually, since standard atmosphere is quite different from the real one, contrails can be seen also when aircraft are flying at lower altitudes (I remember watching an F-104 generating contrails above the mountains in central Italy in 1991 at altitudes around 3,000 meters). Furthermore, temperature aside, condensation depends also on the humidity of the air, that influences persistence and form of the trails. The higher the humidity, the higher the possibility that ice crystals create.

Trails are not static, but can expand or narrow depending on the wind (at the same altitude, that is usually different in direction and intensity from the one on the ground). The contrails can be continuos or intermittent, if the aircraft encounters different temperature and humidity conditions.

Obviously, the trails follow the path of the aircraft, and for this reason, if the airplane turns, the trail will simply follow the same “route”. If the aircraft is orbiting, the trail will assume an elliptical or round shape (according to the type of orbit the aircraft is performing). Should you see such a kind of non-straight contrails, you should not worry: there are many aircraft that need to orbit to perform their normal activities (not related to any weather modification test).

Just think to the AWACS planes that have to maintain a particular working area for several hours, to the aircraft involved in testing activities, to the tankers involved in air-to-air refueling activities that follow the so-called racetraks while waiting for their receivers. If many contrails appear more or less at the same time, or in the same place, don’t be surprised: the sky is crossed by hundreds of invisible airways that connect Reporting Points and Radio Navigation aids. This means that who lives next a waypoint or a VOR of an important airway could be overflown by a large amount number of contrails.

If other aircraft flying nearby don’t generate any contrail is also normal: the Air Traffic Control separates the flight both horizontally and vertically and it is possible (if not probable) that some traffic, encountering certain conditions, generates condensation trails, while others do not.

Under a meteorological point of view, even if they look similar to the clouds, the contrails are not associated to any weather phenomenon. They can move, change shape, traslate but can’t bring rain, snow, turbulence etc. On the opposite, the presence of contrails in a particular area could be a mark a high humidity conditions in that zone.
Needless to say, the condensation clouds I explained in a recent post have nothing to do with chemistry or weather modification tests.

Particular conditions of temperature and humidity, during cruises at high altitudes, can generate condensation clouds along with contrails thus leading to a large trail of condensed vapour, that is much spectacular (a couple of interesting examples can be found on Airliners.net: http://www.airliners.net/open.file/0980583/L/ and http://www.airliners.net/open.file/0695203/L/).

The following pictures depict the contrails generated by a flight of two Swiss F-18 overflying Axalp

I took the following picture on May 18, 2008 with a Nokia E61i mobile phone (hence the poor quality) from my house. It shows a contrail at night, enlightened by the Moon.