Note sul 747 Cargo schiantatosi in Afghanistan

Il protagonista di questo terrificante incidente e’ un Boeing 747-428 (matricola N949CA – cn 25630) di proprieta’ della compagnia National Airlines (New York) in servizio per conto dell’Air Mobility Command dell’US Air Force. A quanto pare l’N949CA stava trasportando cinque veicoli militari, probabilmente MRAP (Mine-Resistant Ambush Protected).

L’aereo si e’ schiantato immediatamente dopo il decollo dalla pista 03 della base aerea di Bagram, Afghanistan alle ore 15:30 del 29 Aprile 2013. La destinazione del volo (N8-102) era l’aeroporto internazionale Al Maktoum di Dubai (Emirati Arabi Uniti). I Jumbo della National stavano ininterrottamente compiendo questa rotta da circa un mese, probabilmente a supporto delle (imponenti) operazioni di ritiro dal teatro afghano.

Nell’incidente sono perite 7 persone: quattro piloti, due meccanici e un load master, tutti civili e di nazionalita’ statunitense. Ecco i nomi:

Brad Hasler (pilota) da Trenton, Michigan
Jeremy Lipka (pilota) da Brooklyn, Michigan
Jamie Brokaw (primo ufficiale) da Monroe, Michigan
Rinku Summan (primo ufficiale) da Canton, Michigan
Michael Sheets (loadmaster) da Ypsilanti, Michigan
Gary Stockdale (manutentore) da Romulus, Michigan
Timothy Garrett (manutentore) da Louisville, Kentucky.

Ignote al momento le cause esatte dell’incidente, ma si ipotizza un caso di “load shift” con conseguente stallo. Come previsto, i Talebani si sono immediatamente autoaccusati del disastro, machevvelodicoaffare?🙂

L’N949CA aveva volato per la prima volta il 29 gennaio 1993, e precedentemente aveva servito con la compagnia Air France. Era in servizio con la National Airlines dal 2010. Questo vettore cargo opera con con altri due B747, matricole N952CA e N919CA.

Una prima analisi dell’incidente e’ stata preparata da David Learmount per la rivista FlightGlobal:

“The fatal departure of a National Air Cargo Boeing 747-400F from Bagram air base on 29 April has been caught on amateur video. This is what the video shows:

The first sight of the aircraft on film shows it in an apparently steady climb through about 200ft (60m) above airfield level, just after take-off, but with an extremely high nose-up attitude.

Within about 3s of appearing on film the aircraft’s port (left) wing begins to drop, and 1s later the roll reverses, the right wing dropping. Simultaneously, the 747 begins a dramatic yaw to the right, the nose dropping fast. The roll stops at an angle of about 110deg to the horizontal, by which time the forward airspeed is well below flying speed and the aircraft is just falling sideways through the air. As some airspeed is recovered in the fall, the pilots manage to roll the wings level.

But recovery would have been impossible, and the big freighter impacts the ground.

Crews taking off from military bases like Bagram in hostile territory normally plan to climb at the maximum climb angle, to put them at the greatest height above ground level achievable by the time they cross the airfield boundary. This entails a high nose attitude that is maintained for longer than normal, rather than trading climb angle for greater airspeed to make the aircraft easier to handle and safer in the event of an engine failure.

In this film there is no clear visual evidence of a missile travelling toward the aircraft, nor of the explosion or fire that a missile would cause if it were to detonate.

The risks of a maximum angle of climb departure are many. If an engine fails very soon after take-off there is a lower airspeed than normal. Slower speed reduces the rudder authority that keeps the aircraft straight and lowers the margin above stalling speed. In the event of an engine failure it is essential for the crew to push the nose down fast to maintain a safe speed with the lower power output.

Another major risk is that if any cargo is not adequately secured in the hold, the high climb angle will cause the payload to slide backward. This could unbalance the aircraft and cause the nose to pitch up, possibly overwhelming the elevator authority available to the pilots if they attempt to push the nose down.

Whatever the crew may have faced, and whatever they may have tried to do, once the aircraft had begun to show signs of being in trouble, the nose remained very high. Whether this was the result of a cargo shift or another factor, the inquiry will provide the answer. The aircraft, although on military operations, carries a flight data and cockpit voice recorder.

The National Transportation Safety Board has dispatched a team to Bagram to launch an investigation of the incident. All seven crew members were killed in the crash.”

Qui sotto un’immagine dell’N949CA fotografato il 3 Aprile 2012 presso l’aeroporto di Riga (Lettonia). Photo courtesy of Aleksandrs Samuilovs.

national747

bagramab

Mappa della base di Bagram

afghanistanmap

Ubicazione geografica di Bagram AB

ROUTE

Ubicazione degli aeroporti di Bagram e Al Maktoum (Dubai)

Note aggiuntive: mi hanno scritto che il 747 cargo non puo’ imbarcare MRAP. Non e’ cosi’. In realta’ e’ dal 2009 che gli USA impiegano (anche) questo vettore per il trasporto di MRAP nel teatro afghano, come potete vedere voi stessi da queste immagini scattate alla base aerea di Charleston (ora Joint Base Charleston), nel South Carolina.

747mrap

Qui vediamo un 747 della Atlas Air imbarcare veicoli protetti tipo M-ATV (MRAP All Terrain Vehicle). Questo veicolo ha un peso a vuoto di 12 tonnellate e mezzo. Photo: US Air Force

747mrap2

Photo: US Air Force

747mrap3

Photo: US Air Force

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