Convair crash del 10 luglio

[mcgyver79]

Video di un pax. L'incidente ha causato due vittime (una a bordo e una a terra).

phpBB [video]

Quel volo non era neppure partito sotto i migliori auspici:

phpBB [video]

[alessandro.capotondi]

edit mcgyver: riporto qui il testo che l'utente ha scritto in un thread simile (cancellato). Se la discussione procederà su argomentazioni tecniche si potrà spostare anche nell'area apposita, altrimenti resta qui


Dal secondo video è molto evidente la perdita di quota durante la virata a dx. Sempre dal video le pale del motore mi sembrano feathered.

Ho trovato anche questo articolo di qualche anno fa (2015) che copre un incidente molto simile e dove si sostiene che l'aereo sia sottopotenziato per poter efficacemente decollare e volare con un singolo motore.

One stated that when the airplane was not fully loaded, it would climb about 500 fpm with an engine out. However, he and several other Convair pilots believed that the aircraft would only hold altitude, at best, on a single engine when heavily loaded — and that only if the crew configured the airplane correctly.

A former Fresh Air Convair first officer stated that the airplane would not maintain altitude in a turn while heavily loaded and operating with a single engine, adding that, “Convair 340s and 440s were underpowered.”

La fine del volo in quel caso è stata molto più drammatica:

The accident airplane crashed into a lagoon about 1 mi. east of the departure end of Runway 10 at Luis Muñoz Marín International Airport (SJU), San Juan, Puerto Rico, on March 15, 2012, at about 0740 (AST). VFR conditions prevailed and a VFR flight plan had been field for Princess Juliana International Airport at St. Maarten. Both pilots were killed and the airplane was destroyed by impact forces.

Fonte: http://aviationweek.com/bca/convair-s-f ... out-return

Edit:
Qui il link all'incidente del 2015:
https://aviation-safety.net/database/re ... 20120315-0

In quel caso si trattava di un Convair CV-440, ma che dovrebbe comunque montare gli stessi Pratt & Whitney R-2800.

[alessandro.capotondi]

riporto qui il link all'articolo avherald:
http://avherald.com/h?article=4bafa778&opt=0

[sigmet]

Dal filmato si notano alcuni particolari: dal colore del fumo e dal tipo di fiamma sembra che a bruciare sia olio.
Probabilmente il fuoco motore deve aver danneggiato una linea idraulica e l'elica non va in bandiera (continua a girare fino al crash). Non mi sembra di ravvisare errori di condotta ma ovviamente con un elica non feathered e' assai difficile mantenere il profilo di volo.

[alessandro.capotondi]

Dal filmato si notano alcuni particolari: dal colore del fumo e dal tipo di fiamma sembra che a bruciare sia olio.
Probabilmente il fuoco motore deve aver danneggiato una linea idraulica e l'elica non va in bandiera (continua a girare fino al crash). Non mi sembra di ravvisare errori di condotta ma ovviamente con un elica non feathered e' assai difficile mantenere il profilo di volo.

Nell'immagine dall'interno, ad una prima visione, l'angolo di incidenza delle pale mi sembravano con un pitch abbastanza alto (la traccia che nera che lascia nel video mi sembrava abbastanza evidente), ma probabilmente è solo un effetto ottico.

Se fossero state feathered, ma fosse stato impossibile spegnere il motore, le pale avrebbero continuato comunque a girare o si sarebbero fermate?

[sigmet]

Quando l'elica e' in bandiera si ferma o gira comunque molto lentamente.

[JT8D]

Anche se non è il thread tecnico,qualche info in più sull'incidente.

"Aug 11th 2018 South Africa's CAA released their preliminary report stating that a camera had been installed in the cockpit (GOPRO). The cockpit was occupied by the captain, a first officer and the Licensed Aircraft Maintenance Engineer (LAME) conducting the final checks for the flight to the Netherlands, all three had also participated in the ferry flight of another CVLP to Australia two years earlier.

Pilanesberg Aerodrome was closed for fixed wing aircraft due to runway maintenance. A related NOTAM was unknown to crew and staff at Wonderboom airport, who accepted the flight plan and issued takeoff clearance.

At about 50 KIAS in the takeoff run the captain commented the manifold pressure was low. After rotation and becoming airborne, one of the passengers - the assistant to the LAME - went to the cockpit and told the crew the left hand engine was on fire. The aircraft continued to climb at about 600-700 fpm until reaching about 800 feet AGL, then began to lose height. The aircraft continued with the left engine fire, the engine fire checklist was never executed and the crew never attempted to extinguish the fire, the engine fire extinguishing system was never activated. The left engine RPM was fluctuating, the engine fire master caution activated and an audible alarm sounded. The control wheel was deflected to the right, the captain commented the ailerons had been lost and requested the first officer to apply rudder. The GOPRO also revealed that the crew was not sure whether they had retracted their landing gear. In addition, crew and LAME were asking each other which engine was on fire although they had been told by the LAME's assistant. At no time the pilots or LAME discussed or attempted the fire drill for the left hand engine, which would have included feathering the propeller, pull the T-Handle to off to shut off all fluids, close the heat source valves, close the cowl doors, place the fuel shut off valve to CLOSED, turn off the fuel boost pump, operate the appropriate fire switch and if needed operate the alternative fire switch. The aircraft lost height, contacted a number of wires parallel to Sakabuka Street just north of the industrial complex, the aircraft impacted, two vehicles and the industrial complex.

Ground witnesses observed and collected melted metal debris, that fell off the aircraft while it remained airborne.

The SACAA reported the inflight left engine fire consumed parts of the left wing structure, the aircraft was destroyed by impact forces, the post impact fire damaged the right main gear and engine. In addition the power lines, the two vehicles and the industrial complex sustained damage.

The SACAA wrote: "Initial on-site investigation identified that the fire was most intense in the left engine. Soot, glazing and heat signatures were evident on a number of electrical, air, oil and hydraulic supply lines. An external fire had developed in the lower left region of the left engine nacelle. Airframe fire damage was found on the aircraft’s left wing rear spar and the exhaust area. The right engine fire was post-impact and was observed after the crash".

(https://avherald.com/h?article=4bafa778&opt=0)

Paolo

[alessandro.capotondi]

Quindi al momento sembra essere più un problema di CRM che meccanico riguardo il feathering del elica.

Esistono dei simulatori per questi volatili classici su cui le crew possano fare un po si training?

[JT8D]

E' stato rilasciato oggi il final report:

http://www.caa.co.za/Accidents%20and%20 ... s/9722.pdf

http://avherald.com/h?article=4bafa778/0005&opt=0

Il motore sx aveva un danno importante, mai riconosciuto durante le manutenzioni precedenti, ben descritto nella relazione.

La gestione dell'emergenza ha mostrato gravi lacune (il pilot flying non era nemmeno abilitato a velivoli con più motori): non è mai stato tagliato il motore in fiamme e messa l'elica in bandiera, tra le altre cose.

Paolo