Description

On 4 March 2013, the professional pilot of a privately-operated Beechcraft Premier 1A (VP-CAZ) which had just taken off from Annemasse for Geneva in day Visual Meteorological Conditions (VMC) lost control of the aircraft and it crashed just outside the aerodrome perimeter. The aircraft was destroyed by the impact and a post crash fire and two of the three occupants were killed and the third ejected from the aircraft during the impact sequence and seriously injured. Before final impact with the ground, the aircraft had hit trees and buildings, substantially damaging the roof of a nearby house.

Investigation

An Investigation was carried out by the French BEA. Although not a mandatory requirement, it was found that the aircraft had been fitted with a Cockpit Voice Recorder (CVR) which, whilst damaged, was successfully downloaded and provided very useful information, validated in respect of time using two sources of radar returns from the aircraft.

It was established that the flight had taken off from the 1300-metre long runway 12 at Annemasse at 0838 Local Time. A number of witnesses saw it take off and they all described a high nose up attitude just after take off followed by a steep bank to the right and then to the left followed by a loss of altitude. The flight lasted only 16 seconds and within 3 seconds of the aircraft becoming airborne, an Terrain Avoidance and Warning System (TAWS) Bank Angle Alert had been activated, followed two seconds later by the Stall Warning horn sounding. Thereafter, two further EGPWS Bank Angle Alerts and two further Stall Warnings had been activated, the final stall warning continuing until impact. Both engines had remained at the take off thrust setting until impact. It was concluded that the low height alone would have made it impossible to achieve stall recovery and regain control so that ground impact was inevitable.

It was found that the pilot, an employee of ‘Global Jet Luxembourg’, flew the accident aircraft exclusively for the benefit of its owner. He had intended to fly from Paris Le Bourget to Geneva the previous day but had been not been able to secure an arrival slot at Geneva and so had instead flown to Annemasse, following which the aircraft was parked on the apron there overnight with the intention being to position to Geneva first thing the following morning. It was noted that the combination of a temperature of around - 2°C and the very high humidity which prevailed at the aerodrome the previous evening and on the morning of the accident would have led to [[Ice Formation on Aircraft |frost or ice deposits forming on the wings]]. It was also noted that the OAT during the cruise on the flight from Paris the day before had been around - 40°C, which would have led to the fuel in the wing tanks reaching very low temperatures. It was therefore considered that the cold-soaked fuel in the wing tanks (which were about 75% full prior to the accident flight) could well have kept the temperature of the wing surfaces at a temperature lower than the external air temperature and thus increased the extent of frozen deposits. However, there was no ground de-anti icing service available at Annemasse, nor was this required since only private flights operated from there.

It was considered that the behaviour of the aircraft just prior to the loss of control “was consistent with a stall due to contamination of the wings with frost or ice - steep uncontrolled banking immediately at lift off and impossibility of establishing an adequate climb speed” despite the use of the correct take off speed and configuration. It was established that the effects of a stall had occurred before the activation of the stall warning device at angles of attack lower than the design threshold for such activation and it was considered that this was “typical of the behaviour of a contaminated wing profile”.

It was noted that the behaviour of the aircraft “was comparable to those of many accidents around the world caused by icing contamination on the wings, leading to a stall then a loss of control on takeoff”. It was also noted that aircraft which have wings with a short chord length or a swept leading edge or which lack leading edge slats are more specifically sensitive to the effects of ground ice and that all three of these characteristics apply to the accident aircraft type.

It was considered that the layer of ice present on the wings was likely to have been thin and therefore difficult to detect with the naked eye, especially as the wings were white. Alternatively, it was considered equally possible that the pilot had detected frozen deposits but considered them to be insufficient to have any consequences for the intended departure.

A pilot who flew the same aircraft type and who knew the accident aircraft pilot told the Investigation that the latter usually put his aircraft in a hangar overnight when he knew that he would be flying the next morning and the weather was cold. At Paris Le Bourget and Geneva, the usual places visited by the aeroplane, he was able to use a dedicated place in a hangar and so only occasionally needed ground de-anti icing before a flight.

The Investigation considered that not all existing recurrent pilot training requirements in respect of wing icing were conducive to the maintenance of adequate risk awareness. The potential for installation of systems for the automatic detection of frozen deposits adhering to wings prior to take off was also noted, as was the ICAO Recommendation in both Annex 14 and in Doc 9640 ‘Manual of Aircraft Ground De-icing/Anti-Icing Operations’ that ground de/anti icing facilities should be available at all aerodromes where there is a risk of such icing.

The Investigation formally concluded that the Cause of the Accident was:

“The pilot’s insufficient appreciation of the risks associated with ground-ice led him to take off with contamination of the critical airframe surfaces. This contaminant deposit then caused the aerodynamic stall of the aeroplane and the loss of control shortly after lift-off.”

Three Safety Recommendations were made as a result of the Investigation as follows:

• that EASA, in coordination with national civil aviation authorities, make changes to the training requirements for pilots so as to include periodic reminders on the effects of contaminants such as ice on stall and loss of control on takeoff. [2014-005]

• that EASA, in coordination with the FAA and the other non-European civil aviation authorities, study the technical and regulatory means to put in place in order to install systems for the detection of frozen contaminants on the critical surfaces of aircraft. [2014-006]

• that the DGAC define criteria intended to make it mandatory for aerodrome operators to have de-icing/anti-icing facilities at aerodromes. [2014-007]

The Final Report was published in English translation on 2 May 2014 following initial publication in French on 10 April 2014.

Further Reading

• Loss of Control
• Stall
• Ice Formation on Aircraft
• Aircraft and In Flight Icing Risks
• Aircraft Ground De/Anti-Icing
• Ice Contaminated Tailplane Stall
• Terrain Avoidance and Warning System (TAWS)

Ground de-anti/icing guidance

ICAO

• Doc 9640 ‘Manual of Aircraft Ground De-icing/Anti-Icing Operations’, 2nd Ed., 2000

AEA

• Recommendations for De-icing/Anti-icing Aeroplanes on the Ground, 30th Edition, July 2015
• Training Recommendations and Background Information for De-Icing /Anti-Icing of Aeroplane on the Ground, 12th Edition, August 2015

Note: Although the AEA ceased to exist in 2016, the most recent of their publications still contain some pertinent information. Readers are cautioned to validate the recommendations of these guidebook using more current information sources.

Transport Canada

• Transport Canada Guidelines for Aircraft Ground Icing Operations

NASA

• The NASA “Pilots Guide to Ground Icing” which reviews the problems caused by ground icing, when ground icing is likely to be encountered, the basics about aircraft de/anti-icing fluids and, in general, how to de-ice and anti-ice an aircraft.

and also, especially for GA:

• The NASA “Pre Flight Icing Checklist”

EASA

• EASA Safety Information Notice (SIN) 2008-29 Ground De-/Anti-Icing of Aeroplanes; Intake/Fan-blade Icing and effects of fluid residues on flight controls
• EASA Safety Information Bulletin (SIB) 2010-26 Potential Performance Degradation of Anti-icing Fluids - Reduced Holdover Times

Similar accidents on SKYbrary

• C208, Helsinki Finland, 2005 - On 31 January 2005, a Cessna 208 stalled and crashed on take off from Helsinki-Vantaa following failure to properly de-ice the aircraft.
• AT43, en-route, Folgefonna Norway, 2005 - (On 14 September 2005, an ATR 42-320 operated by Coast Air AS experienced a continuous build up of ice in the climb, despite the activation of de-icing systems aircraft entered an uncontrolled roll and lost 1500ft in altitude. The crew initiated recovery actions, the aircraft was stabilised, and the flight continued without further event.
• AT73, en-route, Roselawn IN USA, 1994 - On 31 October 1994, an ATR 72 operated by Simmons Airlines, crashed near Roselawn, Indiana, USA, following loss of control due to airframe icing.
• C172, Toronto Canada, 2003 - On 9th October 2003, a Cessna 172, suffered loss of power and made a forced landing after experiencing Carburettor Icing, over Toronto, Canada.
• F70, vicinity Munich Germany, 2004 - On 5 January 2004, a Fokker 70, operated by Austrian Airlines, carried out a forced landing in a field 2.5 nm short of Munich Runway 26L following loss of thrust from both engines due to icing.
• SH36, vicinity East Midlands UK, 1986 - On 31 January 1986, at night during an instrument approach, a Shorts SD3-60 operated by Aer Lingus Commuter experienced a loss of control attributed to airframe ice accretion. When fully established on the Instrument Landing System (ILS), the aircraft began a series of divergent rolling oscillations which were accompanied by a very high rate of descent. The crew was able to regain control of the aircraft just before contact with power cables and subsequent impact with terrain near East Midlands Airport.
• JS41, en-route, North West of Aberdeen UK, 2008 - On 9 April 2008, an Eastern Airways BAe Jetstream 41 operating a passenger charter flight departed Aberdeen for Vagar, Faroe Islands in snow and freezing conditions, but had not been de-iced and anti-iced appropriately. During the flight the crew experienced difficulties controlling the aircraft. Descent into warmer air was initiated after an emergency was declared.