Delaying Engine Anti-ice can cause trouble

[pelmet]

Wasaya flight 809, a Hawker Siddeley HS-748-2A aircraft, registration C-GMAA was enroute from Pickle Lake to Kasabonika. While in cruise the aircraft encoutered icing conditions. After ice had accumulated, the crew selected engine deice for both engines. Shortly after the deice selection was made, the left engine (Rolls Royce Dart RDA7) lost all power and went into auto feather. The right engine then began to run rough with fluctuating torque and RPM indications. The crew declared an emergency and began a double engine failure drill by selecting the engine relight for both engines. The right engine then began to run smoothly and full power was restored. An attempt to re-light the left engine was successful and all engine parameters were normal. The crew withdrew their emergency declaration and landed at their destination without further incident. Information provided indicated that ice accumulation shed after engine deice selection could be ingested into the engine and interrupt engine operation.

[vcollazo]

We had a similar incident many years ago at NWA. One of our DC9s was going into Houston Texas, and ice was the last thing on their minds. Anyhow, they either weren't paying attention or ignored company policy and FOM guidance to turn on engine anti ice with temps 6°C or below in visible moisture. Shortly after entering the clouds they noticed ice building up on the windshield wipers, and turned on engine and wing anti ice. Shortly thereafter both engines compressor stalled and rolled back to near idle. They landed safely, but both engines had to be replaced. As a result of this, guidance was put out that if you were slow to recognize that you had entered icing conditions the correct procedure would be to pull one engine back to idle and then apply engine heat. After a minute or two you could slowly advance power and if everything seemed normal then you would repeat the same procedure on the other engine. Bottom line, don't turn on engine anti ice at medium to high power settings when you suspect or know that ice has already accumulated in the engine intakes and inlet guide vanes.

[Redneck_pilot86]

viewtopic.php?f=118&t=93925

[doorhandle27]

I flew with a guy that hated turning the eng a/i on whenever it was called for by the manufacturer. I used to call for it, he'd say no it's warm below us, I'd just reach up and turn it on much to his displeasure, he was the skipper. Several months later they found FOD to one of the stater vanes, no FOD found in the engine, mtc suspected ice. Idiot.

[Brown Bear]

Another thread? Most of us read the old one. .

[pelmet]

Never heard of this one until just today. Best to turn on the anti-icing one engine at a time if it has been forgotten, perhaps with ignition selected manually on. One almost wonders if it would be better to just leave it off if close to landing......


LOT Polish Airlines Flight 703: The Beginning Of The End For The Carrier's Antonov An-24 Fleet

Exactly 54 years ago today, on November 2, 1968, LOT Polish Airlines Flight 703 crash-landed just over a mile north of Rogóżno railway station. In the crash landing, one person was killed, and several were seriously injured.

The aircraft involved in the accident was a 22-year-old LOT Polskie Linie Lotnicze Antonov An-24V with the registration SP-LTD. The flight was a regularly scheduled regional domestic flight from Warszawa-Okecie Airport (WAW) to Rzeszów Airport (RZE). In command of the aircraft was Captain Kazimierz Rożek, assisted by First Officer Waldemar Wolsk. Onboard the aircraft were 25 passengers, including famous Polish radio presenter Tomasz Beksiński.

Everything was fine until the final approach
The plane took off Wednesday morning from the Polish capital for the 149-mile flight to the southeastern Polish city of Rzeszów. Everything was going to plan until two minutes before the plane was to land. At 10:25, when on final approach to land at Rzeszów-Jasionka Airport's Runway 27, the pilots forgot to switch on the plane anti-icing equipment.

When they realized and eventually turned it on, both of the plane's engines shut down because of ice in the air intakes. Aware that they would not be able to make it to the airport, both pilots initiated a glide while looking for a safe place to land.

The aircraft landed in a field at high speed and became airborne above a drainage ditch before coming to a stop further on. A 69-year-old woman from Rzeszów died in the accident, while the other passengers managed to get off the plane before it caught fire.

LOT Polish Airlines removed the An-24 from its fleet
Following the accident, which remains the last ever fatal accident in Polish aviation, LOT Polish Airlines decided to remove the Soviet-built turboprops from its fleet. The aging Soviet aircraft were replaced with French/Italian ATR 42 and ATR 72 aircraft. During its history LOT Polish Airlines had 20 An-24s in its fleet, with SP-LTD being an An-24B 50-passenger variant of the plane.

[rigpiggy]

The darts have an annular inlet, and a heated prop dome. The Sop was one engine anti ice, 30 secs then other. The chief pilot was very smooth but regularly exceeded limitations, and own sops. Over seattle he selected both engine anti-ice on followed 10 seconds later with silence, and the panicked TILU drill when the ice shed into the inlets