Speed problem!

I'm flying at cruising altitude at the moment and my speed is decreasing for some reason. I'm not climbing or anything its just gone below 250 knots:S What¡s going wrong??

Wind?

No, there's no wind. The weather condition is set to normal, and there's no wind whatsoever. I have to keep manually controling the speed with the throttle, the autothrottle doesnt work for some reason :S Could it be that because im flying in cold area? I'm flying from Seatle to Spokane in the WIner.

Try Pitot Heat.

I tried and it still keeps decreasing :S As im using a different panel i just pressed SHIFT and H for Pitot Heat. Is that the default one right?

Last edited by Mc_GaNgStA on Fri Apr 14, 2006 1:37 pm, edited 1 time in total

Well if you dont have any failure or you are not too high you have to be more specific...Craft,etc.

Hurry up before you crash...

Right, I'm flying at FL210 from Seatle to Spokane in the Winter season. I'm trying to maintain 300 knots using my throttle as the autothrottle isn't working for some reason. I'm flying a Boeing 737-800. That's all i know.

Lol, this was the worst landing i've ever done. When I descended to 4000 my speed indicator and autothrottle finally came to work, but then the radio stack wouldn't switch on for some odd reason. It's probably that new 737 Classic panel i installed. I couldn't use the flight director to see where the runway was and I had to keep looking at the map to see where I was heading.

Thats because the higher you go the thiner the air, so your indicated air speed will be a lot different at 21,000 then 3000.

Yes, I know that, but at FL210 I used autothrottle to maintain280-300 knots, but when I configured it to maintain that speed, then activated the autothrottle, I could hear the engines go slower and the speed was decreasing. I left it for a while incase the autothrottle stabilized itsleft but when it decreased past 240 knots and the aircraft's pitch was beginning to raise up, I disengaged the autothrottle and manually controlled it.

lol couldnt tell you what to do...
maybe you could shut the engines down and restart them in mid-air

It sounds as though you have a freezing problem. Ice has covered the pitot tube so you don't have a speed reading so the autothrottles haven't a clue what they are doing or what speed they are supposed to be maintaining. If it happens again, I suggest you disengage the AT straight away and set power to around 65-70% N1.

Have you made sure you have configured it properly? If it isn't any of the above, then it could be a model problem, but thats quite rare

Perhaps you're right. It was exactly then when I started using the new classic 737 panel I downloaded, which someone advised on the Aircraft Forum. Because then, when I wanted to see what exactly was wrong I tried it with the Boeing 737-400 and the speed was maintained so it was the actual panel.

And btw, today I was flying an IFR from Málaga to Heathrow and I was in the default 737-400 climbing to FL330 and I chose the conditions to Gray and Rainy. I took off fine, but then I experienced problems during climb. Yet again the speed was decreasing. At 4000 I put the speed to 350 knots to fight the wind speed and climb at 3000 fpm. It took me quite a while to reach FL330 as I reduced the climb rate. But then the weird thing was that another aircraft was heading towards Barajas (in the same heading as Heathrow- ish) and it took-off after me and over-took me in both speed and climb rate. It was the AI of FS2004 (I don't have any AI program installed). Now how is that possible and I couldn't maintain that speed nor climb.

AI traffic never flies realistically. Don't think for a second that you could fly similar to AI traffic....

Yeah, I shouldn't. The other day I flew the same destination as the AI traffic and I tried mainting its speed and to my surprise it was cruising at 450 knots.