Re: another plane crash ...

Brian Morrison wrote:
> On Sat, 04 Jul 2009 21:43:56 +0100
> Dave <davenpat@btopenworld.com> wrote:
>
>> Brian Morrison wrote:
>>
>>
>>> OK, useful explanation, a case of balancing conflicting requirements.
>>>
>>> I presume that a GR4 (or even a GR1) with external tanks etc would
>>> struggle mightily to accelerate to much above M1.3 at any time without
>>> running out of fuel after 100 miles or so....
>> No, not really. The GR1 could do mach 2, but the GR4 could not do Mach 1
>> unless it went into a dive.
>>
>> They both had very good acceleration though. I have to admit that this
>> area was not my speciality.
>
> I think you misunderstand me. With the drag of tanks plus other
> ordnance, I suspect the top speed would be very limited. The Tornado is
> not overpowered by any means.

Sorry for the long delay in answering.

As far as under powered goes, I never heard any complaints. I did once
ask flight test to let me know about the performance of the AC but all I
got back was a vague comment about it depended on what was slung under
it. At that time I was trying to establish if the pilot could tell if it
flew as well as I expected it to. There had been conditions in the past
where the RAF had not done some servicing correctly and it had to be
corrected before it flew again.

>> The length of time in the air is not something I ever bothered about.
>> All I was concerned about was that it came back with no snags. Pride
>> restored if it did :-)
>>
>> You mention external tanks. This something that a lot of people do not
>> know about, or understand.
>>
>> There are 2 sizes of external tanks. The smallest one was 1500 Ltrs,
>> known as a ferry tank and supersonic and the larger 2250 Ltrs which was
>> sub sonic. The GR1, GR4, F2 and F3 could all carry 4 external tanks
>> above the internal fuel load. 2 under the centre fuse and one each on
>> the inboard wing pylon. On an F3 efectively doubling the fuel load from
>> 6 tons to 12 tons.
>
> And with the biggest tanks, the drag would probably be higher even if
> the tank itself has a higher fineness ratio. So top speed may be even
> further compromised.
>
> I know that a Phantom, with a top speed of about 1300kts, could make
> about 750kts with external ordnance and 3 tanks. It adds a lot of drag.

This is about aerodynamics here. The only thing I know about that was
when our MD gave an aerodanamics man a right royal bollocking.

My job was to get the modifications on the aircraft, test the systems
and certify them for flight.

Dave
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